Imaging review of spontaneous renal hemorrhage.

Spontaneous renal hemorrhage (SRH) is a diagnostic challenge and a significant cause of morbidity, and sometimes mortality. Early identification is essential to institute lifesaving and reno-protective interventions. In this review, we classify spontaneous renal hemorrhage by location, presentation and etiology. We also discuss the diagnostic approach to renal hemorrhage and optimum imaging modalities to arrive at the diagnosis. Finally, we review strategies to avoid missing a diagnosis of SRH and discuss the pitfalls of imaging in the presence of renal hemorrhage.

Imaging of Unusual Renal Tumors.

PURPOSE OF REVIEW: Renal masses are a wide entity and a common finding in clinical practice. Detection of these masses has increased in the last years, yet mortality rates have slightly decreased. RECENT FINDINGS: According to the World Health Organization classification, there are 8 types, 51 subtypes, and a lot more subsequent subclassifications of renal tumors. Histopathological analysis should always be assessed for final diagnosis of theses tumors. However, imaging can be an important diagnostic guidance. The most common diagnoses of renal tumor are clear cell carcinoma, papillary renal cell carcinoma, angiomyolipoma, and transitional cell carcinoma. Nonetheless, a considerable variety of particular tumors can arise from the kidney, challenging the expertise of radiologists and urologists on this subject. The awareness of these unusual entities is vital for professionals working at a complex medical facility with greater volume of patients. We hereby present uncommon renal tumors and its pathological and radiological features.

A Comprehensive Approach to Hepatic Vascular Disease.

The liver has a complex vascular supply, which involves the inflow of oxygenated blood through the hepatic artery (systemic circulation) and deoxygenated blood through the portal vein (portal circulation), as well as the outflow of deoxygenated blood through the hepatic veins to the inferior vena cava. A spectrum of vascular variants can involve the liver. Some of these variants may result in areas of enhancement that can mimic more serious pathologic conditions. In this article, the authors discuss a spectrum of variants and pathologic conditions that may involve the liver vasculature. These include variants, anomalies, and diseases involving the portal vein, such as rudimentary portal vein, thrombosis, cavernous transformation, thrombotic angiitis, thrombophlebitis, transient hepatic attenuation difference or transient hepatic intensity difference, portal venous aneurysm, and portal vein gas. The hepatic artery can be involved by various diseases, including thrombosis, stenosis, and aneurysm or pseudoaneurysm. Unusual "third inflow" sources of venous inflow are also discussed, including aberrant right gastric vein, aberrant left gastric vein, epigastric-paraumbilical veins, and cholecystic vein. A spectrum of variants and diseases involving the inferior vena cava and hepatic veins, including thrombosis, Budd-Chiari syndrome, veno-occlusive disease, stenosis, torsion, congestive hepatopathy, and peliosis hepatis, are discussed. Vascular shunts are illustrated, including portosystemic shunts (intra- and extrahepatic), arterioportal shunt, shunts of hereditary hemorrhagic telangiectasia, and acquired arteriovenous fistula. Familiarity with the pathogenesis and imaging features of these vascular entities can aid radiologic diagnoses and guide appropriate patient management. ©RSNA, 2017.

Oral Manganese Chloride Tetrahydrate: A Novel Magnetic Resonance Liver Imaging Agent for Patients With Renal Impairment: Efficacy, Safety, and Clinical Implication.

ABSTRACT: Manganese-based contrast agents (MBCAs) show promise to complement gadolinium-based contrast agents (GBCAs) in magnetic resonance imaging (MRI) of the liver. Management of patients with focal liver lesions and severely impaired renal function uses unenhanced liver MRI or GBCA-enhanced MRI. However, unenhanced MRI risks reducing patient's survival.Gadolinium-based contrast agents, which help to detect and visualize liver lesions, are associated with increased risk of nephrogenic systemic fibrosis in renally impaired patients, a severe adverse event (AE) with potentially fatal outcome. Therefore, use of GBCA in patients with impaired renal function requires careful consideration. Other concerns are related to tissue deposition in the brain and other organs due to lack of gadolinium clearance, which could lead to concerns also for other patient populations, for example, those exposed to multiple procedures with GBCA. Of particular concern are the linear chelates that remain available for liver MRI, where there is no replacement technology. This has highlighted the urgency for safer alternatives.An alternative may be the drug candidate Ascelia-MBCA (ACE-MBCA, Orviglance), oral manganese chloride tetrahydrate. This candidate effectively visualizes and detects focal liver lesions, as demonstrated in 8 clinical studies on 201 adults (healthy or with known or suspected focal liver lesions). ACE-MBCA has a low and transient systemic exposure, which is likely the reason for its beneficial safety profile. The AEs were primarily mild and transient, and related to the gastrointestinal tract. This new, orally administered product may offer a simple imaging approach, allowing appropriate patient management in renally impaired patients when use of GBCA requires careful consideration.In this review, we highlight the clinical development of ACE-MBCA-a novel, liver-specific contrast agent. We begin with a brief overview of manganese properties, addressing the need for MBCAs and describing their optimal properties. We then review key findings on the novel agent and how this allows high-quality MRIs that are comparable to GBCA and superior to unenhanced MRI. Lastly, we provide our view of future perspectives that could advance the field of liver imaging, addressing the medical needs of patients with focal liver lesions and severe renal impairment.Our review suggests that ACE-MBCA is a promising, effective, and well-tolerated new tool in the radiologist's toolbox.

Complications of renal transplantation.

Continued improvements in graft survival have led to widespread acceptance of renal transplantation as the preferred treatment for the majority of patients with end-stage renal disease. The long-term care of these patients is often provided away from transplantation centers. This article presents 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.

CT features of renal infarction.

PURPOSE: To demonstrate the different patterns of renal infarction to avoid pitfalls. To present 'flip-flop enhancement' pattern in renal infarction. MATERIALS AND METHODS: Retrospective review of a total of 41 renal infarction in 37 patients were done. These patients underwent initial CT and the diagnosis of renal infarction was confirmed with either follow up CT or at surgery. RESULTS: Twenty-three patients had wedge-shaped focal infarcts, nine patients had global and five patients had multifocal infarcts of the kidneys. Cortical rim sign was seen predominantly with global infarcts. In five patients, a 'flip-flop enhancement' pattern was observed. In two patients, planned renal biopsies due to tumefactive renal lesions were cancelled because of 'flip-flop enhancement' pattern on follow up CTs. CONCLUSION: Although most of our cases were straightforward for the diagnosis of renal infarction, cases with tumefactive lesions and global infarctions without the well-known cortical rim sign were particularly challenging. We describe a new sign, flip-flop enhancement pattern, which we believe solidified the diagnosis of renal infarction in five of our cases. The authors recommend further investigations for association of flip-flop enhancement and renal infarction.

Liver transplantation for hepatocellular carcinoma in the model for end-stage liver disease era.

BACKGROUND: Since March 2002, the United Network for Organ Sharing liver allocation policy has given extra priority to patients with hepatocellular carcinoma (HCC) who meet specific medical criteria. This study reviews our experience with liver transplantation for HCC under this system. STUDY DESIGN: Between March 2002 and April 2009, 244 patients with HCC underwent primary liver or liver-kidney transplantation under the current allocation system at the University of Miami. Outcomes including HCC recurrence-free survival (RFS) and patient survival (PS) were assessed retrospectively. Clinical variables that predicted outcomes were analyzed. RESULTS: The median time from listing to transplantation was 48 days. The median follow-up was 27.4 months, with an observed recurrence rate of 10.7%. The RFS rates at 1, 3, and 5 years after transplantation were 96.0%, 89.0%, and 83.6%, respectively. The PS rates at 1, 3, and 5 years after transplantation were 86.3%, 71.5%, and 61.7%, respectively. Among patients diagnosed with T2 HCC, a trend toward improved RFS was observed for those who received preoperative ablative therapy; PS was similar (p > 0.05). Outcomes (RFS and PS) for patients with T3 HCC were similar to those in patients with T2 HCC (p > 0.05). Patients with an alpha-fetoprotein >100 ng/mL had an RFS that was inferior to that in patients with an alpha-fetoprotein < or =100 ng/mL (p < 0.0001). CONCLUSIONS: Under the current allocation system, transplantation for HCC results in excellent RFS; PS depends on factors other than HCC; the value of preoperative ablative therapy for patients with T2 HCC is uncertain; the current criteria could be expanded to include selected patients with T3 HCC; and an elevated AFP level is associated with an increased risk of HCC recurrence after transplantation.

Innominate artery occlusive disease: sonographic findings.

OBJECTIVE: The objective of this study was to report the sonographic abnormalities in a group of patients with angiographically proven innominate artery stenosis and occlusion. MATERIALS AND METHODS: A review of all cerebrovascular sonograms at our institutions was undertaken to identify patients with complete or partial flow reversal in the right vertebral artery and reversal or midsystolic deceleration of flow in any one of the three major segments of the right carotid system (common, internal, or external carotid artery). The distribution and appearance of these abnormalities was evaluated, and the presence or absence of tardus-parvus waveforms was noted in any segment of the right carotid artery. Additionally, a left to right common carotid peak systolic velocity ratio (LCCA/RCCA) was calculated and compared to published normal values. All patients had correlative contrast or MR angiography. Correlation was made between the severity of stenosis as determined by angiographic images and waveform aberrations as well as the more objective LCCA/RCCA ratios. RESULTS: Twelve patients were identified as having the abnormalities described above in the right vertebral and carotid arteries. Doppler waveforms from the right vertebral artery revealed that eight of the 12 patients had complete reversal of flow at rest. Bidirectional flow was found in the remaining four as manifested by the presence of marked midsystolic deceleration. In the carotid arteries, one patient had complete reversal of flow in all segments of the right carotid system. Waveforms with midsystolic deceleration were identified in at least one of the carotid arteries of the remaining 11 patients: common carotid artery (8/11 = 73%), internal carotid artery (10/11 = 91%), external carotid artery (3/11 = 27%). The average LCCA/RCCA was 3.1 with a range of 1.7 to 5.7 (normal = 0.7-1.3). All patients had severe innominate artery disease (from 70% to occlusion) by contrast angiography or MR angiography. There was no correlation between the angiographically determined degree of stenosis and the Doppler findings. CONCLUSION: A distinctive pattern of hemodynamic alterations occurs in the right vertebral and carotid arteries of patients with severe innominate artery disease. Findings include reversed or bidirectional flow in the right vertebral artery, the presence of midsystolic deceleration in any of the branches of the right carotid system, and elevated LCCA/RCCA ratio.

Uterine artery embolization: sonographic imaging findings.

OBJECTIVE: To examine the sonographic and angiographic imaging findings before and after uterine fibroid embolization for symptomatic leiomyoma. METHODS: This prospective study involved 14 premenopausal women who underwent uterine fibroid embolization for symptomatic leiomyoma. Preprocedure sonography with color Doppler imaging was performed. Bilateral uterine artery embolization was successfully performed with the use of polyvinyl alcohol. Follow-up sonographic examinations were performed between 1 and 3 months after the procedure. The correlation between the sonographic appearance before and after embolization and the degree of decrease in uterine size was evaluated by using the Jonckheere-Terpstra 2-sided P test. RESULTS: Preprocedure sonographic imaging showed a varied appearance to the fibroids. Color Doppler imaging primarily showed the fibroids to be vascular with marked peripheral blood flow. Postprocedure sonographic imaging showed decreased uterine size and echogenicity. Color Doppler imaging showed a marked decrease in the blood flow to the leiomyoma. There was no statistical significance in the relationship between echogenicity and vascularity shown before the procedure and the percent decrease in the size of the uterus. CONCLUSIONS: Although sonography is an efficient method for identifying leiomyomata and determining the reduction in size after uterine artery embolization, we were unable to identify any predictive characteristics of success for aiding the preprocedural assessment.