Diffusion-weighted MRI and FLAIR sequence for differentiation of hydatid cysts and simple cysts in the liver.

PURPOSE: The contribution of DWI and FLAIR to the differential diagnosis of type 1, 2, and 3 hydatid cysts and simple liver cysts was investigated according to the Gharbi classification. This study is the first report using FLAIR sequence for the differential diagnosis of liver hydatid cysts in this regard. METHODS: A total of 82 hydatid cysts and 40 simple cysts were scanned with DWI (in b600-b1000 values) and FLAIR sequence. In 64 patients included in the study, a total of 122 cystic lesions were diagnosed histopathologically or during follow-up. FLAIR and DWI signal characteristics were evaluated, and ADC values were calculated. RESULTS: The mean ADC value of hydatid cysts on DWI (b600) was 3.07 ±â€¯0.41 × 10-3 s/mm2, while it was 3.91 ±â€¯0.51 × 10-3 s/mm2 for simple cysts and the difference was statistically significant (p < 0.05). On b1000 DWI, the mean ADC values of hydatid and simple cysts were 2.99 ±â€¯0.38 × 10-3 s/mm2 and 3.43 ±â€¯0:29 × 10-3 s/mm2, respectively (p < 0.05). The qualitative evaluation of the signal intensity on b600-1000 DWI demonstrated the difference between the simple and hydatid cyst groups (p < 0.05). Type 2 hydatid cysts alone were distinguished from type 2-3 hydatid and simple cysts by FLAIR (p < 0.05). CONCLUSIONS: ADC values can distinguish between hydatid cyst and simple cyst. FLAIR contributes to the differentiation of type 2 hydatid and simple cysts.

Usefulness of Apparent Diffusion Coefficient of Diffusion-Weighted Imaging for Differential Diagnosis of Primary Solid and Cystic Renal Masses.

BACKGROUND: To evaluate the value of diffusion-weighted imaging (DWI) for distinguishing between benign and malignant renal masses. MATERIAL/METHODS: Seventy-five patients with 75 unilateral renal lesions were included, and 75 normal contralateral kidneys served as controls. The lesions were categorized into four groups as malignant cystic, malignant solid, benign cystic and benign solid. The apparent diffusion coefficients (ADCs) were evaluated for two different b values (b=600 s/mm2 and b=1000 s/mm2). Receiving operating characteristic analysis was performed to identify threshold ADCs. RESULTS: Sensitivity and specificity were 67% and 77% (p=0.003) at the cutoff value of 1.5 for b=600 s/mm2, and 79% and 62% (p=0.004) at the cutoff value of 1.99 for b=1000 s/mm2 as regards the differentiation between solid benign and malignant renal lesions. Sensitivity and specificity were 78% and 79% (p=0.001) at the cutoff value of 3.1 for b=600 s/mm2, and 86% and 61% (p=0.003) at the cutoff value of 2.9 for b=1000 s/mm2 as regrads the differentiation between benign and malignant cystic renal lesions. CONCLUSIONS: DWI can be an effective diagnostic method for distinguishing between benign and malignant renal masses.

Primary hepatic carcinosarcoma.

BACKGROUND: Primary hepatic carcinosarcoma is a rare malignant tumor containing an intimate mixture of carcinomatous and sarcomatous elements. Reports on risk factors, epidemiology, and pathogenesis of the tumor as well as the experience in its treatment are limited. METHOD: We present a case of primary carcinosarcoma of the liver in a 69-year-old man who complained of right hypochondrial pain and weight loss for two months. RESULTS: Magnetic resonance imaging revealed a 14 x 12 cm mass in segments 7-8 and 4 of the liver with vena hepatica invasion. An ultrasonography-guided biopsy showed osteoid tissue without osteoblastic rimming. Vascular structures accompanied the osteoid tissue. The patient underwent surgery after a diagnosis of hemangioma. Intraoperative frozen sections revealed a carcinosarcoma associated with an osteosarcoma and cholangiocellular carcinoma components. CONCLUSIONS: Preoperative diagnosis of this rare primary hepatic malignant tumor may be difficult by biopsy owing to intratumoral heterogeneity. Highly mature areas of the osteosarcomatous component may lead to misdiagnosis of metaplastic bone tissue. Clinicopathologic features of this rare entity are discussed.

Value of multislice computed tomography in the diagnosis of acute mesenteric ischemia.

OBJECTIVE: To define the value of multislice computed tomography (CT) in the diagnosis of acute mesenteric ischemia (AMI). MATERIALS AND METHODS: Two hundred patients (age range: 20-92 years) who were referred to the emergency CT department with a clinical suspicion of AMI were prospectively included in the study. CT examinations were performed with a multislice (16) CT scanner and the protocol included pre-contrast, arterial and venous phase acquisitions. Images were evaluated by using multiplanar reconstruction, maximum intensity projection and volume-rendering techniques at the CT workstation. RESULTS: Ninety-four patients (47%) underwent surgery for AMI or for other causes of acute abdominal pain. One hundred-six patients (53%) were followed conservatively according to clinical, radiologic and laboratory findings. Of the 94 patients who underwent surgery, 49 (25%) were found to have AMI. All of these 49 patients with a proven AMI diagnosis were diagnosed with CT. In the other 45 patients who underwent surgery, CT findings were negative for AMI. None of the patients, who were followed conservatively, were eventually diagnosed as having AMI except 1 patient. This patient was unfit for surgery although his clinical and radiologic findings were consistent with AMI and died in 3 days. The sensitivity and specificity values of CT for the detection of AMI were calculated to be 100% for each. CONCLUSIONS: Multislice CT is an effective imaging technique for the diagnosis of AMI with excellent sensitivity and specificity values.

Celiac artery compression syndrome: diagnosis with multislice CT.

Celiac artery compression syndrome is a rare disorder characterized by postprandial intestinal angina caused by insufficient blood supply to the gastrointestinal organs. In this syndrome, the root of the celiac artery is compressed and narrowed by the median arcuate ligament of the diaphragm during expiration. We report here 3 such cases that were diagnosed by the use of multislice computed tomography.

Inferior vena cava obstruction due to cecum adenocarcinoma.

In this paper, we report the radiologic findings of cecal adenocarcinoma with caval invasion in a 60-year-old man. Caval invasion was confirmed by ultrasonographically guided fine-needle aspiration biopsy and by surgery. To our knowledge, this is the first case report demonstrating malignant caval thrombus due to colon cancer. In addition, we suggest that fine-needle aspiration biopsy may be helpful for prompt diagnosis and treatment in such a case.

Hepatic von Meyenburg complex simulating biliary cystadenocarcinoma.

Multiple bile duct hamartomas [von Meyenburg complex (VMC)] are benign liver malformations that include biliary cystic lesions, with congenital hepatic fibrosis being the cause of ductal plate malformations. This rare entity is usually isolated and detected incidentally in 0.6-5.6% of reported autopsy series. Its clinical significance is that it may be misdiagnosed as malignant liver disease. Imaging findings of VMC are nonspecific. We present a rare case of VMC in a patient who presented with epigastric and upper right abdominal pain, and jaundice of 2 months' duration. Ultrasonography, computed tomography, and magnetic resonance imaging showed a periportal multicystic mass simulating biliary cystadenoma/cystadenocarcinoma. The patient underwent laparotomy. A diagnosis of VMC was made after histopathologic examination of the wedge biopsy of the liver.

MR cholangiopancreatography findings of heterotopic pancreatic tissue in the distal common bile duct.

Heterotopic pancreas is defined as the presence of pancreatic tissue at sites other than the pancreas. Involved sites may be the stomach, duodenum, proximal jejunum, ileum, congenital duodenal web, Meckel's diverticulum, ampulla of Vater, and the main pancreatic duct. We report the magnetic resonance cholangiopancreatography findings of a patient who had biliary obstruction due to heterotopic pancreas tissue at the distal common bile duct.

Gastrointestinal carcinoid tumors in rare locations: imaging findings.

In this article, we present radiological findings in three patients with mesenteric, gastric, and rectal carcinoid tumors. More than 90% of the carcinoid tumors arise in the gastrointestinal system (GIS). They comprise 2% of all GIS tumors and are usually located in the small intestine and the appendix. On the other hand, gastric, rectal, and mesenteric carcinoids are rare. Better knowledge of radiological features of carcinoid tumors in rare locations will prevent diagnostic delays and development of carcinoid syndrome.

Angiomyolipoma with cavoatrial extension.

In this paper, we report a case of angiomyolipoma with cavoatrial extension in a 55-yr-old woman. Multislice computed tomography revealed a hypodense mass extending into the right atrium through the right renal vein and inferior vena cava without a renal mass. The patient underwent surgery, and right atrial mass was resected. Pathologic evaluation revealed a tumor consisting of mature adipose tissue, smooth muscle and vessels consistent with angiomyolipoma. Our case reminds us of the rare possibility that angiomyolipoma, which is classified as a benign tumor, may invade the inferior vena cava or right atrium.

Hyperintense globus pallidus on T1-weighted MR imaging in acute kernicterus: is it common or rare?

Globus pallidus involvement is a well-known magnetic resonance (MR) imaging finding of acute kernicterus. However, it is not clear how early the involvement of globus pallidus occurs and whether or not it is seen in every case. Therefore, we aimed to investigate the globus pallidus involvement in 13 neonates with acute kernicterus by MR imaging. Thirteen neonates who were admitted with jaundice, encephalopathy and indirect hyperbilirubinemia (mean, 37.0 mg/dl) were prospectively evaluated with cranial MR imaging. Pathological signal changes were noted concerning the globus pallidus. Eight of the 13 patients demonstrated bilateral, symmetric increased signal intensity in the globus pallidus on T1-weighted MR imaging. These lesions were not apparent on T2-weighted images. Multiple parenchymal punctuate T1 hyperintense lesions were detected in one patient without globus pallidus involvement. This appearance was consistent with hemorrhage. The MR imaging findings of the other four patients showed no evidence of abnormality. The symmetric involvement of globus pallidus seen as hyperintense on T1-weighted MR imaging is a common and characteristic finding of acute kernicterus.

New method for the detection of intraperitoneal free air by sonography: scissors maneuver.

PURPOSE: This study was conducted to investigate the diagnostic value of a new sonographic technique for the detection of intraabdominal free air. METHODS: Seventy-two patients with a suspected gastrointestinal tract perforation were included in the study and prospectively evaluated by sonography and abdominal and chest radiography for the detection of intraperitoneal free air. A new sonographic technique (the scissors maneuver) was used to detect intraperitoneal free air superficial to the liver; the maneuver consists of applying and then releasing slight pressure onto the abdominal wall with the caudal part of a parasagittaly oriented linear-array probe. The results of the imaging studies were correlated with surgical findings when possible. RESULTS: Sixteen patients had a surgically proven gastrointestinal tract perforation causing pneumoperitoneum. Sonography and radiography each showed pneumoperitoneum in 15 patients, with 1 false-negative result for each modality. The sensitivity and specificity values of sonography and radiography were identical; sensitivity was 94% and specificity was 100% for both imaging modalities. The scissors maneuver was positive in all patients with sonographically detected pneumoperitoneum. CONCLUSIONS: Sonography is an effective tool in the diagnosis of pneumoperitoneum, with sensitivity and specificity equal to those of radiography. The scissors maneuver may be a useful adjunct for improving the diagnostic yield of sonography.

[Multicystic encephalomalacia: MR imaging findings and clinical correlation]. / Multikistik ensefalomalazi: MRG bulgulari ve klinik bulgularla korelasyonu.

PURPOSE: To review the MR imaging findings of multicystic encephalomalacia and to investigate the correlation between MR imaging and clinical findings. MATERIALS AND METHODS: Twenty-one patients who presented with convulsion, mental-motor retardation and microcephaly and had evidence of multicystic encephalomalacia on MR images were included in this study. MR imaging patterns and clinical findings were reviewed. Consequently, we correlated MR imaging findings and clinical outcome. RESULTS: All patients had cortical thinning, white matter destruction, atrophy and gliosis. Tetraplegia was seen in 17 out of 19 patients with mixed type cerebral palsy in two patients with diffuse or symmetric involvement on MR imaging. Both of the patients with mixed type cerebral palsy had basal ganglia involvement on MR imaging. Hemiplegia was seen in two patients with asymmetric involvement on MR imaging. Microcephaly was seen in 17 patients with diffuse or symmetrical, and in one patient with asymmetrical, involvement. Microcephaly and tetraplegia was seen in all patients with cerebellar and basal ganglion involvement. CONCLUSION: Microcephaly and spastic tetraplegia were developed mostly in patients with diffuse involvement, whereas hemiplegia was seen in patients with asymmetric involvement. The clinical outcome was worse in patients with cerebellar and brainstem involvement. Therefore, we supposed that the symmetry of lesions and cerebellar or brainstem involvement might be used as a prognostic indicator.