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Appropriateness Criteria

Reference Study Type Patients/Events Study Objective(Purpose of Study) Study Results Study Quality
1. Elsayes KM, Menias CO, Willatt J, Azar S, Harvin HJ, Platt JF. Imaging of renal transplant: utility and spectrum of diagnostic findings. Curr Probl Diagn Radiol 2011;40:127-39. Review/Other-Dx N/A To present a multi-modality review of the spectrum of pathology related to renal transplantation. No results stated in abstract. 4
2. OPTN/SRTR: Transplant Data.  Available at: https://optn.transplant.hrsa.gov/data/view-data-reports/national-data/#. Review/Other-Tx N/A To provide statistics on donation and transplantation in the United States. No results stated in abstract. 4
3. Dubovsky EV, Russell CD, Erbas B. Radionuclide evaluation of renal transplants. Semin Nucl Med. 1995; 25(1):49-59. Review/Other-Dx N/A Review imaging of renal transplants. The article is an update of a more comprehensive previous review (Semin Nucl Med, 181-198, 1988) and emphasizes the changes that have taken place in this field in recent years. Changes in renal transplant comprise new criteria for the selection of transplant candidates, newer techniques for the diagnosis of medical and surgical complications after transplantation, the use of new tracers (Tc-99m MAG3), and new antirejection regimens. 4
4. Sharfuddin A. Imaging evaluation of kidney transplant recipients. Semin Nephrol 2011;31:259-71. Review/Other-Dx N/A To discuss the evaluation of the kidney transplant recipient using these imaging procedures, emphasizing the clinical diagnostic utility and role of each modality. No results stated in abstract. 4
5. Zarzour JG, Lockhart ME. Ultrasonography of the Renal Transplant. Ultrasound Clinics 2014;9:683-95. Review/Other-Dx N/A To describe the role of US of the transplanted kidney. No results stated in abstract. 4
6. Dimitroulis D, Bokos J, Zavos G, et al. Vascular complications in renal transplantation: a single-center experience in 1367 renal transplantations and review of the literature. Transplant Proc 2009;41:1609-14. Review/Other-Tx 1367 consecutive renal transplantations To present our single-center experience concerning vascular complications in 1367 consecutive renal transplantations. We encountered 38 major vascular complications leading to graft loss and 19 transplant renal artery stenoses with successful treatment in the majority of cases. According to these data, we can conclude that renal transplantation is a safe therapeutic procedure for renal failure. 4
7. Eufrasio P, Parada B, Moreira P, et al. Surgical complications in 2000 renal transplants. Transplant Proc 2011;43:142-4. Review/Other-Tx 318 patients To evaluate surgical complications among a large series of 2000 renal transplantations. Among 318 (15.9%) surgical complications, 4.8% of patients had urologic problems. Ureteral stenosis and fistula, stent obstruction, and ureteral necrosis occurred in 2.7%, 1.8%, 0.1%, and 0.2% of patients, respectively. Vascular complications reported in 2.7% of patients included arterial or venous thrombosis (1.0% or 0.4%), both arterial and venous thrombosis (0.1%), renal infarction (0.1%), renal artery aneurysm (0.1%) as well as arterial stenosis (0.5%), kinking (0.4%), or dissection (0.1%). Other complications, not specifically related with transplantation surgery, occurred in 4.4% of patients. 4
8. Akbar SA, Jafri SZ, Amendola MA, Madrazo BL, Salem R, Bis KG. Complications of renal transplantation. Radiographics 2005;25:1335-56. Review/Other-Dx N/A To present both the clinical and imaging features of renal transplantation complications and their interventional management. Urologic and vascular complications may occur. Vascular complications include renal artery stenosis and renal artery and renal vein thrombosis. Ultrasound can accurately depict and characterize many of the potential complications of renal transplantation and increasingly magnetic resonance imaging also facilitates this role. In addition, interventional radiologic techniques allow nonsurgical treatment. 4
9. Sharfuddin A. Renal relevant radiology: imaging in kidney transplantation. Clin J Am Soc Nephrol 2014;9:416-29. Review/Other-Dx N/A To discusses the evaluation of the kidney transplant recipient using these imaging procedures, emphasizing the clinical diagnostic utility and role of each modality. No results stated in abstract. 4
10. Smith AD, Nikolaidis P, Khatri G, et al. ACR Appropriateness Criteria® Acute Pyelonephritis: 2022 Update. J Am Coll Radiol 2022;19:S224-S39. Review/Other-Dx N/A Evidence-based guidelines to assist referring physicians and other providers in making the most appropriate imaging or treatment decision for acute pyelonephritis. No results stated in abstract. 4
11. Kazmierski BJ, Sharbidre KG, Robbin ML, Grant EG. Contrast-Enhanced Ultrasound for the Evaluation of Renal Transplants. [Review]. Journal of Ultrasound in Medicine. 39(12):2457-2468, 2020 Dec. Review/Other-Dx N/A To discuss the role of contrast-enhanced ultrasound for evaluating the transplant kidney. No results stated in abstract. 4
12. Morgan TA, Jha P, Poder L, Weinstein S. Advanced ultrasound applications in the assessment of renal transplants: contrast-enhanced ultrasound, elastography, and B-flow. [Review]. Abdominal Radiology. 43(10):2604-2614, 2018 10. Review/Other-Dx N/A To discuss new ultrasound applications and their diagnostic capability. No results stated in abstract. 4
13. Heaf JG, Iversen J. Uses and limitations of renal scintigraphy in renal transplantation monitoring. Eur J Nucl Med. 2000; 27(7):871-879. Observational-Dx 213 consecutive transplants To investigate the value of thrice weekly technetium-99m mercaptoacetyltriglycine renography after renal transplantation. The initial renogram grade (RG) was primarily a marker of ischaemic damage, being poorer with cadaver donation, long cold ischaemia (>24 h), and high donor and recipient age. High primary RG predicted primary graft non-function, long time to graft function, low discharge Cr EDTA clearance and low 1- and 5-year graft survival. Discharge RG predicted late (>6 months) graft loss. RG was highly correlated (P<0.001) with creatinine and creatinine clearance, and changes in RG were correlated with changes in renal function. A change in RG of 0.5 was non-specific, while a change of 1 or more predicted clinical complications in 95% of cases. The negative predictive value was low (58%). 3
14. Yazici B, Yazici A, Oral A, Akgun A, Toz H. Comparison of renal transplant scintigraphy with renal resistance index for prediction of early graft dysfunction and evaluation of acute tubular necrosis and acute rejection. Clin Nucl Med 2013;38:931-5. Observational-Dx 107 patients including 153 studies To discuss whether resistance index (RI) and renal scintigraphy obtained within 48 hours after operation could predict the early graft dysfunction. Scintigraphic parameters were significantly higher in patients with delayed graft function (DGF) and slow graft function (SGF) than in patients with immediate graft function. These parameters in DGF were also considerably different from those in SGF. The mean RI was significantly high in DGF, but there was no difference between SGF and immediate graft function. In diagnostic groups, the mean values of all tests were significantly different between normal functioning grafts and pathological grafts (ATN + AR). There was no significant difference between AR and ATN. However, renal scintigraphy has higher sensitivity and specificity for AR as compared with RI of Doppler ultrasonography (US). 3
15. Aktas A, Aras M, Colak T, Gencoglu A, Karakayali H. Comparison of Tc-99m DTPA and Tc-99m MAG3 perfusion time-activity curves in patients with renal allograft dysfunction. Transplant Proc. 38(2):449-53, 2006 Mar. Observational-Dx 48 patients with renal allograft dysfunction and 18 recipients with normal graft function. To compare the diagnostic utility of perfusion patterns obtained with DTPA and MAG3 among patients with renal allograft dysfunction. In patients with dysfunction, impaired perfusion was observed in 77% of DTPA and in 54% of MAG3 studies. A flat-descending curve on MAG3 was present in 44% of patients with normal graft function. By MAG3, 67% of acute rejection and 28% of chronic allograft nephropathy (CAN) cases showed deteriorated perfusion. The corresponding values for DTPA were 67% and 94%, respectively. A flat-ascending pattern on DTPA was more frequent in CAN than it was in acute rejection (33% and 17%, respectively). 3
16. Lubin E, Shapira Z, Melloul M, Youssim A. Scintigraphic detection of vascular and urological complications in the transplanted kidney: 133 cases. Eur J Nucl Med 1985;10:313-6. Observational-Dx 133 consecutive kidneys in 125 patients To present our experience scintigraphy in 133 successive kidney transplantations. Vascular thrombosis diagnosed by photodeficiency of the transplanted kidney was diagnosed and confirmed in 10 patients. Fourteen patients having postrenal urological complications (12 leaks and 2 ureteral obstructions) were all recognized in the late phase of the scintigraphic study. The differentiation between the known parenchymatous causes of anuria was less satisfactory. 4
17. Zavos G, Pappas P, Karatzas T, et al. Urological complications: analysis and management of 1525 consecutive renal transplantations. Transplant Proc. 40(5):1386-90, 2008 Jun. Observational-Dx 1525 consecutive renal transplantations. Renal grafts were obtained in 814 cases from living-related and in 711 from cadaveric donors. To analyze the causes of and therapeutic approaches to urological complications in renal transplantation as they related to patient outcomes. Urological complications were classified according to the mechanism and site of urinary tract involvement: graft ureteropelvic junction obstruction/stenosis (A), ureteral obstruction/stenosis (B), ureterovesical anastomosis obstruction/stenosis (C), urinary leakage (D), and other (E). Overall, we encountered 96 urological complications (6.3%). Group C complications occurred in 29 cases (30.2%), followed by 27 cases (28.1%) for group B patients, 25 cases (26.0%) for group D, 12 cases (12.5%) for group A, and 3 cases (3.1%) for group E patients. Surgical intervention was required in 49 (51.0%) of all urological complications. The others (n = 47, 49.0%) were treated either conservatively or by minimally invasive procedures. A rapid diagnosis of urological complications, assisted by early posttransplant DTPA scans, routine ultrasonography, and especially prompt treatment, resulted in compensation of renal graft dysfunction in the vast majority (n = 90, 93.8%) of cases. 4
18. Rodriguez Faba O, Boissier R, Budde K, et al. European Association of Urology Guidelines on Renal Transplantation: Update 2018. Eur Urol Focus. 4(2):208-215, 2018 03. Review/Other-Tx N/A To present the 2018 EAU guidelines on renal transplantation. No results stated in abstract. 4
19. Lee SF, Lichtenstein M, Hughes P, Sivaratnam D. Utility of MAG3 scintigraphy with the use of a 2 min uptake parameter in the assessment of postsurgical renal transplant complications. Nucl Med Commun. 39(10):921-927, 2018 Oct. Observational-Dx 105 patients To examine the utility of Tc MAG3 scintigraphy in the assessment of postsurgical complications using the renal biopsy as the gold standard and examine for any correlation with 2MU with serum creatinine (sCr) at 3 and 12 months. 30/105 patients underwent biopsy less than 7 days of the Tc MAG3 study. Within this 7 day cohort, the negative predictive value for rejection with normal perfusion on Tc MAG3 study was 79% and the positive predictive value for rejection with abnormal Tc MAG3 perfusion was 9%. There was a weak negative correlation between 2MU and 3-month sCr (R=-0.358, P<0.001), and 2MU and 12-month sCr (R=-0.348, P<0.001). 3
20. Aktas A. Transplanted kidney function evaluation. Semin Nucl Med 2014;44:129-45. Review/Other-Dx N/A To review imaging modalities used to assess transplanted kidney function evaluation. No results mentioned in abstract. 4
21. Nankivell BJ, Cohn DA, Spicer ST, Evans SG, Chapman JR, Gruenewald SM. Diagnosis of kidney transplant obstruction using Mag3 diuretic renography. Clin Transplant. 15(1):11-8, 2001 Feb. Observational-Dx 45 patients assessed the utility of technetium-99m mercaptoacetyltriglycine (Tc99m MAG3) diuretic renography for the diagnosis of allograft KTO, using standard visual and quantitative parameters, as well as calculated renal output efficiency (OE), which has been postulated to improve diagnostic yield. KTO was diagnosed independently of the MAG3 scans by a fall in the serum creatinine in response to renal pelvis urinary drainage. OE in 12 renal allografts with KTO was significantly reduced compared with 31 Tc99m MAG3 scans without KTO (59.6±18.9 vs. 81.6±5.4%, p<0.001). In KTO, the mean time of isotope appearance in the bladder (time to bladder [TTB]) was extended compared with unobstructed allografts (7.9±4.1 vs. 3.6±1.5 min, p<0.001). Measurement of OE significantly improved the accuracy of diuretic MAG3 renography in the diagnosis of renal allograft KTO, especially when supplemented by the TTB, parenchymal transit time and shape of the renogram curve. Ureteric obstruction of the kidney transplant can be diagnosed with an OE reduced to <75% (sensitivity 92%, specificity 87%) and confirmed by isotope hold-up in the pelvicalyceal system. A normal or slowly declining renogram curve effectively excluded KTO (sensitivity of 96%, negative predictive value of 84%). A parenchymal transit time of >5 min and a TTB of >7 min both yielded a sensitvity of 92% and a specificity of 81%. 2
22. Buckley AR, Cooperberg PL, Reeve CE, Magil AB. The distinction between acute renal transplant rejection and cyclosporine nephrotoxicity: value of duplex sonography. AJR. 1987; 149(3):521-525. Observational-Dx 119 exams in106 patients with normally functioning renal transplants 65 exams in 34 patients with renal transplant dysfunction To determine the role of pulsed Doppler flow analysis (duplex US) in differentiating acute rejection from cyclosporine nephrotoxicity. In the healthy control subject, the diastolic/systolic velocity ratios varied in the different arterial segments, ranging from a mean of 0.23 in the segmental arteries to a mean of 0.32 in the arcuate arteries. 17 patients experienced acute rejection: 8/9 with acute vascular rejection had abnormal Doppler ratios; 8 patients with acute cellular rejection had normal ratios. 9 patients with cyclosporine nephrotoxicity all had normal duplex scans. 7 patients with chronic rejection had normal ratios. One patient with hemolytic-uremic syndrome had an abnormal flow pattern. Findings indicate that duplex US may be useful in differentiating acute vascular rejection from cyclosporine nephrotoxicity in the transplanted kidney. 3
23. Steinberg HV, Nelson RC, Murphy FB, et al. Renal allograft rejection: evaluation by Doppler US and MR imaging. Radiology. 1987; 162(2):337-342. Observational-Dx 38 renal allograft recipients, 43 Doppler US and 42 MRI exams Prospective study to compare the efficacy of Doppler US and MRI in evaluating renal allografts, with specific attention to transplant rejection. Doppler US was significantly superior to MRI in identifying allograft rejection, demonstrating a higher sensitivity (95% vs 70%), specificity (95% vs 73%), and accuracy (95% vs 71%). Because of its low cost and accessibility, Doppler US should become the primary modality for renal transplant screening. 2
24. Genkins SM, Sanfilippo FP, Carroll BA. Duplex Doppler sonography of renal transplants: lack of sensitivity and specificity in establishing pathologic diagnosis. AJR. 1989; 152(3):535-539. Observational-Dx 77 US exams in 77 renal transplants Combined retrospective and prospective analysis of duplex Doppler examinations performed over a 2-year period to assess the value of such studies in evaluating renal allograft dysfunction. When a RI of =0.9 was used to indicate acute rejection, US had a sensitivity of only 9% and a specificity of 91% for this diagnosis. In 1/8 cases of cyclosporine, a toxicity and in 3 of 6 examples of acute tubular necrosis, the RI was >0.9. In all 6 instances of chronic rejection, the RI was <0.84. None of 8 patients with evidence of infection had a RI >0.9. The RI range of 12 normally functioning allografts was 0.57-0.69. Correlation between the RI and the severity of arterial and arteriolar changes on biopsy was poor. An increased RI of renal transplant blood flow, as measured by duplex Doppler US, usually signals pathologic changes in an allograft. However, the data indicate that this test is not as sensitive or specific in identifying the cause of transplant dysfunction as has been suggested previously. 2
25. Rifkin MD, Needleman L, Pasto ME, et al. Evaluation of renal transplant rejection by duplex Doppler examination: value of the resistive index. AJR. 1987; 148(4):759-762. Observational-Dx 81 patients 145 exams To evaluate the ability of the duplex Doppler examination and RI to identify patients with acute rejection. With a RI >0.90, a 100% PPV was obtained for the diagnosis of acute rejection. A value <0.70 was unlikely to be rejection (NPV, 94%). This approach uses a simple analysis of the waveform. Use of a duplex Doppler examination and the formula described here appears to be an accurate method for the detection of acute rejection and for the differentiation of acute rejection from the various other causes of acute renal failure. 3
26. Radermacher J, Mengel M, Ellis S, et al. The renal arterial resistance index and renal allograft survival. N Engl J Med. 2003; 349(2):115-124. Observational-Dx 601 patients To determine whether a renal arterial resistance index of <80 was predictive of long-term allograft survival. A renal arterial resistance index of 80 or higher measured at least 3 months after transplantation is associated with poor subsequent allograft performance and death. 3
27. McArthur C, Geddes CC, Baxter GM. Early measurement of pulsatility and resistive indexes: correlation with long-term renal transplant function. Radiology. 2011; 259(1):278-285. Observational-Dx 178 consecutive patients Retrospective study to correlate PI and RI measured at early specific intervals after transplantation with 1-year eGFR and death-censored transplant survival to assess the long-term prognostic value of these Doppler indexes. Within 1 week after transplantation, there was a significant association between PI and 1-year eGFR when analyzed as tertiles (P=.02). Between 1 week and 3 months after transplantation, there was a significant relationship between 1-year eGFR and both PI and RI when comparing the lowest and highest tertiles (47.5 mL/min/1.73 m(2) for PI <1.26 vs 32.7 mL/min/1.73 m(2) for PI >1.49 [P=.01], 42.8 mL/min/1.73 m(2) for RI <0.69 vs 32.3 mL/min/1.73 m(2) for RI >0.74 [P=.03]). Both PI and RI were independent predictors of death-censored transplant survival (HR, 1.68 per unit [P<.001] and 260.4 per unit, respectively [P=.02]). PI and RI in the early post-transplantation period correlate with long-term transplant function and can potentially be used as prognostic markers to aid risk stratification for future transplant dysfunction. 2
28. Naesens M, Heylen L, Lerut E, et al. Intrarenal resistive index after renal transplantation. N Engl J Med 2013;369:1797-806. Observational-Tx 321 patients To evaluate the prognostic performance of the intrarenal resistive index with regard to graft function and patient and graft survival in the first years after kidney transplantation. Allograft recipients with a resistive index of at least 0.80 had higher mortality than those with a resistive index of less than 0.80 at 3, 12, and 24 months after transplantation (hazard ratio, 5.20 [95% confidence interval {CI}, 2.14 to 12.64; P<0.001]; 3.46 [95% CI, 1.39 to 8.56; P=0.007]; and 4.12 [95% CI, 1.26 to 13.45; P=0.02], respectively). The need for dialysis did not differ significantly between patients with a resistive index of at least 0.80 and those with a resistive index of less than 0.80 at 3, 12, and 24 months after transplantation (hazard ratio, 1.95 [95% CI, 0.39 to 9.82; P=0.42]; 0.44 [95% CI, 0.05 to 3.72; P=0.45]; and 1.34 [95% CI, 0.20 to 8.82; P=0.76], respectively). At protocol-specified biopsy time points, the resistive index was not associated with renal-allograft histologic features. Older recipient age was the strongest determinant of a higher resistive index (P<0.001). At the time of biopsies performed because of graft dysfunction, antibody-mediated rejection or acute tubular necrosis, as compared with normal biopsy results, was associated with a higher resistive index (0.87 +/- 0.12 vs. 0.78 +/- 0.14 [P=0.05], and 0.86 +/- 0.09 vs. 0.78 +/- 0.14 [P=0.007], respectively). 2
29. Baxter GM, Ireland H, Moss JG, et al. Colour Doppler ultrasound in renal transplant artery stenosis: which Doppler index? Clin Radiol. 1995; 50(9):618-622. Observational-Dx 106 patients Prospective study comparing CDUS with the ‘gold standard’ of IA-DSA in the evaluation of renal transplant artery stenosis was performed. Of 106 patients, 31 had a PSV >1.5 ms-1 in the transplant renal artery and were referred for DSA. Of the multiple renal Doppler indices recorded, the PSV in the transplant artery was the best discriminating measurement for the detection of renal artery stenosis. A PSV of =2.5 ms-1 in the transplant renal artery had a sensitivity of 100% and a specificity of 95% for the detection of renal artery stenosis (>50% diameter reduction). Although a significant difference in PI, RI, Acceleration Index and Acceleration Time was recorded from the intrarenal vessels in the angiographically normal and stenosed groups with Doppler, these measurements were less useful as discriminating diagnostic tests. The PSV in the transplant renal artery is the most sensitive Doppler criterion for renal artery stenosis and is sensitive and specific enough to be used as a screening test. The intrarenal acceleration time and index should not be used in isolation. 3
30. Krumme B, Grotz W, Kirste G, Schollmeyer P, Rump LC. Determinants of intrarenal Doppler indices in stable renal allografts. J Am Soc Nephrol. 1997; 8(5):813-816. Observational-Dx 110 patients Analysis of potential determinants of Doppler resistance parameters in patients with stable renal allografts to determine whether Doppler indices may be useful in gaining information about graft integrity. In multivariate regression analysis, RI and PI correlated significantly with age and arterial pulse pressure of the recipient. There was no correlation with donor age, heart rate, mean arterial blood pressure, and cyclosporine trough levels. Furthermore, parameters of kidney function, such as serum creatinine concentration, creatinine clearance rate, 51Cr-ethylenediaminetetraacetate clearance rate, and proteinuria, showed no significant correlation with the Doppler indices. The data indicate that intrarenal Doppler indices of the grafts are hemodynamic indices, primarily depending on the recipient-related vascular compliance rather than on the function of the graft. Therefore, only intraindividual comparison of the Doppler indices may be useful to detect potential changes of graft resistance during long-term follow-up. 3
31. Patel U, Khaw KK, Hughes NC. Doppler ultrasound for detection of renal transplant artery stenosis-threshold peak systolic velocity needs to be higher in a low-risk or surveillance population. Clin Radiol 2003;58:772-7. Observational-Dx 117 patients To establish the ideal threshold arterial velocity for the diagnosis of renal transplant artery stenosis in a surveillance population with a low pre-test probability of stenosis. Of 144 patients transplanted, full data were available in 117 cases. Five cases had renal transplant artery stenosis-incidence 4.2% [stenosis identified at a mean of 6.5 months (range 2-10 months)]. All five cases had a significant arterial pressure gradient across the narrowing and underwent angioplasty. Threshold peak systolic velocity of > or =2.5 m/s is not ideal [specificity=79% (CI 65-82%), PPV=18% (CI 6-32%), NPV=100% (CI 94-100%)], subjecting many patients to unnecessary angiography-8/117 (6%) in our population. Comparable values if the threshold is set at > or =3.0 m/s are 93% (CI 77-96%), 33% (CI 7-44%) and 99% (CI 93-100%), respectively. The clinical outcome of all patients was satisfactory, with no unexplained graft failures or loss. 3
32. de Morais RH, Muglia VF, Mamere AE, et al. Duplex Doppler sonography of transplant renal artery stenosis. J Clin Ultrasound. 2003; 31(3):135-141. Observational-Dx 22 patients suspected to have TRAS (10 without and 12 with confirmed significant stenosis) and 19 controls To evaluate the accuracy of duplex Doppler US in diagnosing TRAS and to determine which parameter is the most reliable for making that diagnosis. The most accurate parameters to use in diagnosing TRAS were an acceleration time of 0.1 second or higher in the renal and intrarenal arteries, a PSV of >200 cm/sec in the renal artery, and a ratio of PSVs in the renal and external iliac arteries of >1.8. Duplex Doppler US is an excellent method for screening patients suspected to have TRAS and can help select which of those patients should undergo digital subtraction arteriography. 2
33. AbuRahma AF, Srivastava M, Mousa AY, et al. Critical analysis of renal duplex ultrasound parameters in detecting significant renal artery stenosis. J Vasc Surg. 2012; 56(4):1052-1059, 1060 e1051; discussion 1059-1060. Observational-Dx 313 patients (606 renal arteries) To compare RDU imaging vs. angiography and assess various published Doppler criteria to detect significant renal artery stenosis (RAS). The mean PSVs and RARs for normal, <60%, and >/=60% stenosis were 173, 236, and 324 cm/s (P < .0001), and 2.2, 2.9, and 4.5, respectively (P < .0001). The PSV cutoff value that provided the best overall accuracy for >/=60% stenosis was 285 cm/s, with a sensitivity, specificity, and overall accuracy of 67%, 90%, and 81%, respectively. The RAR cutoff value with the best overall accuracy for >/=60% stenosis was 3.7, with a sensitivity, specificity, and overall accuracy of 69%, 91%, and 82%, respectively. 2
34. Fananapazir G, McGahan JP, Corwin MT, et al. Screening for Transplant Renal Artery Stenosis: Ultrasound-Based Stenosis Probability Stratification. AJR Am J Roentgenol. 209(5):1064-1073, 2017 Nov. Observational-Dx 120 patients To evaluate which spectral Doppler ultrasound parameters are useful in patients with clinical concern for transplant renal artery stenosis (TRAS) and create mathematically derived prediction models that are based on these parameters. Ninety-seven patients had stenosis and 23 had no stenosis. The full model had a sensitivity and specificity of 97% and 91%, respectively. The reduced-variable model excluded the ratio and resistive index variables without affecting sensitivity and specificity. We applied cutoff values to the variables in the reduced-variable model, which we refer to as the simple model. Using these cutoff values, the simple model showed a sensitivity and specificity of 96% and 83%. 2
35. Baxter GM. Imaging in renal transplantation. Ultrasound Q. 2003; 19(3):123-138. Review/Other-Dx N/A Review of the use/value of imaging in renal transplants. Renal transplantation is the best treatment option for chronic renal failure, with marked improvement in social activity, work, and family life. In addition to these obvious improvements, it is an extremely cost-effective procedure when successful. Ultrasonography plays a major role in the imaging of these patients, and ultrasound (including color Doppler) is helpful to the transplant physician in detecting graft dysfunction and peritransplant collections, some of which may be drained under ultrasound guidance. It is also helpful in the diagnosis of chronic vascular complications including transplant artery stenosis and arteriovenous fistula. It has no specific application in the diagnosis of chronic rejection. 4
36. Baxter GM, Morley P, Dall B. Acute renal vein thrombosis in renal allografts: new Doppler ultrasonic findings. Clin Radiol. 1991; 43(2):125-127. Review/Other-Dx 2 patients Report of two cases of histologically proven renal vein thrombosis with an 'inverted M' appearance of the diastolic component of the arterial waveform and postulate this as perhaps being more specific for acute renal vein thrombosis. Both cases of acute renal vein thrombosis showed absence of venous flow at parenchymal and hilar level. The arterial waveform in both cases was remarkably similar with a steep rise and fall of the systolic component. In addition, however, the reverse diastolic component showed an 'inverted M' appearance (Fig. la, b, c), a sign previously undescribed in renal vein thrombosis. Real time ultrasound alone showed no textural abnormality or increase in renal size- appearances that may occur in renal vein thrombosis. 4
37. Lockhart ME, Wells CG, Morgan DE, Fineberg NS, Robbin ML. Reversed diastolic flow in the renal transplant: perioperative implications versus transplants older than 1 month. AJR. 2008; 190(3):650-655. Observational-Dx 59 total patients To evaluate the causes, waveform morphology, and clinical outcomes of high-resistance reversed diastolic flow in transplanted kidneys. Acute reversed diastolic flow was associated with higher likelihood of graft survival (p = 0.001, Fisher's exact test) compared with reversed diastolic flow discovered in the perioperative or long-term group. In the acute group, hematoma, acute tubular necrosis, renal vein thrombosis, and vascular kink produced reversed diastolic flow. The causes of reversed diastolic flow for the perioperative group were acute tubular necrosis, rejection, and renal vein thrombosis; for the long-term group, reasons for diastolic reversal were rejection, glomerulosclerosis, low cardiac output, and diabetic nephrosclerosis. 3
38. Glebova NO, Brooke BS, Desai NM, Lum YW. Endovascular interventions for managing vascular complication of renal transplantation. Semin Vasc Surg 2013;26:205-12. Review/Other-Tx N/A To review the contemporary diagnosis and treatment of these complications using endovascular techniques. No results stated in abstract. 4
39. Marini M, Fernandez-Rivera C, Cao I, et al. Treatment of transplant renal artery stenosis by percutaneous transluminal angioplasty and/or stenting: study in 63 patients in a single institution. Transplant Proc 2011;43:2205-7. Observational-Tx 62 patients To evaluate technical procedures, clinical success, and follow-up of renal transplant patients with stenosis in the transplant renal artery (TRAS) after endovascular treatment. Percutaneous transluminal angioplasty (PTA)/stent placement success was 90.3%. Seventy-nine PTAs with 11 stents were primary interventions with 6 PTAs and 4 stent procedures subsequently performed due to restenosis (mean time to event, 1.5 months). The median follow-up was 39 months (range, 1-236). The mean preprocedure creatinine level was 2.8 +/- 1.7 mg/dL, and the 1-month postprocedure value was decreased to 2.1 +/- 1.2 mg/dL (P < .001). Systolic arterial blood pressure fell from 147.2 +/- 18.7 mm Hg to 131.6 +/- 14.2 mm Hg (P < .001) and diastolic blood pressure from 84.4 +/- 9.8 mm Hg to 76 +/- 9.4 mm Hg (P < .001). Postprocedure number of antihypertensive drugs was reduced from 2.3 +/- 1.1 to 1.6 +/- 1 (P < .0001). The patency rates were: 95 +/- 2.8% at 1 month, 87.9 +/- 4.3% at 3 months, and 85 +/- 4.7% at 12 months. Secondary patency was 100% with no restenosis on follow-up. Allograft survival after primary and secondary PTA/stenting was 97% at 1, 93% at 3.89% at 5, and 85% at 10 years. The complication included 2 renal artery thromboses, a dissection treated with stents, and a late arterial graft pseudoaneurysm. 2
40. Sharma S, Potdar A, Kulkarni A. Percutaneous transluminal renal stenting for transplant renal artery stenosis. Catheter Cardiovasc Interv 2011;77:287-93. Observational-Tx 8 patients To document the immediate and intermediate term clinical results of renal stenting in this rare subset of renal artery stenosis. BACKGROUND: There is limited data about the effectiveness of renal stenting in transplant renal artery stenosis. All patients had live donor renal transplant using end to end anastomosis 2 to 11 (6.25 +/- 3.24) months prior to intervention. Angiography revealed discrete stenosis at the anastomotic site. Intrarenal stenting performed from femoral access using 6 F accessories produced excellent angiographic results. There were no access site or procedure related complications. The intervention produced excellent immediate and intermediate term clinical results. In three patients, there was stabilization of renal function during 62 +/- 9.16 months of follow-up with decrease in serum creatinine by 38.86 +/- 6.62 %; P = 0.0476. In four patients with refractory hypertension, excellent blood pressure control was achieved with a reduction in mean blood pressure by 25.95 +/- 5.48 mm Hg (from 122.4 +/- 5.7 to 96.45 +/- 2.45 mm Hg; P = 0.0002) during 65.25 +/- 23.79 months follow-up. There was decrease in antihypertensive drug requirement from 3.75 +/- 0.5 to 1.75 +/- 0.5. During follow-up, Doppler ultrasound documented a high peak systolic velocity in one asymptomatic patient with well controlled blood pressure and preserved renal function. Sustained benefits of percutaneous revascularization were supported by normal Doppler parameters in the remaining patients. 2
41. Audard V, Matignon M, Hemery F, et al. Risk factors and long-term outcome of transplant renal artery stenosis in adult recipients after treatment by percutaneous transluminal angioplasty. Am J Transplant. 2006; 6(1):95-99. Observational-Tx 29 renal allograft recipients, 58 controls Retrospectively review records of renal allograft recipients treated with PTA in order to determine the predisposing factors for TRAS. Predisposing factors for TRAS included cytomegalovirus infection (41.4% vs 12.1% P=0.0018) and initial delayed graft function (48.3% vs 15.5% P=0.0018), respectively in the TRAS and the control group. Acute rejection occurred more frequently in patients from the TRAS group (48.3%) compared with the control group (27.6%), although the difference was not significant (P=0.06). In a multivariate analysis, only cytomegalovirus infection (P=0.005) and delayed graft function (P=0.009) appear to be significantly and independently associated with TRAS. The long-term graft survival was significantly higher in the control group, compared with the TRAS group (P=0.03). Study suggests that cytomegalovirus infection and delayed graft function are two reliable risk factors for TRAS. Despite treatment by PTA with primary successful results, TRAS significantly affects long-term graft outcome. 2
42. Beecroft JR, Rajan DK, Clark TW, Robinette M, Stavropoulos SW. Transplant renal artery stenosis: outcome after percutaneous intervention. J Vasc Interv Radiol. 2004; 15(12):1407-1413. Observational-Tx 21 interventions performed in 18 allografts Retrospective review to assess the outcome of PTA and stent placement as the primary treatment for TRAS. The technical success rate of PTA/stent placement was 100% and the clinical success rate was 94% (17/18 allografts). The mean preintervention serum creatinine level among 12 allografts presenting with elevated creatinine levels was 2.8 mg/dL +/- 1.4 (SD), compared with a 1-month postintervention mean of 2.2 mg/dL +/- 0.7 (P=.03). Of 6 allografts that presented with hypertension, significant improvement was seen between the preintervention and 1-month postintervention mean systolic (174 mm Hg vs 135 mm Hg, P=.003) and diastolic (99 mm Hg vs 82 mm Hg, P=.02) pressures. These patients required a mean of 2.3 medications for blood pressure control before intervention, compared with a mean of 1.0 medications at 1 month after intervention (P=.002). Primary patency rates at 3, 6, and 12 months (+/-95% CI) were 94% +/- 6%, 72% +/- 12%, and 72% +/- 12%, respectively. Secondary patency rates at 3, 6, and 12 months (+/-95 CI) were 100%, 85% +/- 10%, and 85% +/- 10%, respectively. Mean follow-up time was 27 months. Of the 8 allografts that underwent stent placement, all 8 remained patent at last follow-up (mean, 18.3 months +/- 9.2). One major complication of a puncture site pseudoaneurysm occurred (5%). Primary treatment of TRAS with PTA with or without stent placement has good intermediate-term patency and is associated with significant early improvement in blood pressure and creatinine level. 2
43. Geddes CC, McManus SK, Koteeswaran S, Baxter GM. Long-term outcome of transplant renal artery stenosis managed conservatively or by radiological intervention. Clin Transplant 2008; 22(5):572-578. Observational-Tx 43 patients: 27 had percutaneous intervention (including 10 patients with >1 intervention) and 16 were managed conservatively Patients diagnosed with TRAS were analyzed to report long-term clinical outcomes. Patients in the intervention group had lower mean eGFR (36.3 mL/min/1.73 m(2) vs 46.3 mL/min/1.73 m(2); P=0.07) at baseline. Five transplants in the intervention group failed (including two as a direct result of intervention) and one in the conservative group failed. There was no significant difference in the rate of deterioration in renal function (mean slope of eGFR minus 0.8 mL/min/yr and minus 1.0 mL/min/yr in the intervention and conservative groups, respectively; P=0.79). There was no significant difference in blood pressure or number of anti-hypertensive agents between the groups at any time point. Baseline Doppler US indices showed no significant correlation with slope of eGFR in either group. Data demonstrate that selected patients with TRAS can be managed without intervention and that this approach is associated with good long-term outcome. Selection of appropriate patients for intervention remains difficult and larger randomized studies are required. 2
44. Ghazanfar A, Tavakoli A, Augustine T, Pararajasingam R, Riad H, Chalmers N. Management of transplant renal artery stenosis and its impact on long-term allograft survival: a single-centre experience. Nephrol Dial Transplant. 2011; 26(1):336-343. Observational-Tx 67 patients Retrospective study to compare management strategies and outcomes of TRAS and its impact on long-term allograft survival. 44, 9 and 14 patients were managed with primary PTRA, surgical intervention and conservative treatment, respectively. Uncontrolled hypertension was the most common presentation noted in 74.62%. Post-anastamotic single stenosis was the commonest occurrence (n=53). Angioplasty had the highest 1- and 5-year graft survival rate of 91% and 86%, respectively. The worst prognosis was noted in patients treated with secondary PTRA after failed surgery or secondary surgery after failed primary PTRA. TRAS is a recognized complication resulting in loss of renal allografts. Early Doppler US is a good primary diagnostic tool. Early intervention is associated with a good long-term graft function. 2
45. Hagen G, Wadstrom J, Magnusson M, Magnusson A. Outcome after percutaneous transluminal angioplasty of arterial stenosis in renal transplant patients. Acta Radiol. 2009; 50(3):270-275. Observational-Tx 24 patients 28 stenoses treated To evaluate the technical and clinical success rate of renal transplant patients with stenosis in the transplant renal artery or in the iliac artery after PTA. The immediate technical success rate after PTA was 93%. The clinical success rate after 1 month was 58%, increasing to 75% after 3 months. The technical success rate is not equivalent to the clinical success rate when treating TRAS with PTA. Furthermore, there is a delay in clinical response, sometimes of 3 months, after a technically successful PTA. 2
46. Henning BF, Kuchlbauer S, Boger CA, et al. Percutaneous transluminal angioplasty as first-line treatment of transplant renal artery stenosis. Clin Nephrol. 2009; 71(5):543-549. Observational-Tx 11 patients with TRAS To determine whether PTA should be first-line treatment of TRAS. The immediate success rate for PTA was 92.3% (12/13). The beneficial effect of PTA of TRAS on renal function is long-lasting. Therefore, PTA, usually combined with stent placement, should be first-line treatment in TRAS in all patients. Surgical revascularization is only warranted, if PTA fails. 2
47. Pappas P, Zavos G, Kaza S, et al. Angioplasty and stenting of arterial stenosis affecting renal transplant function. Transplant Proc. 2008; 40(5):1391-1396. Observational-Tx 24 patients To evaluate the efficacy of percutaneous angioplasty and stenting in cases of artery stenosis of the transplanted kidney or proximal iliac artery stenosis causing transplant dysfunction and/or increase of the arterial blood pressure. Successful angioplasty and stenting were performed in 22 patients. The method was technically feasible in 100%. The procedure-related morbidity was 0%. During the follow-up period (range: 3 to 104 months), two patients died with normal transplant function, two suffered transplant failure, and the remaining 18 still have normal transplant function and easily controlled hypertension. Percutaneous angioplasty and stenting in cases of arterial stenosis affecting the renal transplant function are safe and effective procedures. Even more, the strong clinical suspicion must lead to angiographic investigation regardless of the results of other imaging approaches. 2
48. Peregrin JH, Stribrna J, Lacha J, Skibova J. Long-term follow-up of renal transplant patients with renal artery stenosis treated by percutaneous angioplasty. Eur J Radiol. 2008; 66(3):512-518. Observational-Tx 58 PTRA in 55 adults (three times Re-PTRA) To evaluate if PTRA in patients with transplanted kidney and TRAS can have long-term effect on hypertension and renal function. PTRA technical success was 88.4%. In 51 kidney recipients at the end of follow-up, blood pressure improved in 65.2% of patients (mean arterial pressure decreased from 123+/-13.1 to 107+/-12.1 mmHg), but no patient remained normotensive medication free. Graft function improved in 44.8% of patients and was stabilized in 20.7% of them (average creatinine clearance before PTRA: 0.48+/-0.29, after PTRA: 0.78+/-47 ml/s). PTRA complications were observed in 25.5% of procedures, most often with no clinical sequel. Thirty days mortality was 1.8% (one patient). PTRA results in kidney recipients are valuable mainly in preserving graft function. 2
49. Polak WG, Jezior D, Garcarek J, et al. Incidence and outcome of transplant renal artery stenosis: single center experience. Transplant Proc. 2006; 38(1):131-132. Review/Other-Tx 793 kidney allograft recipients Retrospective study to examine incidence, analyze the treatment options, and ascertain the outcomes of TRAS. Screening CDUS showed hemodynamic changes in 6 patients with the definitive diagnosis confirmed by angiography in all patients. One patient with an anastomotic stenosis was treated with a surgical operation and 6 patients, PTA, with stenting in three cases. Both surgical as well as PTA treatment were successful in all but one patient, who underwent PTA alone, developed chronic renal insufficiency necessitating hemodialysis and finally lost his allograft. In the other patients all symptoms resolved after treatment and the patients are doing well with functioning allografts. Although TRAS was an uncommon complication, if recognized promptly it could be treated by surgery or PTA with a high success rate. 4
50. Seratnahaei A, Shah A, Bodiwala K, Mukherjee D. Management of transplant renal artery stenosis. Angiology. 2011; 62(3):219-224. Review/Other-Tx N/A Review the existing data and analyze management of TRAS as reported in multiple case series including findings from the authors’ center. PTA has now become the initial treatment of choice for TRAS. However, there are conflicting data regarding the efficacy of PTA, with growing evidence showing lack of significant benefit in blood pressure or renal function in patients undergoing PTA vs medical management. However, there have been no randomized control studies that have established the superiority of either method. 4
51. Valpreda S, Messina M, Rabbia C. Stenting of transplant renal artery stenosis: outcome in a single center study. J Cardiovasc Surg. (Torino) 2008; 49(5):565-570. Observational-Tx 32 interventions in 30 allografts To retrospectively evaluate the clinical outcome of patients with TRAS or post-PTA recurrent TRAS treated by endoluminal stenting. The technical success rate of stenting was 100% with a single major complication event (a puncture site pseudoaneurysm). Mean follow-up time was 7.1 years; of the 30 allograft that underwent stent placement, all were patent at the last follow-up, with five restenosis (15.6%) of which only one needed to be retreated endoluminally. A reduction of the mean serum creatinine levels and of the number of blood pressure medications was observed. There was no difference in the survival curve of the grafts without TRAS compared to those with stenting treated TRAS. The treatment of the TRAS with selective or primary stenting is safe with a long-term patency rate. The efficacy of the stenting in this study is suggested by a decrease in mean systolic and diastolic blood pressure, serum creatinine levels and number of blood pressure medications. 3
52. Voiculescu A, Schmitz M, Hollenbeck M, et al. Management of arterial stenosis affecting kidney graft perfusion: a single-centre study in 53 patients. Am J Transplant. 2005; 5(7):1731-1738. Observational-Tx 53 patients To assess the clinical and duplex US findings and outcome in patients with stenosis of the TRAS or the aorto-iliac segment proximal to the graft (TRAS) treated with dilatation (PTA), stenting and surgery. 52 patients underwent invasive treatment (21 PTA, 10 PTA/stenting and 21 surgery) after which hypertension and creatinine significantly improved. PI increased. Restenosis occurred in 16 (52%) cases of the interventional (PTA 62% and PTA/stenting 30%) and in 3 (14%) of the surgical group (P=0.011). Hypertension and graft dysfunction due to perfusion problems are rare. Clinical findings are nonspecific but duplex US findings are helpful to select patients for angiography. Invasive treatment leads to clinical improvement. Surgery yields better results than PTA, but additional stenting will probably improve the outcome of angioplasty. 2
53. Laberge JM. Interventional management of renal transplant arteriovenous fistula. Semin Intervent Radiol 2004;21:239-46. Review/Other-Tx N/A To describe the occurrence, detection, and treatment of biopsy-related renal transplant injury. No results stated in abstract. 4
54. Nicolini A, Ferraresso M, Lovaria A, Biondetti P, Raiteri M, Berardinelli L. Carbon dioxide as a valuable contrast agent for identifying iatrogenic arteriovenous fistulas in transplanted kidneys. Nephrol Dial Transplant 2003;18:2189-92. Review/Other-Tx 3 patients To report the use of CO2 contrast for both locating the shunt and for CO2-guided embolotherapy of post-biopsy arteriovenous fistulas in transplant patients with hypertension and progressive deterioration of graft function. Overall, angiographic images of good diagnostic quality were obtained in all three patients. In our hands, the CO2 digital subtraction angiography al-lowed very selective trans-catheter embolization of the post-biopsy fistulas with a high degree of confidence. The procedures were well tolerated by the patients, who had a median hospitalization time of only 4 days. 4
55. Rountas C, Vlychou M, Vassiou K, et al. Imaging modalities for renal artery stenosis in suspected renovascular hypertension: prospective intraindividual comparison of color Doppler US, CT angiography, GD-enhanced MR angiography, and digital substraction angiography. Ren Fail. 2007; 29(3):295-302. Observational-Dx 58 patients To evaluate the diagnostic accuracy of CDUS, CTA, and Gd-enhanced MRA compared with DSA (gold standard) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. CDUS failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and PPV and NPV were 75%, 89.6%, 60% and 94.6%, respectively, for CDUS; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for Gd-enhanced MRA. CTA and Gd-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions. 1
56. Helck A, Bamberg F, Sommer WH, et al. Optimized contrast volume for dynamic CT angiography in renal transplant patients using a multiphase CT protocol. Eur J Radiol. 2010 [Epub ahead of print]. Observational-Dx 36 patients Prospective, clinically controlled cohort study to examine the feasibility of an optimized multiphase renal-CTA protocol in patients with history of renal transplantation compared with Doppler-US (standard of reference). Using the best of 12 phases in each patient, optimal attenuation was 353±111 HU, 337±98 HU and 164±51 HU in the iliac arteries, renal arteries, and renal veins, respectively. Mean image quality was 1.1±0.3 (n=36) and 2.1±0.6 (n=30) for the transplant renal arteries and veins, respectively. Six renal veins were non-diagnostic in multiphase-CTA. In 36 patients, multiphase-CTA showed 13 vascular complications and 10 parenchymal perfusion defects. Doppler US was not assessable in 8 patients. Overall, multiphase-CTA showed 15 cases with pathology (42%) not identifiable with Doppler US. The mean effective radiation dose of the multiphase-CTA protocol was 13.5±5.2mSv. Multiphase-CTA can be sufficiently performed with reduced contrast volume at reasonable radiation dose in renal transplant patients, providing substantially higher diagnostic yield than Doppler US. 3
57. Gaddikeri S, Mitsumori L, Vaidya S, Hippe DS, Bhargava P, Dighe MK. Comparing the diagnostic accuracy of contrast-enhanced computed tomographic angiography and gadolinium-enhanced magnetic resonance angiography for the assessment of hemodynamically significant transplant renal artery stenosis. Curr Probl Diagn Radiol 2014;43:162-8. Observational-Dx 27 patients To compare diagnostic accuracy of contrast-enhanced computed tomographic angiography (CTA) and gadolinium-enhanced magnetic resonance angiography (MRA) for the assessment of hemodynamically significant transplant renal artery stenosis (TRAS). The correlation between MRA and DSA measurements of stenosis was r = 0.57 (95% CI:-0.02, 0.87; P = 0.052) and between CTA and DSA measurements was r = 0.63 (95% CI: 0.14, 0.87; P = 0.015); the difference between the 2 techniques was not significant (P = 0.7). Both imaging modalities tended to underestimate the degree of stenosis when compared with DSA. MRA group (SN and SP: 56% and 100%, respectively) and CTA group (SN and SP: 81% and 67%, respectively). 2
58. Mousa D, Hamilton D, Miola UJ, et al. The importance of the perfusion index in the evaluation of captopril renography for transplant renal artery stenosis. Nucl Med Commun 1994;15:949-52. Observational-Dx 26 captopril renogram test To report the evaluation of 26 captopril renography investigations on hypertensive renal transplant patients with a suspected diagnosis of RAS. Each renogram study was correlated with an arteriogram as the 'gold standard' which was undertaken within 28 days of the renography. A sensitivity of 92%, a specificity of 86% and an accuracy of 88% were achieved by including a consideration of the change in perfusion to the kidney between pre- and post-challenge studies. 3
59. Erbas B. Peri- and Postsurgical Evaluations of Renal Transplant. [Review]. Seminars in Nuclear Medicine. 47(6):647-659, 2017 11.Semin Nucl Med. 47(6):647-659, 2017 11. Review/Other-Dx N/A To review the main complications after renal transplantation, their imaging findings, and the role of renal scintigraphy No results stated in abstract. 4
60. Omary RA, Baden JG, Becker BN, Odorico JS, Grist TM. Impact of MR angiography on the diagnosis and management of renal transplant dysfunction. J Vasc Interv Radiol. 2000; 11(8):991-996. Observational-Dx 31 patients To evaluate the impact of MRA on referring physicians’ diagnoses and treatment of patients with renal transplant dysfunction. Pre-MRA and post-MRA questionnaires were prospectively completed on 31 separate patients. The mean gain in diagnostic certainty percentage from MRA was 33% (95% CI, 19%-51%; P<.001). MRA changed physicians' initial diagnoses in 20 patients (65%; 95% CI, 47%-79%). Immediate clinical management changed in 16 patients (52%; 95% CI, 35%-68%). Invasive procedures were avoided in 12 patients (39%). MRA has considerable impact on referring physicians’ diagnoses and treatment of patients with suspected renal allograft dysfunction. 3
61. Sharafuddin MJ, Stolpen AH, Dixon BS, Andresen KJ, Sun S, Lawton WJ. Value of MR angiography before percutaneous transluminal renal artery angioplasty and stent placement. J Vasc Interv Radiol.2002; 13(9 Pt 1):901-908. Observational-Dx 39 patients had attempted percutaneous renal angioplasty with or without stent placement; 48 renal arteries treated To determine the benefit of preprocedural 3D Gd-enhanced MRA before PTRA and stent placement in terms of procedural success, iodinated contrast material load, and procedure duration. Two subgroups: patients who had preprocedural Gd-enhanced MRA (“prior MRA group”) and those who did not (“no MRA” group). Preprocedural planning with use of Gd-enhanced MRA significantly reduces the iodinated contrast material requirement during percutaneous renal artery interventions. It can also significantly shorten procedure duration. 3
62. Neimatallah MA, Dong Q, Schoenberg SO, Cho KJ, Prince MR. Magnetic resonance imaging in renal transplantation. J Magn Reson Imaging. 1999; 10(3):357-368. Review/Other-Dx N/A Review the role of MRI in renal transplantation, technical aspects of image acquisition, and MR findings of post-transplantation complications. Imaging modalities that are currently used to evaluate transplanted kidneys are US, CT, scintigraphy, intravenous urography, contrast angiography, and MRI. MRI offers multiple advantages. MRI provides cross sectional and vascular information without the risks of ionizing radiation, iodinated contrast, or arterial catheterization. 4
63. Ismaeel MM, Abdel-Hamid A. Role of high resolution contrast-enhanced magnetic resonance angiography (HR CeMRA) in management of arterial complications of the renal transplant. Eur J Radiol. 2011; 79(2):e122-127. Observational-Dx 30 renal patients To assess the accuracy of CeMRA in the detection of arterial complications after renal transplantation. The HR CeMRA shows 93.7% sensitivity, 80% specificity, 88.2% positive predictive value, 88.9% negative predictive value and 88.5% accuracy. 2
64. Liu X, Berg N, Sheehan J, et al. Renal transplant: nonenhanced renal MR angiography with magnetization-prepared steady-state free precession. Radiology. 2009; 251(2):535-542. Observational-Dx 15 patients, 2 blinded reviewers Retrospective study to examine nonenhanced MRA with steady-state free precession with inversion recovery for assessing renal arteries in patients with renal transplants. Thirteen recipients of renal transplants underwent steady-state free precession MRA before contrast material-enhanced MRA. Three stenoses (two mild, one severe) were identified at steady-state free precession MRA in agreement with findings at contrast-enhanced MRA. There was no significant difference in image quality between the two methods. Results suggest steady-state free precession MRA permits image quality of renal transplant arteries and detection of arterial stenosis comparable with those at contrast-enhanced MRA. 2
65. Lanzman RS, Voiculescu A, Walther C, et al. ECG-gated nonenhanced 3D steady-state free precession MR angiography in assessment of transplant renal arteries: comparison with DSA. Radiology 2009;252:914-21. Observational-Dx 20 patients To evaluate noncontrast material-enhanced steady-state free precession (SSFP) magnetic resonance (MR) angiography in the assessment of transplant renal arteries (RAs) by using digital subtraction angiography (DSA) as the reference standard. One patient was excluded because SSFP MR angiography failed to adequately visualize the allograft vasculature owing to low cardiac output. The mean image quality assessed by both readers was 3.98 +/- 0.16 (standard deviation), 3.5 +/- 0.68, 2.71 +/- 1.12 and 2.03 +/- 1.09 for segments I, II, III, and IV, respectively (kappa = 0.80). DSA helped identify eight relevant (> or =50%) stenoses in six transplant RAs. Kinking of the transplant artery without relevant stenosis was found in seven patients. The degree of stenosis was overestimated in three patients by using SSFP MR angiography. As compared with DSA, the sensitivity, specificity, and accuracy of SSFP MR angiography to help detect relevant TRAS were 100% (six of six), 88% (14 of 16), and 91% (20 of 22), respectively. 2
66. Bultman EM, Klaers J, Johnson KM, et al. Non-contrast enhanced 3D SSFP MRA of the renal allograft vasculature: a comparison between radial linear combination and Cartesian inflow-weighted acquisitions. Magn Reson Imaging. 32(2):190-5, 2014 Feb. Observational-Dx 21 patients To evaluate the performance of a non-inflow weighted 3D radial balanced steady-state free precession acquisition – VIPR-SSFP – in renal NCE-MRA compared to Inflow IR (IFIR). Diagnostic efficacy of the sequences was scored using a four point Likert scale according to the following criteria: overall image quality, fat suppression, and arterial/venous visualization quality. Average scores for each criterion were compared using the Wilcoxon signed-rank test. In addition to significantly improved venous visualization, the VIPR-SSFP sequence provided significantly improved fat suppression quality (p<0.03) compared to IFIR. VIPR-SSFP also identified several pathologies such as renal arterial pseudoaneurysm that were not visible on the IFIR images. However, IFIR afforded superior quality of arterial visualization (p<0.005). 3
67. Tang H, Wang Z, Wang L, et al. Depiction of transplant renal vascular anatomy and complications: unenhanced MR angiography by using spatial labeling with multiple inversion pulses. Radiology. 271(3):879-87, 2014 Jun. Observational-Dx 75 patients To evaluate the ability to depict anatomy and complications of renal vascular transplant with unenhanced magnetic resonance (MR) angiography with spatial labeling with multiple inversion pulses (SLEEK) and to compare the results with color Doppler (CD) ultrasonography (US), digital subtraction angiography (DSA), and intraoperative findings. Transplant renal vascular anatomy was assessed in 87 arteries and 78 veins. Renal vascular complications from transplantation were diagnosed in 23 patients, which included 14 with arterial stenosis, three with arterial kinking, two with arteriovenous fistulas, two with venous stenosis, one with pseudoaneurysms, and one with fibromuscular dysplasia. Three patients had two renal transplants and nine patients had nine accessory renal arteries. More accessory renal arteries were detected with SLEEK than with CD US. Correlation was excellent between the stenosis degree with SLEEK and DSA (r = 0.96; P < .05). For those with significant artery stenosis (>50% narrowing) proved with DSA (n = 7) or surgery (n = 3), positive predictive value was 91% (10 of 11). 3
68. Zhang LJ, Peng J, Wen J, et al. Non-contrast-enhanced magnetic resonance angiography: a reliable clinical tool for evaluating transplant renal artery stenosis. Eur Radiol. 28(10):4195-4204, 2018 Oct. Observational-Dx 330 patients receiving 369 non-contrast-enhanced MRA examinations. To evaluate image quality of non-contrast-enhanced magnetic resonance angiography (MRA) and compare transplant renal artery stenosis (TRAS) seen by non-contrast-enhanced MRA with digital subtraction angiography (DSA) as the gold standard. Good or excellent image quality was found in 95.4 % (352/369) of examinations with good inter-observer agreement (K=0.760). Twenty-two patients with DSA had 28 non-contrast-enhanced MRA examinations within a 2-month period. Of these, 19 patients had TRAS, two patients had pseudoaneurysms, and one patient had a normal transplant renal artery but an occluded external iliac artery. Non-contrast-enhanced MRA correctly detected 19 TRAS and nine normal arteries, giving 96.6 % accuracy on a per-artery basis. 3
69. Pan FS, Liu M, Luo J, et al. Transplant renal artery stenosis: Evaluation with contrast-enhanced ultrasound. European Journal of Radiology. 90:42-49, 2017 May. Observational-Dx 78 patients To assess the efficacy of contrast-enhanced ultrasound (CEUS) in depicting transplant renal artery stenosis (TRAS). TRAS was diagnosed in 32 out of 78 cases by CTA. The AUC, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CEUS in predicting TRAS were 0.92, 92.3%, 87.5%, 95.7%, 93.3%, and 91.7%, respectively. CEUS rectified 13 (28.3%) false-positive cases on DUS, which were confirmed by CTA. Compared to DUS parameters, CEUS showed the highest AUC, statistically significant differences of AUC were found (P=0.006-0.039), except for that of the PSV ratio in the main transplant renal artery to that in interlobar artery (PSV-ratio) (AUC: 0.92 versus 0.86, P=0.422). However, CEUS showed a significantly higher specificity (95.7% versus 76.1%, P=0.008) and the same sensitivity compared to PSV-ratio. 3
70. Advances in Biomedical Alcohol Research. Proceedings of the 5th ISBRA/RSA Congress. Toronto, Canada, 17-22 June 1990. Alcohol Alcohol Suppl 1991;1:1-534. Review/Other-Tx N/A To present the proceedings of the fifth ISBRA congress No results stated in abstract. 4
71. Kim HS, Fine DM, Atta MG. Catheter-directed thrombectomy and thrombolysis for acute renal vein thrombosis. J Vasc Interv Radiol 2006;17:815-22. Observational-Tx Seven thrombosed renal veins in six patients. To evaluate the technical success and clinical outcome of the percutaneous treatment of acute renal vein thrombosis (RVT). Seven thrombosed renal veins in six patients (mean age, 51.5 +/- 18.8 years) were treated with percutaneous catheter-directed thrombectomy/thrombolysis. Thrombosed renal veins included two allografts and five native veins, and diagnosis was confirmed in all cases by direct renal venography. Inferior vena cava thrombosis was the cause of RVT in one patient, and glomerulopathy was the cause in the remaining patients. Percutaneous mechanical thrombectomy was performed in all cases, and five renal veins were additionally treated with thrombolysis for a mean duration of 22.1 +/- 21.0 hours. Restoration of flow to renal veins was achieved in all thrombosed renal veins. Clinical improvement occurred in all patients: the mean serum creatinine level improved from a preoperative level of 3.3 +/- 1.92 mg/dL to a postoperative level of 1.92 +/- 1.32 mg/dL (P = .008). Mean glomerular filtration rate improved from a preoperative level of 30.8 +/- 23.0 mL/min per 1.73 m(2) to 64.2 +/- 52.4 mL/min per 1.73 m(2) (P = .04). There were no pulmonary emboli or hemorrhagic complications, and no RVT recurrence was documented during a median follow-up of 22.5 months. 2
72. Sciascia N, Zompatori M, Di Scioscio V, et al. Multidetector CT-urography in the study of urological complications in renal transplant. Radiol Med 2002;103:501-10. Observational-Dx 15 patients 3
73. Cohnen M, Brause M, May P, et al. Contrast-enhanced MR urography in the evaluation of renal transplants with urological complications. Clin Nephrol. 58(2):111-7, 2002 Aug. Observational-Dx 35 patients To assess sensitivity and specificity of non-invasive contrast-enhanced MR urography (MRU). In all patients, images with sufficient contrast in the renal collecting system were obtained. Hydronephrosis was confirmed in 20 patients, 8 patients showed a different pathology while 7 had normal findings. Compared to operative results, sensitivity of MRU was 100% with a specificity of 78%, respectively. One ureteral stone was misdiagnosed as a stricture, and 2 suspected ureteral stenoses could not be found upon operation. 3
74. Blondin D, Koester A, Andersen K, Kurz KD, Moedder U, Cohnen M. Renal transplant failure due to urologic complications: Comparison of static fluid with contrast-enhanced magnetic resonance urography. Eur J Radiol 2009;69:324-30. Observational-Dx 35 patients To retrospectively compare the diagnostic accuracy of static fluid (T2-)MRU compared to contrast enhanced (CE-)MRU in patients with renal transplant failure. CE-MRU yielded a sensitivity of 85.7% (T2-MRU 76.2%), and a specificity of 83.3% (T2-MRU: 73.7%), however statistical significance was not reached. The subjective image quality was significantly better in CE-MRU. 3
75. Grzelak P, Kurnatowska I, Nowicki M, et al. The diagnostic value of contrast-enhanced ultrasonography in the assessment of perirenal hematomas in the early post-operative period after kidney transplantation. Clin Transplant. 27(6):E619-24, 2013 Nov-Dec. Observational-Dx 102 patients To evaluate the diagnostic value of contrast-enhanced ultrasound (CE-US) in diagnosing PH of KTx in the early post-operative period. The difference in echogenicity between PH and kidney parenchyma was modest in rB-US (mean of 5.7 dB). However, in CE-US, the difference in echogenicity was significantly increased (mean of 31.4 dB). Routine B-US did not allow PH to be recognized in 18 patients. The application of CE-US results in a twofold increase in PH detection when compared with rB-US (33.3% vs. 15.7%). 3
76. Williams WW, Taheri D, Tolkoff-Rubin N, Colvin RB. Clinical role of the renal transplant biopsy. Nat Rev Nephrol 2012;8:110-21. Review/Other-Dx N/A To provide a broad outline of the utility of performing kidney graft biopsies after transplantation, highlighting the relevance of biopsy findings in the immediate and early post-transplant period (from days to weeks after implantation), the first post-transplant year, and the late period (beyond the first year). No results stated in abstract. 4
77. Pascual M, Vallhonrat H, Cosimi AB, et al. The clinical usefulness of the renal allograft biopsy in the cyclosporine era: a prospective study. Transplantation 1999;67:737-41. Observational-Dx 54 renal allograft biopsies (47 patients, 7 patients underwent a biopsy twice). To evaluate the clinical usefulness of the allograft biopsy in renal transplant recipients receiving cyclosporine (CyA). The biopsy findings resulted in a change in patient management in 22 (41.5%) of the remaining 53 cases (change group). The incidence of altered patient management was 38.7% in biopsy specimens taken in the first month, 55.6% between 1 and 12 months, and 38.5% after 1 year posttransplantation. A change in management was required in 2 of 2 patients with chronic allograft dysfunction, in 44.4% of the 45 patients with acute allograft dysfunction, and in none of the patients with delayed graft function (n=6). Within the first week of treatment 19 of 22 (86.4%) in the change group and 25 of 31 (80.6%) in the no change group had a positive response to therapy. The 1-year allograft survival rate was also similar between the two groups. None of the clinical and laboratory data was useful in distinguishing ACR from CyA toxicity. 3
78. Schwarz A, Gwinner W, Hiss M, Radermacher J, Mengel M, Haller H. Safety and adequacy of renal transplant protocol biopsies. Am J Transplant 2005;5:1992-6. Observational-Tx 1171 protocol biopsies in 508 patients after renal transplantation, as well as 499 biopsies as indicated in 429 transplant patients. To test the risks of renal Transplant protocol biopsies. Complications were: gross hematuria 3.5%, perirenal hematomas 2.5%, arterio-venous fistulas 7.3% and vasovagal reactions 0.5%. Major complications requiring invasive procedures such as blood transfusions or urinary catheter were seen in 1% of cases. The hospitalization rate for observation was 1.9%. According to the Banff criteria of specimen adequacy, biopsies with 18-gauge needles yielded >7 glomeruli and at least one artery in 53% of cases. Changing the needle size in October 2003, those biopsies done with 16-gauge needles yielded >7 glomeruli and at least one artery in 76% of cases, while the rate of major complications did not change. 3
79. Furness PN, Philpott CM, Chorbadjian MT, et al. Protocol biopsy of the stable renal transplant: a multicenter study of methods and complication rates. Transplantation. 2003; 76(6):969-973. Review/Other-Dx 2,127 biopsy events for major complications and 1,486 events for minor ones Retrospective audit of a sequential series of protocol biopsies was performed in four major transplant centers to determine risk of biopsy of a stable kidney. The incidence of clinically significant complications after protocol biopsy of a stable renal transplant is low. Direct benefits to the patients concerned (irrespective of the benefit that may accrue in clinical trials) were not formally assessed but seem likely to outweigh the risk of the procedure. Authors believe that it is ethically justifiable to ask renal transplant recipients to undergo protocol biopsies in clinical trials and routine care. 4
80. Benozzi L, Cappelli G, Granito M, et al. Contrast-enhanced sonography in early kidney graft dysfunction. Transplant Proc 2009;41:1214-5. Observational-Dx 39 kidney recipients: examinations at 5 (T0), 15 (T1), and 30 (T2) days after grafting. To compare contrast-enhanced sonography (CEUS) and power Doppler ultrasound (US) findings in renal grafts within 30 days posttransplantation. Fourteen patients displayed early acute kidney dysfunction: 10 had acute tubular necrosis (acute tubular necrosis [ATN] group); four acute rejection episodes (ARE group); 25 with normal evolution (as control, C group). Renal biopsies were performed to obtain a diagnosis in the four ATN cases and in all ARE patients. Creatinine and estimated glomerular filtration rate were used as kidney function parameters. CEUS analysis was performed both on cortical and medullary regions while US resistivity indexes (RI) were obtained on main, infrarenal, and arcuate arteries. From an analysis of CEUS time-intensity curves, we computed peak enhancement (PEAK), time to peak (TTP), mean transit time (MTT), regional blood flow (RBF) and volume (RBV), and cortical to medullary ratio of these indies (RATIO). 2
81. Goyal A, Hemachandran N, Kumar A, et al. Evaluation of the Graft Kidney in the Early Postoperative Period: Performance of Contrast-Enhanced Ultrasound and Additional Ultrasound Parameters. Journal of Ultrasound in Medicine. 40(9):1771-1783, 2021 Sep. Observational-Dx 105 patients To evaluate the various quantitative parameters of Doppler ultrasound, contrast-enhanced ultrasound (CEUS), and shear wave elastography (SWE) of graft kidneys in the early postoperative period and to explore their utility in the diagnosis of parenchymal causes of graft dysfunction. The peak systolic velocity in the interpolar artery showed a significant difference between control and graft dysfunction groups (P < .001) as well as between ATN and AR (P = .019). Resistive indices and SWE did not show significant differences. Ratios of the time to peak showed a significant difference between control and graft dysfunction groups (P < .05). The rise time and fall time of the large subcapsular region of interest and the rise time ratio were significantly different between ATN and AR (P = .03). 3
82. Zhou Q, Yu Y, Qin W, et al. Current Status of Ultrasound in Acute Rejection After Renal Transplantation: A Review with a Focus on Contrast-Enhanced Ultrasound. [Review]. Annals of Transplantation. 26:e929729, 2021 May 04. Review/Other-Dx N/A To review the current status of and recent research on contrast-enhanced ultrasound in acute rejection after renal transplantation. No results stated in abstract. 4
83. Fontanilla T, Minaya J, Cortes C, et al. Acute complicated pyelonephritis: contrast-enhanced ultrasound. Abdom Imaging. 2012;37(4):639-646. Review/Other-Dx 48 patients To describe in detail the contrast-enhanced US findings in APN, and to determine if abscess and focal pyelonephritis may be distinguished. No results stated. 4
84. Mueller-Peltzer K, Rubenthaler J, Fischereder M, Habicht A, Reiser M, Clevert DA. The diagnostic value of contrast-enhanced ultrasound (CEUS) as a new technique for imaging of vascular complications in renal transplants compared to standard imaging modalities. Clinical Hemorheology & Microcirculation. 67(3-4):407-413, 2017. Observational-Dx 33 renal transplant recipients with elevated kidney function parameters. To analyse the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) in comparison to the standard imaging modalities CT, DSA and radioisotope renography in the diagnosis of vascular complications in renal transplant patients. CEUS showed a sensitivity of 100%, a specificity of 66.7%, a positive predictive value (PPV) of 71.4%, and a negative predictive value (NPV) of 100%. 4
85. National Academies of Sciences, Engineering, and Medicine; Division of Behavioral and Social Sciences and Education; Committee on National Statistics; Committee on Measuring Sex, Gender Identity, and Sexual Orientation. Measuring Sex, Gender Identity, and Sexual Orientation. In: Becker T, Chin M, Bates N, eds. Measuring Sex, Gender Identity, and Sexual Orientation. Washington (DC): National Academies Press (US) Copyright 2022 by the National Academy of Sciences. All rights reserved.; 2022. Review/Other-Dx N/A Sex and gender are often conflated under the assumptions that they are mutually determined and do not differ from each other; however, the growing visibility of transgender and intersex populations, as well as efforts to improve the measurement of sex and gender across many scientific fields, has demonstrated the need to reconsider how sex, gender, and the relationship between them are conceptualized. No abstract available. 4
86. 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
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