Vascular complications in hepatic transplantation: single-center experience in 14 years.

PURPOSE: To evaluate the spectrum of liver transplantation-related vascular complications that occurred in a single center over the past 14 years. MATERIALS AND METHODS: Vascular complications and their clinical outcomes were reviewed among 744 liver transplant recipients. All patients underwent Doppler ultrasound with findings correlated with conventional or computed tomography angiography (CTA) in 111 patients. RESULTS: Among 70 recipients with vascular complications (%0.9), 14/26 patients with hepatic artery thrombosis underwent thrombectomy and arterial reanastomosis; six were retransplanted and six died. Among hepatic artery stenoses, three of nine were treated with balloon angioplasty and six underwent reanastomosis. Among 20 portal vein thromboses, 16 underwent thrombectomy, two patients retransplantation and two died. Seven patients with portal vein stenosis were followed. Two of six hepatic vein stenosis were restored with balloon angioplasty and three patients with metallic stent placement; the one other died. One patient with hepatic vein thrombosis died while the other patient was retransplanted. CONCLUSION: Transplantation related hepatic vascular complications diagnosed and managed in timely fashion showed a low mortality rate in our series.

Cryopreserved aortic quilt plasty for one-step reconstruction of multiple hepatic venous drainage in right lobe living donor liver transplantation.

Hepatic venous outflow should be maintained for the success of living right lobe liver transplantation. In cases when the right hepatic vein is not the dominant venous drainage, the anterior branch of the middle hepatic vein and the accessory hepatic veins should be adequately drained to preserve graft function. One-step reconstruction of the hepatic veins became a preferred technique to create separate outflow for each of the graft's veins. In this report, we have described a quilt plasty technique for 1-step reconstruction of living donor hepatic veins using cadaveric cryopreserved aorta and iliac vein grafts.

Focal pancreatitis mimicking pancreatic mass: magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) findings including diffusion-weighted MRI.

BACKGROUND: Focal pancreatitis (FP) is a confined inflammation that mimics a pancreatic mass. Its imaging diagnosis is important to avoid unnecessary procedures. PURPOSE: To describe the spectrum of magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted MRI (DWI) findings of focal pancreatitis mimicking pancreatic masses. MATERIAL AND METHODS: Findings of MRI/MRCP including DWI with a b value of 0 and 600 s/mm(2) in 14 patients with pancreatic masses on MRI were retrospectively reviewed and compared to normal pancreas in 14 patients as a control group. RESULTS: FP revealed hypointense signal intensity (SI) (3/14), hypo- to isointense SI (7/14), or isointense SI (4/14) on T1-weighted images, and hypointense SI (1/14), isointense SI (5/14), iso- to hyperintense SI (7/14), or hyperintense SI (1/14) on T2-weighted images compared to remaining pancreas (RP). MRCP images revealed dilatation of the common bile duct (CBD) and main pancreatic duct (MPD) (5/14), dilatation of the MPD only (3/14), dilatation of the CBD only (3/14), and normal MPD and CBD (3/14). Both FP and RP revealed three types of time-signal intensity curves: 1) rapid rise to a peak, with a rapid decline (FP=2, RP=4), 2) slow rise to a peak, followed by a slow decline (FP=5, RP=4), and 3) slower rise to a peak, with a slow decline or plateau (FP=7, RP=6). Mean apparent diffusion coefficient (ADC) values for FP and RP were 2.09+/-0.18 and 2.03+/-0.2 x 10(-3) mm(2)/s, respectively. ADC values of FP and RP revealed no significant difference. CONCLUSION: The spectrum of imaging findings of focal pancreatitis on MRI/MRCP including DWI was described. Findings of FP were not distinctive as compared to the remaining pancreas.

Magnetic resonance imaging measurement of left ventricular blood flow and coronary flow reserve in patients with chronic heart failure due to coronary artery disease.

BACKGROUND: Coronary sinus flow reflects global cardiac perfusion and has been used for the assessment of myocardial flow reserve, which is reduced in chronic heart failure(CHF). Coronary flow reserve (CFR) can be measured by using phase-contrast (PC)velocity-encoded cine (VEC) magnetic resonance imaging (MRI). PURPOSE: To quantify and compare global left ventricular (LV) perfusion and CFR inpatients with CHF and in a healthy control group by measuring coronary sinus flow with PC VEC MRI, and to correlate this with global LV perfusion, segmental first-pass perfusion, and viability in the same patients. MATERIAL AND METHODS: Cardiac MRI was performed in 20 patients with CHF of ischemic origin and in a control group of healthy subjects (n=11) at rest and after pharmacological stress induced by i.v. dipyridamole. The MRI protocol included cine MRI, VEC MRI, first-pass perfusion, and delayed contrast-enhanced MRI for viability.Global LV perfusion was quantified by measuring coronary sinus flow on VEC MRI at rest in all subjects. CFR was determined as the ratio of global LV perfusion before and after pharmacologic stress. RESULTS: At rest, global LV perfusion was not significantly different in patients with CHF and the control group. After administration of dipyridamole, global LV perfusion and CFR were significantly lower in patients with CHF compared to the control group(P<0.001). An inverse correlation was observed between CFR and the number of infarcted and/or ischemic segments (P=0.083, P=0.037). CONCLUSION: A combined cardiac MRI protocol including function and perfusion techniques together with VEC MRI can be used to evaluate global LV perfusion and CFR in patients with CHF. Global LV perfusion and CFR measurements may have potential in the monitoring of CHF. Impaired CFR may contribute to progressive decline in LV function in patients with CHF.

Anomalous pancreaticobiliary junction (APBJ) with the drainage of the uncinate process into the minor papilla: demonstration by MRI.

We report a case of a 30-year-old patient with anomalous pancreaticobiliary junction (APBJ) that has not been described before. The patient had a clinical history of recurrent attacks of pancreatitis, cholangitis and cholecystitis that were confirmed by abnormal laboratory values. Endoscopic retrograde cholangiopancreatography revealed a 20 mm long junction of choledoc and pancreatic duct, and uncinate process draining into the minor papilla. On MR cholangiopancreatography, strictures at the junction of hepatic duct, increased gallbladder wall thickness and intraductal stone in the pancreatic duct were demonstrated as complementary findings. Other MRI findings included decreased signal intensity of the pancreas consistent with fibrosis from past pancreatitis attacks and atrophy of the left liver lobe.

Granulomatous hepatitis: MRI findings.

The purpose of this study was to describe the magnetic resonance imaging findings of granulomatous hepatitis on T1-weighted, T2-weighted and postgadolinium images. Eight patients with histopathological diagnosis of granulomatous hepatitis were evaluated in this study. MRI examinations included precontrast T1-weighted breath-hold spoiled gradient echo, breathing independent STIR sequences, and T1-weighted breath-hold spoiled gradient-echo sequence following after i.v. gadolinium administration in arterial, intermediate and late phases. Diffuse nodular liver involvement was visualized in all patients. Nodules were consistent with granulomas and were 0.5-4.5 cm in diameter. Caseating granulomas were intermediate and high signal on T2-weighted, low signal on T1-weighted images. They revealed no enhancement in two patients, and enhanced in one patient. Noncaseating granulomas revealed intermediate signal on T1, and T2-weighted images and increased enhancement on arterial phase images with persisting enhancement in late phase images. Portal lymph nodes were visible in five patients. Splenomegaly was present in five patients. Granulomatous hepatitis has spectrum of MRI features, to be considered in differential diagnosis with other diffuse nodular liver pathologies.

Spontaneous retroperitoneal hemorrhage secondary to subcapsular renal hematoma: MRI findings.

Spontaneous retroperitoneal hemorrhage is a rare intraabdominal bleeding. In this report we present a case of a nontraumatic retroperitoneal hemorrhage secondary to spontaneous subcapsular renal hematoma. A 54-year-old patient who was under warfarin therapy, developed subcapsular right renal hematoma. Subcapsular and retroperitoneal hemorrhage were low signal on T1- and T2-weighted images consistent with acute stage of blood. The source of subcapsular hematoma was shown to be the rupture of hemorrhagic renal cyst on MRI. Extension of hemorrhage into the retroperitoneal space anterior to right psoas muscle was also successfully shown on MRI. Patient underwent nephrectomy and retroperitoneal blood was evacuated.

Radiologic diagnosis and staging of pancreatic ductal adenocarcinoma.

This article presents imaging modalities in the diagnosis and staging of pancreatic ductal adenocarcinoma. Magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS) have the highest accuracy in detection of pancreatic cancer. MRI and EUS have similar accuracy in determining the local extent of pancreatic cancer. Angiography, computed tomography (CT) angiography and EUS are similarly accurate in evaluating peripancreatic vascular involvement. MRI is the superior method for detecting liver metastases and peritoneal implants of pancreatic ductal adenocarcinoma. Endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance cholangiopancreatography (MRCP) are used to assess the biliary tract of patients with pancreatic cancer. Positron emission tomography (PET) is useful in distinguishing pancreatic cancer from focal pancreatic inflammation.

Radiologic features of cystic, endocrine and other pancreatic neoplasms.

This article presents imaging features of cystic, endocrine and other pancreatic neoplasms. Microcystic adenoma which is composed of small cysts (<2 cm), its macrocystic subgroup contains solitary cyst. Multiple cysts larger than 2 cm are associated with mucinous cystic neoplasm. Swiss cheese appearence with central calcification is characteristic for microcystic adenomas. Septal and mural enhancement as well as larger size (>2 cm) are accounted for mucinous cystic neoplasms, its variant along pancreatic duct is ductectatic mucinous cystic neolasm. Endocrine tumors of pancreas are hypervascular and can be depicted on early dynamic enhanced crosssectional imaging modalities or on angiography when they are <1 cm. Pancreatic metastases and lymphomas are rare neoplasms which should also be included in differential diagnosis for pancreatic masses.

Uterine artery embolization in a 10-week cervical pregnancy with coexisting fibroids.

A 36-year-old woman, gravid 3, para 1, abortus 1, was admitted to our department at 10 weeks and 4 days of gestation with the diagnosis of cervical pregnancy and multiple uterine fibroids. After admission she underwent angiographic embolization of bilateral uterine arteries followed by intraamniotic 70-mg methotrexate injection. Despite being given a second dose of methotrexate injection 1 week later, the gestational sac did not resolve spontaneously, thus vacuum evacuation and curettage of the cervical canal was required on the 15th day of embolization. The patient was discharged in good condition. She had no complaints by post-operative at month 11, except amenorrhea. Her uterine fibroids markedly decreased in size after the procedure. As a result, embolization of uterine arteries provided surgical evacuation of cervical pregnancy with minimal hemorrhage, and the patient's potential fertility was preserved, but a long-term amenorrhea was observed.

Sequential use of gadolinium chelate and mangafodipir trisodium for the assessment of focal liver lesions: initial observations.

The purpose of this study was to assess the feasibility of sequential administration of 2 different MR imaging contrast agents using a single visit protocol to image focal liver abnormalities. Twenty-one patients with known or suspected liver lesions were included in the study. All patients received a bolus intravenous injection of gadolinium chelate (Gd) and dynamically enhanced imaging performed. The patients then received an injection of mangafodipir trisodium (Mn) contrast and a second scan performed with an average delay of 62 min after the Gd bolus injection. The images were evaluated to determine the appearance of liver lesions after administration of each contrast agent, and for evidence of prior Gd administration adversely affecting evaluation of images acquired after Mn administration. Focal liver lesions were present in 19 patients, including 8 with liver metastases, 1 with liver lymphoma, 6 with hemangiomas, 3 with focal nodular hyperplasia (FNH), and 1 with hepatic abscess. In 2 other patients no liver lesions were identified in either the post-Gd or post-Gd-post-Mn scans. All malignant lesions identified on the post-Gd scan were also identified on post-Gd-post-Mn scans. Although the potential benefit for increasing detection sensitivity for hepatic metastases was not demonstrated, this is a preliminary series. This study does demonstrate the practicality for use a single visit sequential Gd-Mn protocol described here, with possible application of this technique for further assessment of the utility of combining Gd and Mn for detection of liver metastases.

Adult intussusception secondary to inflammatory fibroid polyp: demonstration by MRI.

Adult intussusception secondary to inflammatory polyp occurs rarely. Imaging of intussusception on ultrasound, CT and MRI has been previously described. In this report we describe a case of an adult intussusception secondary to inflammatory fibroid polyp. Both the lead point (inflammatory fibroid polyp) and intussusception were depicted on multiplanar MR images. Findings on MRI were confirmed at surgery and histopathological examination.

Hepatic alveolar echinococcosis: MRI findings.

The purpose of this study was to describe the magnetic resonance imaging (MRI) appearance of hepatic alveolar echinococcosis (HAE) on T(1)-weighted, T(2)-weighted and postgadolinium images. A total of 13 lesions were demonstrated in 13 patients. All patients underwent MR examination at 1 T imager. MR examinations included precontrast T(1)-weighted breathing averaged spin echo (SE), breath-hold spoiled gradient echo, T(2)-weighted TSE sequences with and without fat suppression, and T(1)-weighted breath-hold spoiled gradient echo (SGE) sequence following i.v. after gadolinium administration. All lesions were confirmed with histopathology. HAE hepatic lesions revealed geographic patterns of variable signal intensities on noncontrast T(1)- and T(2)-weighted images. Slightly hyperintense, iso- and hypointense signal on T(1)-weighted images corresponded to calcified regions, which appeared hypo-isointense signal on T(2)-weighted images. Necrotic areas were hypointense signal on T(1)-weighted and hyperintense signal on T(2)-weighted images. On postgadolinium images, lesions did not reveal enhancement. Dilatation of intrahepatic bile ducts distal to HAE abscesses were observed in five patients and portal vein invasion or compression was observed in four patients, lobar atrophy of the liver was coexistent finding in cases with portal vein compression. The MRI appearance of HAE abscesses included large irregularly marginated masses with heterogenous signal on T(1)- and T(2)-weighted images and lack of enhancement with gadolinium.

Budd-Chiari syndrome: spectrum of appearances of acute, subacute, and chronic disease with magnetic resonance imaging.

The purpose of this study was to describe our collective experience in the magnetic resonance (MR) investigation of patients with proven acute, subacute, and chronic Budd-Chiari syndrome and to demonstrate the spectrum of appearances on T1- and T2-weighted as well as dynamic post-gadolinium spoiled gradient-echo imaging. All patients with proven Budd-Chiari syndrome who underwent MR examinations between June, 1992 and October, 1998 were included in the study. Fourteen patients were included in the study: four with acute, three with subacute, three with chronic, and four with acute superimposed on either subacute (two) or chronic (two) Budd-Chiari syndrome. MR imaging features were retrospectively evaluated to determine: a) liver morphology, b) pattern of signal intensity (SI) on T1-weighted images, c) pattern of SI on T2 weighted images, d) dynamic enhancement characteristics, e) presence or absence of visible venous thrombosis, and f) presence or absence of venous macroscopic collaterals. The MR findings were correlated with surgical, histopathological, and laboratory data to determine imaging characteristics related to the chronicity of the disease process. Hepatic venous thrombosis or absence of hepatic venous flow was demonstrated in all patients in the study. In the four patients with acute Budd-Chiari syndrome, the liver periphery was moderately low signal on T1 and moderately high signal on T2-weighted images relative to the central liver; both early and late gadolinium-enhanced images revealed diminished peripheral enhancement. In the three patients with subacute Budd-Chiari syndrome, the liver periphery was moderately low signal on T1, and moderately high signal on T2-weighted images, while early and late gadolinium-enhanced images revealed heterogenously increased enhancement within the liver periphery. In the three patients with chronic Budd-Chiari syndrome, the SI differences between peripheral and central liver were minimal on T1- and T2-weighted images, and enhancement differences were also minimal. Extensive bridging intrahepatic and capsular venous collaterals were visualized in chronic cases. In the four patients with acute Budd-Chiari syndrome superimposed on more chronic disease, a combination of gadolinium enhancement patterns was observed on MR images. Enhancement patterns between central and peripheral liver were different for acute, subacute, and chronic Budd-Chiari syndromes, suggesting differentiation between these phases of the disease process. Application of this pattern approach permitted recognition of acute changes superimposed on more chronic disease.

Islet cell tumor of the pancreas associated with tumor thrombus in the portal vein.

We report the MR findings of a 70-year-old man with an islet cell tumor that diffusely involved the body of the pancreas associated with enhancing portal vein tumor thrombus and cavernous transformation. The diffusely infiltrative tumor mass was best shown on early post gadolinium spoiled gradient echo. The tumor thrombus enhanced intensely on early post gadolinium images and was also well shown on true FISP (Fast Imaging with Steady State Precession) images. The extent of liver metastases was best shown on fat suppressed T2-weighted images. The most unusual finding was tumor thrombus involving the SMV and portal vein.

Common occurrence of benign liver lesions in patients with newly diagnosed breast cancer investigated by MRI for suspected liver metastases.

The purpose of this study was to determine the prevalence of benign liver lesions in patients with breast cancer who are referred to magnetic resonance (MR) imaging for suspected breast cancer metastases at initial presentation. The original MR imaging reports of consecutive patients with breast cancer were reviewed; these patients had undergone MR imaging at our institution to investigate for suspected breast cancer liver metastases, at initial presentation between April 1993 and May 1998. Determination of the presence of benign and malignant liver lesions in each patient was made, as well as their relative frequencies. Diagnostic accuracy of MR imaging was evaluated by correlation with histologic specimens (5 patients) and imaging follow-up (27 patients). Thirty-four patients with newly diagnosed breast carcinoma were evaluated with MR imaging. A total of 11 (32%) of these patients had benign lesions only. Of 21 (62%) total patients who had malignant liver lesions, 19 had breast cancer metastases (2 had coexistent benign lesions), 1 had metastatic carcinoid, and 1 had hepatocellular carcinoma. No liver lesions were detected in two patients (6%). In one patient with biopsy-proven subcentimeter breast metastases, no focal lesions were shown on MR imaging. No other diagnostic errors in classification of liver lesions by MR imaging occurred, as shown by clinical correlation and imaging follow-up in all patients. True positive detection of malignant liver lesion was 20/21, true negative was 13/13, false positive was 0/13, and false negative was 1/21, for a sensitivity of 95% and a specificity of 100% for the detection of malignant liver lesions. Benign liver lesions are common in breast cancer patients suspected clinically of having liver metastases. Benign lesions alone were observed in one-third of our patients. The high diagnostic accuracy of MR imaging in the evaluation of hepatic lesions underscores the value of this technique for baseline investigation of breast cancer patients with clinically suspected liver metastases, particularly patients in whom treatment approaches are dramatically affected by the presence of liver metastases. J. Magn. Reson. Imaging 1999;10:165-169.

Complex renal cysts: findings on MR imaging.

OBJECTIVE: We retrospectively evaluated our experience with complex cystic renal masses on MR imaging, using T1-weighted, T2-weighted, and gadolinium-enhanced images, to determine whether imaging features could permit distinction between benign and malignant lesions. MATERIALS AND METHODS: Thirty-seven patients with complex cystic renal lesions were included in this retrospective study. The patients selected had undergone T1-weighted, T2-weighted, and gadolinium-enhanced MR imaging examinations using 1.5-T scanners, with at least one of the following findings: cyst fluid of heterogeneous signal intensity, mural irregularity, septa, mural masses or nodules, increased mural thickness, or intense mural enhancement. The diagnosis was established by histology in 19 patients and by follow-up studies in the remaining 18 patients. RESULTS: Fifty-five complex renal cystic lesions were present in the 37 patients. Among the 55 lesions, of 37 that contained fluid of a heterogeneous signal intensity, eight were malignant (22%); of 16 with irregular walls, 10 were malignant (63%); of four with septa, two were malignant (50%); of four with mural masses or nodules, three were malignant (75%); of 14 with a thick wall (>2 mm), 10 were malignant (71%); and of 32 with intense mural enhancement, 14 were malignant (44%). As independent variables, mural irregularity, mural masses or nodules, increased mural thickness, and intense mural enhancement each were highly associated with malignancy (p = .0003-.0022). The combination of mural irregularity and intense mural enhancement had the highest correlation with malignancy (p = .0002). CONCLUSION: The combination of mural irregularity and intense mural enhancement is a strong predictor of malignancy in renal cystic lesions. However, the appearance of benign and malignant lesions may overlap, suggesting that distinct separation of these entities is not currently possible in all cases with MR imaging.

Adrenal neuroblastoma in an adult with tumor thrombus in the inferior vena cava.

We describe the appearance of an adrenal neuroblastoma associated with tumor thrombus occurring in an adult patient. The tumor measured 14 x 12 x 12 cm, showed heterogeneous signal intensity on both T1-weighted and T2-weighted images, and displayed peripheral nodular enhancement on early post-gadolinium images. Tumor thrombus was identified within the inferior vena cava, which extended into the right atrium.

Acute and subacute liver-related hemorrhage: MRI findings.

We retrospectively reviewed the MR studies on all patients with liver-related fluid collections compatible with acute or early subacute hemorrhage, who underwent MR imaging at our center between June 1994 and January 1998. All patients had a clinical history of an underlying liver lesion or injury with a duration of symptomatology of less than 5 days. In three patients with only 2-3 days of symptoms, the liver-related hemorrhagic fluid was hypointense on T1-weighted images and markedly hypointense on T2-weighted images relative to liver, consistent with intracellular deoxyhemoglobin. The fluid was relatively homogeneous in signal intensity. In three patients with 3-5 days of symptoms, the majority of liver-related fluid was hyperintense on T1-weighted images and hypointense on T2-weighted images relative to liver, consistent with intracellular methemoglobin. Three of these latter four patients also had fluid collections of varying T1-and T2-weighted signal intensity consistent with blood breakdown products of varying ages. Clinical findings matched the MR findings of acute/early subacute blood in all cases. Our results describe the findings of acute and early subacute liver hemorrhage. The most helpful MR feature of bleeding of recent origin is very low signal intensity of the fluid on T2-weighted imaging.

Intrahepatic arterioportal fistula: gadolinium-enhanced 3D magnetic resonance angiography findings and angiographic embolization with steel coils.

We describe a case of a 59-year-old patient with intrahepatic arterioportal fistula secondary to blunt trauma sustained by a motor vehicle accident 36 years earlier. The fistula was demonstrated 36 years after the accident in a clinical work-up for diarrhea of 1 month's duration, using contrast enhanced three-dimensional breath-hold MRA. A communication between the dilated portal vein and dilated hepatic artery was shown at the level of distal branches. After subsequent demonstration by conventional angiography, the fistula was embolized using steel coils. Following the therapeutic intervention, the patient's diarrhea ceased.