The Usefulness of Diffusion Weighted Imaging in the Differential Diagnosis of Various Intracranial Cystic Lesions

PURPOSE: The purpose of this study was to evaluate the usefulness of diffusion-weighted imaging (DWI) for the differential diagnosis of various intracranial cystic lesions. MATERIALS AND METHODS: This study included 19 patients (13 males, 6 females) with a mean age of 42.5 years. The final histopathological diagnoses for 14 patients were pyogenic brain abscess (n=3), glioblastoma (n=3), ependymoma (n=1), anaplastic astrocytoma (n=1), pilocytic astrocytoma (n=1), hemangioblastoma (n=2), arachnoid cyst (n=1), epidermoid (n=1) and schwannoma (n=1). The other cases of metastasis (n=4) and arachnoid cyst (n=2) were diagnosed on the basis of clinical, laboratory and imaging data. DWI imaging studies were performed with a 1.5 T MR system. A single shot spin echo EPI pulse sequence was applied. B values were set at 0 and 1000 sec/mm2. The apparent diffusion coefficient (ADC) were calculated from the ADC map of 10 different cystic brain lesions. Conventional MR imaging included T2WI, T1WI, FLAIR and contrast enhanced T1WI. We analyzed the location, nature, signal intensity on DWI, and the enhancement pattern of the lesions. RESULTS: All of the 3 cases of brain abscess, 1 of 4 cases of metastasis and 1 case of epidermoid showed hyperintensity on DWI. The mean ADC value of brain abscess (2 cases) was less than 1.15 (0.13x10-3 mm2/s). The mean ADC values of the other cystic lesions (8 cases) were variable, ranging from 2.840.66 to 3.100.16 (10-3 mm2/sec). CONCLUSION: DWI and ADC values were useful in the differential diagnosis of various intracranial cystic lesions, but some metastatic tumors may mimic a brain abscess on DWI. Therefore, a clinical correlation is mandatory.

CT and MR Findings of the Telangiectatic Osteosarcoma Arising from the Skull: Case Report

Telangiectatic osteosarcoma is rare malignant tumor causing aggressive bone destruction, though the skull is very rarely involved. We report a case in which the condition affected the skull of a 17-year-old male, involving the parietal bone and with intracranial and extracranial extension. CT and MR images depict an osteolytic lesion of the right parietal bone and an enhancing solid mass in the intracranial and extracranial portions. Matrix calcifications, periosteral reaction, and multiple fluid-fluid levels are seen within the masses.

A Case of Lymphocytic Hypophysitis Presented with Hypoglycemia after Delivery / 대한내분비학회지

Lymphocytic hypophysitis, an inflammatory disease of the pituitary gland that is often associated with pregnancy, is caused by autoimmune destruction of the pituitary gland evidenced by diffuse inflammatory cell infiltration of the pituitary gland and some kinds of detectable autoantibodies. We report a case of lymphocytic hypophysitis in a 31-year-old woman presenting with severe hypoglycemia and hyponatremia after delivery. Hormonal study revealed panhypopituitarism and magnetic resonance imaging with enhancement showed the bulging contour of the right side pituitary gland with an ill-defined mass-like lesion and nodular thickening of the stalk. The patient's symptoms and biochemical data improved greatly with replacement of L-thyroxine and glucocorticoid. Partial recovery of panhypopituitarism was also seen. The follow-up tests revealed dramatic resolution of the pituitary lesion.

Osteonecrosis of the Hip in Patients with Aplastic Anemia

The incidence and clinical and magnetic resonance imaging features of osteonecrosis of the hip were evaluated in patients with aplastic anemia. Two hundred and forty-one patients with aplastic anemia were examined using MR imaging of bone marrow during the five years from 1994 to 1998. Osteonecrosis of the hip was observed on MR imaging in nineteen (15 males and 4 females, mean age 35 yr) of the 241 patients. It was present in both hips in 14 patients, and there were five cases with unilateral occurrence, with a total of 33 involved hips. All except for five hips with associated bone marrow edema revealed increased fatty marrow conversion in the proximal femoral metaphysis. In nine patients, osteonecrosis was detected without any pain. Five patients already had osteonecrosis before any medication was administered. Twelve patients received antilymphocyte globulin, and seven patients received a low dose of steroids before the MR diagnosis of osteonecrosis. Osteonecrosis of the hip frequently develops in patients with aplastic anemia (7.9%), associated with fatty marrow conversion of the proximal femoral metaphysis.

Use of High-dose Steroid in a Case of Scrub Typhus with Acutely Progressive Local Neurologic Symptoms / 감염

Scrub typhus, which is caused by Orientia tsutsugamushi, is systemic illness that causes generalized vasculitis. The central nervous system (CNS) is the most crucial target in scrub typhus as in other rickettsial disease. A 54-year-old woman, who was receiving doxycycline under the diagnosis of scrub typhus, developed rapidly progressive neurologic symptoms. During the treatment, abnormal mental function, abnormal lateral gaze, paralysis in upper extremities and dysphasia occurred in the patient. To investigate CNS involvement in the patients, CSF profile (cell count and levels of protein and glucose) and brain radiologic image (brain CT, brain MRI) were concurrently examined. And ampicillin and high-dose steroid were empirically added to her treatment with doxycycline. With use of high-dose steroid, the initial neurologic symptoms such as restlessness and irritability and other disorders like abnormal lateral gaze and paralysis in upper extremities were recovered. And also any other neurologic sequelae did not appear. We could observe the clinical improvements of abnormal neurologic symptoms and signs after use of high-dose steroid in the Orientia tsutsugamushi infected patients. A further intensive study about the steroid therapy in Orientia tsutusgamushi infected patients with focal neurologic symptoms is required.