Biomedical subjects
Publications and source records attributed to T Sagoh.
We describe unusual findings obtained by diffusion-weighted magnetic resonance imaging (MRI) in a patient with acute purulent meningitis caused by penicillin-resistant Streptococcus pneumoniae. Along cerebral convexities and the Sylvian fissure, multiple small intense lesions showed high signal intensity in these sequences. This may be the first report of diffusion-weighted in purulent meningitis.
The results of intraarterial chemotherapy (IACT) combined with definitive radiation therapy for 23 advanced and bulky carcinomas of uterine cervix are reported. IA-CT with cisplatin 50 mg and doxorubicin 30 mg was administered by one shot method in bilateral internal iliac arteries. The protocol consisted of one to three treatment session every 3 weeks. Nine of eleven patients with clinical stage III achieved a complete local response (82%), and the 3- and 5-year survival in these cases were 72% and 72%, respectively. These results were superior to the response (58%), 3- and 5-year survivals (68%, 58%) obtained in 19 patients treated mainly with radiation therapy alone. The side effect of grade 2 and 3 for the intestine, such as ileus and hemorrhagic colitis, was noted in 3 patients (15%). In addition, 3 of 8 patients with radical surgery and postoperative radiation therapy after IA-CT developed insufficient fracture of pelvic bone. These complications accompanied by IA-CT combined with radiation therapy and/or surgery increased slightly, compared with that by the previous therapy without IA-CT, but were not critical. The results suggest that IA-CT following radiation therapy is effective to improve the prognosis of patients with Stage III cervical cancer.
Follow-up studies using monitoring with alpha1-feto protein (AFP), ultrasonography (US), and computed tomography (CT) were carried out in 75 patients who had prior partial hepatectomy for hepatocellular carcinoma (HCC). Recurrence in the remaining liver was confirmed in 31 patients (41.3%) during the 4 month to 3 years 7 month period. Ultrasonography detected recurrence in 29 cases (sensitivity: 93.5%), CT in 26 (83.9%), and AFP assay in 12 (38.7%). In 4 patients, ultrasonography detected four recurrent nodules that CT missed. In 1 patient, two subphrenic nodules were detected with CT but not with ultrasonography. The specificity of US, CT, and AFP assay was 90.9%, 95.5%, and 93.2% respectively. Frequent follow-up study with ultrasonography in combination with CT and AFP assay should be recommended for the early detection of recurrent HCC. Ultrasonography is mandatory for the follow-up of patients with a prior hepatectomy for HCC.
Magnetic resonance (MR) images of 19 patients with histologically proved gallbladder carcinoma were retrospectively reviewed to determine the appearance of the primary tumor, and to assess the ability of MR imaging to demonstrate the various modes of tumor spread beyond the gallbladder. The primary tumor, as well as tumor spread beyond the gallbladder, was hyperintense on T2-weighted images and hypointense on T1-weighted images when compared with the liver parenchyma. Liver invasion and metastasis could be depicted by MR imaging with both sequences, unless the tumors were small or the extent of invasion was minimal. Duodenal invasion was difficult to evaluate because of motion artifacts, paucity of fat, and partial volume effects. T1-weighted images readily demonstrated extension of the tumor to the hepatoduodenal ligament and para-aortic region with good contrast between tumor and surrounding tissue. The extent of tumor extension to the blood vessels was also easily evaluated because of flow void in the vasculature. MR imaging can help determine the extent of gallbladder carcinoma and can contribute to the staging of this disease.
Demonstration and staging of carcinoma of the cervix with magnetic resonance (MR) imaging was evaluated prospectively in 67 patients with histologically proven lesions. Findings were correlated with surgical/pathologic results obtained within 2 weeks. MR imaging had an accuracy of 95% in demonstrating invasive disease (stage IB or higher). It was capable of depicting the location and extent of tumor invasion of cervical stroma and helped detect tumor beneath relatively normal epithelium or within the endocervical canal that had not been detected by means of colposcopic biopsy. The overall accuracy of MR imaging in staging carcinoma of the cervix was 76%, and in demonstrating parametrial status, the overall accuracy was 89%. In 39 patients with proven invasive disease, the accuracy in demonstrating parametrial status was 82%. In 13 of these 39 patients the low-signal-intensity stromal ring of the cervix on MR images was completely preserved and there were no false-positive results. MR imaging is a highly promising method for directly demonstrating and staging carcinoma of the cervix and seems to be capable of providing answers to crucial questions regarding mode of therapy.
The potential of magnetic resonance (MR) imaging in differentiation of adenomyosis from leiomyoma was evaluated in 93 patients who had a palpable enlarged uterus that was suspect for leiomyoma or adenomyosis. In all cases, MR images were correlated with surgical/pathologic findings. Pathologic findings showed that 71 enlarged uteri were due to leiomyoma, including one leiomyosarcoma, and 16 were due to adenomyosis. The other six patients were shown to have an enlarged uterus attributable to simultaneous involvement of both lesions. On T2-weighted images, adenomyosis appeared as an ill-defined, relatively homogeneous low-signal-intensity area embedded with sparse high-intensity spots. In contrast, leiomyomas were well-circumscribed masses with a spectrum of signal intensity. The cause of uterine enlargement was correctly diagnosed with MR images in 92 of the 93 cases. It is concluded that MR imaging is highly accurate in helping to distinguish between adenomyosis and leiomyoma in cases of enlarged uterus.
The authors retrospectively evaluated magnetic resonance (MR) images obtained in 64 patients with portal hypertension. Multiple low-intensity nodules were noted within the spleen in eight patients. In all eight cases, these nodules were most apparent on images obtained with the GRASS (gradient-recalled acquisition in the steady state) technique, which is known to be more sensitive to heterogeneity of the magnetic susceptibility, usually caused by hemosiderin deposition. In one of these cases, ultrasonography demonstrated diffuse hyperechoic spots that had been reported to represent Gamna-Gandy bodies of the spleen (ie, organized hemorrhage caused by portal hypertension). Although there was no pathologic proof in their series, the authors believe these low-intensity nodules seen on MR images may represent the hemosiderin deposits of Gamna-Gandy bodies.
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We examined thirty-five patients with various chest diseases with cardiac gated Magnetic Resonance Imaging (MRI) at 1.5 tesla. Major advantages of MRI of the thorax are its abilities to display sagittal and coronal planes and to disclose vessels clearly without contrast media. We conclude MRI is useful in evaluating, 1) masses at the lung apex or base, 2) chest wall invasion, 3) hilar and mediastinal lymphadenopathy, 4) aortic aneurysm, and 5) bronchogenic cyst.
Myeloperoxidase gene transcription in isolated nuclei from HL-60 cells induced to differentiate into granulocytes by dimethyl sulfoxide or into macrophages by 12-O-tetradecanoylphorbol-13-acetate was studied by dot-blot hybridization of a myeloperoxidase cDNA to the 32P-labeled nuclear transcripts. Myeloperoxidase gene transcription, like that of c-myc gene transcription, was reduced to a low level within 12 h after the inductions of these differentiations. In contrast, transcription of the actin gene remained constant. These results indicate that decrease in myeloperoxidase synthesis in HL-60 cells during differentiation is regulated at a transcriptional level.
The authors explored the capability of high-field-strength surface coil magnetic resonance (MR) imaging in disclosing the gross pathologic characteristics of thyroid masses (especially pseudocapsular and hemorrhagic degeneration). Twenty-four patients were examined, including 12 with papillary carcinoma, eight with adenoma, and four with adenomatous goiter. All patients underwent surgery within 2 days after MR imaging. Specimens were cut and correlated directly with MR images. The appearance of the pseudocapsule was classified into four types: A, intact and even thickness around the tumor; B, only partially present or even absent; C, intact but with uneven thickness; D, partially destroyed by tumor. MR imaging findings corresponded precisely with those of gross pathologic examination in all cases but four of adenoma. Type A pseudocapsules were found only in adenoma and type D only in papillary carcinoma. Although the number of cases in the series was limited, the authors conclude that MR images reflect gross pathologic findings well and that some characteristic findings are suggestive of benign or malignant disease.
Ten patients with spinal arteriovenous malformations (AVMs) were examined with high-field-strength (1.5-T) magnetic resonance (MR) imaging and a surface coil (eight patients) or head coil (two patients). Four AVMs were intramedullary, and six were extramedullary. There was one case of Foix-Alajouanine disease (subacute necrotizing myelitis; thrombosed AVM). Three important pathologic findings--myelomalacia, total thrombosis, and wall thickening of the draining vein--were clearly demonstrated at MR imaging and confirmed at autopsy. A flow-sensitive sequence was valuable in the depiction of one intramedullary AVM as hyperintense, the postoperative evaluation of AVM, and the differentiation of nidus from old intramedullary hematoma. In other AVMs, cord edema, periradicular hematoma, and reversible changes of cord scalloping after surgery were demonstrated. MR imaging demonstrated various pathologic changes of the spinal cord that could not be detected with any other imaging method.
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Sixty patients with hepatocellular carcinoma (HCC) were studied with computed tomography (CT) and magnetic resonance (MR) imaging at 1.5 T. MR imaging was equivalent to CT in detection of HCC. MR imaging was superior to CT in demonstrating the details of tumors, especially pseudocapsules. In 58 cases, main tumors were detected with MR imaging. On spin-echo (SE) 600/25 (repetition time msec/echo time msec) sequences, tumors were hyperintense in 18 cases, isointense in ten, and hypointense in 30. On SE 2,000/60 sequences, all but two tumors had high signal intensity. Pseudocapsules, intratumoral septa, daughter nodules, and tumor thrombi, which are important characteristics of HCC, were demonstrated in 22, three, six, and six cases, respectively, on MR imaging. MR imaging is useful for characterizing the internal architecture of HCC.
Eleven patients with moyamoya disease were studied with magnetic resonance (MR) imaging performed with a high-field-strength (1.5-T) superconducting magnet. In all cases a fundamental pathologic change of moyamoya disease--occlusion or stenosis of the terminal portion of the internal carotid artery and the proximal portion of anterior and middle cerebral arteries--was clearly demonstrated. The characteristic collateral network from the suprasellar cistern to the basal ganglia, which corresponds to the "moyamoya vessels" on angiograms, was seen in several patients. Various ischemic changes, including infarction, brain atrophy, and ventricular dilatation, were also well demonstrated. MR imaging plays an important role in the diagnosis of moyamoya disease.
Magnetic resonance (MR) imaging was performed in ten patients with pituitary stalk transection who had idiopathic pituitary dwarfism. Contiguous sagittal T1-weighted images were obtained in all cases, and, in some, axial or coronal images were taken for further evaluation. On MR images, normal anterior and posterior lobes of the pituitary gland can be clearly differentiated because the posterior lobe has a characteristic high intensity on T1-weighted images. In the ten patients, the high-intensity posterior lobe was not seen, but a similar high signal intensity was observed at the proximal stump in seven patients. This high-intensity area is the newly formed ectopic posterior lobe, which secretes antidiuretic hormone just as the posterior lobe would. When the ectopic lobe completely compensates for the impaired posterior lobe, endocrinologic data indicate normal posterior lobe function. However, MR imaging can reveal the transection of the pituitary stalk and formation of the ectopic lobe.
Computed radiography was combined with a 0.1-mm microfocus radiographic tube to obtain radiographic magnification of a x3 to x5. Gray-scale image processing compensated for the loss of radiographic contrast associated with the high-kilovoltage, short-exposure technique. The high-pass spatial frequency filtering capability of the computed radiography resulted in enhanced edges and increased displayed latitude. The improved image quality obtained by magnification computed radiography allowed delineation of subtle abnormalities and small anatomic structures not apparent on conventional screen-film contact or magnification radiographs.
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