Kazuyuki Kojima

Relapsing acute disseminated encephalomyelitis associated with chronic Epstein-Barr virus infection: MRI findings

SummaryA 25-year-old women had a fever, left cervical lymphadenopathy, neurological symptoms and signs, CSF pleocytosis and persistent high serum antibodies to the Epstein-Barr virus (EBV); she had a recurrence 1 year later. She was thought to have relapsing acute disseminated encephalomyelitis associated with chronic EBV infection. MRI revealed abnormalities, mainly in the right basal ganglia and left midbrain. At the time of the recurrence, further abnormalities appeared in the opposite basal ganglia and right cerebral white matter.

Localization of ectopic parathyroid glands using technetium-99m sestamibi imaging: Comparison with magnetic resonance and computed tomographic imaging

The aim of the study was to compare the accuracy of technetium-99m sestamibi imaging for localization of ectopic parathyroid glands in patients with hyperparathyroidism with that of magnetic resonance (MR) and computed tomographic (CT) imaging. Eleven patients with primary (n=3) or secondary (n=8) hyperparathyroidism were studied with99mTc sestamibi parathyroid imaging CT and MR imaging. Images of the neck were acquired at 10 min and 2–3 after tracer injection. The three patients with primary hyperparathyroidism and five patients with secondary hyperparathyroidism underwent parathyroidectomy. The ectopic glands were confirmed by histopathological examination of the resected specimens. In respect of 20 parathyroid glands in the eight patients explored surgically, the sensitivity and specificity of sestamibi imaging were 70% (14/20) and 88%, respectively, those of CT, 40% (8/20) and 88%, and those of MR imaging, 60% (12/20) and 88%. Of these patients, three had parathyroid adenomas while five had hyperplasia (17 glands). Sestamibi imaging localized eight ectopic parathyroid glands, which were surgically confirmed (six were located in the thymus and two in the mediastinum). In one patient explored surgically, the ectopic gland was located outside the field of the MR coil. Although the remaining three cases of secondary hyperparathyroidism were not confirmed surgically, these patients demonstrated sestamibi uptake in five parathyroid glands, including three ectopic glands. MR images demonstrated abnormal parathyroid glands in the same regions as sestamibi imaging. Our data indicate that99mTc-sestamibi imaging should be used initially to localize the ectopic parathyroid glands in patients with hyperparathyroidism for anatomical guidance prior to MR or CT imaging.

MRI of ganglioneuroma: Histologic correlation study

Purpose The purpose of this study was to evaluate the MR findings of ganglioneuroma and to correlate imaging and histologic features. Method Conventional SE and contrast-enhanced dynamic MRI was used to examine 10 patients with pathologically confirmed ganglioneuroma. The morphologic features, signal intensity, and dynamic enhancement pattern of the tumors were retrospectively analyzed and correlated with histologic features. Results Capsules were present in all tumors histologically and were also detected in five tumors on postcontrast T1-weighted images. A whorled appearance corresponding to interlacing bundles of Schwann cells and collagen fibers on histologic specimens was visualized in five tumors on T1-and/or T2-weighted images. Tumors with markedly high signal intensity on T2-weighted images consisted histologically of a large amount of myxoid stroma and relatively few cellular and fibrous components. Tumors with intermediate to high signal intensity consisted of numerous cellular and fibrous components and little myxoid stroma. Early enhancement of tumors was usually lacking in dynamic MR studies; however enhancement gradually increased. Conclusion The results suggest that the MR features of ganglioneuroma are well correlated with histologic findings.

A follow-up study by CT and MRI in 3 cases of Japanese encephalitis

SummaryA follow-up study by CT and MRI in 3 cases of Japanese encephalitis (JE) was performed. Neurologically dementia, forced laughing, tetraplegia and parkinsonism were observed as sequelae. In the CT and MR scans about 3 years after the onset of JE, low-density areas (LDAs) or abnormal signal intensities had remained in the thalamus and basal ganglia. The abnormalities were also found in the brain stem. When the main lesions shown by CT and MRI were compared with those of the acute stage, T2-weighted MRI clearly revealed multiple small areas with high signal intensities, although those in the acute stage had shown diffuse abnormal signals. These findings may be useful in helping to identify JE a long time after the onset.

Collagen Production at the Edge of Ruptured Rotator Cuff Tendon is Correlated With Postoperative Cuff Integrity

PURPOSE The purpose was to evaluate the correlation between messenger RNA (mRNA) expression of collagen at the edge of the ruptured rotator cuff tendon and postoperative cuff integrity. METHODS The edge of the ruptured tendon was sampled during open rotator cuff surgery in 12 patients with full-thickness rotator cuff tears (mean age, 58.2 years). The mean period from symptom onset was 9.3 months (range, 1 to 36 months), and the mean tear size was 4.1 cm. As controls, rotator cuff tendons with no gross rupture were taken from 5 fresh cadavers. Production of type I and type III collagen was examined by real-time reverse transcription polymerase chain reaction. By use of magnetic resonance imaging, postoperative cuff integrity was evaluated based on the classification of Sugaya et al. and then scored, ranging from 5 points for type I to 1 point for type V. RESULTS Looking at the mRNA of type I and type III collagen in tendons, we found that the expression of mRNA for both collagen types in ruptured tendons was significantly greater than in control tendons (P = .0462 for type I collagen and P = .0306 for type III collagen). Correlating the mRNA of type I and type III collagen with repaired cuff integrity on postoperative magnetic resonance imaging, we found a close relation between expression of mRNA for both collagen types and postoperative rotator cuff integrity (r = 0.63 [P = .038] for type I collagen and r = 0.626 [P = .03] for type III collagen). Furthermore, expression of type I collagen mRNA showed a significant inverse correlation with the period from symptom onset (r = -0.845, P < .0005). CONCLUSIONS This study showed that expression of mRNA for type I and type III collagen at the edge of the ruptured rotator cuff tendon was significantly correlated with postoperative cuff integrity and that mRNA expression for type I collagen was significantly associated with the period from symptom onset. These results may suggest that conservative treatment should not be prolonged if patients do not respond within a certain period. LEVEL OF EVIDENCE Level III, prognostic case-control study.

Hemiatrophy of the tongue due to hypoglossal schwannoma shown by MRI

Schwannomas acount for 8.5% of all intracranial tumours; more than 90% arise from the 8th cranial nerve. Only 42 cases of schwannoma of the hypoglossal nerve have been reported. A 59 year-old woman developed right hemiatrophy of the tongue, clearly demonstrated on MRI, as was a small hypoglossal schwannowa. High signal was seen in the atrophic side of the tongue on both T1- and T2-weighted dimages, as described in the literature.

CT and MR imaging of acute cerebellar ataxia

SummaryAn adult female showed mild cerebellar ataxia and CSF pleocytosis following an acute infection of the upper respiratory tract, and was diagnosed as having acute cerebellar ataxia (ACA). CT and MR appearances in the acute stage revealed moderate swelling of the cerebellum and bilaterally increased signal intensity in the cerebellar cortex.

Factors contributing to blood-brain barrier disruption following intracarotid injection of nonionic iodinated contrast medium for cerebral angiography : experimental study in rabbits

PurposeThis study was performed to investigate the role of injection methods and conditions under a fixed dose of radiographic contrast medium (CM) in respect to promoting blood–brain barrier (BBB) disruption.Materials and methodsA total of 44 white rabbits (average body weight 2.7 ± 0.4 kg) were used, and their carotid injection was performed with nonionic CM. The variables assessed for the carotid injections included the following: iodine content (300 or 150 mg I/ml), liquid temperature (37° or 24°C), and the injection time duration (1 or 30 s). The rabbits were divided into five groups. To evaluate BBB disruption, pre- and post-contrast-enhanced magnetic resonance (MR) studies were performed.ResultsAbnormal enhancement of the brain parenchyma in MRI was noted in only one group, which consisted of high-iodine concentration CM injected at a low temperature over a short injection interval. Statistically significant increased values for the percentage of relative enhancement (RE%) were demonstrated (P < 0.05) in comparison with the saline-injected control group.ConclusionThis result suggests variables that may need to be carefully considered to prevent BBB injury induced by nonionic CM for cerebral angiography, especially in the setting of a neurointerventional procedure.

Baló's concentric sclerosis in a 4-year-old Japanese infant

We report the youngest known case with Balós concentric sclerosis (Balós disease), a variant of multiple sclerosis. This 4-year-old Japanese boy was diagnosed by clinical manifestations and by characteristic findings on magnetic resonance imaging (MRI). Dexamethasone was given intravenously, 3 mg twice daily for 10 days. The clinical manifestations were resolved within 2 weeks, and the MRI findings were markedly improved after 3 weeks. Following the initiation of steroid therapy, he showed remarkable clinical and physical improvement. It cannot be excluded that the clinical improvement resulted from the steroid therapy.

Serial magnetic resonance images in a patient with congenital sensory neuropathy with anhidrosis and complications resembling heat stroke

We report the results of serial computerized tomography (CT) and magnetic resonance imaging (MRI) in a 9-month-old Japanese girl with the rare disorder, congenital sensory neuropathy with anhidrosis (CSNA). She developed a prolonged high fever, anorexia, and weight loss with laboratory findings of hemoconcentration and elevated levels of GOT, LDH and creatine phosphokinase (CK) in May 1995, and was hospitalized. The cerebrospinal fluid (CSF) was normal on admission. Elevation of CSF myelin basic protein on the 16th hospital day suggested a destruction of the myelin sheath. The first MRI performed on the 16th hospital day revealed no marked abnormalities when the patient exhibited a high fever, generalized tonic-clonic convulsions, and impaired consciousness. The patient had a persistent high fever, and developed a second generalized tonic clonic convulsion and became comatose. A second MRI on the 20th hospital day showed a bilateral symmetrical paracentral hypo-intensity of the white matter with occipital hypo-intensity on T2-weighted images. MRI findings were considered to represent the complications of the high fever with a loss of water from the cerebral cortices and deep white matter. MRI and CSF findings indicated the presence of brain damage due to the high fever.