Osamu Ishida

MRI of head injury using FLAIR

Abstract We studied the utility of fluid-attenuated inversion-recovery (FLAIR) MRI in the investigation of head injury. We examined 56 patients with head injuries with T2-weighted spin-echo (SE) and FLAIR sequences. In all cases, the sensitivity of FLAIR images to equal or superior to that of conventional SE images to the traumatic lesions. In 9 cases, central diffuse axonal injury of the fornix and corpus callosum could be seen only on sagittal FLAIR images.

Benign fibrous histiocytoma of the femur: review of three cases

Abstract Objective. Benign fibrous histiocytoma is a tumor with histologic features similar to those of xanthofibromas, which include fibrous cortical defects and nonossifying fibromas, but with different clinical features. This study investigated the findings of benign fibrous histiocytoma on various imaging modalities. It emphasized the importance of clinical and imaging features as well as histologic findings in establishing the diagnosis. Design. We reviewed three cases of benign fibrous histiocytoma of the femur that had been diagnosed histologically as (fibro)xanthoma during a retrospective analysis of 187 primary benign and malignant bone lesions. Patients. All the patients were middle-aged women with various knee complaints. Results and conclusions. Radiologically, the lesions were all lytic with well-defined geographic margins and sclerotic rims. The tumors arose within the medullary cavity in the distal metaphysis of the femur and involved the epiphysis. CT showed lytic destruction with well-defined marginal sclerosis. T1-weighted MR images showed that the lesions had predominantly the same signal intensity as that of skeletal muscle. The lesions were hypovascular on angiography. Bone scintigraphy showed moderately increased uptake. It was concluded that multiple images as well as clinical features can be useful in differentiating benign fibrous histiocytoma from fibroxanthoma, giant cell tumor, and other fibrohistiocytic tumors of bone.

MR imaging of meniscal tears with discoid lateral meniscus

OBJECTIVE To study MR findings of meniscal tears with discoid lateral menisci (DLMs) and to evaluate the incidence and accuracy of MRI compared to arthroscopical surgery. MATERIAL AND METHODS MR appearances of surgically proved torn discoid lateral menisci (DLM) were studied in 57 knees (40 patients). They were all performed with a 1.5T MR before surgery. MR sequences included T1- and T2* weighted images on both coronal and sagittal planes and 3D-axial images with a slice thickness of 0.7 mm. RESULT Of 57 DLMs, there were 32 complete DLMs and 25 incomplete DLMs. Twenty-five of 32 complete DLMs had tears; including seven with intrasubstance tear, five with radial tear, five with other kinds of tears and eight with severe tears involving whole meniscus. On the other hand, 13 of 25 incomplete DLMs had tears; including two with intrasubstance tear, six with radial tear, four with other kinds of tears and one with severe tears. All DLMs were correctly diagnosed on MR images. Twenty-seven of 38 tears with DLM were correctly identified on conventional 2D MR images. This yielded 71.1% sensitivity, 100% specificity and 80.7% overall accuracy. When adding axial 3D MR images to 2D MR images, 36 of 38 tears were correctly diagnosed. A combination of both techniques yielded a sensitivity of 94.7% and a specificity of 100%. Ten of 11 radial tears with DLM were correctly identified on 3D axial images, where only three of them could be diagnosed on conventional 2D images. Eight of nine intrasubstance tears were correctly identified on 3D axial images, where six of them could be diagnosed on conventional 2D images. CONCLUSION DLMs had a much higher incidence of meniscal tears than normally shaped lateral menisci and MR is the only modality of choice to evaluate them before surgery. Especially 3D axial MR images were quite useful in the detection of intrasubstance and radial tears often associated with DLMs.

Long-term results of fractionated strontium-90 radiation therapy for pterygia

PURPOSE The long-term safety and effectiveness of fractionated strontium-90 radiation therapy (RT) for pterygium were reviewed retrospectively. METHODS AND MATERIALS Between 1984 and 1996, 399 patients with 490 pterygia were treated with a strontium-90 eye applicator following surgical removal of the pterygium. The median follow-up period was 61 months (range 2-178). Of the 490 pterygia, 452 were fresh, 17 were recurrences after surgical removal alone, and 21 were recurrences after surgical removal plus postoperative RT. Fractionated RT of 31-42 Gy/4-5 fractions/22-29 days was given for 95.1% of the pterygia. RESULTS In total, 58 (11.8%) local recurrences of pterygia were noted. The median time of local recurrences was 10 months, ranging from 2 to 93 months, and 16 recurrences (28%) were noted later than 24 months after treatment. The interval between surgery and the start of RT (1-3 days vs. >3 days) and recurrent pterygia were significant variables for local control in the multivariate analysis, while total RT dose (7-29 Gy vs. 31-50 Gy) was a marginally significant variable. Late toxicities that may be associated with strontium-90 RT were scleromalacia (scleral thinning) in 4 eyes, adhesion of eyelids in 3 eyes, and scleral ulcer in 2 eyes. CONCLUSION Fractionated strontium-90 RT of approximately 40 Gy/4-5 fractions was safe and effective for preventing recurrence of pterygia, when RT was started within 3 days of surgery.

Cranial MRI in chronic thinner intoxication

We studied a 19-year-old man with thinner and toluene poisoning for 5 years by CT and MRI. Symmetrical lesions were seen in the basal ganglia and cingulate gyri.

Bilateral aberrant internal carotid arteries

An aberrant course of the internal carotid artery is a rare vascular anomaly. This is the only known reported case of bilateral aberrant internal carotid arteries examined with CT and MRI.

Multiple intramuscular myxomas associated with polyostotic fibrous dysplasia

Intramuscular myxoma is one of the rare but important associations of skeletal fibrous dysplasia. The association has been seen most frequently with polyostotic fibrous dysplasia, and occurs years after fibrous dysplasia has presented in most cases. The clinical behavior and pathological appearance of soft-tissue myxoma are sometimes mistaken for myxoid liposarcoma. A case of multiple intramuscular myxomas of the bilateral hips and right thigh, associated with polyostotic fibrous dysplasia of the right tibia and right ribs is presented. sive ground glass lesions (Fig. l a). The right tibia presented a radiolucent lesion with marginal sclerosis in the proximal diaphysis and a radiolucency without marginal sclerosis in the metaphysis (Fig. lb). A

Pulmonary and Mediastinal Lymphography

The lymphatic involvement of lung cancer plays an important part in deciding on the treatment policy and the estimation of its prognosis (13, 29). The development of a satisfactory primary examination of the pulmonary and mediastinal lymphatic system has therefore been greatly desired. Since the development of Kinmonths method of lymphography (11), thoracic ductography has been frequently performed for the detection of invasive intrathoracic malignant tumor. Its diagnostic value is limited, however, by the anatomic variation of the thoracic duct and also by difficulty in visualizing it continuously with a conventional amount of oily contrast medium. It has been proved experimentally that an injection of oily contrast medium as well as of Thorotrast or of Micropaque into the peritoneal or pleural cavity stains the retrosternal lymphatics but few of the mediastinal lymphatics relating to the lung (9, 10, 15, 18, 26). The authors have attempted pulmonary and mediastinal lymphography by contrast injection in...

NMR Images of Non-communicating Hydrocephalus Associated with Dandy-Walker Variant and Achondroplasia

Two cases of non-communicating hydrocephalus caused by a relatively rare etiology were reported. The causes of hydrocephalus in these 2 cases were associated with congenital anomaly in the posterior fossa. Previously these lesions were very difficult to make diagnoses using CT scan due to the complicated structure in the narrow posterior fossa, and artefact by the bony structure. After the advent of nuclear magnetic resonance (NMR), NMR became an effective tool for the diagnosis of the posterior fossa lesion, as was presented in this paper. The first patient, a 4-month-old boy, had Dandy-Walker variant, manifesting enlargement of the torcular Herophilii, straight sinus, and vein of Galen, hypoplasia of the inferior vermis and corpus callosum, and a large cyst behind the vermis as well as hydrocephalus. The longitudinal length of the floor of the fourth ventricle was short, possibly associated with hypoplasia of the inferior vermis, but the shape of the fourth ventricle was essentially reserved. Communication of cerebro-spinal fluid between the cyst and subarachnoid space was demonstrated by CT cisternography.