Magnetic resonance imaging and computed tomography for diagnosing semicircular canal dehiscence.

OBJECTIVES: We investigated the semicircular canal (SC) dehiscence using temporal computed tomography (CT) and magnetic resonance (MR) imaging. METHODS: We retrospectively reviewed 114 (228 ears) consecutive MR images and CT scans of the temporal bones for dehiscence of the SCs. In the 1.5 Tesla (T) MR imaging, T1 and T2-weighted images were obtained. Dehiscence of the SCs was defined by absence of high attenuation bone coverage on the CT scans, and absence of low-signal bone margins on the MR images. RESULTS: Superior SC dehiscence was detected in 4 (1.8%) ears using CT scans and 5 (2.2%) ears using MR imaging. Posterior SC dehiscence was detected in 4 (1.8%) ears using CT scans and 4 (1.8%) ears using MR imaging. In the non-dehiscent cases, there was hypointense bone coverage between the canal and the cerebrospinal fluid (CSF). However, in the cases of semicircular canal dehiscence, hypointense bone tissue did not appear between the canal and the CSF in the MR imaging. CONCLUSION: If there is clinical doubt about the presence of SC dehiscence, we recommend that MR imaging be conducted first. When dehiscence is not seen in the MR, a CT examination should be performed. MR imaging is preferred primarily, because it does not contain ionizing radiation.

Superior mesenteric artery syndrome accompanying with nutcracker syndrome: a case report.

INTRODUCTION: Superior mesenteric artery syndrome is an uncommon cause of duodenal obstruction, and its manifestations are generally associated with compression on the third part of the duodenum between the abdominal aorta and superior mesenteric artery. CASE PRESENTATION: In this report, a patient is described presenting with epigastric pain and weight loss due to superior mesenteric artery syndrome. The patient has also nutcracker syndrome, which is the compression of the left renal vein between the aorta and the superior mesenteric artery at its origin. CONCLUSIONS: In addition to an appropriate clinical history, CT findings indicating decreased aortomesenteric angle and a shortened aortomesenteric distance can suggest the diagnosis for both the superior mesenteric artery syndrome and accompanying nutcracker syndrome.