BACKGROUND: To examine the incidence and predisposing factors of gallbladder opacification in delayed computed tomography (CT) after angiography. METHODS: CT examination 12-24 h after angiography was performed in 389 patients. Univariate and multivariate analyses were made. RESULTS: Two hundred thirty-three of 389 patients (60%) revealed gallbladder opacification. Type of contrast medium (P < 0. 01), total bilirubin (P < 0.01), and serum creatinine (P < 0.01) were significant and independent factors relating to gallbladder opacification. Ioxaglate (70%, relative odds = 2.86) and iohexol (63%, relative odds = 2.03) showed higher gallbladder opacification rates than that of iopamidol (45%, relative odds = 1.43) and diatrizoate (30%). Patients with a lower serum bilirubin level (relative odds = 1.67) and a raised serum creatinine level (relative odds = 2.01) showed higher incidence of gallbladder opacification. CONCLUSION: Gallbladder opacification after angiography is not an abnormal finding on delayed CT in patients with not only abnormal renal function but also normal hepatobiliary and normal renal function, especially for modern contrast media.

Angiography↗

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Magnetic resonance imaging of post-surgical pseudomeningocele.

Three cases of post-surgical pseudomeningocele (PSPM) are presented. MR imaging proved useful in diagnosing PSPM because, in the orthogonal planes, it demonstrated precisely the leakage site and the extent of the PSPM. MR imaging was also useful in demonstrating the presence of communication between the PSPM and the subarachnoid space.

Adult↗

PubMedDate not supplied

MR imaging of orbital mass lesions with contrast agent: a preliminary report.

To investigate the advantage and limit of contrast enhancement in the examination of orbital mass lesions, precontrast T1- and T2-weighted, and postcontrast T1-weighted spin-echo images were retrospectively compared by two experienced observers. Using contrast material, intraocular tumors were well detected and characterized, and several orbital tumors were characterized as to whether cystic or necrotic and intracranial involvement was better evaluated. On the other hand, tumor-fat interface lost conspicuity when tumors showed enhancement. We conclude that gadopentetate-dimeglumine-administered T1-weighted images were helpful in detecting, differentiating and characterizing tumors of the orbit. However, the loss of contrast with fatty tissue is a disadvantage to be considered.

Contrast Media↗

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Peripheral findings in MR using surface coil.

Incidental peripheral lesions found during neuroradiological MR examinations with surface coils are reviewed. These include intracranial metastases during orbital examinations, cerebellar and thyroid lesions during cervical spine examinations, and dissecting and saccular abdominal aneurysms, as well as renal and intrapelvic abnormalities during lumbar spine examinations. Because of the reduced field-of-view and rapid signal drop-off in deeper portions of the body when examinations are performed with surface coils, peripheral and deep regions also need careful attention during routine evaluation.

Aged↗

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Focal fatty infiltration of the liver mimicking a tumor: sonographic and CT features.

Focal fatty infiltration of the liver detected by ultrasonography (US) in this asymptomatic woman had unusual features. It appeared as a sharply marginated, spherical mass lesion on CT, with soft tissue attenuation values of 30 HU unenhanced and 50 HU with enhancement. This tumor-like zone completely resolved on follow-up US and CT, underscoring the need for follow-up examinations to exclude primary or metastatic tumors. Our review of the literature failed to reveal previous reports of features such as these.

Biopsy↗

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Computed tomography of residual hepatomas following transcatheter arterial embolization.

Computed tomography and angiography following transcatheter arterial embolization (TAE) was performed for 29 patients with hepatomas. In three cases crescent-shaped isodense regions were observed posterior to the necrotic tumor after TAE. They were located in the superior posterior segments of the right hepatic lobes and were consistent with residual tumor supplied by the right inferior phrenic artery. Recognition of this CT finding after TAE is important for evaluating the extent of embolization of the tumor.

Aged↗

PubMedDate not supplied

MRI of bronchogenic cysts.

The MR appearance of eight bronchogenic cysts is reported. All the cysts appeared homogeneous and were of very high signal intensity, approximating that of CSF on spin-echo T2-weighted imaging, and of relatively high intensity, between that of muscle and subcutaneous fat on T1-weighted imaging. The cysts were round or ovoid and were well demarcated. These findings are consistent with the fluid-containing properties of cysts.

Adipose Tissue↗

PubMedDate not supplied

"CT angiogram sign" in obstructive pneumonitis and pneumonia.

OBJECTIVE: The "CT angiogram sign" in dynamic pulmonary CT consists of enhanced branching pulmonary vessels in a homogeneous hypoattenuating consolidation of lung parenchyma and is reportedly useful for diagnosing lobar bronchioloalveolar cell carcinomas. MATERIALS AND METHODS: To identify cases exhibiting the CT angiogram sign, we retrospectively reviewed the reports of 5,500 dynamic incremental CT examinations of the chest. RESULTS: We identified the CT angiogram sign in five patients with obstructive pneumonitis due to lung tumors and four patients with pneumonias. CONCLUSION: The CT angiogram sign can be observed in pulmonary consolidation of varying etiologies.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMedDate not supplied

MR evaluation of intrapulmonary hematoma.

We report a case of circumscribed intrapulmonary hematoma, in which MR findings were useful in establishing the diagnosis. It is usually easy to make a diagnosis of intrapulmonary hematoma using conventional methods, when clinical history of trauma and regression of the mass can be observed on serial radiography. However, in this case the mass remained almost unchanged 4 months after trauma on chest radiography and CT. Magnetic resonance revealed a hyperintense mass with an even higher signal rim on T1-weighted imaging and an irregular hyperintense mass on T2*-weighted imaging. We made a diagnosis of pulmonary hematoma based on these MR findings. Follow-up chest radiography and CT taken 1 year after the injury, revealed a substantial decrease in the size of the mass, which confirmed the diagnosis. As in this case, some intrapulmonary hematomas regress very slowly or may even increase in size, and diagnosis can be difficult with conventional methods. In such cases, MRI can be helpful.

Adult↗

PubMedDate not supplied

Signal intensity characteristics of mediastinal cystic masses on T1-weighted MRI.

OBJECTIVE: We evaluated the intracystic MR signal intensity of mediastinal cystic masses to identify characteristic intensity patterns according to histologic type. MATERIALS AND METHODS: Magnetic resonance imaging was performed on 26 cystic mediastinal masses consisting of 8 thymic cysts, 5 bronchogenic cysts, 4 pericardial cysts, 5 cystic teratomas, and 4 cystic neurogenic tumors. Signal intensity ratios of each cyst to muscle were calculated on T1-weighted imaging. Surgical records were reviewed to document the presence of intracystic hemorrhage. Chemical analysis of intracystic fluid was performed in three cases. RESULTS: Bronchogenic cysts, cystic teratomas, and cystic neurogenic tumors had relatively high levels of signal intensities. Each pericardial cyst had a lower signal intensity than muscle. The signal intensities of thymic cysts were variable. Intracystic hemorrhage was present in 1 bronchogenic cyst, 2 cystic neurogenic tumors, 4 cystic teratomas, and 3 thymic cysts. No hemorrhage was found in any of the pericardial cysts. Sebaceous fluid was present in 1 cystic teratoma. CONCLUSION: The varying intensities of different cysts were considered to reflect the nature of the intracystic fluid. Since the nature of the fluid can reflect the histology to some extent, T1-weighted MRI will help to differentiate cystic mediastinal masses.

Bronchogenic Cyst↗

PubMedDate not supplied

Helical CT imaging of bronchial arteries with curved reformation technique in comparison with selective bronchial arteriography: preliminary report.

PURPOSE: Our goal was to evaluate the ability of helical CT to identify and demonstrate the origins and courses of bronchial arteries, using the curved reformation technique, in patients undergoing bronchial arterial interventional procedures. METHODS: Thin section helical CT was performed on seven patients before bronchial arterial interventional procedures. The curved reformation technique was used to demonstrate the origins and continuous vessel tracing of bronchial arteries and compared with bronchial arteriographic findings. RESULTS: In all, 16 bronchial arteries were evaluated, 8 on the right and 8 on the left. The origins of 12 bronchial arteries were identified. In the demonstration of tracing vessels, seven right bronchial arteries and three left were classified as excellent or fair. CONCLUSION: Helical CT imaging with the curved reformation technique is helpful in identifying bronchial arteries, especially on the right, in patients with indications for bronchial arterial interventional procedures.

Adult↗

PubMedDate not supplied

Patterns of peripheral enhancement in breast masses: correlation of findings on contrast medium enhanced MRI with histologic features and tumor angiogenesis.

PURPOSE: Our goal was to review patterns of peripheral enhancement on contrast-enhanced MRI of the breast and to correlate radiologic findings with pathologic features. METHOD: We reviewed the MR images of 124 consecutive women with breast lesions. Peripheral enhancement was identified in 35 (32 malignant, 3 benign) lesions. MRI findings were correlated with pathologic features including microvessel density and distribution determined histologically. RESULTS: Early peripheral enhancement with centripetal progression was seen in invasive carcinomas with a high peripheral and a low central microvessel density, associated with fibrosis and/or necrosis (n = 18; 15 with central fibrosis, 2 with fibrosis and necrosis, and 1 with necrosis alone). Early peripheral enhancement with minimal or no change in enhancement was seen in both malignant (n = 10) and benign (n = 3) lesions. Delayed peripheral enhancement with centrifugal progression was seen in carcinomas that had an expansive growth pattern and a high marginal vessel density with or without a vascularized rim of connective tissue (n = 4). CONCLUSION: Early peripheral enhancement with centripetal progression appears to be fairly specific for carcinomas, whereas early enhancement with minimal or no centripetal progression, although more common in malignant tumors, may be seen in some benign lesions as well.

Adult↗