| 1. Jonisch AI, Rubinowitz AN, Mutalik PG, Israel GM. Can high-attenuation renal cysts be differentiated from renal cell carcinoma at unenhanced CT? Radiology. 2007; 243(2):445-450. |
Observational-Dx |
54 pathologically proved RCCs in 54 patients; 56 high-attenuation renal cysts in 51 patients |
To retrospectively determine if RCC can be differentiated from high-attenuation renal cysts at unenhanced CT based on HU measurements and heterogeneity. |
The average attenuation of cysts for reader 1 was 53.4 HU (range, 23-113 HU) and for reader 2 was 53.8 HU (range, 21-108 HU). The average attenuation of neoplasms for reader 1 was 34.7 HU (range, 21-60 HU) and for reader 2 was 38.4 HU (range, 22-60 HU). For cyst heterogeneity, a score of 1 was given in 55/56 (98%) cysts for reader 1 and in 53/56 (95%) cysts for reader 2. For neoplasm heterogeneity, a score of 1 was given in 35/54 (65%) neoplasms for reader 1 and in 36/54 (67%) for reader 2. Given the distribution of cyst and tumor attenuation values and lesion heterogeneity, a homogeneous mass measuring 70 HU or greater at unenhanced CT has a greater than 99.9% chance of representing a high-attenuation renal cyst. |
4 |
| 2. Pooler BD, Pickhardt PJ, O'Connor SD, Bruce RJ, Patel SR, Nakada SY. Renal cell carcinoma: attenuation values on unenhanced CT. AJR Am J Roentgenol. 2012;198(5):1115-1120. |
Observational-Dx |
189 consecutive patients with 193 pathologically proven RCCs |
To analyze the attenuation values of pathologically proven RCCs on unenhanced CT and to determine the range of values wherein malignancy should be considered. |
The 193 malignant tumors ranged in size from 1.1 to 20.1 cm (mean [+/- SD], 5.1 +/- 3.4 cm). 18 RCCs (9.3%) were homogeneous in appearance on unenhanced CT. The minimum and maximum region of intrest attenuation values obtained by sampling throughout each tumor were 27.5 +/- 10.4 HU (range, 4-67 HU) and 39.7 +/- 10.6 HU (range, 21-80 HU), respectively. Regional areas of minimum attenuation <20 HU and maximum attenuation >70 HU were seen in 24.9% (48/193) and 2.1% (4/193) of RCCs, respectively. However, all 193 RCCs (100%) were predominantly composed of noncalcific regions within 20-70 HU; 72.5% (140/193) fell entirely within this 20-70 HU "danger zone," including all 18 homogeneous lesions. |
4 |
| 3. O'Connor SD, Silverman SG, Ip IK, Maehara CK, Khorasani R. Simple cyst-appearing renal masses at unenhanced CT: can they be presumed to be benign?. Radiology. 269(3):793-800, 2013 Dec. |
Review/Other-Dx |
15695 patients |
To determine renal cancer incidence in simple cyst–appearing renal masses detected at unenhanced computed tomography (CT). |
Simple cyst–appearing renal masses were identified in 2669 patients (17%), no renal masses in 11 844 (75%), and nonsimple cystic or solid renal masses in 1182 (8%). Of 1159 patients with simple cyst–appearing renal masses and a minimum of 5 years of follow-up, six (0.52%) subsequently developed renal cancers, all of which were separate from the simple cyst–appearing renal mass, rather than within it. Of 446 patients with nonsimple or solid renal masses and sufficient follow-up, 50 (11%) developed renal cancer. There was no difference in renal cancer incidence in patients with simple cyst–appearing renal masses versus those without renal masses (P = .54). The incidence of renal cancer was significantly lower in patients with simple cyst–appearing renal masses than that in nonsimplecystic or solid renal masses (P < .0001). |
4 |
| 4. Agochukwu N, Huber S, Spektor M, Goehler A, Israel GM. Differentiating Renal Neoplasms From Simple Cysts on Contrast-Enhanced CT on the Basis of Attenuation and Homogeneity. AJR Am J Roentgenol. 208(4):801-804, 2017 Apr. |
Observational-Dx |
125 subjects |
To compare the attenuation and homogeneity of renal neoplasms with those of cysts on contrast-enhanced CT. |
A total of 116 heterogeneous renal cell carcinomas (RCCs) (99 clear cell, four papillary, four oncocytic, seven chromophobe, and two unclassified RCCs), 13 homogeneous RCCs (10 papillary, two oncocytic, and one chromophobe RCC), and 24 cysts (all of which were homogeneous) were evaluated. All homogeneous RCCs had mean attenuation values of more than 42 HU, whereas renal cysts had mean attenuation values of up to 30 HU (p < 0.001). Two readers qualitativelyand identically categorized all RCCs as homogeneous or heterogeneous (? = 1.0; p < 0.001) |
3 |
| 5. Corwin MT, Hansra SS, Loehfelm TW, Lamba R, Fananapazir G. Prevalence of Solid Tumors in Incidentally Detected Homogeneous Renal Masses Measuring > 20 HU on Portal Venous Phase CT. AJR Am J Roentgenol. 211(3):W173-W177, 2018 09. |
Review/Other-Dx |
267 Patients |
To determine the prevalence of solid tumors in incidental homogeneous renal masses with attenuation greater than 20 HU on portal venous phase CT images. |
There were 322 masses in 267 patients. The mean lesion size was 16.6 (SD, 9.8) mm (range, 9-45 mm). Lesions were = 50% exophytic in 92 cases, < 50% exophytic in 111 cases, and completely surrounded by renal parenchyma in 119 cases. All nonsolid lesions were characterized as benign cysts. The numbers of solid lesions per total number of lesions in each attenuation group were: 20-30 HU (0/140), 30-40 HU (0/67), 40-50 HU (1/38), 50-60 HU (3/24), 60-70 HU (5/17), 70-80 HU (5/17), and > 80 HU (8/19). All 207 lesions in the 20- to 40-HU range were benign cysts with no solid lesions (0%; 95% CI, 0.0-1.4%). |
4 |
| 6. Hu EM, Ellis JH, Silverman SG, Cohan RH, Caoili EM, Davenport MS. Expanding the Definition of a Benign Renal Cyst on Contrast-enhanced CT: Can Incidental Homogeneous Renal Masses Measuring 21-39 HU be Safely Ignored?. Acad Radiol. 25(2):209-212, 2018 02. |
Review/Other-Dx |
1387 subjects |
to determine the frequency and clinical significance of homogeneous renal masses measuring 21-39 Hounsfield units on contrast-enhanced computed tomography (CT). |
Eligible masses (n?=?74) were found in 5% (63/1387) of subjects. Of those with a reference standard (n?=?42), none (0% [95% CI: 0.0%-8.4%]) were determined to be clinically significant. |
4 |
| 7. Silverman SG, Pedrosa I, Ellis JH, et al. Bosniak Classification of Cystic Renal Masses, Version 2019: An Update Proposal and Needs Assessment. Radiology. 292(2):475-488, 2019 Aug. |
Review/Other-Dx |
N/A |
To propose an update to the Bosniak classification to incorporate MRI, establish definitions for previously vague imaging terms, and enable a greater proportion of masses to enter lower-risk classes. |
No results stated in abstract. |
4 |
| 8. Ascenti G, Mileto A, Krauss B, et al. Distinguishing enhancing from nonenhancing renal masses with dual-source dual-energy CT: iodine quantification versus standard enhancement measurements. Eur Radiol. 23(8):2288-95, 2013 Aug. |
Observational-Dx |
52 patients, 72 renal masses |
To compare the diagnostic accuracy of iodine quantification and standard enhancement measurements in distinguishing enhancing from nonenhancing renal masses. |
Sensitivity, specificity, PPV, NPV and diagnostic accuracy for standard enhancement measurements and iodine quantification were 77.7 %, 100 %, 100 %, 81.8 %,89 % and 100 %, 94.4 %, 94.7, 100 % and 97 %, respectively. The McNemar analysis showed that the accuracy of iodine quantification was significantly better (P<0.001) than that of standard enhancement measurements. |
3 |
| 9. Kaza RK, Caoili EM, Cohan RH, Platt JF. Distinguishing enhancing from nonenhancing renal lesions with fast kilovoltage-switching dual-energy CT. AJR Am J Roentgenol. 2011; 197(6):1375-1381. |
Observational-Dx |
39 patients |
To evaluate the accuracy of dual-energy CT in distinguishing enhancing from nonenhancing or equivocally enhancing renal lesions. |
83 renal lesions were evaluated. On the basis of attenuation measurements, there were 20 enhancing and 63 nonenhancing lesions. The sensitivity, specificity, and accuracy for the detection of enhancement according to the lesion appearance were 70%, 98.4%, and 91.6%, respectively, on iodine density images and were 85%, 90.5%, and 89.2%, respectively, on iodine overlay images generated from contrast-enhanced dual-energy CT scans. Of the various thresholds of measured lesion iodine density (1-3 mg/cm(3)), a threshold of 2 mg/cm(3) showed the highest accuracy for the detection of enhancement, with sensitivity, specificity, and accuracy of 90%, 93.7%, and 92.8%, respectively. |
3 |
| 10. Marin D, Davis D, Roy Choudhury K, et al. Characterization of Small Focal Renal Lesions: Diagnostic Accuracy with Single-Phase Contrast-enhanced Dual-Energy CT with Material Attenuation Analysis Compared with Conventional Attenuation Measurements. Radiology. 284(3):737-747, 2017 Sep. |
Observational-Dx |
136 patients |
To determine whether single-phase contrast material–enhanced dual-energy material attenuation analysis improves the characterization of small (1–4 cm) renal lesions compared with conventional attenuation measurements by using histopathologic analysis and follow-up imaging as the clinical reference standards. |
By using cross-validated optimal thresholds at 100% sensitivity, iodine-water material attenuation images significantly improvedspecificity for differentiating between benign and malignant renal lesions compared with conventional enhancement measurements(93% [103 of 111]; 95% confidence interval: 86%, 97%; vs 81% [90 of 111]; 95% confidence interval: 73%, 88%) (P = .02). Sensitivitywith iodine-water and calcium-water material attenuation images was also higher than that with conventional enhancement measurements,although the difference was not statistically significant. |
3 |
| 11. Mileto A, Marin D, Ramirez-Giraldo JC, et al. Accuracy of contrast-enhanced dual-energy MDCT for the assessment of iodine uptake in renal lesions. AJR Am J Roentgenol. 202(5):W466-74, 2014 May. |
Observational-Dx |
59 patients |
To assess the accuracy of iodine-related attenuation and iodine quantification as imaging biomarkers of iodine uptake in renal lesionson a single-phase nephrographic image with dual-energy MDCT. |
A significant difference in sensitivity and specificity was found between iodine-related attenuation with the thresholds of 15 HU (sensitivity, 91.4%; specificity, 93.3%; PPV, 91.4%; NPV, 93.3%) and 20 HU (sensitivity, 77.1%; specificity, 100%; PPV, 100%; NPV, 84.9%) (p = 0.008) and between iodine quantification (sensitivity, 100%; specificity, 97.7%; PPV, 97.2%; NPV, 100%) and iodine-related attenuation with a threshold of 20 HU (p = 0.004). No significant difference in sensitivity and specificity was found between iodine quantification and iodine-related attenuation with a threshold of 15 HU. |
2 |
| 12. Mileto A, Nelson RC, Samei E, et al. Impact of dual-energy multi-detector row CT with virtual monochromatic imaging on renal cyst pseudoenhancement: in vitro and in vivo study. Radiology. 272(3):767-76, 2014 Sep. |
Observational-Dx |
28 patients |
To investigate whether dual-energy multi–detector row computed tomography (CT) with virtual monochromatic imaging can overcome renal cyst pseudoenhancement in a phantom experiment and a clinical study. |
In the phantom experiment, all polychromatic image data sets showed pseudoenhancement (postcontrast attenuation increase .10 HU) in all investigated conditions, with a significant effect on cyst size (P <.001), location (P < .001), and renal background attenuation level (P <.001). Virtual monochromatic images at energy levels ranging from 80 to 140 keV did not show pseudoenhancement, with the minimum attenuation increase (mean, 6.1 HU +- 1.6; range, 1.6–7.7 HU) on 80-keV images. In patients, pseudoenhancement never occurred on virtual monochromatic images at energy levels ranging from 90 to 140 keV. Patient body size had a significant effect (P = .007) on selection of the optimal monochromatic energy level. |
3 |
| 13. Cha D, Kim CK, Park JJ, Park BK. Evaluation of hyperdense renal lesions incidentally detected on single-phase post-contrast CT using dual-energy CT. Br J Radiol. 89(1062):20150860, 2016 Jun. |
Observational-Dx |
79 patients |
To investigate the utility of dual-energy CT (DECT) for differentiating between solid and benign cystic lesions presenting as hyperdense renal lesionsincidentally detected on single-phase post-contrast CT. |
In total, 47 benign cystic and 43 solid renal lesions were analyzed. For differentiating between solid and benign cystic lesions on the two phases, the specificityand accuracy of all lesions and lesions <1.5 cm were statistically lower in IO images than in linearly blended images (p < 0.05), while those for lesions >=1.5 cm were not statistically different between them (p >0.05). For all types of lesions >=1.5 cm, the CT numbers between linearly blended and IO images and between TNC and virtual non-contrast images were not statistically different (p>0.05). |
3 |
| 14. Liu Xl, Zhou Jj, Zeng MS, Ma Zp, Ding Yq. Homogeneous high attenuation renal cysts and solid masses--differentiation with single phase dual energy computed tomography. Clin Radiol. 68(4):e198-205, 2013 Apr. |
Observational-Dx |
40 patients, 43 lesions |
To assess the feasibility of using single-phase dual-energy computed tomography (DECT) to differentiate between homogeneous high attenuation renal cysts and solid renal masses. |
Using 17.6 HU as the cutoff value for enhancement, resulted in a sensitivity, specificity and accuracy of 96.6%, 100% and 97.7%, respectively. Corresponding values were 100%, 92.9% and 97.7% using a D-value cutoff of 15.6 HU, and 100%, 85.7% and 95.3% using a DEratio cutoff of 1.3. There were no significant differences in the AUCs obtained from the ROC curves for enhancement, D-value or DE-ratio. The mean effective radiation dose was 6.04 mSvwith biphasic scanning compared with 2.91 mSv for single dual-energy nephrographic phase scanning. |
2 |
| 15. Mileto A, Allen BC, Pietryga JA, et al. Characterization of Incidental Renal Mass With Dual-Energy CT: Diagnostic Accuracy of Effective Atomic Number Maps for Discriminating Nonenhancing Cysts From Enhancing Masses. AJR Am J Roentgenol. 209(4):W221-W230, 2017 Oct. |
Observational-Dx |
206 patients |
To assess the diagnostic accuracy of effective atomic number maps reconstructed from dual-energy contrast-enhanced data for discriminatingbetween nonenhancing renal cysts and enhancing masses. |
Significant differences in mean effective atomic numbers (Zeff) were observed between nonenhancing and enhancing masses (set A, 8.19 vs 9.59 Zeff; set B, 8.05 vs 9.19 Zeff; sets combined, 8.13 vs 9.37 Zeff) (p < 0.0001). An effective atomic number value of 8.36 Zeff was the optimal threshold, rendering an AUC of 0.92 (95% CI, 0.89–0.94), sensitivity of 90.8% (158/174 [95% CI, 85.5–94.7%]), specificity of 85.2% (445/522 [95% CI, 81.9–88.2%]),and overall diagnostic accuracy of 86.6% (603/696 [95% CI, 83.9–89.1%]). |
3 |
| 16. Barr RG, Peterson C, Hindi A. Evaluation of indeterminate renal masses with contrast-enhanced US: a diagnostic performance study. Radiology. 271(1):133-42, 2014 Apr. |
Observational-Dx |
721 patients |
To determine the utility of contrast material–enhanced ultrasonography (US) in the characterization of indeterminate renal masses. |
Contrast-enhanced US had a sensitivity of 100% (126 of 126; 95% confidence interval [CI]: 97.1%, 100%), specificity of 95.0% (132 of 139; 95% CI: 89.9%, 98.0%), positive predictive value (PPV) of 94.7% (126 of 133), and negative predictive value (NPV) of 100% (132 of 132). The five false-positive masses included three oncocytomas and two Bosniak category 3 cystic lesions. Of the 290 lesions that had follow-up of at least 36 months, none of the lesions demonstrated changes that necessitated lesion reclassification. If these lesions were included, assuming lesions classified as malignant were malignant, then of the 596 lesions, sensitivity was 100% (161 of 161), specificity was 96.6% (420 of 435), PPV was 91.5% (161 of 176), and NPV was 100% (420 of 420). |
3 |
| 17. Nicolau C, Bunesch L, Pano B, et al. Prospective evaluation of CT indeterminate renal masses using US and contrast-enhanced ultrasound. Abdom Imaging. 40(3):542-51, 2015 Mar. |
Observational-Dx |
72 patients |
To assess the accuracy of Ultrasound (US) and contrast-enhanced ultrasound (CEUS) in the characterization of renal nodules indeterminate on CT by identifying benign cystic lesions not requiring further examination. |
Final diagnoses comprised 50 benign complex cysts, 1 focal nephritis, 1 multilocular cystic nephroma, 3 oncocytomas, 1 transitional cell carcinoma and 27 renalcell carcinomas. Unenhanced US correctly classified 18/50 (36%) benign cysts and 17/33 (51.5%) of the potentially malignant lesions obtaining a sensitivity of 36%, specificity of 51.5%, and overall accuracy of 42.2%. The addition of CEUS allowed a correct diagnosis of 48 /50 (96%) benign cysts and of 31/33 (93.9%) nodules as potentially malignant, with a sensitivity of 96%, specificity of 93.9%, and overall accuracy of 95.2%. |
2 |
| 18. Zarzour JG, Lockhart ME, West J, et al. Contrast-Enhanced Ultrasound Classification of Previously Indeterminate Renal Lesions. Journal of Ultrasound in Medicine. 36(9):1819-1827, 2017 Sep. |
Observational-Dx |
134 lesions, 116 patients |
To determine the utility of contrast-enhanced ultrasound (US) for characterizing renal lesions that were indeterminate on prior imaging. |
A total of 134 lesions were evaluated with contrast-enhanced US, and 106 were indeterminate by preceding computed tomography, magnetic resonance imag-ing, or US. Only the largest lesion per patient was included in analysis. A total of 95.7% (90 of 94) of the previously indeterminate lesions were successfully classified with contrast-enhanced US. The sensitivity was 100% (20 of 20; 95% confidence interval [CI], 83%–100%; P<.0001); specificity was 85.7% (18 of 21; 95% CI, 62%–97%; P5.0026); positive predictive value was 87.0% (20 of 23; 95% CI, 66%–97%; P5.0005); negative predictive value was 100% (18 of 18; 95% CI, 81%–100%; P<.001); and accuracy was 90.2% (37 of 41; 95% CI, 80%–98%; P<.0001). |
3 |
| 19. Park BK, Kim B, Kim SH, Ko K, Lee HM, Choi HY. Assessment of cystic renal masses based on Bosniak classification: comparison of CT and contrast-enhanced US. Eur J Radiol. 61(2):310-4, 2007 Feb. |
Observational-Dx |
31 patients |
To compare retrospectively the imaging features of computed tomography (CT) and contrast-enhanced US (CEUS) imaging for the assessment of cystic renal masses using the Bosniak classification system. |
Diagnostic accuracies of CT and CEUS for malignant renal tumor were 74% and 90%, respectively, but there were not statisticallydifferent (P > 0.05). CEUS and CT images showed same Bosniak classification in 23 (74%) lesions and there were differences in 8 (26%) lesions,all of which were upgraded by CEUS; one lesion from I to IV, two lesions from II to IV, two lesions from IIF to III, and three lesions from III toIV. CEUS images depicted more septa in 10 (32%) lesions, more thickened wall and/or septa in 4 (13%) lesions, and stronger enhancement in 19(61%) lesions. Moreover, for six lesions, solid component was detected by CEUS but not by CT. |
3 |
| 20. Xue LY, Lu Q, Huang BJ, et al. Contrast-enhanced ultrasonography for evaluation of cystic renal mass: in comparison to contrast-enhanced CT and conventional ultrasound. Abdominal Imaging. 39(6):1274-83, 2014 Dec. |
Observational-Dx |
70 Patients |
To assess the value of contrast-enhanced ultrasonography (CEUS) in evaluating cystic renal lesions compared with conventional ultrasound (US) and contrast-enhanced computed tomography (CECT). |
In malignancies, CEUS demonstrated more septa, thicker wall or septa, and more solid components than US and CECT. CEUS permitted categorization of 51.7% (30/58) and 28.6% (10/35) of malignant tumors in higher grade than by US and CECT, respectively. In benign lesions, CEUS detected more septa than CECT and correctly diagnosed benign cysts which appeared as solid lesions in US. CEUS permitted downgrading of 71.1% (32/45) and 17.1% (6/35) of benign lesions compared to US and CECT. The diagnostic performance of CEUS was better than US for benign cystic lesions. The phenomenon that solid-like component by US did not enhance by CEUS was a strong predictor of benign disease, with a positive predictive value (PPV) of 100%. Enhancement of solid, soft tissue by CEUS was highly predictive of malignancy, with a PPV of 100%. |
2 |
| 21. Rowe SP, Gorin MA, Solnes LB, et al. Correlation of 99mTc-sestamibi uptake in renal masses with mitochondrial content and multi-drug resistance pump expression. EJNMMI Res. 7(1):80, 2017 Oct 02. |
Observational-Dx |
50 patients |
To investigate potential molecular mechanisms underlying the discriminatory ability of (99m)Tc-sestamibi SPECT/CT for renal masses. Fifty renal masses imaged with (99m)Tc-sestamibi SPECT/CT prior to surgical resection were evaluated by immunohistochemistry for mitochondrial content and expression of the multi-drug resistance pump 1 (MDR1/P-gp). Immunohistochemical staining was scored semi-quantitatively, and results were compared across renal tumor histologies and correlated with (99m)Tc-sestamibi uptake. |
In total, 6/6 (100%) and 2/2 (100%) HOCTs demonstrated strong mitochondrial content staining combined with low MDR1 staining. Clear cell renal cell carcinoma showed an opposite pattern with the majority having low mitochondrial (14/26, 54%) and high MDR1 staining (18/26, 69%). Other tumor types were more variable in staining pattern, although the staining pattern reliably predicted (99m)Tc-sestamibi uptake in almost all tumors except chromophobe renal cell carcinoma. |
3 |
| 22. Gorin MA, Rowe SP, Baras AS, et al. Prospective Evaluation of (99m)Tc-sestamibi SPECT/CT for the Diagnosis of Renal Oncocytomas and Hybrid Oncocytic/Chromophobe Tumors. Eur Urol. 69(3):413-6, 2016 Mar. |
Observational-Dx |
50 patients |
to evaluate the accuracy of technetium-99m ((99m)Tc)-sestamibi single-photon emission computed tomography/x-ray computed tomography (SPECT/CT) for the differentiation of oncocytomas and hybrid oncocytic/chromophobe tumors (HOCTs) from other renal tumor histologies. |
With the exception of 1 (2%) angiomyolipoma, all other tumors were renal cell carcinomas (82%). (99m)Tc-sestamibi SPECT/CT correctly identified 5 of 6 (83.3%) oncocytomas and 2 of 2 (100%) HOCTs, resulting in an overall sensitivity of 87.5% (95% confidence interval [CI], 47.4-99.7%). Only two tumors were falsely positive on SPECT/CT, resulting in a specificity of 95.2% (95% CI, 83.8-99.4%). |
2 |
| 23. Tzortzakakis A, Gustafsson O, Karlsson M, Ekstrom-Ehn L, Ghaffarpour R, Axelsson R. Visual evaluation and differentiation of renal oncocytomas from renal cell carcinomas by means of 99mTc-sestamibi SPECT/CT. EJNMMI Res. 7(1):29, 2017 Dec. |
Observational-Dx |
24 patients identified with 31 solid renal lesions |
To examine whether (99m)Tc-sestamibi SPECT/CT can play a crucial role in the characterization of solid renal neoplasms and the differentiation of oncocytomas from renal cell carcinomas |
Eleven out of 12 oncocytomas (91.6%) displayed positive uptake of (99m)Tc-sestamibi. Three hybrid tumours (mixed-type oncocytoma and chromophobe renal cancer) were positive on SPECT/CT. One papillary renal cell carcinoma had a slight uptake of (99m)Tc-sestamibi. The remaining 11 renal cell carcinomas were sestamibi negative. |
2 |
| 24. Kim JH, Sun HY, Hwang J, et al. Diagnostic accuracy of contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging of small renal masses in real practice: sensitivity and specificity according to subjective radiologic interpretation. World J Surg Oncol. 14(1):260, 2016 Oct 12. |
Observational-Dx |
68 patients |
To investigate the diagnostic accuracy of contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) of small renal masses in real practice. |
Among the 68 patients, 60 (88.2 %) had RCC and eight had benign disease. The diagnostic accuracy rates of contrast-enhanced CT and MRI were 79.41 and 88.23 %, respectively. Diagnostic accuracy was greater when using contrast-enhanced MRI because too many masses (67.6 %) were characterized as “4 (probably solidcancer) or 5 (definitely solid cancer).” The sensitivity of contrast-enhanced CT and MRI for predicting RCC were 79.7 and 88.1 %, respectively. The specificities of contrast-enhanced CT and MRI for predicting RCC were 44.4 and 33.3 %, respectively. Fourteen diagnoses (20.5 %) were missed or inconsistent compared with the final pathological diagnoses. One appropriate nephroureterectomy and five unnecessary percutaneous biopsies were performed for RCC. Seven unnecessary partial nephrectomies were performed for benign disease. |
3 |
| 25. Kwon T, Jeong IG, Yoo S, et al. Role of MRI in indeterminate renal mass: diagnostic accuracy and impact on clinical decision making. Int Urol Nephrol. 47(4):585-93, 2015 Apr. |
Observational-Dx |
120 patients |
To evaluate the diagnostic accuracy of MRI in distinguishing renal cell carcinoma (RCC) from indeterminate renal masses on CT scans and investigate the impact of MRI on clinical decision making. |
Of the 120 patients, 47 (39.2 %) had benign masses, including 32 (26.7 %) angiomyolipomas, 5 (4.2 %) oncocytomas, and 10 (8.3 %) complicated cysts. The specificity of MRI was significantly superior to that of CT in diagnosing RCC (68.1 vs. 27.7 %, p = 0.001), whereas their sensitivities were equivalent (91.8 vs. 94. 5 %, p = 0.754). Multivariate analysis showed that female gender [odds ratio (OR) 0.11, p < 0.001] and MRI diagnosis of RCC (OR 23.35, p < 0.001) were independently associated with a final diagnosis of RCC. MRI results showed that 15 patients (12.5 %) thought to have RCC on CT scans could have avoided unnecessary surgery, whereas three patients (2.5 %) thought to have benign masses on CT scans could have undergone appropriate surgery. |
2 |
| 26. Patel J, Davenport MS, Khalatbari S, Cohan RH, Ellis JH, Platt JF. In vivo predictors of renal cyst pseudoenhancement at 120 kVp. AJR Am J Roentgenol. 202(2):336-42, 2014 Feb. |
Observational-Dx |
33 patients, 110 nonenhancing cysts |
To assess the effects of various CT, patient, and renal cyst characteristics on the occurrence of pseudoenhancement in in vivo renal mass CT examinations using subtraction MRI as the reference standard. |
On univariate assessment, cysts that exhibited pseudoenhancement (> 10 HU) were significantly more endophytic (p = 0.02), significantly smaller (p = 0.0004), and adjacent to significantly higher attenuation renal parenchyma in the nephrographic phase (p = 0.02). On multivariate assessment, cyst diameter (p < 0.0001) and background nephrographic phase parenchymal attenuation (p = 0.003) were the strongest in vivo predictors of pseudoenhancement. The odds of pseudoenhancement occurring increased by 2.14 (95% CI, 1.41–3.23) for every 5-mm decrease in renal cyst diameter and increased by 2.45 (95% CI, 1.41–4.26) for every 25-HU increase in enhanced renal parenchymal attenuation. Endophytic growth was not significant in the multivariate analyses (p = 0.07). |
3 |
| 27. Patel NS, Poder L, Wang ZJ, et al. The characterization of small hypoattenuating renal masses on contrast-enhanced CT. Clin Imaging. 33(4):295-300, 2009 Jul-Aug. |
Observational-Dx |
20 patients |
To determine if small hypoattenuating renal masses can be characterized as simple cysts or renal cell carcinomas on contrast-enhanced computed tomography (CT). |
The overall area under the receiver operator characteristic curves for subjective visual impression, CT attenuation, border, and shape were 0.97, 0.82, 0.59, and 0.55, respectively. Using dichotomized ratings (1–2=cyst and 3–5=carcinoma), subjective impression had a sensitivity and specificity of 100% and 79–100%, respectively, for the diagnosis of renal cell carcinoma. Using a threshold of 50 Hounsfield Units (HU) or more, CT attenuation had a sensitivity and specificity of100% and 43–64%, respectively. |
2 |
| 28. Israel GM, Bosniak MA. How I do it: evaluating renal masses. Radiology. 2005; 236(2):441-450. |
Review/Other-Dx |
N/A |
To summarize current approach to the imaging evaluation of renal masses, to review imaging findings in these lesions, and to discuss the limitations of CT and MRI. |
Accurate imaging diagnosis will be dependent on the radiologist to perform high quality imaging examinations, to correlate these imaging findings with clinical and pathologic results and to be aware of the potential pitfalls in renal mass diagnosis so that proper management options can be instituted. |
4 |
| 29. Israel GM, Hindman N, Bosniak MA. Evaluation of cystic renal masses: comparison of CT and MR imaging by using the Bosniak classification system. Radiology. 2004; 231(2):365-371. |
Review/Other-Dx |
59 patients with 69 renal masses/ 2 reviewers |
To retrospectively compare CT and MRI in the evaluation of cystic renal masses by using the Bosniak classification system. |
CT and MRI demonstrate similar findings in most cystic renal lesions, but in some cases MRI may depict more septa, thickening of the wall or septa and enhancement which may upgrade a lesion. Renal cystic lesions that are on the borderline between category IIF and III need to be interpreted with caution and perhaps compared with CT prior to recommending treatment strategies. |
4 |
| 30. Hindman NM, Hecht EM, Bosniak MA. Follow-up for Bosniak category 2F cystic renal lesions. Radiology. 272(3):757-66, 2014 Sep. |
Review/Other-Dx |
144 patients |
To determine percentage of Bosniak category 2F complex cystic renal masses that progress to malignancy based on serial follow-up studies,and to determine if there are demographic and/or imaging features associated with progression. |
Identified in 144 patients (98 men, 46 women; age range, 31–83 years; average, 63 years) were 156 category 2F lesions. Follow-up studies were from 6 months to 13 years (median, 3.6 years; average, 4.2 years). Nineteen of 156 lesions progressed to category 3 or 4 in 6 months to 3.2 years; 17 lesions (89.5% of those that progressed and 10.9% of initial 2F lesions) were malignant and two were benign. To date, no patients had recurrent or metastatic disease. Men had significant risk for progression to malignancy (P = .003). Of 17 category 2F lesions that progressed to malignancy, 12 were endophytic (P = .02). Category 2F lesions with minimally irregular septa (nine of 17; P= .001) or wall (seven of 17; P = .016), and lesions with indistinct parenchymal interface (nine of 17; P < .001) were associated with progression to cancer. A multilobulated border was not associated with progression (P = .999). |
4 |
| 31. Smith AD, Remer EM, Cox KL, et al. Bosniak category IIF and III cystic renal lesions: outcomes and associations. Radiology. 262(1):152-60, 2012 Jan. |
Observational-Dx |
62 patients with 69 Bosniak IIF lesions; 131 patients with 144 Bosniak III lesions |
To evaluate clinical outcomes, pathologic subtypes, metastatic disease rate, and clinical features associated with malignancy in Bosniak category IIF and III cystic renal lesions. |
The malignancy rate of resected Bosniak IIF lesions was 25% (4/16) and that for Bosniak III lesions was 54% (58/107) (P=.03). 13% (9/69) of Bosniak IIF lesions progressed at follow-up, and 50% (4/8) of these resected cysts were malignant. History of primary renal malignancy, coexisting Bosniak category IV lesion and/or solid renal mass, and multiplicity of Bosniak III lesions were each associated with an increased malignancy rate in Bosniak III lesions. No patients developed locally advanced or metastatic disease from a Bosniak IIF or III lesion. |
3 |
| 32. Smith AD, Allen BC, Sanyal R, et al. Outcomes and complications related to the management of Bosniak cystic renal lesions. AJR Am J Roentgenol. 204(5):W550-6, 2015 May. |
Observational-Tx |
286 patients |
To evaluate outcomes and complications related to the management of Bosniak category IIF, III, and IV renal cysts. |
The malignancy rate at surgical pathology was 38% (3/8) for Bosniak IIF, 40% (29/72) for Bosniak III, and 90% (18/20) for Bosniak IV renal cysts. There were no metastases or deaths (0/144) directly related to Bosniak IIF renal cysts. There were no deaths (0/113) directly related to Bosniak III renal cysts, although one patient (1/113) developed local progression and lung metastases after thermal ablation. One patient with a Bosniak IV renal cyst (1/29) presented with and died of metastatic disease. Moderate to severe complications occurred in 19% (16/86), 5% (1/19), and 0% (0/181) of patients managed by surgery, ablation, and imaging surveillance, respectively (p < 0.0001). Severe complications occurred in 7% (6/86) of surgical patients and included multiorgan failure (n = 2), acute myocardial infarction (n = 1), acute ischemic stroke (n = 1), conversion to hemodialysis-dependent chronic kidney disease (n = 1), and postoperative severe hemorrhage (n = 1). |
2 |
| 33. Davenport MS, Neville AM, Ellis JH, Cohan RH, Chaudhry HS, Leder RA. Diagnosis of renal angiomyolipoma with hounsfield unit thresholds: effect of size of region of interest and nephrographic phase imaging. Radiology. 260(1):158-65, 2011 Jul. |
Observational-Dx |
217 RCCs and 65 AMLs |
To retrospectively determine the optimal Hounsfield unit threshold and region of interest (ROI) size required to accurately diagnose renal angiomyolipoma (AML) and differentiate it from renal cell carcinoma (RCC). |
There were 217 RCCs and 65 AMLs. With an attenuation threshold of -10 HU or lower at nonenhanced CT, RCC would be misdiagnosed as AML in 11 (5.1%) cases, one (0.5%) case, and one (0.5%) case with use of the tiny, small, and medium ROIs, respectively. With use of the tiny, small, and medium ROIs, misdiagnosis rates would be 2.3%, 0.5%, and 0.5%, respectively, at a threshold of 2 15 HU or lower and 1.8%, 0%, and 0%, respectively, at a threshold of 2 20 HU or lower. Areas under the ROC curve for the nonenhanced phase images (range, 0.874–0.889) were superior to those for the nephrographic phase images (range, 0.790–0.826). |
3 |
| 34. Kim JK, Park SY, Shon JH, Cho KS. Angiomyolipoma with minimal fat: differentiation from renal cell carcinoma at biphasic helical CT. Radiology. 230(3):677-84, 2004 Mar. |
Observational-Dx |
81 patients (19 with AML with minimal fat and 62 with RCC); 2 blinded reviewers |
To compare various CT features of AML with minimal fat with those of size-matched RCC in a retrospective study. |
When both CT findings were used as a criterion for differentiating AML from RCC, PPV and NPV were 91% (10/11 tumors) and 87% (61/70 tumors), respectively. 53% of AML vs 13% of RCC showed high tumor attenuation on unenhanced scans (P=.04), whereas, RCC showed greater mean enhancement than AML (114 HU +/- 44 [SD] vs 73 HU +/- 30 in corticomedullary phase and 66 HU +/- 24 vs 49 HU +/- 20 in early excretory phase) and a male predominance (male-to-female ratio, 50:12 vs 8:11; P=.001). Biphasic helical CT may be useful in differentiating AML with minimal fat from RCC, with homogeneous tumor enhancement and prolonged enhancement pattern being the most valuable CT findings. |
3 |
| 35. Takahashi N, Leng S, Kitajima K, et al. Small (< 4 cm) Renal Masses: Differentiation of Angiomyolipoma Without Visible Fat From Renal Cell Carcinoma Using Unenhanced and Contrast-Enhanced CT. AJR Am J Roentgenol. 205(6):1194-202, 2015 Dec. |
Observational-Dx |
Twenty-three patients with 24 angiomyolipomas without
visible fat and 130 patients with 148 RCCs |
To evaluate if small (< 4 cm) angiomyolipoma without visible fat can be differentiated from renal cell carcinoma (RCC) using contrast enhancedCT alone and using unenhanced and contrast-enhanced CT in combination. |
Logistic regression model from contrast-enhanced CT data included sex, percentage of exophytic growth, entropy, and CT attenuation on contrast-enhanced CT. Model from both unenhanced and contrast-enhanced CT data included age, sex, short-axis diameter, percentage of exophytic growth, lesion-to-kidney CT attenuation difference on unenhanced CT, and CT attenuation on contrast-enhanced CT. The contrast-enhanced CT–based model and combined unenhanced and contrast-enhanced CT–based model differentiated angiomyolipoma from RCC with sensitivity and specificity of 42% and 98% versus 50% and 98%, respectively. |
2 |
| 36. Silverman SG, Israel GM, Trinh QD. Incompletely characterized incidental renal masses: emerging data support conservative management. [Review]. Radiology. 275(1):28-42, 2015 Apr. |
Review/Other-Dx |
N/A |
To review the rationale for conservative approaches to small renal masses, describe the types of incompletely characterized renal masses, and provide recommendations for management. |
No results stated in the abstract. |
4 |
| 37. McGahan JP, Lamba R, Fisher J, et al. Is segmental enhancement inversion on enhanced biphasic MDCT a reliable sign for the noninvasive diagnosis of renal oncocytomas? AJR Am J Roentgenol. 2011; 197(4):W674-679. |
Observational-Dx |
29 patients with 32 oncocytomas |
To retrospectively determine whether segmental enhancement inversion or other CT patterns seen at enhanced biphasic MDCT are predictive for the diagnosis of renal oncocytoma. |
Of the 32 renal oncocytomas, 16 oncocytomas were eliminated from analysis. These masses were eliminated because they were <4 cm (n=4), the CT examinations were inadequate (n=10), or the pathology results were questionable (n=2). The remaining 16 tumors (mean size, 2.6 cm; range, 1.8-3.9 cm) were included in our study. Only 2 tumors showed distinct segments of variable degrees of enhancement, with one of those tumors having segmental enhancement inversion. Three masses had a central region of low density. The most common feature, identified in 8 of the 16 oncocytomas, was a slightly heterogeneous mass that became homogeneous on the later phase of CT. Three oncocytomas had a homogeneous appearance on both phases. |
3 |
| 38. Young JR, Margolis D, Sauk S, Pantuck AJ, Sayre J, Raman SS. Clear cell renal cell carcinoma: discrimination from other renal cell carcinoma subtypes and oncocytoma at multiphasic multidetector CT. Radiology. 267(2):444-53, 2013 May. |
Observational-Dx |
298 cases of RCC and oncocytoma |
To determine whether enhancement at multiphasic multidetector computed tomography (CT) can help differentiate clear cell renal cell carcinoma (RCC) from oncocytoma, papillary RCC, and chromophobe RCC. |
Mean enhancement of clear cell RCCs and oncocytomas peaked in the corticomedullary phase; mean enhancement of papillary and chromophobe RCCs peaked in the nephrographic phase. Enhancement of clear cell RCCs was greater than that of oncocytomas in the corticomedullary (125 HU vs 106 HU, P = .045) and excretory (80 HU vs 67 HU, P = .034) phases. Enhancement of clear cell RCCs was greater than that of papillary RCCs in the corticomedullary (125 HU vs 54 HU, P < .001) , nephrographic (103 HU vs 64 HU, P < .001) , and excretory (80 HU vs 54 HU, P < .001) phases. Enhancement of clear cell RCCs was greater than that of chromophobe RCCs in the corticomedullary (125 HU vs 74 HU, P < .001) and excretory (80 HU vs 60 HU, P = .008) phases. Thresholding of enhancement helped to discriminate clear cell RCC from oncocytoma, papillary RCC, and chromophobe RCC with accuracies of 77% (83 of 108 cases), 85% (101 of 119 cases), and 84% (81 of 97 cases). |
2 |
| 39. Raza SA, Sohaib SA, Sahdev A, et al. Centrally infiltrating renal masses on CT: differentiating intrarenal transitional cell carcinoma from centrally located renal cell carcinoma. AJR Am J Roentgenol. 198(4):846-53, 2012 Apr. |
Observational-Dx |
98 pathologically proven central renal tumors. |
To retrospectively determine the accuracy of CT for differentiating intrarenal transitional cell carcinoma (TCC) from centrally located renal cell carcinoma (RCC) and to define the most discriminating diagnostic CT features. |
All five readers recognized intrarenal TCCs with a high diagnostic accuracy (sensitivity, 90%; specificity, 90%; area under ROC curve [AUC], 0.80-0.95 for global assessment) with moderate-to-excellent interobserver agreement (? = 0.72-1). Six CT features were most diagnostically specific for identifying intrarenal TCCs: tumor centered within the collecting system; focal filling defect in the pelvicalyceal system; preserved renal shape; absence of cystic or necrotic change; homogeneous tumor enhancement; and tumor extension toward the ureteropelvic junction (sensitivity, 68-82%; specificity, 79-89%; AUC, 0.75-0.84). There was moderate-to-good agreement among the readers over all these features (? = 0.44-0.69). |
2 |
| 40. Volpe A, Finelli A, Gill IS, et al. Rationale for percutaneous biopsy and histologic characterisation of renal tumours. [Review]. Eur Urol. 62(3):491-504, 2012 Sep. |
Review/Other-Dx |
112 articles |
To review the current rationale, indications, and outcomes of percutaneous biopsies and histologic characterisation of renal tumours. |
No results stated in abstract. |
4 |
| 41. Vasudevan A, Davies RJ, Shannon BA, Cohen RJ. Incidental renal tumours: the frequency of benign lesions and the role of preoperative core biopsy. BJU Int. 97(5):946-9, 2006 May. |
Observational-Dx |
92 patients |
To determine the incidence of benign renal lesions in incidentally discovered small renal tumours, increasingly detected by the widespread use of abdominal imaging, and to evaluate whether preoperative renal core biopsy is effective in identifying benign lesions. |
Of 70 diagnostic core biopsies, a third of cases were considered benign. The sensitivity and specificity for both benign and malignant lesions when compared to definitive pathology was 100% in all cases subjected to nephrectomy. Of the 30 non-diagnostic biopsies, three were proved to be benign, and 18 likely to be benign. The only complication of renal biopsy was one case of bleeding after biopsy. |
3 |
| 42. Smaldone MC, Uzzo RG. Active surveillance: a potential strategy for select patients with small renal masses. Fut Oncol. 7(10):1133-47, 2011 Oct. |
Review/Other-Dx |
N/A |
To review active surveillance as a potential strategy for select patients with small renal masses. |
No results stated in abstract. |
4 |
| 43. Jason Abel E.. Percutaneous biopsy facilitates modern treatment of renal masses. [Review][Erratum appears in Abdom Radiol (NY). 2016 Oct;41(10):2087; PMID: 27259337]. Abdom Radiol. 41(4):617-9, 2016 04. |
Review/Other-Dx |
N/A |
To review percutaneous biopsy as a tool to guide treatment decision making of renal masses. |
No results stated in abstract. |
4 |
| 44. Herts BR, Silverman SG, Hindman NM, et al. Management of the Incidental Renal Mass on CT: A White Paper of the ACR Incidental Findings Committee. J. Am. Coll. Radiol.. , 2017 Jun 22. |
Review/Other-Dx |
N/A |
To improve quality of care by providing guidance for managing incidentally detected renal masses. |
No results stated in abstract. |
4 |
| 45. Heilbrun ME, Yu J, Smith KJ, Dechet CB, Zagoria RJ, Roberts MS. The cost-effectiveness of immediate treatment, percutaneous biopsy and active surveillance for the diagnosis of the small solid renal mass: evidence from a Markov model. J Urol. 2012; 187(1):39-43. |
Review/Other-Tx |
N/A |
To assess the cost-effectiveness of adding percutaneous biopsy or active surveillance to the diagnosis of a 2 cm or less solid renal mass. |
Immediate treatment was the highest cost, most effective diagnostic strategy, providing the longest overall survival of 18.53 life-years. Active surveillance was the lowest cost, least effective diagnostic strategy. On cost-effectiveness analysis using a societal willingness to pay threshold of $50,000 active surveillance was the preferred choice at a $75,000 willingness to pay threshold while biopsy and treatment were acceptable ($56,644 and $70,149 per life-year, respectively). When analysis was adjusted for quality of life, biopsy dominated immediate treatment as the most cost-effective diagnostic strategy at $33,840 per quality adjusted life-year gained. |
4 |
| 46. Pandharipande PV, Gervais DA, Hartman RI, et al. Renal mass biopsy to guide treatment decisions for small incidental renal tumors: a cost-effectiveness analysis. Radiology. 2010;256(3):836-846. |
Review/Other-Dx |
N/A |
To evaluate the effectiveness, cost, and cost-effectiveness of using renal mass biopsy to guide treatment decisions for small incidentally detected renal tumors. |
Under base-case assumptions, the biopsy strategy yielded a minimally greater quality-adjusted life expectancy (4 days) than did empiric surgery at a lower lifetime cost ($3466), dominating surgery from a cost-effectiveness perspective. Over the majority of parameter ranges tested in one-way sensitivity analysis, the biopsy strategy dominated surgery or was cost-effective relative to surgery based on a $75 000-per-QALY willingness-to-pay threshold. In twoway sensitivity analysis, surgery yielded greater life expectancy when the prevalence of malignancy and propensity for biopsy-negative cancers to metastasize were both higher than expected or when the sensitivity and specificity of biopsy were both lower than expected. |
4 |
| 47. Shannon BA, Cohen RJ, de Bruto H, Davies RJ. The value of preoperative needle core biopsy for diagnosing benign lesions among small, incidentally detected renal masses. J Urol. 180(4):1257-61; discussion 1261, 2008 Oct. |
Observational-Dx |
235 biopsy sets, 221 patients |
To determine the safety and accuracy of preoperative needle core biopsy for diagnosing benign lesions among small incidental asymptomatic renal masses. |
Of the 235 biopsies 184 (78%) were diagnostic, whereas 51 (22%) were nondiagnostic due to insufficient material or contents of only normal, inflammatory, fibrotic or necrotic tissue, or blood clot. Diagnostic biopsies revealed 138 malignant (75%) and 46 benign (25%) lesions. Of these patients 108 (59%) underwent renal surgery, which showed a 100% biopsy accuracy rate for distinguishing malignant from benign lesions and a 98% rate for determining histological tumor type.Followup with radiological imaging was performed for 59 lesions in patients with nondiagnostic biopsies or benign masses and for 16 low grade malignant tumors in elderly patients. Lesions remained stable in 61 cases, showed minor size changes in 9 and resolved in 5. No patient has shown symptoms or required renal surgery to date. Significant biopsy related complications were noted in only 2 patients (0.9%). |
3 |
| 48. Leveridge MJ, Finelli A, Kachura JR, et al. Outcomes of small renal mass needle core biopsy, nondiagnostic percutaneous biopsy, and the role of repeat biopsy. Eur Urol. 60(3):578-84, 2011 Sep. |
Review/Other-Dx |
345 biopsies |
To determine the results of small renal mass biopsy and the outcomes of nondiagnostic biopsy and repeat biopsy. |
345 biopsies were performed (mean diameter: 2.5 cm). Biopsy was diagnostic in 278 cases (80.6%) and nondiagnostic in 67 cases (19.4%). Among diagnostic biopsies, 221 (79.4%) were malignant, 94.1% of which were RCC. Histologic subtyping and grading of RCC was possible in 88.0% and 63.5% of cases, respectively. Repeat biopsy was performed in 12 of the 67 nondiagnostic cases, and a diagnosis was possible in 10 (83.3%). Eight lesions were malignant and two were oncocytic neoplasms. Pathology was available for 15 masses after initial nondiagnostic biopsy; 11 (73%) were malignant. Larger tumor size and a solid nature on imaging predicted a successful biopsy on multivariate analysis. Grade 1 complications were experienced in 10.1% of cases, with no major bleeding and no seeding of the biopsy tract. There was one grade 3a complication (0.3%). This is a retrospective study and some data are unavailable on factors that may affect biopsy success rates. Repeat biopsy was not standard practice prior to this analysis. |
4 |
| 49. Dilauro M, Quon M, McInnes MD, et al. Comparison of Contrast-Enhanced Multiphase Renal Protocol CT Versus MRI for Diagnosis of Papillary Renal Cell Carcinoma. AJR Am J Roentgenol. 206(2):319-25, 2016 Feb. |
Observational-Dx |
27 pRCCs;
Control group: Twenty consecutive
hemorrhagic/proteinaceous cysts |
To compare contrast-enhanced (CE) CT with MRI for the diagnosis of papillary renal cell carcinoma (pRCC). |
There was no statistically significant difference in patient age (p = 0.22), patient sex (p = 0.36), or tumor size (p = 0.29), when pRCCs were compared with hemorrhagic/proteinaceous cysts. On unenhanced CT, attenuation of pRCCs (mean ± SD, 35.7 ± 12.9 HU; range, 19–66 HU) was similar to that of hemorrhagic/proteinaceous cysts (mean, 38.9 ± 16.9; range, 8–71 HU) (p = 0.48). A total of 51.9% of pRCCs (14/27) had either absent or indeterminateenhancement on corticomedullary phase CECT images (mean attenuation difference, 23.2 ± 20.3 HU; range, 6–105 HU), and 14.8% of pRCCs (4/27) had indeterminate enhancement on nephrographic phase CECT images (mean attenuation difference, 36.4 ± 24.9; range, 10–128 HU). No pRCC was nonenhancing on nephrographic phase CECT. Qualitatively, pRCCs were more heterogeneous (80% vs 45%; p = 0.02; ? = 0.24), irregular (50% vs 5%; p < 0.001; ? = 0.21), and calcified (25% vs 0%; p = 0.004; ? = 0.67), with overlap existing between hemorrhagic/proteinaceous cysts. On CE-MRI, all pRCCs were quantitativelyenhanced by phase 2 (95.4 ± 83.1; percentage change in signal intensity ratio, 16–450%) and qualitatively enhanced after consensus review. No hemorrhagic/proteinaceous cyst enhanced on MRI when quantitative or subjective analysis was performed. |
2 |
| 50. Egbert ND, Caoili EM, Cohan RH, et al. Differentiation of papillary renal cell carcinoma subtypes on CT and MRI. AJR Am J Roentgenol. 201(2):347-55, 2013 Aug. |
Review/Other-Dx |
82 patients |
To determine the frequency of atypical papillary renal cell carcinomas (RCCs) and identify imaging differences between type 1 and type 2 papillary RCCs once atypical papillary RCC tumors have been excluded. |
There were 43 type 1 and 13 type 2 tumors. Atypical histologic features (i.e., tumors containing both type 1 and type 2 components, clear cells, or components with atypically high nuclear grade [in type 1 tumors] or low nuclear grade [in type 2 tumors]) were seen in 26 tumors. On CT, type 2 tumors more commonly had infiltrative margins (p = 0.05) and were more likely to have calcifications (p = 0.04) than type 1 tumors, although these features were seen in all tumor types. Type 2 tumors were also more heterogeneous than type 1 tumors (p = 0.04). On CT, 11 papillary RCCs showed enhancement of less than 20 HU, seven of which showed enhancement of less than 10 HU. On MRI, all tumors showed enhancement on subtraction images. |
4 |
| 51. Ho VB, Allen SF, Hood MN, Choyke PL. Renal masses: quantitative assessment of enhancement with dynamic MR imaging. Radiology. 2002; 224(3):695-700. |
Observational-Dx |
74 patients |
Retrospective study to establish a quantitative MRI contrast enhancement criterion for distinguishing cysts from solid renal lesions. |
The optimal percentage of enhancement threshold for distinguishing cysts from malignancies with the imaging technique prescribed was 15%, and the optimal timing for measurement was 2-4 minutes after administration of contrast material. |
3 |
| 52. Hecht EM, Israel GM, Krinsky GA, et al. Renal masses: quantitative analysis of enhancement with signal intensity measurements versus qualitative analysis of enhancement with image subtraction for diagnosing malignancy at MR imaging. Radiology. 2004; 232(2):373-378. |
Observational-Dx |
71 patients with 93 renal lesions: Quantitative 1 investigator; Qualitative 2 independent investigators |
To retrospectively compare the accuracy of quantitative and qualitative contrast enhancement of renal mass lesions on MRI, using contrast enhancement as the basis for malignancy. |
For diagnosing malignancy based on enhancement alone, sensitivity and specificity, respectively, were 95% (70/74 lesions) and 53% (10/19 lesions) at quantitative analysis and 99% (73/74 lesions) and 58% (11/19 lesions) at qualitative analysis. When the oncocytomas were excluded, specificities increased to 83% (10/12 lesions) and 92% (11/12 lesions) for the quantitative and qualitative evaluations, respectively. 3 of 4 malignant lesions incorrectly characterized as benign at quantitative assessment were hyperintense on unenhanced MRIs; all were diagnosed correctly at qualitative evaluation. Both techniques have high sensitivity, but qualitative enhancement analysis is superior for diagnosing malignancy in renal lesions that are hyperintense prior to contrast enhancement. |
2 |
| 53. Davarpanah AH, Spektor M, Mathur M, Israel GM. Homogeneous T1 Hyperintense Renal Lesions with Smooth Borders: Is Contrast-enhanced MR Imaging Needed?. Radiology. 280(1):128-36, 2016 07. |
Observational-Dx |
84 patients with hemorrhagic or proteinaceous cysts and 50 patients with renal cell carcinoma (RCC) |
To retrospectively determine if homogeneous high T1 signal intensity (SI) masses with smooth borders on unenhanced magnetic resonance (MR) images can be characterized as benign. |
SI ratio and attenuation of hemorrhagic or proteinaceous cysts were significantly higher than those of RCCs (SI ratio: cyst 2.4 +- 0.8, RCC 1.5 +- 0.3; attenuation: cyst 51.9 +- 21.5, RCC: 34.8 +- 10.0). Reader 1 scored morphology of 68 (81%) hemorrhagic or proteinaceous cysts as score 1 on MR images and as score 45 (71%) on CT scans. Reader 2 scored morphology of 59 (70%) hemorrhagic or proteinaceous cysts as score 1 on MR images and as score 43 (68%) on CT scans. Two-step classification tree suggested that homogeneous high T1 SI lesions with smooth borders and SI ratio of greater than 1.6 predict the lesion as benign cysts. Similar algorithm for CT suggested threshold of 51 HU. Increasing threshold to 2.5 for SI ratio and 66 for Hounsfield units resulted in 99.9% confidencefor characterizing benign cysts. |
2 |
| 54. Kim CW, Shanbhogue KP, Schreiber-Zinaman J, Deng FM, Rosenkrantz AB. Visual Assessment of the Intensity and Pattern of T1 Hyperintensity on MRI to Differentiate Hemorrhagic Renal Cysts From Renal Cell Carcinoma. AJR Am J Roentgenol. 208(2):337-342, 2017 Feb. |
Observational-Dx |
144 T1-hyperintense renal lesions |
To apply a visual assessment of the intensity and pattern of T1 hyperintensity at MRI to differentiate hemorrhagic renal cysts from renal cell carcinoma (RCC). |
The T1 hyperintensity was considered marked in 62.9% of cysts and 17.1% of RCCs for reader 1 and in 46.8% of cysts and 8.5% of RCCs for reader 2 (p < 0.001). The T1 hyperintensity exhibited a diffusely homogeneous distribution in 88.7% of cysts and 7.3% of RCCs for reader 1 and in 72.6% of cysts and 4.9% of RCCs for reader 2 (p < 0.001). The combination of both diffusely homogeneous distribution and marked degree of T1 hyperintensity achieved sensitivities of 40.3–56.5%, specificities of 97.6–98.8%, and accuracies of 73.6–79.9% for the diagnosis of T1-hyperintense cysts. The two cases of RCC exhibiting this imaging pattern for atleast one reader were both papillary RCCs. Normalized signal intensity was 2.39 ± 0.99 in T1-hyperintense cysts versus 2.12 ± 0.84 in T1-hyperintense RCCs (p = 0.088). |
3 |
| 55. Verma SK, Mitchell DG, Yang R, et al. Exophytic renal masses: angular interface with renal parenchyma for distinguishing benign from malignant lesions at MR imaging. Radiology. 2010; 255(2):501-507. |
Observational-Dx |
162 exophytic (2 cm or greater) renal masses in 152 patients |
To retrospectively determine whether benign exophytic renal masses can be distinguished from RCC on the basis of angular interface at single-shot fast spin-echo T2-weighted MRI. |
Of 162 masses, 65 were benign, and 97 were RCCs. The sensitivity, specificity, PPV, NPV, and A(z) of angular interface for diagnosing benign masses were 78%, 100%, 100%, 87%, and 0.813, respectively. Angular interface (P<.001) was a significant predictor of benign renal mass but mass size (P=.66) was not. There was almost perfect interobserver agreement for mass size (ICC=0.96) and angular interface (kappa = 0.91). |
2 |
| 56. Taouli B, Thakur RK, Mannelli L, et al. Renal lesions: characterization with diffusion-weighted imaging versus contrast-enhanced MR imaging. Radiology. 2009; 251(2):398-407. |
Observational-Dx |
109 renal lesions in 64 patients |
To compare the diagnostic performance of DWI MRI with that of contrast material-enhanced MRI and to assess the performance of these examinations combined for the characterization of renal lesions, with MRI follow-up and histopathologic analysis as the reference standards. |
The 109 renal lesions; 81 benign lesions and 28 RCCs, had a mean diameter of 4.2 cm +/- 2.5 (SD). The mean ADC for RCCs (1.41 x 10(-3) mm(2)/sec +/- 0.61) was significantly lower (P<.0001) than that for benign lesions (2.23 x 10(-3) mm(2)/sec +/- 0.87) at DWI performed with b values of 0, 400, and 800 sec/mm(2). At a cutoff ADC of =1.92 x 10(-3) mm(2)/sec, the area under the ROC curve, sensitivity, and specificity of DWI for the diagnosis of RCCs (excluding AMLs) were 0.856, 86%, and 80%, respectively. The corresponding area under the ROC curve, sensitivity, and specificity of contrast-enhanced MRI were 0.944, 100%, and 89%, respectively. Combined DWI and contrast-enhanced MRI had 96% specificity. The area under the ROC curve for the DWI-based diagnosis of solid RCC vs oncocytoma was 0.854. Papillary RCCs had lower ADCs than nonpapillary RCCs. |
3 |
| 57. Pedrosa I, Rafatzand K, Robson P, et al. Arterial spin labeling MR imaging for characterisation of renal masses in patients with impaired renal function: initial experience. Eur Radiol. 2012; 22(2):484-492. |
Observational-Dx |
11 patients |
To retrospectively evaluate the feasibility of arterial spin labeling MRI for the assessment of vascularity of renal masses in patients with impaired renal function. |
17 renal lesions were evaluated in 11 patients (8 male; mean age = 70 years) (range 57-86). The median eGFR was 24 mL/min/1.73 m(2) (range 7-39). The average blood flow of 11 renal masses interpreted as arterial spin labeling-positive (134 +/- 85.7 mL/100 g/min) was higher than that of 6 renal masses interpreted as arterial spin labeling-negative (20.5 +/- 8.1 mL/100 g/min)(P=0.015). Arterial spin labeling-positivity correlated with malignancy (n=3) or epithelial atypia (n=1) at histopathology or progression at follow-up (n=7). |
3 |
| 58. Rosenkrantz AB, Wehrli NE, Mussi TC, Taneja SS, Triolo MJ. Complex cystic renal masses: comparison of cyst complexity and Bosniak classification between 1.5 T and 3 T MRI. Eur J Radiol. 83(3):503-8, 2014 Mar. |
Observational-Dx |
33 cystic renal lesions; 26 patients |
To retrospectively compare perceived complexity and Bosniak cyst classification of cystic renal lesions between 1.5 T and 3 T MRI. |
Two radiologists (R1, R2) independently assessed lesions. R1 observed increases in septal number, septal thickening, mural thickening, and presence ofmural nodule at 3 T in 8, 7, 4, and 2 lesions, and at 1.5 T in 3, 3, 2, and 0 lesions, respectively; R2 observed increases in septal number, septal thickening, mural thickening, and presence of mural nodule at 3 T in 3, 4, 3, and 0 lesions, and at 1.5 T in 2, 0, 0, and 0 lesions, respectively. R1 provided higher Bosniak categoryat 3 T in 9 cases and at 1.5 T in 4 cases; R2 provided higher Bosniak category at 3 T in 4 cases and at 1.5 T in 0 cases. Higher scores at 3 T than 1.5 T were associated with differences in advised clinical management in 7/9 cases for R1 and 4/4 cases for R2. |
2 |
| 59. Sasiwimonphan K, Takahashi N, Leibovich BC, Carter RE, Atwell TD, Kawashima A. Small (<4 cm) renal mass: differentiation of angiomyolipoma without visible fat from renal cell carcinoma utilizing MR imaging. Radiology. 263(1):160-8, 2012 Apr. |
Observational-Dx |
69 men and 42 women |
To determine whether a combination of MR parameters can help differentiate small AMLs without visible fat from RCCs. |
AML had significantly higher T1 SI ratio (P=.04), lower T2 SI ratio (P=.001), higher SII (P=.02), and higher arterial-to-delayed enhancement ratio (P<.001) than RCC. Sensitivity, specificity, and accuracy for combination of T2 SI ratio <0.9 and ([SII <20% and T1 SI ratio <1.2] or arterial-to-delayed enhancement ratio <1.5) were 73% (11/15), 99% (103/104), and 96% (114/119), respectively, for differentiating AML from RCC. |
3 |
| 60. Schieda N, Dilauro M, Moosavi B, et al. MRI evaluation of small (<4cm) solid renal masses: multivariate modeling improves diagnostic accuracy for angiomyolipoma without visible fat compared to univariate analysis. Eur Radiol. 26(7):2242-51, 2016 Jul. |
Observational-Dx |
Ten AMLwvf and 77 RCC |
To assess MRI for diagnosis of angiomyolipoma without visible fat (AMLwvf). |
T2W-SIR was lower in AMLwvf (0.64±0.12) compared to cc-RCC (1.37±0.30, p<0.001), ch-RCC (0.94±0.19, p=0.005) but not p-RCC (0.74±0.17, p=0.2). CS-SI index was higher in AMLwvf (16.1±31.5 %) compared to p-RCC (-5.2±26.1 %, p=0.02) but not ch-RCC (3.0±12.5 %, p=0.1) or cc-RCC (7.7±17.9 %,p=0.1). CE-AUC was higher in AMLwvf (515.7±144.7) compared to p-RCC (154.5±92.8, p<0.001) but not ch-RCC (341.5±202.7, p=0.07) or cc-RCC (520.9±276.9,p=0.95). Univariate ROC-AUC were: T2SIR=0.86 (CI 0.77–0.96); CE-AUC=0.76 (CI 0.65–0.87); CS-SI index=0.66 (CI 0.4.3–0.85). Logistic regression models improved ROCAUC, A) T2 SIR + CE-AUC=0.97 (CI 0.93–1.0) and T2 SIR + CS-SI index=0.92 (CI 0.84–0.99) compared to univariate analyses (p<0.05). The optimal sensitivity/specificity of T2SIR + CE-AUC and T2SIR + CS-SI index were 100/88.8 % and 60/97.4 %. |
3 |
| 61. Murray CA, Quon M, McInnes MD, et al. Evaluation of T1-Weighted MRI to Detect Intratumoral Hemorrhage Within Papillary Renal Cell Carcinoma as a Feature Differentiating From Angiomyolipoma Without Visible Fat. AJR Am J Roentgenol. 207(3):585-91, 2016 Sep. |
Observational-Dx |
11 AMLs without visible fat; 58 papillary RCCs;
Control group: 11 patients with 11 AMLs
without visible fat. |
To determine whether hemorrhage within papillary renal cell carcinoma (RCC) can be detected using T1-weighted MRI and to ascertain whether it can be used to differentiate papillary RCC from angiomyolipoma (AML) without visible fat. |
When AMLs without visible fat were compared with papillary RCCs, no statistically significant difference in the T2-weighted SI ratio was noted (p = 0.08). Papillary RCCs had a lower mean (± SD) SI loss index (-3.7% ± 17.3%; range, -51.3% to 31.3%) than did AMLs without visible fat (37.8% ± 76.1%; range, -15.6% to 184.4%) (p < 0.001). A mean SI loss index of less than -16% resulted in an AUC of 0.71 (95% CI, 0.52–0.91), with a sensitivity and specificityof 22.8% and 100%, respectively, for the diagnosis of papillary RCC. After consensus review, none of the AMLs without visible fat and 16 of the 58 papillary RCCs (27.6%) were found to have a decrease in SI on subjective analysis (p = 0.06, ? = 0.60). Between groups, no differences were noted in the SI ratio on fat-suppressed T1-weighted MRI (p = 0.58) or in the SI observed on subjective analysis of fat-suppressed T1-weighted MRI (p = 0.20, ? = 0.48). |
3 |
| 62. Sun MR, Ngo L, Genega EM, et al. Renal cell carcinoma: dynamic contrast-enhanced MR imaging for differentiation of tumor subtypes--correlation with pathologic findings. Radiology. 250(3):793-802, 2009 Mar. |
Observational-Dx |
112 patients |
To retrospectively evaluate whether the enhancement patterns of pathologically proved clear cell, papillary, and chromophobe renal cell carcinomas (RCCs) measured on clinical dynamic contrast agent–enhanced magnetic resonance (MR) images permit accurate diagnosis of RCC subtype. |
On both the corticomedullary and nephrographic phase images, clear cell RCCs showed greater signal intensity change (205.6% and 247.1%, respectively) than did papillary RCCs (32.1% and 96.6%, respectively) (P < .001). Chromophobe RCCs showed intermediate change (109.9% and 192.5%, respectively). The tumor-to-cortex enhancement indexes at corticomedullary and nephrographic phases were largest for clear cell RCCs (1.4 and 1.2, respectively), smallest for papillary RCCs (0.2 and 0.4, respectively), and intermediate for chromophobe RCCs (0.6 and 0.8, respectively). Signal intensity changes on corticomedullary phase images were the most effective parameter for distinguishing clear cell and papillary RCC (area under ROC curve, 0.99); a threshold value of 84% permitted distinction with 93% sensitivity and 96% specificity. |
3 |
| 63. Hotker AM, Mazaheri Y, Wibmer A, et al. Differentiation of Clear Cell Renal Cell Carcinoma From Other Renal Cortical Tumors by Use of a Quantitative Multiparametric MRI Approach. AJR Am J Roentgenol. 208(3):W85-W91, 2017 Mar. |
Observational-Dx |
119 patients |
To develop a quantitative multiparametric MRI approach to differentiating clear cell renal cell carcinoma (RCC) from other renal cortical tumors |
Interreader agreement was excellent (intraclass correlation coefficient, 0.815–0.994). The parameters apparent diffusion coefficient (reader 1 AUC, 0.804; reader 2, 0.807), peak enhancement (reader 1 AUC, 0.629; reader 2, 0.606), and downslope (reader 1 AUC, 0.575; reader 2, 0.561) were significantly associated with discriminating clear cell RCC from other renal cortical tumors. The combination of all three parameters further increased diagnostic accuracy (reader 1 AUC, 0.889; reader 2, 0.907; both p = 0.001), yielding sensitivities of 0.897 for reader 1 and 0.897 for reader 2, and specificities of 0.762 for reader 1 and 0.738for reader 2 in the identification of clear cell RCC. With maximized sensitivity, specificities of 0.429 and 0.262 were reached for readers 1 and 2, respectively. |
2 |
| 64. Kay FU, Canvasser NE, Xi Y, et al. Diagnostic Performance and Interreader Agreement of a Standardized MR Imaging Approach in the Prediction of Small Renal Mass Histology. Radiology. 287(2):543-553, 2018 05. |
Observational-Dx |
103 patients with 109 SRMs resected |
To assess the diagnostic performance and interreader agreement of a standardized diagnostic algorithm in determining the histologic type of small (</=4 cm) renal masses (SRMs) with multiparametric magnetic resonance (MR) imaging. |
Clear cell renal cell carcinoma (RCC) and papillary RCC were diagnosed, with sensitivities of 85% (47 of 55) and 80% (20 of 25), respectively, and specificities of 76% (41 of 54) and 94% (79 of 84), respectively. Interreader agreement was moderate to substantial (clear cell RCC, kappa = 0.58; papillary RCC, kappa = 0.73). Signal intensity (SI) of the lesion on T2-weighted MR images and degree of contrast enhancement (CE) during the corticomedullary phase were independent predictors of clear cell RCC (SI odds ratio [OR]: 3.19; 95% confidence interval [CI]: 1.4, 7.1; P = .003; CE OR, 4.45; 95% CI: 1.8, 10.8; P < .001) and papillary RCC (CE OR, 0.053; 95% CI: 0.02, 0.2; P < .001), and both had substantial interreader agreement (SI, kappa = 0.69; CE, kappa = 0.71). Poorer performance was observed for chromophobe histology, oncocytomas, and minimal fat angiomyolipomas, (sensitivity range, 14%-67%; specificity range, 97%-99%), with fair to moderate interreader agreement (kappa range = 0.23-0.43). Segmental enhancement inversion was an independent predictor of oncocytomas (OR, 16.21; 95% CI: 1.0, 275.4; P = .049), with moderate interreader agreement (kappa = 0.49). |
2 |
| 65. Quaia E, Bertolotto M, Cioffi V, et al. Comparison of contrast-enhanced sonography with unenhanced sonography and contrast-enhanced CT in the diagnosis of malignancy in complex cystic renal masses. AJR Am J Roentgenol. 2008; 191(4):1239-1249. |
Observational-Dx |
40 patients |
To evaluate contrast-enhanced sonography in the diagnosis of malignancy in complex cystic renal masses. |
Final diagnoses comprised two multilocular cystic nephromas, two inflammatory and seven hemorrhagic cysts, and eight uncomplicated benign cysts and 21 cystic RCCs. The overall diagnostic accuracy of contrast-enhanced sonography was better than unenhanced sonography and CT (contrast-enhanced sonography vs unenhanced sonography vs CT: reader 1, 83% vs 30% vs 75%; reader 2, 83% vs 30% vs 63%; reader 3, 80% vs 30% vs 70%; P<0.05, McNemar test). |
2 |
| 66. Atri M, Tabatabaeifar L, Jang HJ, Finelli A, Moshonov H, Jewett M. Accuracy of Contrast-enhanced US for Differentiating Benign from Malignant Solid Small Renal Masses. Radiology. 276(3):900-8, 2015 Sep. |
Observational-Dx |
91 patients, 94 lesions |
To test the hypothesis that qualitative and quantitative features of contrast material–enhanced ultrasonography (US) can be used to differentiate benign from malignant small renal masses. |
The study population consisted of 91 patients (35 women and 56 men) with 94 lesions. The mean age was 62 years +- 14 (range, 21–91). Three patients had two lesions each, which were evaluated at two different sessions. There were 26 benign small renal masses (including 18 oncocytomas, seven lipid-poor angiomyolipomas, and one hemangioblastoma) and 68 malignant masses (including 41 clear cell, 20 papillary, and seven chromophobe renal cell carcinomas [RCCs[) that were 1.1–4.0 cm in diameter (mean, 2.7 cm +- 0.9). All patients underwent contrast-enhanced US on the same one machine, and 68 patients wereimaged on all three machines. Vascularity was present in all lesions (n= 94) at contrast-enhanced US. Lesion hypovascularity relative to the adjacent cortex in the arterial phase was seen in only malignant lesions by both reviewers; reviewer 1 saw hypovascularity in 24 of 94 lesions (P = .0001), and reviewer 2 saw hypovascularity in 21 of 94 lesions (P= .0006), for a specificity of 100% (95% confidence interval [CI]: 84, 100). This feature had k values of 0.91 (95%CI: 0.82, 1.00) between the two reviewers and 0.85 (95% CI: 0.72, 0.99) between the three machines. Eighteen of 20 papillary RCCs were hypovascular. Quantitativeparameters of area under the receiver operating characteristics curve, peak intensity, wash-in slope of 10%–90% and 5%–45%, and washout slope of 100%–10% and 50%–10% were significantly higher in malignant renal masses (P = .018, P = .002, P = .036, P = .016, P =.001, and P = .005, respectively) than in benign lesions. |
2 |
| 67. Cai Y, Du L, Li F, Gu J, Bai M. Quantification of enhancement of renal parenchymal masses with contrast-enhanced ultrasound. Ultrasound Med Biol. 40(7):1387-93, 2014 Jul. |
Observational-Dx |
73 solid renal parenchymal masses |
To investigate the value of quantitative assessment of enhancement in diagnosing renal cell carcinoma (RCC) with contrast-enhanced ultrasound (CEUS). |
The diameters of renal cancer were found to be larger on CEUS than on conventional ultrasound (p < 0.05). When cutoff values of 4.74 s for washout time and 8.52% for enhancement intensity at 60 s for diagnosing RCCs were applied, the sensitivity, specificity and area under the receiver operating characteristic curve were 67.3%, 95.2%, 86.5% and 65.4%, 81.0%, 68.4%, respectively. The sensitivity and specificity for these two enhancement characteristics combined as a criterion for differentiating RCCs from benign lesions were 44.0% and 99.1%, respectively. |
3 |
| 68. Li CX, Lu Q, Huang BJ, et al. Quantitative evaluation of contrast-enhanced ultrasound for differentiation of renal cell carcinoma subtypes and angiomyolipoma. Eur J Radiol. 85(4):795-802, 2016 Apr. |
Observational-Dx |
341 RCCs and 88 AMLs |
To investigate the value of quantitative parameters of contrast-enhanced ultrasound (CEUS) in the differentiation of subtypes of renal cell carcinoma (RCC) and angiomyolipoma (AML). |
All time-related parameters (including RT, TTP and mTT) of ROImax were shorter than the corresponding parameters of ROItumor in RCC subtypes (all p < 0.05), but made no statistical difference in AMLs (all p > 0.05). There were significant differences of all delta Par.s among RCC subtypes and AML (all p < 0.01). delta IMAX and delta AUC showed the trend that ccRCC > AML > pRCC = chRCC. Delta TTP showed AML = pRCC = chRCC > ccRCC, delta RT and delta mTT showed AML > pRCC = chRCC = ccRCC. Delta mTT could distinguish RCC from AML with the area under the ROC curve (AUC) of 0.86. The AUC of delta IMAX and delta AUC was 0.89 and 0.92 vs 0.85 and 0.85 for discriminating between pRCC (or chRCC) and AML vs ccRCC and AML. |
2 |
| 69. Siddaiah M, Krishna S, McInnes MDF, et al. Is Ultrasound Useful for Further Evaluation of Homogeneously Hyperattenuating Renal Lesions Detected on CT?. AJR Am J Roentgenol. 209(3):604-610, 2017 Sep. |
Observational-Dx |
107 consecutive homogeneously hyperattenuating
renal lesions |
To evaluate the ability of ultrasound (US) to characterize hyperattenuating cysts detected as indeterminate hyperattenuating renal lesions on unenhanced and single phase enhanced CT. |
Mean lesion size ± SD was 20 ± 16 mm (range, 6–96 mm) and mean distance to skin on CT was 62 ± 25 mm (range, 18–125 mm). In all, 89.7% (96/107) of the lesions were visible on US, including all lesions that were 15 mm or larger. Nonvisible lesions were smaller than visible ones (10.0 ± 3.6 mm vs 20.7 ± 16.3 mm, p = 0.03) regardless of location (p > 0.05). CT overestimated lesion distance to skin compared with US (46.6 ± 18.6 mm, p < 0.001). Final diagnoses for US visible lesions (n = 96) were hyperattenuating cyst (n = 66), Bosniak IIF cyst (n = 13), and cystic or solid neoplasm (n = 15); two patients were lost to follow-up. Of the 66 hyperattenuating cysts, 54 (81.8%) appeared as simple cysts on US with sensitivity and specificity for diagnosis of hyperattenuating cyst of 81.8% (95% CI,75.6–84.3%) and 92.9% (95% CI, 78.1–98.7%), respectively. The other 12 (18.2%) hyperattenuating cysts appeared complex. Two of the 13 Bosniak IIF lesions were incorrectly classified as simple cysts with US. Including the 11 (10%) nonvisible lesions reduced sensitivity and specificity for diagnosis of hyperattenuating cyst to 73.0% (95% CI, 66.9–75.9%) and 89.7% (95% CI, 74.2–97.2%), respectively. |
2 |
| 70. Doshi AM, Ayoola A, Rosenkrantz AB. Do Incidental Hyperechoic Renal Lesions Measuring Up to 1 cm Warrant Further Imaging? Outcomes of 161 Lesions. AJR Am J Roentgenol. 209(2):346-350, 2017 Aug. |
Review/Other-Dx |
161 hyperechoic renal lesions |
To determine the outcomes of hyperechoic renal lesions measuring 1 cm or less at ultrasound examination. |
Follow-up included 11 unenhanced CT, 39 contrast-enhanced CT, 52 unenhanced and contrast-enhanced CT, two unenhanced MRI, 50 unenhanced and contrast-enhanced MRI, and 87 ultrasound examinations. At CT or MRI 58.4% of lesions were confirmed to be angiomyolipomas. At CT, one lesion represented a stone, and one a hyperdense cyst. At CT or MRI 11.8% of the lesions had no correlate; 3.1% were not visualized at follow-up ultrasound. An additional 23.6% were stable at 2-year follow-up imaging or beyond. Two lesions were evaluated with only contrast-enhanced CT less than 1 month after ultrasound, and the CT imagesdid not show macroscopic fat or calcification or meet the criteria for a simple cyst. These lesions were considered indeterminate. One lesion in a 65-year-old man was imaged with unenhanced and contrast-enhanced CT 23 months after ultrasound, and the CT showed an increase in size, solid enhancement, and no macroscopic fat. This lesion was presumed to represent renal cell carcinoma. Overall, the one lesion presumed malignant and the two indeterminate lesions constituted1.9% of the cohort. The other 98.1% of lesions were considered clinically insignificant. |
4 |
| 71. American College of Radiology. Manual on Contrast Media. Available at: https://www.acr.org/Clinical-Resources/Contrast-Manual. |
Review/Other-Dx |
N/A |
To assist radiologists in recognizing and managing risks associated with the use of contrast media. |
No abstract available. |
4 |
| 72. Grobner T. Gadolinium--a specific trigger for the development of nephrogenic fibrosing dermopathy and nephrogenic systemic fibrosis? Nephrol Dial Transplant. 2006; 21(4):1104-1108. |
Review/Other-Dx |
9 patients |
To describe a possible relationship between gadolinium and nephrogenic systematic fibrosis. |
5/9 end-stage renal disease patients developed nephrogenic systematic fibrosis after receiving gadolinium. |
4 |
| 73. American College of Radiology. ACR Appropriateness Criteria® Radiation Dose Assessment Introduction. Available at: https://www.acr.org/-/media/ACR/Files/Appropriateness-Criteria/RadiationDoseAssessmentIntro.pdf. |
Review/Other-Dx |
N/A |
To provide evidence-based guidelines on exposure of patients to ionizing radiation. |
No abstract available. |
4 |
