Percutaneous management of ureteral stenosis of transplanted kidney: technical and clinical aspects.

In the field of renal transplantation, advances in the management of graft rejection have led to improved graft and patient survival rates, however other types of complications have now become more apparent, e.g. vascular or urological. The most common urological complications following renal transplantation are ureteral stenosis or obstruction, constituting a significant problem of the renal graft's survival. The most important aspects concerning these complications are early diagnosis and prompt treatment since any delay in their management may lead to renal graft dysfunction or even graft loss. Developments in interventional radiology have provided minimally invasive means to treat urological complications with low complication rates. Herein we review the literature in order to evaluate the efficacy of percutaneous management of ureteral stenosis regarding its safety, immediate and long-term results, complications as well as rate of recurrence.

Overlap syndrome of autoimmune chronic liver diseases: MRI findings.

PURPOSE: To describe the MR findings of overlap syndromes of autoimmune chronic liver diseases. METHODS: Review of clinical and radiological databases between March 2001 and July 2008 for patients with a clinical diagnosis and liver biopsy features compatible with overlap syndrome who had also undergone an abdominal MRI yielded 15 adult patients. MR features of overlap syndrome were reviewed by two radiologists by consensus. Two radiologists independently reviewed the studies in a blinded fashion for primary sclerosing cholangitis (PSC)-type or non-PSC-type features to assess interobserver agreement. RESULTS: PSC-type and non-PSC-type overlap syndrome had distinctive MR features. In the consensus review, all 12 patients with PSC-type overlap syndrome were correctly identified. Imaging findings included central macroregeneration (N = 9), peripheral atrophy (N = 7), biliary duct beading (N = 12), biliary dilation (N = 10), or a combination of all four findings (N = 7). The presence of any of the first three features had 100% specificity for a PSC-type overlap syndrome. Patients with non-PSC-type overlap (N = 3) showed relatively normal liver morphology (N = 3) and minimal biliary ductal dilatation in one patient. There was good interobserver agreement (kappa = 0.76). CONCLUSION: Patients with serologic or pathologic evidence of AIH or PBC with imaging features of PSC may have PSC-type overlap syndrome.

Thermoablative treatments for malignant liver lesions: 10-year experience of MRI appearances of treatment response.

OBJECTIVE: The objective of our study was to describe our 10-year experience using MRI to evaluate response to local thermoablative interventions in the treatment of malignant liver lesions. MATERIALS AND METHODS: This retrospective study was conducted from 1998 to 2008. MRI studies were performed at 1.5 and 3 T and were acquired < 4, 4-9, and > 9 months after radiofrequency ablation (RFA), cryoablation, and microwave ablation. MR features were evaluated on the basis of signal intensity on unenhanced T1-weighted images and the presence of ill-defined perilesional enhancement, well-defined lesional enhancement, or washout on contrast-enhanced images. Imaging features were evaluated with all interventional modalities together and separately. RESULTS: The study population was composed of 135 men and 36 women (203 ablated lesions) with a mean age of 65 years (range, 39-78 years). When the data for all treatment methods were combined, well-defined lesional enhancement and washout were significant findings among the resolved and unresolved outcome groups regardless of follow-up time category. After RFA, ablated areas had a tendency to show high signal intensity on T1 images, whereas low signal was seen after cryoablation and a hyperintense rim was seen after microwave ablation. Washout was only depicted 9 months after cryoablation but was seen in 12% of lesions < 4 months after RFA. No difference was appreciated on ill-defined perilesional enhancement with all methods combined or separately. CONCLUSION: MRI findings after ablation are dependent on the treatment modality and the length of time between the procedure and follow-up examination.

Emergency helical CT scan in acute abdomen: a case of intestinal intussusception.

Surgeons are familiar to the nosological entity "partial intestinal obstruction". Intussusception constitutes a rare etiologic factor for this entity but usually remains undiagnosed preoperatively. Several imaging techniques have been proposed as useful in the diagnosis of intussusception but none of these has a remarkable sensitivity and specificity. In the following case of partial intestinal obstruction, we performed an helical CT scan of the abdomen. The method revealed with an excellent accuracy the nature (intussusception) and the location (ascending colon) of the partial intestinal obstruction. Having the extra advantage of the shorter examination time than the classical CT scan, we propose the helical CT as an alternative diagnostic modality for preoperative evaluation of patients with partial intestinal obstruction.

Hepatic nodules in liver transplantation candidates: MR imaging and underlying hepatic disease.

OBJECTIVE: To assess by MR imaging the frequency of hepatic nodules in patients waiting on the liver transplant list and to determine whether certain underlying hepatic diseases were more often associated with the development of such hepatic nodules. MATERIAL AND METHODS: We reviewed the MR and clinical records in all patients seen by the liver transplant service at our center since its inception in January 1998 until September 2002. A total of 371 patients (207 men and 164 women, age range 18-68 years, mean 45 years) were included in the study. The presence of hepatic nodules, size, number and underlying hepatic diseases were determined in all patients. Magnetic resonance imaging was performed on a 1.5-T MR imager using T1-weighted, T2-weighted and multi-phase gadolinium-enhanced sequences. Odds ratio (OR) and 95% confidence intervals (CIs) were computed to evaluate the association between the underlying hepatic disease and the development of hepatic nodule. RESULTS: Among 371 liver transplantation candidates, the most common underlying hepatic disease was hepatitis C virus (HCV) infection, either alone (n=93; 25%) or associated with other hepatic diseases (n=40; 10.8%). Of all patients, 33 (8.9%) had regenerative nodules (RNs), 40 (10.7%) dysplastic nodules (DNs) and 57 (15.3%) hepatocellular carcinomas (HCCs). Hepatocellular carcinoma was observed in 35.3% of patients with HCV infection and alcohol abuse combined, 24.5% with cryptogenic cirrhosis, 25% with hemochromatosis and 19% with alcohol abuse. Patients who had either DNs or HCC were 2.5 times more likely to have either alcohol abuse or HCV, alone or combined, as the substrate of their liver disease (OR 2.54, 95% CI 1.56-4.13). Our data suggest a supra-additive interaction between HCV infection and ethanol in their association with MR imaging detected lesions. CONCLUSION: Patients with cryptogenic cirrhosis, alcohol abuse, HCV infection (alone or combined) and hemochromatosis had the greatest likelihood of having HCC, with the combination of HCV infection and alcohol abuse having the highest of all.

Primary malignant mesothelioma of the liver: MR imaging findings.

We report the MR imaging findings of a primary malignant mesothelioma of the liver arising from Glisson's capsule. A 54-year-old woman, presenting with acute abdominal pain and a large liver mass previously shown on CT, underwent MR imaging to characterize the lesion. The tumor was a greater than 12 cm tumor located in the right lobe of the liver, which was sharply marginated, with heterogeneous internal signal, septations and central necrosis. The tumor was considered a hepatocellular carcinoma. The diagnosis of malignant mesothelioma was established by immunohistochemical staining and electron microscopy of the resected tumor.

Epithelioid hemangioendothelioma of the liver. MR imaging findings.

We report the MR appearance of epithelioid hemangioendothelioma (EHE) in a 51 year old man, who presented with a 14-month history of fatigue and anemia to his physician. The tumor showed massive replacement of the liver and had an unusual appearance of multiple high fluid content focal lesions with diminished vascularity.

Cavernous hemangiomas in patients with chronic liver disease: MR imaging findings.

The purpose of our study was to assess the difference in magnetic resonance imaging (MRI) features of cavernous hemangiomas in patients with chronic liver disease compared them with hemangiomas in normal livers. We retrospectively searched our records of MRI of the liver between October 1998 and June 2002, and identified 76 hemangiomas in 49 patients (18 men and 31 women; age range 29-81 years [mean, 57 years]). Hemangiomas were classified into 3 groups: patients with cirrhosis [group 1, 8 lesions in 8 patients], patients with chronic hepatitis [group 2, 6 lesions in 5 patients], and patients without underlying liver disease [group 3, 62 lesions in 36 patients]. Four radiologists, blinded to clinical information, retrospectively reviewed in consensus the MRI findings of hemangiomas for number, size, signal intensities on T1- and T2-weighted images, and enhancement patterns on early- and late-phase postcontrast images. The mean lesion numbers and sizes were 1.0 and 16.2 +/- 9.6 mm, 1.2 and 15.3 +/- 7.1 mm, and 1.7 and 26.1 +/- 24.7 mm in groups 1-3, respectively. There was a correlation (p < 0.05, coefficient: 0.35) between lesion number and severity of liver disease. Although there was no significant difference in lesion size among the 3 groups, all of 11 lesions larger than 4 cm in diameter belonged to group 3. Almost all lesions appeared moderately hypointense on T1-weighted images and moderately hyperintense on T2-weighted images. Twenty-seven lesions showed immediate homogeneous enhancement (pattern 1), and 49 showed peripheral nodular enhancement with centripetal enhancement progression (pattern 2). There was no difference in frequency of enhancement patterns among the 3 groups. Hemangiomas were more often solitary in livers with chronic liver disease, large lesions were exclusively seen in livers without chronic liver disease, and there was a trend for small lesions in patients with chronic liver disease.

Renal cell carcinoma in a transplanted kidney: MR imaging findings.

We report the MR findings of a 42-year-old man who developed renal cell carcinoma in an allograft kidney, 10 years after transplantation. The lower pole of the transplant kidney showed a solid lesion which was well shown on the post gadolinium fat suppressed images as a heterogeneously enhancing 2 cm mass lesion.

Gastrointestinal and extragastrointestinal stromal tumors: report of two cases and review of the literature.

We present two cases, one of a gastrointestinal stromal tumor (GIST) in the stomach and one of an extragastrointestinal stromal tumor (EGIST) in the hepatogastric ligament, which were discovered as incidental findings during computed tomography (CT) scans performed for other reasons. In both cases the diagnosis of the tumor was confirmed histologically and immunohistochemically. During the follow-up CT examinations these tumors proved to have a completely different natural course. The first case refers to an 82-year-old male patient with GIST of the stomach who refused to be operated and was followed by CT scans for a 4-year period. This patient did not show any significant changes in the morphology, size and density of the lesion. The second case refers to a 58-year-old female patient with EGIST of the hepatogastric ligament who presented with simultaneous liver metastases and remained healthy for 2 years after surgical resection, but developed local recurrence later. As a conclusion, both GISTs/EGISTs can be revealed as incidental findings in a CT scan performed for other purposes. Moreover, an untreated GIST located in the stomach can remain unchanged and without metastatic lesions for a long period of time, as in our case for a 4-year period. To our knowledge, this is the first report in the literature in whom a GIST was proved to remain almost unchanged for many years without any treatment, and we therefore attempt a further review of the current literature on stromal tumors.

Urgent endovascular treatment of iatrogenic subclavian artery rupture: report of three cases.

The increased use of central venous catheters in modern medical practice has brought a proportional increase in the number of cases of iatrogenic vascular injuries. Concerning the subclavian artery, the site of the lesion and the vessel size demand urgent and effective treatment in order to obtain a favorable prognosis. It has been common practice for a long time to consider this type of lesion as a surgical emergency. Nevertheless, emerging endovascular interventional procedures appear to offer an alternative that is effective and safe as well. We hereby report three cases of subclavian artery injury, in which repair was achieved by endovascular approach with the placement of a cover stent. Hypovolemic shock (demonstrated in two patients) as well as brachial plexus palsy due to pseudoaneurysm of the subclavian artery (presented in another patient) were successfully managed by percutaneous brachial (in two patients) or right femoral (in the patient with the pseudoaneurysm) approach and placement of balloon expandable covered stents (4-9 mm x 38 mm). No procedure-related complications were observed. Short-term follow-up results in two of the three patients were quite satisfactory concerning patency.

Mycotic pseudoaneurysms complicating renal transplantation: a case series and review of literature.

INTRODUCTION: Kidney transplantation can be complicated by infection and subsequent development of mycotic aneurysm, endangering the survival of the graft and the patient. Management of this condition in five cases is discussed, accompanied by a review of the relevant literature. CASE PRESENTATIONS: Five patients, three men 42-, 67- and 57-years-old and two women 55- and 21-years-old (mean age of 48 years), all Caucasians, developed a mycotic aneurysm in the region of the anastomosis between renal graft artery and iliac axes. Four patients presented with systemic fever and iliac fossa pain and one presented with hemorrhagic shock. Morphologic investigation by color doppler ultrasonography revealed a pseudoaneurysm at the anastomotic site. A combination of antibiotic therapy, surgery and interventional procedures was required as all kidney transplants had to be removed. No recurrence was recorded during the follow-up period. CONCLUSIONS: A high index of suspicion is required for the timely diagnosis of a mycotic aneurysm; aggressive treatment with cover stents and/or surgical excision is necessary in order to prevent potentially fatal complications.

Stents in renal artery bifurcation stenosis: a case report.

A 39-year-old patient presented with poorly controlled hypertension, and she was referred to renal angiogram and potential renal angioplasty. Renal angiogram showed a bifurcation lesion of the right renal artery. A guide wire was used to cross the upper branch, while the lower branch was protected by another same-type guide wire through the same introducer. Two thin monorail balloons were used to dilate the two branches; however, despite balloon dilatation, the stenosis of the vessels persisted. The "kissing balloon" technique was then attempted by simultaneously inflating both branches using the same balloons, but more than a 70% residual stenosis persisted in each branch. Two stents were finally placed in a "kissing" way through the main renal artery. The imaging and clinical results were good, without any procedure-related complications. Three years clinical followup was also good, without any reason for further interventional approach.

Transluminal angioplasty of transplanted renal artery stenosis: a review of the literature for its safety and efficacy.

Transplant renal artery stenosis (TRAS) is a well-known cause of posttransplant hypertension accompanied by possible graft dysfunction and is potentially curable when is diagnosed early. Colour Doppler Ultrasonography (CDU) is the screening procedure of choice in most studies whereas some centers employ Magnetic Resonance Angiography (MRA), if available. Although both CDU and MRA can arouse suspicion of disease in less symptomatic cases, angiographic techniques are essential for confirmation of TRAS. Percutaneous Transluminal Angioplasty (PTA) is a good and widespread therapeutic approach for the treatment of TRAS due to its acceptable complication rate and high technical success rate. The purpose of this paper is to assess the safety and efficacy of PTA in the treatment of TRAS, to compare the long-term outcomes between different reports, and to examine the role of PTA with stenting in inhibiting recurrence of the disease.

MRI findings of rapidly progressive hepatocellular carcinoma.

PURPOSE: The purpose of this study is to determine the magnetic resonance imaging (MRI) and patient characteristics in subjects with hepatocellular carcinoma (HCC) that exhibit rapid progression. MATERIALS AND METHODS: In this unblinded retrospective study, initial and follow up MR images were reviewed, before and after rapid progression of HCC, respectively. Rapid progression was defined as a lesion <3 cm which exhibited >3 cm increase in one year or 2 cm increase in 6 months. Patient characteristics and MRI findings were determined using clinical information from the institution clinical information system and records from the Radiology and Pathology Departments, Hepatology Division and Liver Transplant Service of the Department of Medicine. RESULTS: Seven individuals were identified with HCC that showed rapid progression. Five of the patients had underlying hepatitis C, one had alcoholic hepatitis, and one had immunosuppression due to liver transplantation. On initial MRI, six patients had early intense ring enhancing lesions, which rapidly progressed in size. Five patients died within 6 months, one within 1 year after progression despite treatment. Six of the seven patients also had multiple other liver nodules on initial MRI; those that showed ring enhancement rapidly progressed but those without, did not show rapid progression. CONCLUSION: Patients with rapidly progressive HCC had underlying hepatitis C and intense ring enhancement on initial MRI. This group of patients should be evaluated further to determine if they might benefit from early intervention.

MR imaging findings of small bowel hemorrhage: two cases of mural involvement and one of perimural.

PURPOSE: To demonstrate the MR appearance of small bowel wall hemorrhage. MATERIALS AND METHODS: A search was performed of the clinical information system (CIS) and the abdominal MRI databases of our institution for patients diagnosed with bowel hemorrhage on MRI between January 1, 2000, and July 31, 2008. All patients were imaged using a protocol that included noncontrast T1- and T2-weighted images and postgadolinium gradient echo images. RESULTS: Two male patients, 44 and 55 years of age, were identified with small bowel mural hemorrhage, one in the duodenum and one in the jejunum. A third patient, a 66-year-old man, was identified with perimural hematoma. The following imaging features were observed: for mural hemorrhage, mural-based increased signal intensity (SI) in the bowel wall on fat suppressed T1-weighted images, variable increased SI on T2-weighted images and no appreciable enhancement on the postcontrast T1-weighted image; perimural hemorrhage exhibited normal thickness low SI wall on T2-weighted single shot images, with ill-defined material surrounding the bowel. SI features of this material, was similar to mural-based abnormality. CONCLUSION: In two patients with small bowel wall hemorrhage, the wall showed increased thickness with increased SI on noncontrast T1-weighted images and lack of enhancement on postgadolinium images. Perimural hematoma showed an intact normal thickness wall that was low SI on T2 with surrounding material that was high SI on noncontrast T1-weighted images and did not enhance.

Urgent superselective segmental renal artery embolization in the treatment of life-threatening renal hemorrhage.

INTRODUCTION: Renal hemorrhage is a major life-threatening condition that can be caused by trauma, operation, biopsy, as well as sudden spontaneous rupture of renal tumors or aneurysms. We report our experience with superselective segmental renal artery catheterization and embolization as therapeutic options for such cases. PATIENTS AND METHODS: Over the last 8 years, 28 patients with severe renal hemorrhage were admitted for evaluation and possible further treatment. Twenty of them had a history of previous biopsy (6 of them one of a transplanted kidney), 1 patient had a recent percutaneous nephrostomy, 4 patients presented with renal mass ruptures (2 patients renal cell carcinoma, 1 patient angiomyolipoma, 1 patient hemorrhagic cysts), 1 patient had rupture of a renal aneurysm during delivery, 1 patient suffered bleeding after partial nephrectomy, and 1 patient was hospitalized after a car accident. They all presented with clinical signs of hemodynamic instability. Angiographic investigation of the kidneys preceded further intervention in all cases. 26 out of the 28 patients underwent superselective embolization of the specific bleeding vessel with the use of microcoils and/or Gelfoam particles. RESULTS: All patients treated by superselective segmental renal artery embolization had a successful outcome, including a steady renal function and a stable clinical course. No complications occurred. CONCLUSION: Superselective segmental renal artery catheterization and embolization is a safe and efficient method for the treatment of patients with severe renal hemorrhage, preserving healthy renal parenchyma and renal function.

Hepatocellular carcinoma of diffuse type: MR imaging findings and clinical manifestations.

PURPOSE: To assess MR imaging findings and clinical manifestations of diffuse-type hepatocellular carcinoma (HCC). MATERIALS AND METHODS: We retrospectively reviewed our experience with diffuse HCC from November 1994 to October 2001. MR imaging findings and clinical features were assessed. RESULTS: Twenty-two consecutive patients with diffuse-type HCC (19 men and three women, age range 16-80 years [mean, 52 years]) were identified in a review of liver MR studies. This represented 13% of all patients with HCC imaged during this time period. Diffuse HCC showed a permeative, infiltrative pattern with ill-defined borders and no evidence of convex margination in all cases. At least 50% of the liver volume was involved with tumor. Diffuse-type HCC showed hypointensity in 15 patients, mixed intensity in three, and isointensity in four on T1-weighted images; heterogeneous hyperintensity in 16 patients; and homogeneous hyperintensity in six on T2-weighted MR images. Diffuse-type HCC showed patchy enhancement in 12 patients, miliary enhancement in nine, and minimal enhancement in one on postcontrast early-phase images, and showed heterogeneous wash-out in all patients on postcontrast late-phase images. Proximal portal venous tumor thrombosis was seen in all patients. Serum alpha-fetoprotein (AFP) value was elevated (>10 ng/mL) in 14 of 18 patients, and 13 showed a value greater than 500 ng/mL. The four patients who did not have elevated AFP had tumors which were indistinguishable from those in patients with elevated AFP; they also did not have a distinctive clinical history. CONCLUSION: Diffuse-type HCC was typically seen as an extensive, heterogeneous permeative hepatic tumor, with portal venous tumor thrombosis on MR images in all cases. Early enhancement, observed as patchy in 12 and miliary in nine of 22 patients, was a distinctive imaging feature. Elevated serum AFP value was a common finding; however, 22% had normal values.

Autosomal dominant polycystic kidney disease: MR imaging evaluation using current techniques.

PURPOSE: To determine the MR imaging findings of autosomal dominant polycystic kidney disease using current imaging techniques. MATERIALS AND METHODS: We reviewed our five-year experience with MR imaging of autosomal dominant polycystic kidney disease (ADPKD) to determine the spectrum of appearance of kidney disease, the occurrence of cysts in other abdominal organs, the size and number of cysts in the kidneys and other organs, and the association with other benign or malignant disease. Thirty patients (17 men and 13 women, age range 30 to 88 years old) with ADPKD were included in this study. All patients were examined by MR imaging including T2-weighted single-shot echo-train spin-echo and pre- and post-gadolinium chelate spoiled gradient-echo imaging. RESULTS: All kidneys were involved with multiple, varying sized cysts scattered throughout the parenchyma. Giant renal cysts (>8 cm) were associated with pain in the only two patients who possessed them. Hemorrhage in renal cysts was observed in all kidneys with a heterogeneous pattern of involvement on non-contrast T1- and T2-weighted images, reflecting hemorrhage of varying age. The mean kidney size for the right kidney was 17.4 cm in length, 10.3 cm in transverse, and 9.4 cm in antero-posterior diameter (AP); and for the left kidney, 15.9 cm in the length, 9.3 cm in the transverse, and 9.3 cm in AP diameter. Other organs involved included the liver (22 patients), the pancreas (three patients), with two of the above-mentioned patients having both liver and pancreas cysts, and the spleen (one patient) who had both liver and splenic cysts. Massive liver involvement with large cysts was associated with abdominal pain. Malignant disease was present in five patients, including two patients with renal cell carcinoma, one with bladder cancer, one with lung cancer, and one patient with anal adenocarcinoma. Comparison of pre- and post-contrast T1-weighted images was essential to detect renal cancer. CONCLUSION: All kidneys in patients with ADPKD had extensive, varying-sized cysts and in all cases some cysts showed evidence of hemorrhage. The liver was the second most common organ to be involved with cystic disease, in 73% of patients. Large cysts in the kidneys and liver were associated with abdominal pain.