T1-weighted fluid-attenuated inversion recovery at low field strength: a viable alternative for T1-weighted intracranial imaging

BACKGROUND AND PURPOSE: T1-weighted spin-echo imaging has been widely used to study anatomic detail and abnormalities of the brain; however, the image contrast of this technique is often poor, especially at low field strengths. We tested a new pulse sequence, T1-weighted fluid-attenuated inversion recovery (FLAIR), which provides good contrast between lesions, surrounding edematous tissue, and normal parenchyma at low field strengths and at acquisition times comparable to those of T1-weighted spin-echo imaging. METHODS: Thirteen patients with brain lesions underwent T1-weighted spin-echo and T1-weighted FLAIR imaging during the same imaging session. T1-weighted spin-echo and T1-weighted FLAIR images were compared on the basis of four quantitative (lesion-white matter [WM] contrast-to-noise ratio [CNR], lesion-CSF CNR, gray matter-WM CNR, and WM-CSF CNR) and three qualitative criteria (conspicuousness of lesions, image artifacts, and overall image contrast). RESULTS: CNRs obtained with T1-weighted FLAIR were comparable but statistically superior to those obtained with T1-weighted spin-echo imaging. In general, T1-weighted FLAIR and T1-weighted spin-echo imaging produced comparable image artifacts. Conspicuousness of lesions and the overall image contrast were judged to be superior on T1-weighted FLAIR images. CONCLUSION: T1-weighted FLAIR imaging may be a valuable alternative to conventional T1-weighted imaging, because the former technique offers superior image contrast at low field strengths and comparable acquisition times.     

The improvement in regional cerebral blood flow in the anterior cranial fossa which was affected by a dural arteriovenous fistula: case report

We report a case of dural arteriovenous fistula of the anterior cranial fossa with venous ischemia. A 55-year-old man presented with headache and visual disturbance. Neurological examination showed no abnormality. MR images demonstrated flow void at the right anterior cranial fossa. Right internal carotid angiograms showed a dural arteriovenous fistula of the anterior cranial fossa, fed by the anterior ethmoidal artery. The draining vein was the leptomeningeal vein draining into the basal vein, the straight sinus, and the left transverse sinus. 123I-IMP SPECT revealed a low perfusion area in the left occipital region. We interrupted the draining vein at the anterior cranial fossa. Angiographic cure was obtained and venous circulation was improved. 123I-IMP SPECT revealed improvement in the low perfusion area in the left occipital region. The postoperative course was uneventful. We discuss the clinical features, the hemodynamic findings and the management of this case.     

Clinical evaluation of gastric diverticulum on indirect radiograph for gastric mass survey

The aim of this study was to evaluate the clinical conditions of gastric diverticulum. Fifty-four patients with gastric diverticulum (20 men and 34 women among 34,314 patients who underwent medical check-ups) were evaluated on indirect radiographs, for an incidence of 0.16% among the total number of examined cases, a rate lower than that of previous reports. Almost all cases were asymptomatic, had a single diverticulum, and showed a saccular shape. The age distribution indicated higher frequencies in the 5th and 6th decades, and the posterior wall of the fornix was the most common location. Size ranged from 0.6 cm to 12 cm, and 41 cases (75.9%) were between 1.0 cm and 4.0 cm in size. This entity should be kept in mind when reading radiographs of upper gastrointestinal series as well as recognition of pseudodiverticulum and aberrant pancreas as noted for the stomach in several past report. Diverticulum on the cardia, which was previously classified as gastric diverticulum, should be excluded because of the possibility of normal variation.     

In vivo histological changes occurring in hydroxyapatite cranial reconstruction--case report

Histological changes were observed in a hydroxyapatite plate and hydroxyapatite granules used to repair a craniotomy defect and removed after 2 years and 9 months of use. The hydroxyapatite plates and granules had completely fused to the cranium, with new bone formation on the dural side extending in a three-dimensional matrix along the pores with the Haversian system in the center. New bone formation was less extensive under the artificial dura than under normal dura. This finding suggests that the dura has the ability to promote bone formation. A new vessel was found along the interconnecting pores. The interconnecting pores allow osteoconduction in the hydroxyapatite plate, so new bone formation can progress. Hydroxyapatite has osteoconduction properties and is biocompatible, so gains strength in vivo through new bone formation, and is the ideal material for artificial bones. Factors important to achieving good bone formation after cranial reconstruction surgery include presence of the dura, and pore size approximate to the Haversian system (100-500 microns) and interconnecting pores in the hydroxyapatite plate.     

A case of pituitary adenoma with simultaneous secretion of TSH and GH detected by double immunostaining method

A rare case of simultaneous hypersecretion of thyroid stimulating hormone (TSH) and growth hormone (GH) in a pituitary adenoma is reported. A 59-year-old male complaining of general fatigue, dyspnea on exertion and finger tremor was admitted. Examination on admission, he revealed with hyperthyroidism and hypersecretion of TSH and thyroid hormones. Administration of TRH did not further increase serum TSH level, and administration of T3 also had no effect on TSH secretion. CT scan showed a pituitary macroadenoma 13mm in diameter. MRI demonstrated a homogenously hypointense mass with Gd-DTPA enhancement in the left side of the sella turcica. The entire chromophobic adenoma was removed by trans-sphenoidal surgery. Immunostaining of the specimen showed that the cytoplasm of the adenoma cells was positive for both TSH and GH. Double immunostaining using avidin-biotin-peroxidase complex (ABC) method and immunogold silver staining (IGSS) method, showed that the adenoma cells had been secreting both GH and TSH at the same time. After the adenomectomy, the hyperthyroidism disappeared, and all altered indicators of pituitary function returned to normal.     

Purification and biochemical characterization of streptothricin acetyltransferase coded by the cloned streptothricin-resistance gene of Streptomyces lavendulae

Streptothricin acetyltransferase was purified from Streptomyces lividans harboring a plasmid which carried the streptothricin-resistance gene cloned from a streptothricin-producing strain, Streptomyces lavendulae No. 1080. Some properties of the enzyme were determined and the reaction product was identified to be N beta-acetylstreptothricin by NMR spectroscopy.     

Randomized study of initial treatment with radiation.MCNU or radiation.MCNU.interferon-beta for malignant glioma. Hiroshima Brain Tumor Study Group

The efficacy of radiation.MCNU (MR group) or radiation.MCNU.interferon-beta (IMR group) for malignant glioma was studied by a randomized trial at numerous medical facilities. MR group was irradiated with 50-60 Gy and intravenously injected with 2 mg/kg of MCNU on the initial day of irradiation and 6 weeks later. IMR group was also given intravenous administration of interferon-beta at the dose of 2 x 10(6) IU/m2 for 5 serial-days every eight weeks. There was no difference in background between the two groups. The response rate in MR group and IMR group was 44.4% (4/9) and 30.0% (3/10), respectively, showing no significant difference. The resected tumor volume before the start of these regimens seemed to correlate the response to the treatment in both groups. The major toxicity was myelosuppression, especially using MCNU with interferon-beta. These results indicated that this combined therapy is effective for malignant glioma, and should be executed further trials and follow up study.     

Clinical study of hypertensive cerebellar hemorrhage: surgical indication and measurement of volume of hematoma

There have been a few reports available for determining surgical indications in hypertensive cerebellar hemorrhage based on volume of hematoma on computerized tomography (CT). The authors then studied the clinical results of hypertensive cerebellar hemorrhage, and the surgical indication based on clinical findings and volume of hematoma on CT scan was considered. Forty-five patients with hypertensive cerebellar hemorrhage diagnosed by CT scan who were hospitalized to Matsue Red Cross Hospital from January 1980 up to December 1986 were studied. The 25 male and 20 female patients ranged in age from 52 to 85 years, and 16 of them were operated on. The results were as follows: 1) The Kanaya's neurological grading tended to be high in the patients with cerebellar vermis hemorrhage or a large volume of hematoma (greater than or equal to 30 ml). 2) In patients with grade I or II and a moderate volume of hematoma (15-30 ml), the patient complicated with hydrocephalus should be treated with ventricular drainage. The patients with grade III and IVa should be treated with surgical therapy (suboccipital craniectomy and evacuation of the hematoma). The patients with cerebellar vermis hemorrhage should be treated with surgical therapy. The patients with a large volume of hematoma (greater than or equal to 30 ml) should be treated with surgical therapy. The patients with grade IVb and V should not be treated actively because the prognosis is bad.(ABSTRACT TRUNCATED AT 250 WORDS)