Renal Transplant Complications: Diagnostic and Therapeutic Role of Radiology  Mehmet Fatih Inci, MD, Fuat Ozkan, MD, Teik Choon See, MB, FRCS, FRCR, Servet Tatli, MD  Canadian Association of Radiologists Journal  Volume 65, Issue 3, Pages 242-252 (August 2014) DOI: 10.1016/j.carj.2013.06.002 Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 1 Normal ultrasound (US) findings of a transplanted kidney. (A) Grey-scale US, showing normal size and echogenicity of the kidney. (B) Colour-Doppler US, showing a resistive index within normal limits in the interlobar arteries. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 2 Axial (A) and coronal (B) sections from a contrast-enhanced (cortical nephrogram–phase) computed tomography of normal renal transplantation, showing intense cortical enhancement and mild stranding in the renal pelvis without hydronephrosis or perirenal fluid. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 3 Maximum intensity projection magnetic resonance images of a transplanted kidney obtained during arterial (A) and venous (B) phase, showing normal calibre and intensity of the renal artery (arrow) and vein (arrow), respectively. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 4 (A) Duplex ultrasound, showing an increased peak systolic velocity (232.2 cm/s) at the proximal segment of the transplanted renal artery. (B) The peak systolic velocity at the external iliac artery was found as 57.2 cm/s. The renal-iliac ratio (232.2/57.2 = 4.06) is greater than 3, which indicates a hemodynamically significant stenosis. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 5 Maximum intensity projection magnetic resonance image of a patient with severe hypertension who underwent a renal transplantation, showing a severe stenosis at the anastomosis (arrow) of the renal artery. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 6 Percutaneous transluminal angioplasty of a transplanted renal artery stenosis. (A) Angiogram, showing a focal narrowing at the anastomosis of the renal artery (arrow). (B) An angiography image obtained during angioplasty, showing a catheter with the balloon placed across the area of stenosis (arrow). (C) An angiogram obtained after angioplasty, showing restoration of a near-normal arterial lumen (arrow). Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 7 (A) Axial contrast-enhanced computed tomography, demonstrating a large amount of high-density peritransplantation fluid collection (arrowheads) suggestive of hematoma, with extraluminal contrast pooling near the anastomosis (arrow). (B) A catheter angiogram, confirming extraluminal contrast (arrow) consistent with a pseudoaneurysm at the origin of the arterial anastomosis. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 8 (A) Grey-scale ultrasound, showing moderate obstructive hydronephrosis secondary to distal ureteral stricture. (B) Coronal radiography obtained during fluoroscopy-guided nephrostomy for urinary diversion, showing marked lumen stenosis, which consisted of a distal ureteric stricture (arrows) and a 8F catheter in the collecting system. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 9 Axial contrast-enhanced computed tomography, showing a linear high-density region suggestive of active bleeding from a cortical defect in the transplanted kidney (arrow). Note perirenal hyperattenuating collection, consistent with hematoma secondary to a recent percutaneous biopsy procedure. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 10 (A) Grey-scale ultrasound (US), showing a peritransplantation fluid collection with multiple septations. (B) An axial contrast-enhanced computed tomography, showing a hypoattenuating collection (arrows) that surrounds the transplanted kidney (arrowheads). US-guided aspiration of the fluid confirmed the diagnosis of a lymphocele. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 11 (A) Grey-scale ultrasound (US) obtained 2 days after transplantation, showing an enlarged transplanted kidney, with prominent renal pyramids and medulla (arrows). (B) Power-Doppler US, showing good perfusion of the kidney. Duplex colour-Doppler US images of the renal artery (C) and interlobar artery (D), showing normal flow in the renal artery (C) but a brisk systolic upstroke and low end-diastolic flow with increased resistive index in the interlobar artery, which is typical for acute rejection. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 12 Transverse ultrasound image obtained during biopsy of a transplanted kidney, showing the needle path (arrows) through the cortex of the anterolateral aspect of the transplanted kidney. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 13 Cinememory of a transplanted kidney elastography of a 32-year-old woman. The strain ratio (arrow) was 3.25, calculated based on the cinememory of the elastography, highly suggestive of rejection. Ultrasound-guided percutaneous biopsy confirmed the diagnosis of chronic allograft nephropathy. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions

Figure 14 (A) Contrast-enhanced computed tomography, showing a spherical mass (arrow) in the transplanted kidney proven to be a renal cell carcinoma. (B) Axial T2-weighted magnetic resonance image obtained during cryoablation, showing a well-marginated, hypointense ice ball (arrows) covering the tumour. (C) T1-weighted, gradient-echo magnetic resonance image obtained at 24 hours, demonstrating an increase in signal intensity within the tumour (arrow), suggestive of coagulation necrosis. Canadian Association of Radiologists Journal 2014 65, 242-252DOI: (10.1016/j.carj.2013.06.002) Copyright © 2014 Canadian Association of Radiologists Terms and Conditions