Imaging of vascular complications associated with renal transplants

Vascular complications associated with renal transplants are a significant cause of graft dysfunction. The most common complications are arterial and venous stenoses and thromboses and intrarenal and extrarenal arteriovenous fistulas and pseudoaneurysms. Although angiography is the imaging gold standard for the diagnosis of these disorders, Doppler sonography, scintigraphy, and occasionally CT are capable of detecting them. An awareness of the different imaging appearances of each complication will aid in their early detection and treatment. In this review, we present this information and provide a perspective on the relative roles of these techniques in the detection of vascular complications from renal transplants.     

A review of commonly performed bariatric surgeries: Imaging features and its complications

Obesity is a disease that has achieved the level that can be considered an epidemic. According to the National Center for Health Statistics data, the prevalence of obesity has increased from 30.5% in 1999–2000 to 42.4% in 2017–2018. During the same period, severe obesity has increased from 4.7% to 9.2%. With the growing prevalence of obesity, related conditions such as coronary artery disease, diabetes, and strokes have also become more prevalent.In the past few years, the need for bariatric surgeries such as laparoscopic Roux-en-Y gastric bypass, sleeve gastrectomy, and laparoscopic adjustable gastric banding has increased considerably. With an increasing number of bariatric surgeries, multiple postoperative complications have become common. In this review, we have attempted to describe normal postsurgical anatomical findings after bariatric surgeries and pictorial review of a few common postoperative complications.     

Challenges in mammography: part 2, multimodality review of breast augmentation--imaging findings and complications

OBJECTIVE: Breast augmentation is common throughout the world; however, there is variation in materials and surgical techniques. This review illustrates the mammographic, sonographic, and MRI characteristics of the different types of breast augmentation, including silicone, saline, polyacrylamide gel, and autologous fat augmentation. CONCLUSION: The imaging findings of complications such as implant rupture, free silicone, and fat necrosis in association with augmentation will be illustrated.     

MRI of pancreatic transplants

The value of MRI in assessing pancreatic transplants was studied in 37 patients. Sixty-seven MRI examinations were performed in patients with an uncomplicated transplant, a4 in patients with poorly functioning gransplant, and 10 in patients with a non-functioning graft. On the basis of 54 follow-up studies, it was shown that the volume of the graft decreased systematically during the 8 months after transplantation. On T1-weighted images the normal transplant was poorly delineated, with an almost homogeneous isointense or slightly hyperintense structure when compared with either renal transplant cortex or muscle. On T2-weighted images the organ was isointense or slightly hypointense compared with fat and hyperintense compared with muscle. T2-weighted delayed echo time image (TR = 2000 ms, TE = 150–200 ms) showed transplanted pancreas as well-delineated, hypointense and with a lobulated structure. This structure was characteristic of normal whole pancreatic grafts. Patent transplant vessels were seen as tubular structures of low signal intensity on T2-weighted short echo time images (TR = 2000 ms, TE = 50 ms). In the 10 patients with a non-functioning pancreatic transplant there were: 4 cases of focal intraparenchymal abnormalities, 6 cases in which the lobular structure was absent, and 4 cases of absence of patent graft main vessels (3 thromboses). There was no configuration of signal intensity of pancreatic parenchyma on MRI which could be considered typical for normal or non-functioning transplant. Correspondence to: A. Pinet     

Adnexal torsion -- a multimodality imaging review

Adnexal torsion is a gynaecological surgical emergency as prompt restoration of ovarian blood flow may prevent permanent irreversible damage. Patients frequently present with non-specific symptoms and signs and therefore adnexal torsion is often an unexpected radiological diagnosis. Although ultrasound is the initial imaging technique of choice in suspected adnexal torsion, many patients undergo computed tomography (CT) or magnetic resonance imaging (MRI) either as a first-line test following non-specific presentation, or as a confirmatory test following equivocal ultrasound findings. Using multiple techniques, this review illustrates the wide variety of imaging features observed in adnexal torsion enabling a confident diagnosis that may result in a more favourable surgical outcome.     

Angiography of segmental pancreatic transplants

Arteriography was routinely performed in patients with suspected vascular complications after pancreas transplantation. Dysfunction of the grafts was suggested by 99mTc-DTPA scanning and metabolic tests. Thirty arteriograms obtained in 25 patients were evaluated. Nineteen conventional film angiograms and 11 intraarterial DSA were performed. Five different angiographic patterns were observed: normal vascular anatomy, low-flow phenomenon, arterial or venous thrombosis, and venous neovascularity. On the basis of the angiographic findings, various reasons for graft failure were identified. Recipient venous collaterals or well-functioning grafts without angiographically detectable blood supply were observed in 9 cases, and must be considered to represent neovascularisation by donor and recipient vessels.     

Imaging and interventional radiology for pancreatitis and its complications

Complications of pancreatitis are common, protean in their manifestations, and can be catastrophic. When complications occur, the morbidity and mortality are high. Expeditious radiologic detection of the complication, together with the plethora of nonoperative interventional techniques, offers new and improved methods for diagnosis and treatment. This article focuses on the essential role of radiology and the natural integration of imaging and interventional radiology for pancreatitis and its complications.     

Pulmonary complications of multimodality therapy for esophageal carcinoma

Thirty patients with cancer of the esophagus were treated with multimodality therapy. We studied the incidence of pulmonary complications in these patients. The value of chest radiographs and sequential measurements of carbon monoxide diffusing capacity (DLco) in predicting pulmonary toxicity was determined. Patients were divided into two groups, according to treatment. Patients in group I (n = 16) received two cycles of chemotherapy (bleomycin 15 units/m2, cisplatinum 120 mg/m2, vincristine 2 mg) and radiotherapy (50 Gy). Based on the presence of interstitial lesions on chest radiographs in five patients the incidence of pulmonary toxicity was 32%. In four of these five patients such an appearance was preceded by a drop in DLco: this was documented in 8 of the 16 patients. Nine patients of group I underwent esophagectomy and four (44%) developed adult respiratory distress syndrome (ARDS). In group II (n = 14) the tumor was resected without other treatment and four (29%) of these patients developed ARDS. The incidence of ARDS in both groups demonstrates that pulmonary complications are mainly related to surgical manipulation and to preexisting lung disease. Preoperative radiotherapy and chemotherapy may be associated factors. Sequential measurements of DLco are more sensitive for detecting pulmonary damage than chest radiographs and should be used to predict pulmonary toxicity.     

新生儿肺透明膜病及并发症的影像分析

目的探讨新生儿肺透明膜病及其并发症的影像表现,提高早期诊断能力。方法根据X线诊断标准及分级回顾性分析了经临床及病理证实的87例新生儿肺透明膜病的影像表现。结果本组87例中,Ⅰ级11例,Ⅱ级2 7例,Ⅲ级31例,Ⅳ级18例。其各种并发症如下动脉导管开放38例,肺出血2 9例,肺炎14例,气漏7例,缺氧缺血性脑病6例,颅内出血5例,支气管肺发育不良3例。结论新生儿肺透明膜病及并发症的影像表现多种多样,支气管充气征是诊断新生儿肺透明膜病最可靠的影像表现,结合临床大都可以作出肯定诊断。X线、B超等影像检查的常规、动态观察能及时发现并发症。     

Renal transplant evaluation: multimodality imaging of post-transplant complications

With advancements in surgical techniques and immuno-suppression, renal transplantation is established as the most effective treatment option in patients with end-stage renal disease. Early detection of renal allograft complications is important for long-term graft survival. Late clinical presentation often causes diagnostic delays till the time allograft failure is advanced and irreversible. Imaging plays a key role in routine surveillance and in management of acute or chronic transplant dysfunction. Multimodality imaging approach is important with ultrasound-Doppler as the first-line imaging study in immediate, early and late post-transplant periods. Additional imaging studies are often required depending on clinical settings and initial ultrasound. Renal functional MRI is a rapidly growing field that has huge potential for early diagnosis of transplant dysfunction. Multiparametric MRI may be integrated in clinical practice as a noninvasive and comprehensive “one-stop” modality for early diagnosis and longitudinal monitoring of renal allograft dysfunctions, which is essential for guiding appropriate interventions to delay or prevent irreversible renal damage. With rapidly increasing numbers of renal transplantation along with improved patient survival, it is necessary for radiologists in all practice settings to be familiar with the normal appearances and imaging spectrum of anatomical and functional complications in a transplant kidney. Radiologist”s role as an integral part of multidisciplinary transplantation team continues to grow with increasing numbers of successful renal transplantation programs across the globe.     

Imaging spectrum of central nervous system complications of hematopoietic stem cell and solid organ transplantation.

Neurologic complications are common after hematopoietic stem cell transplantation (HSCT) and solid organ transplantation (SOT) and affect 30–60% of transplant recipients. The aim of this article is to provide a practical imaging approach based on the timeline and etiology of CNS abnormalities, and neurologic complications related to transplantation of specific organs. The lesions will be classified based upon the interval from HSCT procedure: pre-engraftment period <30 days, early post-engraftment period 30–100 days, late post-engraftment period >100 days, and the interval from SOT procedure: postoperative phase 1–4 weeks, early posttransplant syndromes 1–6 months, late posttransplant syndromes >6 months. Further differentiation will be based on etiology: infections, drug toxicity, metabolic derangements, cerebrovascular complications, and posttransplantation malignancies. In addition, differentiation will be based on complications specific to the type of transplantation: allogeneic and autologous hematopoietic stem cells (HSC), heart, lung, kidney, pancreas, and liver. Thus, in this article we emphasize the strategic role of neuroradiology in the diagnosis and response to treatment by utilizing a methodical approach in the work up of patients with neurologic complications after transplantation.     

Imaging pitfalls of pancreatic serous cystic neoplasm and its potential mimickers

The aim of this article is to clarify diagnostic pitfalls of pancreatic serous cystic neoplasm (SCN) that may result in erroneous characterization. Usual and unusual imaging findings of SCN as well as potential SCN mimickers are presented. The diagnostic key of SCN is to look for a cluster of microcysts (honeycomb pattern), which may not be always found in the center. Fibrosis in SCN may be mistaken for a mural nodule of intraductal papillary mucinous neoplasm (IPMN). The absence of cyst wall enhancement may be helpful to distinguish SCN from mucinous cystic neoplasm. However, oligocystic SCN and branch duct type IPMN may morphologically overlap. In addition, solid serous adenoma, an extremely rare variant of SCN, is difficult to distinguish from neuroendocrine tumor.     

Indium-111-labeled platelets in monitoring human pancreatic transplants

We have performed 59 111In-labeled platelet scintigraphies in 12 patients with pancreas transplant, and we have compared retrospectively the 111In platelet uptake with the graft immunological situation. A diffuse uptake in the graft was seen in five of six patients with pancreatic rejection. The scans became positive before changes in biochemical tests were detected. No 111In platelet uptake was seen in five of seven normally functioning grafts. Two cases of venous thrombosis and two perigraft hematomas appeared like a focal 111In platelet accumulation. Indium-111-labeled platelet scintigraphy can be a useful method for monitoring pancreas transplants. It may be helpful in the early detection of pancreatic allograft rejection and in the differential diagnosis between this and other complications such as thrombosis or hematomas.     

Imaging of pancreatic trauma

This pictorial review discusses the imaging findings in acute pancreatic injury and its delayed complications. These findings are related to key decisions in surgical management. Emphasis is placed on the difficulty of acute diagnosis using CT and the pivotal role of endoscopic retrograde pancreatography (ERP) in the definition of ductal anatomy with delayed diagnosis.