Biomedical subjects

H Aibe

Publications and source records attributed to H Aibe.

36 records · Page 2Linked to original sources

PubMedDate not supplied

Fat in liver metastasis from renal cell carcinoma detected by chemical shift MR imaging.

A case with liver metastasis from papillary renal cell carcinoma (RCC) is presented, in which intratumoral fat was detected on dual-echo chemical shift magnetic resonance imaging (MRI). The preoperative chemical shift MR image of the primary RCC also suggested the presence of intratumoral fat. Liver metastasis from fat-containing RCC should be included in the differential diagnosis of fat-containing liver masses as observed on chemical shift MRI.

Adipose Tissue↗

PubMedDate not supplied

Fat detection in gallbladder carcinoma with extensive xanthogranulomatous change demonstrated by chemical shift MR imaging.

We present a case of gallbladder carcinoma, in which fat was detected on dual-echo chemical shift magnetic resonance imaging (MRI). Histologic analysis showed poorly differentiated adenocarcinoma associated with massive xanthogranulomatous change. Sudan IV staining successfully confirmed the presence of fat within the interstitial histiocytes. Although rare, gallbladder carcinoma with xanthogranulomatous change should be included in the differential diagnosis of fatty tumor involving the region of the liver as observed on chemical shift MRI.

Adenocarcinoma↗

PubMedDate not supplied

Bilateral ovarian leiomyomas: CT and MRI features.

We recently treated a 21-year-old woman with leiomyomas arising from the bilateral ovaries, a very rare condition. On magnetic resonance imaging, more than half of the left adnexal mass showed low signal intensity on T2-weighted images and good enhancement by gadolinium-DTPA, and the remaining part showed high signal intensity on T2-weighted images, so the lesions initially were diagnosed as ovarian fibromas or as thecomas with a certain degree of degeneration. Pathologic examination of the excised tumors proved that they were bilateral ovarian leiomyomas; in addition, the tumor from the left side showed hemorrhagic and myxoid changes with torsion of 180 degrees.

Adult↗

PubMedDate not supplied

Abdominal cystic tumors containing small amount of fat in the septa: report of two cases.

We present two cases of abdominal cystic tumors containing small amounts of fat in their septa. Although the final pathologic diagnoses of these tumors were cystic lymphangioma and angiomatosis, the computed tomographic and magnetic resonance imaging features were almost identical and indistinguishable; a purely cystic mass around the region of the pancreas head associated with little mass effect on the surrounding organs and septa containing a radiologically evident fatty component. Radiologists should be aware of these two entities as differential diagnoses of abdominal cystic masses containing small amounts of septal fat.

Abdominal Neoplasms↗

PubMedDate not supplied

Metastatic adrenal tumor from clear-cell renal cell carcinoma: a pitfall of chemical shift MR imaging.

We present a case of adrenal metastasis from clear-cell renal cell carcinoma in which presence of a small amount of fat was shown on chemical shift gradient-echo magnetic resonance imaging. Radiologists should be aware that signal loss of the adrenal tumor on out-of-phase gradient-echo images does not always suggest the diagnosis of benign adenoma, particularly in patients with a history of renal cell carcinoma.

Adenocarcinoma, Clear Cell↗

PubMedDate not supplied

Sclerosed hemangioma of the liver.

We report the radiologic findings of sclerosed hemangioma (SH), a rare variant of hepatic hemangioma. Dynamic contrast-enhanced computed tomography showed a hypodense mass in the liver with delayed enhancement. T2-weighted magnetic resonance imaging showed the mass as hypointense in relation to cerebrospinal fluid. The final diagnosis of SH was made pathologically. Although SH is rare, understanding its radiologic appearance is important to avoid unnecessary surgery and should be included in the differential diagnoses of hepatic lesion with delayed enhancement.

Aged↗

PubMedDate not supplied

Primary malignant lymphoma in the porta hepatis: a case report.

A case of primary lymphoma in the porta hepatis is presented here. Cholangiography, angiography, ultrasonography and computed tomography suggested the presence of a mass in the porta hepatis, but all these failed to demonstrate the tumor clearly. Magnetic resonance imaging was very useful in defining the characteristics of the tumor and in delineating its extent, though it was not specifically diagnostic.

Aged↗

PubMedDate not supplied

Complications encountered with a transfemorally placed port-catheter system for hepatic artery chemotherapy infusion.

A port-catheter system was implanted via femoral artery access for hepatic artery chemotherapy infusion. Implantation was attempted in 90 patients and was successful in 88. Blood flow redistribution was performed using embolization coils. In the first ten patients a soft heparin-coated infusion catheter was used. For the following 78 patients we used a stiffer catheter coated with fluorine-acryl-styrene-urethane-silicone (FASUS) copolymer. The catheter was connected to a port implanted subcutaneously below the level of the inguinal ligament. Complications during the procedure and after placement were observed in 7 of 90 patients and 24 of 88 patients, respectively. These included catheter obstruction (11%), dislocation of the catheter tip (10%), drug toxicity (5.7%), and catheter infection (3.4%). In 6 of 10 patients with catheter obstruction, recanalization of the port system was achieved. In 7 of 9 patients with dislocation of the indwelling catheter tip, replacement of the port system was successful. Our complications appear to be comparable with those encountered with the subclavian/brachial approach when the new catheter coating is used. Notable is the avoidance of cerebral infarcts.

Adolescent↗

PubMedDate not supplied

Temporary spontaneous regression of intrahepatic cholangiocarcinoma.

A 34-yr-old man with a liver mass was referred to the hospital. The mass showed temporary spontaneous regression during the follow-up, however, subsequent regrowth of the tumor prompted surgical resection. The specimen revealed intrahepatic cholangiocarcinoma with two distinct components which had been clearly demonstrated on serial CT. Spontaneous resolution of a lesion does not necessarily suggest the lesion's benign, self-limiting entity. Intrahepatic cholangiocarcinoma should be included in the tumors that could spontaneously regress.

Adult↗

PubMedDate not supplied

MR imaging and MR angiography of persistent trigeminal artery and its variant.

Six patients with persistent trigeminal artery (PTA) and one patient with its variant (PTAV) were studied using a 1.0-T magnetic resonance unit. With both magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), four of the six PTAs were detected as abnormal connecting arteries between the cavernous internal carotids and the basilar arteries. The remaining two PTAs and one PTAV were not detected using MRI, but were imaged by MRA. It was concluded that relatively large PTAs can be detected using MRI, but small PTAs and PTAVs may be missed using MRI.

Adult↗

PubMedDate not supplied

Spiral-shaped iatrogenic arterial dissection during superior mesenteric arteriography: a latent risk of diagnostic angiography using the power injector.

We report a rare case of iatrogenic arterial dissection of the superior mesenteric artery (SMA) during diagnostic angiography. A conventional superior mesenteric arteriogram obtained using an automated power injector revealed an arterial dissection 2s after the initiation of contrast-medium injection. This case indicates that although careful catheter manipulations during angiography are essential, certain unavoidable complications may occur.

Aged↗

PubMedDate not supplied

Radiologically identified molar invasion into pelvic arteriovenous shunts.

A case of radiologically identified molar invasion into extensive arteriovenous shunts (AVSs) is described. CT and MRI revealed a large uterine mass, accompanied by multiple AVSs. Dynamic MRI and pelvic angiography demonstrated multiple trophoblastic cysts invading into the AVSs. Resected specimen confirmed the diagnosis of invasive mole. Dynamic MRI was very useful in determining the etiology of AVS.

Arteriovenous Malformations↗

PubMedDate not supplied

Efficacy of three-dimensional fast imaging with steady precession dynamic MR imaging in evaluating pancreatic ductal adenocarcinoma.

To compare the diagnostic efficacy of three-dimensional fast imaging with steady precession (3D-FISP) dynamic MR imaging in assessing pancreatic ductal adenocarcinoma with conventional MR imaging and helical CT, 15 patients with surgically proven pancreatic ductal adenocarcinoma were studied. Contrast-to-noise ratio (CNR) of the tumor, tumor detectability, local tumor extension, and vascular involvement were evaluated for all techniques. The results indicate that 3D-FISP dynamic MR imaging may improve the imaging assessment of pancreatic ductal adenocarcinoma.

Adenocarcinoma↗

PubMedDate not supplied

Superficial siderosis of the central nervous system. Its MRI manifestations.

Three cases of superficial siderosis of the central nervous system are reported here. Using a 1.0-T magnetic resonance (MR) unit, typical hypointense rims were observed under the brain surface on T2-weighted images. In one patient, marked atrophy of the superior cerebellar vermis and cerebellar parenchymal hyperintensity were also detected. The spinal cord was involved in two of the three patients. On T1-weighted images, hyperintense rims were demonstrated over the brain surface in two of the three patients. This finding has not been previously reported.

Aged↗

PubMedDate not supplied

Inflammatory pseudotumors of the spleen: CT and MRI findings.

OBJECTIVE: Our goal was to elucidate the CT and MRI findings of inflammatory pseudotumors of the spleen. METHODS: The CT and MRI findings of three patients with inflammatory pseudotumors of the spleen were reviewed and compared with the pathologic findings. RESULTS: On the early phase of CT, the masses were hypodense to the normal spleen, and on the delayed phase, they demonstrated delayed enhancement. On T1-weighted MR images, the masses were isointense to the normal spleen, and on T2-weighted images, the masses had heterogeneous low signal intensities. After administration of Gd-DTPA, the masses showed delayed enhancement. CONCLUSION: Inflammatory pseudotumors of the spleen were characterized by low signal intensity on T2-weighted MR images and delayed enhancement after contrast material administration on CT and MRI. The fibrous stroma may contribute to these unusual findings.

Adult↗

PubMedDate not supplied

Radiologic features of intrahepatic bile duct adenoma: a look at the surface of the liver.

We report the radiological features of intrahepatic bile duct adenoma (BDA) in three patients. BDA was shown as a small mass located in the peripheral region of the liver with each imaging modality: a hypervascular mass on angiography and a mass appearing as early nodular enhancement found disproportionately evident compared with their small size and distinct delayed or prolonged enhancement on CT. BDA should be included in the diseases to be differentiated from hypervascular hepatic tumors.

Adenoma↗

PubMedDate not supplied

Radiologic diagnosis of adenomyomatosis of the gallbladder: comparative study among MRI, helical CT, and transabdominal US.

PURPOSE: The goal of this work was to evaluate the diagnostic accuracy of transabdominal ultrasound (US), helical CT, and MRI in the diagnosis of adenomyomatosis (ADM) of the gallbladder. METHOD: Twenty patients with surgically proven ADM were included, all of whom underwent preoperative US, helical CT with 3 mm collimation, and MRI with half-Fourier rapid acquisition with relaxation enhancement (RARE). All images were retrospectively reviewed by two radiologists, and the presence of ADM was assessed at three compartments (neck, body, and fundus) of the organ. Receiver operating characteristic analysis was performed, and sensitivity, specificity, and accuracy were calculated for each modality. RESULTS: The A z values (area under the curve) for MRI, helical CT, and US were 0.98, 0.85, and 0.72 for the Reader 1, respectively, showing no statistically significant interobserver difference in any of the three modalities. MRI showed a significantly higher A z value than helical CT or US (p < 0.1). The accuracies of MRI, helical CT, and US were 93, 75, and 66%, respectively. CONCLUSION: Among the three modalities tested, MRI with half-Fourier RARE sequence was the most accurate for diagnosing ADM.

Adenomyoma↗

PubMedDate not supplied

Pitfalls in MR cholangiopancreatographic interpretation.

Magnetic resonance (MR) cholangiopancreatography (MRCP) is widely used in the evaluation of pancreatobiliary disorders. However, numerous related pitfalls may simulate or mask pancreatobiliary disease. Maximum-intensity-projection (MIP) reconstructed images completely obscure small filling defects and may demonstrate respiratory motion artifacts. T2 weighting may vary with different MR imaging sequences and influence MRCP findings. Incomplete imaging may create confusion regarding ductal anatomy or disease. Furthermore, MRCP yields only static images and thus may fail to depict various anomalies. Limited spatial resolution makes differentiation between benign and malignant strictures with MRCP alone extremely difficult. Susceptibility artifacts may be caused by metallic foreign bodies or gastric-duodenal gas. Fluid accumulation may produce a pseudolesion or pseudostricture, although changing the imaging angle or section thickness may be helpful. Pneumobilia may be misinterpreted as bile duct stones, and true stones may be overlooked. Pulsatile vascular compression can cause pseudo-obstruction of the bile duct. Use of both source and MIP reconstructed images obtained from different angles can help avoid cystic duct-related pitfalls. Repeat MRCP or conventional MR imaging can help avoid pitfalls related to the periampullary region. Segmental collapse of the normal main pancreatic duct may be misinterpreted as stenosis, but administration of secretin is helpful. An awareness of these pitfalls and possible solutions is crucial for avoiding misinterpretation of MRCP images.

Biliary Tract↗