Yousuke Kakitsubata

MRI of ossification of ligamentum flavum

Magnetic resonance imaging of 28 patients with radiological and/or histopathologically proved ossification of the ligamentum flavum (OLF) was reviewed. The locations of OLF were cervical (n = 4), thoracic (n = 22), and lumbar (n = 2). On T1- and T2-weighted images, OLF demonstrated low signal intensity. Areas of high or intermediate signal intensity within the OLF on T1-weighted images were observed in three cases and were interpreted to be due to fat infiltration. In six cases, high intensity areas in the spinal cord caused by compressing OLF were demonstrated on T2-weighted images. Gadolinium-diethylenetriamine pentaacetic acid, which was used in four cases, showed cord enhancement at the level of compression by OLF in three cases.

Spontaneous spinal subarachnoid hemorrhage associated with subdural hematoma at different spinal levels

We describe the clinical features and MR-imaging findings of spontaneous spinal subarachnoid hemorrhage located in the lumbar spine associated with subdural hematoma at a higher, thoracic level in a 66-year-old man without neurological deficit. The sequential MR-imaging changes of hemorrhage at various stages in its evolution are portrayed. The possible pathogenetic mechanism for these very unusual, combined hemorrhages in both spinal compartments is discussed.

CT manifestations of lipomas of the small intestine and colon

Seven cases of lipoma of the intestine demonstrated by computed tomography (CT) are reported. There were three men and four women who ranged in age from 47 to 78 years. The lipomas were in the small intestine in four patients, and in the colon in three. CT documented the characteristic low attenuation (fat density) of these masses in all patients. It is concluded that intestinal lipomas are important indications for CT evaluations.

Magnetic Resonance Discography in Cadavers: Tears of the Annulus Fibrosus

The purpose of this study was to investigate the diagnostic capabilities of magnetic resonance discography in the detection of tears of the annulus fibrosus, and to compare the findings with those derived from conventional magnetic resonance imaging. Twenty-four intervertebral discs from cadavers were examined with magnetic resonance imaging and magnetic resonance discography, and anatomic correlation was done. Forty-six annular tears were documented on anatomic inspection of the specimens. Magnetic resonance discography allowed significantly better observation of radial than transverse annular tears, and identification of radial tears was significantly better than that of concentric tears. With magnetic resonance discography, detectability of concentric tears was not significantly better than that of the transverse tears. No significant differences in the detection of different types of annular tears were appreciated on the magnetic resonance images obtained before discography. Magnetic resonance discography allowed direct diagnosis of radial, transverse, and concentric tears in 100%, 57%, and 21% of specimens, respectively. With magnetic resonance imaging, the diagnosis of radial, transverse, and concentric tears was possible in 67%, 71%, and 21% of specimens, respectively. Magnetic resonance discography does well in the evaluation of the clinically important radial tears of the annulus fibrosus, although not uniformly well in the identification of other types of annular tears.

Mesenteric plexiform neurofibroma associated with Recklinghausen's disease

Abstract We present a rare case of plexiform neurofibroma involving the ileal mesentery of a 10-year-old boy with Recklinghausens disease. MRI showed multiple ring-like structures in the masses on T2-weighted and contrast enhanced T1-weighted images. Probably these findings reflect enlarged peripheral nerves with myxoid degeneration. MRI is useful for the diagnosis of mesenteric plexiform neurofibroma because of this characteristic appearance.

Symptomatic epidural gas cyst associated with discal vacuum phenomenon.

Study Design. Four cases of computed tomography and magnetic resonance imaging documented lumbar nerve root compression associated with a vacuum disc communicating with the epidural space are presented. Objective. To give an insight into the mechanism of nerve root compression associated with vacuum disc phenomenon. Summary of Background Data. Few cases of lumbar radiculopathy resulting from epidural gas have been reported and illustrated using cross-sectional imaging studies. Methods. The medical records, imaging examinations, and surgical findings (when available) of 4 symptomatic patients with epidural and intradiscal gas collections were reviewed. Three patients underwent surgery with needle aspiration of the epidural gas, and 1 patient was treated conservatively. Results. Clinical symptoms of epidural gas cyst were similar to those of other more common causes of nerve root compression. Computed tomography and magnetic resonance imaging findings showed intraspinal gas collection associated with a vacuum disc. One patient had an additional vertebral pneumatocyst. Although evacuation of intraspinal gas resulted in complete cure or major neurologic improvement in 3 patients, an initial period of observation is warranted because gas may disappear spontaneously as in 1 of our patients. All 4 patients recovered full motor and sensory functions of the lower extremities. One year later, patients were completely free of symptoms. Conclusion. Although the vacuum disc is considered a common imaging finding of no or not much pathologic significance, occasionally intradiscal gas may leak into the spinal canal. Detection of an epidural gaseous collection at the same level with a vacuum disc strongly suggests a communication between the intervertebral disc and the epidural space. Epidural gas collections can be implicated as a possible cause of radicular symptoms and should be considered in the differential diagnosis of lumbar radiculopathy.

CT and MRI manifestations of intraabdominal panniculitis.

We report a case of intraabdominal panniculitis. Computed tomography (CT) showed diffuse increased attenuation in the omentum, mesentery, and retroperitoneal region. As the disease progressed, the entire mesentery and retroperitoneal regions were involved. On magnetic resonance imaging (MRI), the lesion demonstrated an intermediate signal intensity on T1-weighted images and a slightly high signal intensity on T2-weighted images. Though the radiologic findings are not specific, this condition should be considered in the appropriate clinical context.

Absence of the left lobe of the liver: US and CT appearance

We report five cases of absence of the left liver lobe diagnosed by ultrasonography (US) and/or computed tomography (CT). There were four men and one woman, with an average age of 62.8 years. The right lobe was normal in four patients and enlarged in one. A tongue-like hypertrophy of the caudate lobe was present in two patients. The gallbladder was located at the left portion of the liver. Elevation of the antrum of the stomach was also seen.

Neurofibromatosis type 1 involving the liver: ultrasound and CT manifestations.

We present a rare case of neurofibromatosis type 1 (NF-1) involving the liver in a 15-year-old girl. Abdominal ultrasonography revealed infiltrative hypoechoic masses around the porta hepatis and intrahepatic portal branches. CT also revealed extensive low-attenuation masses in the hepatic hilum and retroperitoneum. The tumor spread into the liver along the portal vein. It should be borne in mind that the liver may be involved by neurofibromas in patients with NF-1.

Intraspinal gas associated with intestinal necrosis detected by CT

We report the case of a 63-year-old woman with necrosis of the small intestine and intraspinal collections of gas, which were detected using computed tomography (CT). Abdominal CT revealed extensive collections of gas in the portal and mesenteric veins and within the intestinal walls. Gas radiolucencies were also noted in the epidural spaces of her spine. This gas was considered to have migrated from the pelvic venous system into the internal venous plexus of the spine. Intestinal necrosis should be included in the differential diagnosis of intraspinal gas collections during CT.