The role of three-dimensional computed tomography in the management of maxillofacial bone fractures

The findings of three-dimensional computed tomography (3DCT) and two-dimensional computed tomography (2DCT) with helical CT scanning were compared for 21 patients with maxillofacial bone fractures. The results of this study suggest that the 3DCT evaluation can be divided into 3 groups. The first group, in which 3DCT is superior to 2DCT, includes severe complicated midface fractures, for example, tripod fractures and complicated maxillary bone fractures. The second group, in which 3DCT is equal to 2DCT, includes simple fractures, for example, nasal bone fractures and isolated zygomatic fractures. In this group, patients and their families could easily understand the nature of the fracture and clinical course shown by 3DCT as compared with conventional X-ray and 2DCT. The third group, in which 3DCT is inferior to 2DCT, includes blowout fractures. Although 3DCT does not provide additional information in blowout fractures, helical scanning permits clear observation of multiplanar images without artifacts arising from metal prostheses by excluding lower slices during image reconstruction. We conclude that 3DCT provides useful information, especially in regard to the extent of complex fracture lines, as in tripod fractures.</p

Use of fluid-attenuated inversion recovery (FLAIR) pulse sequences for differential diagnosis of hepatic hemangiomas and hepatic cysts

Fluid-attenuated inversion recovery (FLAIR) imaging of hepatic hemangiomas (10 patients, 16 lesions) and hepatic cysts (8 patients, 10 lesions) was performed. All hemangiomas were hypointense on T1-weighted images and hyperintense on T2-weighted images. With Gd-DTPA (0.1 mmol/kg), all hemangiomas were enhanced but not all cysts. It was necessary to perform contrast enhanced imaging to differentiate hepatic hemangiomas from hepatic cysts. However, on FLAIR imaging, hepatic hemangiomas were strongly hyperintense and 9 of the 10 hepatic cysts were isointense. One of the hepatic cysts was slightly hyperintense. FLAIR images were useful in differential diagnosis of hepatic hemangiomas and hepatic cysts without using Gd-DTPA.</p

Detection of subependymal veins using high-resolution magnetic resonance venography

High-resolution magnetic resonance venography (HR-MRV) of intracranial subependymal veins using a two-dimensional Fourier-transform time-of-flight technique was performed on normal volunteers and clinical cases of cerebral disease. For the pulse sequence, fast-field-echo sequence was used with the following parameters: TR/TE/ flip angle = 34ms/12ms/50deg., 256 x 256 matrix, 1 mm effective slice thickness, 150mm field of view, and one signal acquisition. Sequential vertical coronal sections were taken against the skull base. The anterior septal vein, the medial atrial vein, the anterior caudate vein and thalamostriate vein were detected in all subjects. In all clinical cases, HR-MRV was equal in diagnostic capability to conventional cerebral angiography.</p