T. Kuroiwa

Comparison of helical CT and MR imaging in detecting and staging small pancreatic adenocarcinoma

Abstract.Background: To compare the value of helical computed tomography (CT) and various pulse sequences of magnetic resonance (MR) imaging in the detection and staging of small pancreatic adenocarcinoma. Methods: Small pancreatic adenocarcinomas (≤2 cm in diameter) in eight patients were evaluated with both helical CT and MR imaging. Five MR imaging pulse sequences that included fat-suppressed T1-weighted images and dynamic study using fast multiplanar spoiled gradient-recalled technique were compared for the tumor detectability. To evaluate the tumor vascularity, angiographic findings were also investigated. Results: Helical CT delineated the tumor in five cases, and MR imaging depicted the tumor in seven cases. MR imaging could detect the tumor of 0.8 cm in diameter clearly. Although helical CT and dynamic MR imaging missed the tumor of 2 cm with relative hypervascularity, fat-suppressed T1-weighted MR imaging demonstrated it precisely. As for the tumor staging, MR imaging was equal or slightly superior to helical CT. Conclusion: MR imaging is the first modality of choice to evaluate small pancreatic adenocarcinoma, and fat-suppressed T1-weighted images and dynamic study must be performed.

Pulmonary Complications after Hepatic Artery Chemoembolization or Infusion via the Inferior Phrenic Artery for Primary Liver Cancer

PURPOSE The purpose of this study was to determine the frequency, patterns of disease, and risk factors for development of pulmonary complications after liver chemoembolization via the inferior phrenic artery (IPA). MATERIALS AND METHODS Forty-four selective transcatheter hepatic chemoembolization (THCE) procedures via the IPA were performed in patients with primary liver cancers with use of a mixture of anticancer agents and iodized oil (Lipiodol) with or without transcatheter arterial embolization. The grades of pulmonary complications were assessed on triphasic helical computed tomographic (CT) images after THCE and were correlated with angiographic findings of the IPA, infused dosages of Adriamycin and Lipiodol, and hepatic venous tumor thrombus on triphasic CT images before THCE. RESULTS THCE via the IPA frequently resulted in lung CT changes: Lipiodol accumulation in the lung field (52%), consolidation (68%), and pleural effusion (41%). Among 44 patients, two (5%) developed respiratory symptoms. An excellent correlation was shown between Lipiodol accumulation and the presence of angiographic abnormalities of the IPA (P <.005). A significant correlation was also shown between the grades of pulmonary complications and the numbers of angiographic abnormalities (P <.01). The grades of pulmonary complications increased according to the infused dosage of Adriamycin and Lipiodol (P <.05). CONCLUSIONS Angiographic abnormalities such as arteriovenous shunts, dilated anastomotic branches, and dense pleural staining are important risk factors for pulmonary complications of THCE via the IPA. Embolization for shunts may be required to prevent such complications, especially in cases with shunts to pulmonary vessels or hepatic veins.

Measurement of the apparent diffusion coefficient in intraductal mucin-producing tumor of the pancreas by diffusion-weighted echo-planar MR imaging

AbstractBackground: We investigated whether diffusion-weighted echo-planar magnetic resonance (MR) imaging can help differentiate intraductal mucin-producing tumors of the pancreas from other cystic lesions. Methods: Diffusion-weighted echo-planar MR imaging was performed in patients with mucin-producing tumors (n= 19), pseudocysts (n= 9), chronic pancreatitis with diffuse main pancreatic dilatation (n= 5), and serous cystadenomas (n= 2). Images were obtained with diffusion sensitizing gradients of 30, 300, and 900 s/mm2. The apparent diffusion coefficient (ADC) was calculated. Results: The mean (± standard deviation) ADCs of mucin-producing tumors (2.8 × 10−3 mm2/s ± 1.0 × 10−3), pseudocysts (2.9 × 10−3 mm2/s ± 1.2 × 10−3), dilated main pancreatic duct in chronic pancreatitis (3.3 × 10−3 mm2/s ± 1.2 × 10−3), serous cystadenomas (2.9 × 10−3 and 2.6 × 10−3 mm2/s), and cerebrospinal fluid (3.5 × 10−3 mm2/s ± 1.1 × 10−3) were not statistically different. Conclusion: It is difficult to differentiate between mucin-producing tumors and other cystic lesions by ADC measurements when using diffusion-weighted echo-planar MR imaging.

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.

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.

Pseudolesion in segment II of the liver observed on CT during arterial portography caused by the aberrant left gastric venous drainage.

A rare case with a pseudolesion in segment II of the liver observed on computed tomography (CT) during arterial portography caused by the aberrant left gastric venous drainage is presented. Close observation of the celiac angiography was helpful in recognizing this pseudolesion. Selective catheterization of the left gastric artery and CT during its venous phase confirmed the etiology of the pseudolesion.

Gallbladder torsion: case report

Torsion of the gallbladder (GB) is a rare, acute abdominal condition. The treatment of choice is cholecystectomy. Even with recent advances in radiologic imaging modalities, it is difficult to make a correct preoperative diagnosis of GB torsion. We report a case of GB torsion with a retrospective review of the radiologic findings of magnetic resonance imaging, computed tomography, and ultrasonography. Those findings were compared with the histopathologic findings of the surgical specimen. The radiologic findings in our case were useful for making a preoperative diagnosis of GB torsion. We postulate the characteristic magnetic resonance findings and discuss discrepancies in the evaluations of the GB wall.

Uterine lipoleiomyoma: MRI appearances

Abstract. A case of uterine lipoleiomyoma demonstrated on computed tomography (CT) and magnetic resonance imaging (MRI) is described and usefulness of MRI is discussed in diagnosing this entity.

Small Hepatocellular Carcinoma on Magnetic Resonance Imaging: Relation of Signal Intensity to Angiographic and Clinicopathologic Findings

RATIONALE AND OBJECTIVES The authors discuss the clinicopathologic features and angiographic vascularity of various signal intensity patterns on magnetic resonance (MR) imaging of small hepatocellular carcinomas (HCCs). METHODS Magnetic resonance images of 88 resected HCCs (< or = 3 cm) were obtained using T1- and T2-weighted spin-echo images and T1-weighted images after gadolinium (Gd)-DTPA administration. Images were compared with angiographic and histopathologic findings. RESULTS Forty HCCs (45%) were depicted on T1-weighted images, 51 (58%) on T2-weighted images, and 41 (49%) on T1-weighted images after Gd-DTPA administration. Overall, 64 (76%) were found on at least one image. On T1-weighted images, hyperintense HCCs histologically showed fatty metamorphosis and portal tracts within the tumor. On T2-weighted images, HCC hyperintensity correlated with expansive growth, peliotic change, and hypervascularity. By contrast, HCCs that were undetected or hypointense on T2-weighted images were well differentiated with replacing growth and portal tracts. On T1-weighted images after Gd-DTPA, hyperintense HCCs had peliotic change; undetected HCCs were well differentiated and hypovascular. CONCLUSIONS Histologic grade, vascularity, portal tracts and peliotic change correlate with MR signal intensity. For hyperintense HCCs on T1-weighted images and hypo- or isointense HCCs on T2-weighted images, treatment methods must be assigned with the consideration that HCCs may be receiving transsinusoidal and portal blood supplies.

Chronic expanding hematoma of the spleen caused by angiomyolipoma in a patient with tuberous sclerosis.

Abstract We report a case of a chronic expanding hematoma caused by an angiomyolipoma of the spleen in a patient diagnosed with tuberous sclerosis in infancy. Computed tomography showed large bilateral renal angiomyolipomas. A splenic mass that increased in size during the follow-up period of 62 months was also noted. A large subcapsular hematoma of the spleen finally developed, and a splenectomy was performed. The splenic mass consisted of a chronic hematoma with prominent granulation tissue, which was considered to be caused by repeated bleeding from a small angiomyolipoma in the spleen.