Renal Transplant Evaluation with MR Angiography and MR Imaging1
Mark D. Hohenwalter, MD,
Christopher J. Skowlund, MD,
Scott J. Erickson, MD,
Sundaram Hariharan, MD,
William S. Rilling, MD,
Martin R. Crain, MD and
Peter Drescher, MD
1 From the Departments of Radiology (M.D.H., C.J.S., S.J.E., W.S.R., M.R.C., P.D.) and Medicine (S.H.), Medical College of Wisconsin, 9200 W Wisconsin Ave, Milwaukee, WI 53226. Presented as an education exhibit at the 2000 RSNA scientific assembly. Received April 17, 2001; revision requested May 21 and received June 18; accepted June 18. Address correspondence to M.D.H. (e-mail: mhohen@mcw.edu).
View larger version (71K):
[in a new window]
|
Figure 1a. (a) Drawing illustrates a normal transplanted kidney with vascular and ureteric anastomoses. (b) Drawing illustrates selected posttransplantation abnormalities, including arterial stenosis, infarction, a peritransplant fluid collection, and hydronephrosis.
|
|
View larger version (61K):
[in a new window]
|
Figure 1b. (a) Drawing illustrates a normal transplanted kidney with vascular and ureteric anastomoses. (b) Drawing illustrates selected posttransplantation abnormalities, including arterial stenosis, infarction, a peritransplant fluid collection, and hydronephrosis.
|
|
View larger version (85K):
[in a new window]
|
Figure 2. Fat-suppressed T2-weighted MR image demonstrates a normal transplanted kidney and peritransplant region.
|
|
View larger version (146K):
[in a new window]
|
Figure 3a. (a) Coronal arterial-phase 3D time-of-flight source MR angiogram demonstrates the aorta. (b) Source MR angiogram demonstrates the main transplant renal artery. The transplanted kidney is shown in the corticomedullary phase.
|
|
View larger version (151K):
[in a new window]
|
Figure 3b. (a) Coronal arterial-phase 3D time-of-flight source MR angiogram demonstrates the aorta. (b) Source MR angiogram demonstrates the main transplant renal artery. The transplanted kidney is shown in the corticomedullary phase.
|
|
View larger version (166K):
[in a new window]
|
Figure 4. MIP reformatted MR angiogram depicts the normal aortoiliac system as well as the main and segmental transplant renal arteries.
|
|
View larger version (112K):
[in a new window]
|
Figure 5a. (a-c) MPVR images show the normal aortoiliac system (a), main renal artery anastomosis (b), and segmental transplant renal arteries (c). (d) MPVR image demonstrates usefulness of the reformatted image for estimating transplanted kidney size.
|
|
View larger version (71K):
[in a new window]
|
Figure 5b. (a-c) MPVR images show the normal aortoiliac system (a), main renal artery anastomosis (b), and segmental transplant renal arteries (c). (d) MPVR image demonstrates usefulness of the reformatted image for estimating transplanted kidney size.
|
|
View larger version (107K):
[in a new window]
|
Figure 5c. (a-c) MPVR images show the normal aortoiliac system (a), main renal artery anastomosis (b), and segmental transplant renal arteries (c). (d) MPVR image demonstrates usefulness of the reformatted image for estimating transplanted kidney size.
|
|
View larger version (128K):
[in a new window]
|
Figure 5d. (a-c) MPVR images show the normal aortoiliac system (a), main renal artery anastomosis (b), and segmental transplant renal arteries (c). (d) MPVR image demonstrates usefulness of the reformatted image for estimating transplanted kidney size.
|
|
View larger version (85K):
[in a new window]
|
Figure 6a. Volume-rendered MR angiograms obtained from the same data set but displayed with different magnification and rotation demonstrate a normal transplant artery anastomosis (b) and normal segmental vessels (a).
|
|
View larger version (78K):
[in a new window]
|
Figure 6b. Volume-rendered MR angiograms obtained from the same data set but displayed with different magnification and rotation demonstrate a normal transplant artery anastomosis (b) and normal segmental vessels (a).
|
|
View larger version (103K):
[in a new window]
|
Figure 7a. (a, b) Volume-rendered images obtained with different preset algorithms depict normal transplant anatomy. (c) Volume-rendered image demonstrates the usefulness of thresholding to "remove" the renal parenchyma and highlight the segmental arteries.
|
|
View larger version (142K):
[in a new window]
|
Figure 7b. (a, b) Volume-rendered images obtained with different preset algorithms depict normal transplant anatomy. (c) Volume-rendered image demonstrates the usefulness of thresholding to "remove" the renal parenchyma and highlight the segmental arteries.
|
|
View larger version (102K):
[in a new window]
|
Figure 7c. (a, b) Volume-rendered images obtained with different preset algorithms depict normal transplant anatomy. (c) Volume-rendered image demonstrates the usefulness of thresholding to "remove" the renal parenchyma and highlight the segmental arteries.
|
|
View larger version (119K):
[in a new window]
|
Figure 8. Contrast-enhanced fat-suppressed fast multiplanar spoiled gradient-echo MR image demonstrates a normal transplanted kidney with uniform enhancement.
|
|
View larger version (136K):
[in a new window]
|
Figure 9a. Main transplant renal artery kinking in a 64-year-old woman with kidney dysfunction. The patient had undergone renal transplantation 4 years earlier. MPVR (a) and volume-rendered (b, c) images demonstrate an apparent kink in the midportion of the transplant renal artery (arrow).
|
|
View larger version (115K):
[in a new window]
|
Figure 9b. Main transplant renal artery kinking in a 64-year-old woman with kidney dysfunction. The patient had undergone renal transplantation 4 years earlier. MPVR (a) and volume-rendered (b, c) images demonstrate an apparent kink in the midportion of the transplant renal artery (arrow).
|
|
View larger version (112K):
[in a new window]
|
Figure 9c. Main transplant renal artery kinking in a 64-year-old woman with kidney dysfunction. The patient had undergone renal transplantation 4 years earlier. MPVR (a) and volume-rendered (b, c) images demonstrate an apparent kink in the midportion of the transplant renal artery (arrow).
|
|
View larger version (147K):
[in a new window]
|
Figure 10a. Segmental artery stenosis in an 82-year-old man with an elevated serum creatinine level. The patient had undergone transplantation 4 months earlier. MPVR (a) and volume-rendered (b) images demonstrate a segmental transplant renal artery stenosis (arrow). This finding was not believed to be clinically significant because the patient presented with renal dysfunction rather than hypertension.
|
|
View larger version (136K):
[in a new window]
|
Figure 10b. Segmental artery stenosis in an 82-year-old man with an elevated serum creatinine level. The patient had undergone transplantation 4 months earlier. MPVR (a) and volume-rendered (b) images demonstrate a segmental transplant renal artery stenosis (arrow). This finding was not believed to be clinically significant because the patient presented with renal dysfunction rather than hypertension.
|
|
View larger version (133K):
[in a new window]
|
Figure 11a. Fibromuscular dysplasia in a 46-year-old man who had undergone transplantation 4 years earlier. The patient underwent MR angiography because of an elevated serum creatinine level and hypertension. (a, b) MPVR (a) and volume-rendered (b) images demonstrate the proximal transplant artery, which has an irregular beaded appearance, a finding that suggests fibromuscular dysplasia. (c) CO2 angiogram demonstrates corresponding vessel irregularity; however, there was no significant pressure gradient to warrant angioplasty. The patient subsequently underwent transplant biopsy, which demonstrated rejection.
|
|
View larger version (75K):
[in a new window]
|
Figure 11b. Fibromuscular dysplasia in a 46-year-old man who had undergone transplantation 4 years earlier. The patient underwent MR angiography because of an elevated serum creatinine level and hypertension. (a, b) MPVR (a) and volume-rendered (b) images demonstrate the proximal transplant artery, which has an irregular beaded appearance, a finding that suggests fibromuscular dysplasia. (c) CO2 angiogram demonstrates corresponding vessel irregularity; however, there was no significant pressure gradient to warrant angioplasty. The patient subsequently underwent transplant biopsy, which demonstrated rejection.
|
|
View larger version (159K):
[in a new window]
|
Figure 11c. Fibromuscular dysplasia in a 46-year-old man who had undergone transplantation 4 years earlier. The patient underwent MR angiography because of an elevated serum creatinine level and hypertension. (a, b) MPVR (a) and volume-rendered (b) images demonstrate the proximal transplant artery, which has an irregular beaded appearance, a finding that suggests fibromuscular dysplasia. (c) CO2 angiogram demonstrates corresponding vessel irregularity; however, there was no significant pressure gradient to warrant angioplasty. The patient subsequently underwent transplant biopsy, which demonstrated rejection.
|
|
View larger version (164K):
[in a new window]
|
Figure 12. Transplanted kidney infarction in a 71-year-old man who presented with renal dysfunction and hypertension. The patient had undergone transplantation 4 months earlier. Source MR angiogram demonstrates multiple peripheral wedge-shaped perfusion defects representing multifocal infarcts (arrow). Subsequent MR angiograms (not shown) demonstrated that the renal artery was widely patent. The cause of the infarcts was not determined.
|
|
View larger version (113K):
[in a new window]
|
Figure 13. Lymphocele in a 72-year-old woman who presented with transplant dysfunction. The patient had undergone renal transplantation 11 years earlier. Axial T2-weighted MR image demonstrates a peritransplant fluid collection with homogeneous hyperintensity (arrow). These findings are consistent with an incidental lymphocele that did not result in significant parenchymal, vascular, or ureteral compression.
|
|
View larger version (76K):
[in a new window]
|
Figure 14. Mild hydronephrosis in a 46-year-old man who presented with hypertension and an elevated serum creatinine level. The patient had undergone renal transplantation 7 months earlier. Axial T2-weighted MR image demonstrates mild prominence of the transplanted kidney collecting system.
|
|
View larger version (123K):
[in a new window]
|
Figure 15. Renal transplant cyst in a 56-year-old man. Axial T2-weighted MR image demonstrates an incidental parapelvic cyst in a transplanted kidney.
|
|
View larger version (76K):
[in a new window]
|
Figure 16a. Complex vascular anatomy in a 31-year-old woman. The patient had undergone renal transplantation 9 years earlier and placement of a venous patch graft due to renal artery stenosis 4 years after transplantation. Anteroposterior (a) and oblique (b) volume-rendered MR angiograms demonstrate clear patency of the patch graft between the external iliac artery and the main transplant renal artery (arrow), thereby illustrating the usefulness of being able to view MR angiograms in any 3D projection.
|
|
View larger version (86K):
[in a new window]
|
Figure 16b. Complex vascular anatomy in a 31-year-old woman. The patient had undergone renal transplantation 9 years earlier and placement of a venous patch graft due to renal artery stenosis 4 years after transplantation. Anteroposterior (a) and oblique (b) volume-rendered MR angiograms demonstrate clear patency of the patch graft between the external iliac artery and the main transplant renal artery (arrow), thereby illustrating the usefulness of being able to view MR angiograms in any 3D projection.
|
|
View larger version (156K):
[in a new window]
|
Figure 17a. Surgical clip artifact in a 28-year-old man who presented with hypertension. The patient had undergone renal transplantation 3 years earlier. (a, b) Source MR angiogram (a) and MPVR image (b) demonstrate an apparent metallic clip artifact in the distal external iliac artery, just proximal to the transplant artery anastomosis (arrow). (c) Volume-rendered image shows a small corresponding irregularity in the vessel (arrowhead). (d) CO2 angiogram helps confirm that the irregularity was caused by a clip artifact (arrowhead).
|
|
View larger version (143K):
[in a new window]
|
Figure 17b. Surgical clip artifact in a 28-year-old man who presented with hypertension. The patient had undergone renal transplantation 3 years earlier. (a, b) Source MR angiogram (a) and MPVR image (b) demonstrate an apparent metallic clip artifact in the distal external iliac artery, just proximal to the transplant artery anastomosis (arrow). (c) Volume-rendered image shows a small corresponding irregularity in the vessel (arrowhead). (d) CO2 angiogram helps confirm that the irregularity was caused by a clip artifact (arrowhead).
|
|
View larger version (79K):
[in a new window]
|
Figure 17c. Surgical clip artifact in a 28-year-old man who presented with hypertension. The patient had undergone renal transplantation 3 years earlier. (a, b) Source MR angiogram (a) and MPVR image (b) demonstrate an apparent metallic clip artifact in the distal external iliac artery, just proximal to the transplant artery anastomosis (arrow). (c) Volume-rendered image shows a small corresponding irregularity in the vessel (arrowhead). (d) CO2 angiogram helps confirm that the irregularity was caused by a clip artifact (arrowhead).
|
|
View larger version (166K):
[in a new window]
|
Figure 17d. Surgical clip artifact in a 28-year-old man who presented with hypertension. The patient had undergone renal transplantation 3 years earlier. (a, b) Source MR angiogram (a) and MPVR image (b) demonstrate an apparent metallic clip artifact in the distal external iliac artery, just proximal to the transplant artery anastomosis (arrow). (c) Volume-rendered image shows a small corresponding irregularity in the vessel (arrowhead). (d) CO2 angiogram helps confirm that the irregularity was caused by a clip artifact (arrowhead).
|
|
View larger version (126K):
[in a new window]
|
Figure 18a. Surgical clip artifact mimicking stenosis in a 56-year-old man who presented with renal dysfunction and hypertension. The patient had undergone renal transplantation 9 years earlier. (a) MPVR MR angiogram demonstrates an area of apparent narrowing in the main renal artery (arrow). (b) Subsequent contrast-enhanced MR angiogram demonstrates a widely patent main renal artery with a clip at the site of the MR imaging pseudostenosis (arrowhead).
|
|
View larger version (126K):
[in a new window]
|
Figure 18b. Surgical clip artifact mimicking stenosis in a 56-year-old man who presented with renal dysfunction and hypertension. The patient had undergone renal transplantation 9 years earlier. (a) MPVR MR angiogram demonstrates an area of apparent narrowing in the main renal artery (arrow). (b) Subsequent contrast-enhanced MR angiogram demonstrates a widely patent main renal artery with a clip at the site of the MR imaging pseudostenosis (arrowhead).
|
|
Copyright © 2001 by the Radiological Society of North America.
