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Biomedical subjects

M Iio

Publications and source records attributed to M Iio.

At least 361 records · Page 20Linked to original sources
PubMedDate not supplied

Magnetic resonance imaging in chronic liver disease evaluated in relation to hepatic fibrosis--clinical and experimental results.

In 21 patients with chronic liver disease, the ratio of liver to muscle signal intensity on T1-weighted images was negatively correlated with the progression of hepatic fibrosis defined according to findings by laparoscopy and liver biopsy, and differentiated six patients with early chronic hepatitis from eight with liver cirrhosis. On T2-weighted images, the number of low intensity nodules comparable in size to regenerating nodules surrounded by connective tissues showed a positive correlation with stage. When hepatic fibrosis with no necrosis or fat infiltration was induced in rats, T2 values were positively correlated with hepatic hydroxyproline content, though there was no such correlation for T1 values. These results suggest that MR imaging may be useful for determining the progression of hepatic fibrosis in chronic liver disease. T2 values may directly reflect hepatic fibrosis.

Adult↗
PubMedDate not supplied

Hepatocellular carcinoma: MR appearance mimicking cavernous hemangioma.

A case of hepatocellular carcinoma is reported in which a calculated T2 value of the tumor was exceptionally long and differentiation from cavernous hemangioma based on T2 signal intensity was difficult. Pathologically, the mass consisted of dense, homogeneous acinar formation (pseudoglandular type). The T2 prolongation of the mass was probably due to abundant fluid in the acini.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Computerized three-dimensional normal atlas.

This paper presents our ongoing project in which normal human anatomy and its quantitative data are systematically arranged in a computer. The final product, the Computerized Three-Dimensional Normal Atlas, will be able to supply tomographic images in any direction, 3-D images, and coded information on organs, e.g., anatomical names, CT numbers, and T1 and T2 values.

Computer Graphics↗
PubMedDate not supplied

CT diagnosis of retrocaval ureter associated with double inferior vena cava: report of a case.

A case of retrocaval ureter associated with double inferior vena cava, an exceedingly rare venous anomaly, is reported. This anomaly was correctly diagnosed by CT. CT after intravenous contrast injection showed the double inferior vena cavae on both sides of the abdominal aorta and the right ureter crossing the right inferior vena cava posteriorly. CT is a good diagnostic modality with which to demonstrate such a vascular anomaly, and the clinical usefulness of CT is stressed.

Abnormalities, Multiple↗
PubMedDate not supplied

Analysis of imaging parameters, relaxation time (T1,T2), and relative proton density as they influence the signal intensity of spin echo images.

It is difficult to recognize signal intensity changes on spin echo (SE) images. Clinically both T1-weighted and T2-weighted images are now used in most institutions to evaluate signal intensity changes due to different T1 and T2 of the lesions in MRI. However, these are not sufficient to understand signal intensity changes completely. The authors attempted to summarize on a two-dimensional graph the effects of T1, T2, proton density, and imaging parameters that influence signal intensities on SE images. Both end point (E) and start point (S), as defined later, depended mainly on proton density, but the former also depended on T2 and the later on T1 value. The image obtained in the former situation (near point E) was then called the T2-weighted image. Conditions to accelerate recovery and attenuation velocities (VR and VA), also mentioned later, were the same as those that increased points E and S, respectively. However, when TR was relatively short, the effect of a shorter T1 on VR was greatly emphasized. Such an image was then called the T1-weighted image.

Adult↗
PubMedDate not supplied

Transhepatic portosystemic collateral pathway via an accessory left gastric vein.

An unusual transhepatic collateral was found in a patient with portal hypertension. This pathway originated from an anomalous portal branch that arose from the left portal vein branch, and was considered a venous analogy to an accompanying accessory left gastric artery. A relation between the development of the intrahepatic pathway and variation in the hepatic artery is suggested.

Aged↗
PubMedDate not supplied

Radiation therapy of carcinoma of the oropharynx.

Forty consecutive cases of carcinoma of the oropharynx were treated by irradiation from 1973 through 1987. The overall five-year survival rate calculated by the Kaplan-Meier method was 21%. Data were also analyzed retrospectively to investigate the factors associated with prognosis. The following results were obtained. (1) The results of re-irradiation as salvage treatment were poor. (2) Irradiation to neck lymph node metastases was not particularly effective, especially under 50 Gy. (3) Stage T2(-4) primary tumors were difficult to control with irradiation of 50 Gy.

Adult↗
PubMedDate not supplied

Effect of cervical spinal cord stimulation (cSCS) on cerebral glucose metabolism and blood flow in a vegetative patient assessed by positron emission tomography (PET) and single photon emission computed tomography (SPECT).

This paper presents, for the first time, assessments of cerebral glucose metabolism and cerebral blood flow before and after cervical spinal cord stimulation (cSCS) in a vegetative patient. Regional cerebral metabolic rates for glucose (rCMRglc) were measured with positron emission tomography and 18F-fluoro-2-deoxy-D-glucose. Regional cerebral blood flow (rCBF) was determined with single photon emission computed tomography and N-isopropyl p-123I-iodoamphetamine. Global CMRglc in the patient was less than one-third of that in normal control subjects. An increase in rCMRglc after one week of cSCS was observed in the cerebral cortex, predominantly on the right side, where the baseline level of rCMRglc before cSCS was more severely depressed. The pattern of increase in rCBF was almost the same as that in rCMRglc. The results suggest that cSCS activates glucose metabolism and that this is followed by an increase in cerebral blood flow.

Amphetamines↗
PubMedDate not supplied

Development of multi-purpose catheter for visceral arteriography.

We developed a multi-purpose catheter for visceral arteriography. The outer diameter of the catheter is 5 Fr and the inner diameter admits a 3 Fr catheter. The catheter is made of soft nylon, with a shaft enforced with stainless wire mesh to improve torque transmission. The head is shaped into a three-dimensional configuration, enabling the superselective catheterization that is required for interventional technique as well as arteriography of first-order branches of the abdominal aorta, e.g. the celiac artery and superior mesenteric artery. Using the catheter, we performed 275 arteriographies in 100 cases (first-order-branch arteriography in 190; superselective technique in 85). Arteriography of first-order branches was successful in all cases. The superselective technique was successful without using any other catheters in 89% of cases.

Angiography↗
PubMedDate not supplied

Radiation therapy for primary non-Hodgkin's lymphoma of the head and neck in stages I and II.

From January 1975 through December 1986, 58 previously untreated patients with primary non-Hodgkin's lymphoma of the head and neck in stages I and II were treated at our department. Thirty-seven patients were classified as stage I and 21 as stage II. Complete local remission was obtained in all cases. The 5-year survival rates were 68% and 79% in stages I and II, respectively. The 5-year survival rates according to site of origin were as follows: Waldeyer's ring 77% and neck lymph node 63%. The 5-year survival rates according to the histological classification of the Working Formulation were 73% intermediate grade malignancy and 63% for high grade malignancy. Chemotherapy combined with radiotherapy was essential, especially for cases in stage II. The 5-year survival rate was 100% for patients with chemotherapy and 71% without chemotherapy. The relapse-free 5-year survival rate was 67% with chemotherapy and 36% without chemotherapy. Most first failures were due to the development of generalized disease and the 5-year survival rate after salvage was 44%.

Adolescent↗
PubMedDate not supplied

Carcinoma of the maxillary sinus: the role of radiotherapy.

From 1975 to 1986, 75 M0 patients with squamous cell carcinoma of the maxillary sinus were treated at the Department of Radiology, Tokyo University Hospital. The overall 5-year survival rate calculated with the Kaplan-Meier method was 24%. During the period of the study, the method of treatment used in our hospital changed. From 1975 to 1979 (the first period), the treatment of choice was low-dose irradiation and frequent necrotomy. From 1980 to 1982 (the second period), more extensive surgery was performed and 50 to 60 Gy of irradiation was given. The 5-year survival in the first period was 20%, that in the second 14%. From 1983 to 1986 (the third period), trimodal therapy (surgery + radiation + intra-arterial infusion) was introduced and 5-year survival was improved to 50%. Intra-arterial cisplatinum infusion and treatment planning using CT scans were especially useful in improving survival.

Adult↗
PubMedDate not supplied

A new method for brain functional study using Tc-99m HMPAO SPECT.

The distribution of 99mTc-HMPAO in brain is in proportion to regional cerebral blood flow (rCBF) and can be interpreted as functional mapping. To evaluate local changes in CBF during neuropsychological testing, we developed a new subtraction method using HMPAO and SPECT. With patients resting, 15 mCi of HMPAO was injected and the first acquisition was performed, lasting a total of 10 minutes. Soon after the end of the first scan, patients were requested to undergo Buschke's memory test or to repeat words or numbers (repetition test). During the task, an additional 15 mCi of HMPAO was injected using the same position as in the first scan, and a second acquisition was started. A functional image was made by subtracting the image in the first scan from that in the second. In two patients with transient global amnesia and two normal controls, Buschke's memory test was performed in combination with SPECT. A Relative increase in activity was seen in the thalamus, subthalamic area, hippocampus, and some cortical areas, apparently reflecting local functional change induced by the memory task. In two patients with moderate Alzheimer's disease with severe memory loss, no increase was detected in these areas. In one patient with aphasia, the repetition test with SPECT was correlated with the WADA test and dichotic listening test, and good agreement was obtained. In conclusion, our new SPECT technique is useful in detecting alterations in rCBF during mental activity and can be applied to neurophysiological studies.

Alzheimer Disease↗
PubMedDate not supplied

Transcatheter arterial embolization for spontaneous rupture of hepatocellular carcinoma.

Transcatheter arterial embolization (TAE) was performed in 20 patients with ruptured hepatocellular carcinoma (HCC). Bleeding was improved in all patients, but only four survived for over three months. Rerupture occurred in seven patients (35%) and the prognosis was extremely poor. TAE should be considered the treatment of choice for ruptured HCC; however, long-term survival was limited to those patients without portal extension of HCC. The severity of rupture also influenced the prognosis.

Adult↗
PubMedDate not supplied

Magnetic resonance imaging (MRI) of primary liver cancer--MRI-pathologic correlation.

In seven primary liver cancers (HCC 5, CCC 1, mixed 1), MR images (0.35 Tesla super-conducting) were compared with macroscopic appearances, and relaxation times (T1 and T2) with microscopic characteristics. MRI was able to reveal the gross appearance of five nodular lesions, but did not reveal one diffuse HCC and one nodular HCC with marked extracapsular extension. T2-weighted SE images could not demonstrate fibrous capsules around the tumor in four nodular HCCs. The T1 and T2 values of the tumors were longer than those of the surrounding liver parenchyma, and the T1 elongation corresponded roughly to the degree of necrosis and fibrosis within the tumors.

Adult↗
PubMedDate not supplied

Transcatheter arterial embolization (TAE) in treatment for hepatoma--analysis of three-year survivors.

Among 224 hepatomas treated with transcatheter arterial embolization, ten patients who survived for three years are presented. All cases had nodular lesions and the volume ratio of tumor to liver was less than 10% in nine cases. Eight cases had no large venous extension, however, one had 90% occlusion of the portal trunk and the other had tumor thrombus within the inferior vena cava. Laboratory data showed liver function was largely spared in eight cases, whereas the other two had severe liver cirrhosis. CT and/or angiography showed an increase in tumor volume in eight cases after three years of survival. Beneficial factors for long-term survival and the limitations of embolization are also discussed.

Adult↗
PubMedDate not supplied

31P-NMR spectroscopy of myopathies: clinical application of whole-body MR.

Patients with myopathies were examined by 31P-NMR spectroscopy using a whole body MR system operating at 1.5 T. Spectra from the femoral muscles were measured as a function of time during a post-exercise recovery period. A 4-min scanning time was used to obtain a good S/N ratio and enable us to evaluate the relative intensity and position of each absorption line. The results were expressed by PCr/Pi ratio and pH value and compared with values before exercise. Clear changes were observed in the recovery process after workload depending on the stage of disease. We were able to observe the in vivo dynamic energy metabolism of myopathies by whole-body MR.

Adult↗
PubMedDate not supplied

Dynamic MRI of hepatic tumors using gadolinium-DTPA--preliminary results.

Dynamic magnetic resonance imaging (MRI) was performed in two patients with hepatic tumors (one cavernous hemangioma and one hepatoma). A sequential timed scanning technique with spin echo images (TR: 100 msec; TE: 20 msec; data acquisition time: 26 sec) was used with a bolus injection of 0.05 mmol/kg gadolinium DTPA. Dynamic MRI findings in the two cases were similar to those obtained with dynamic CT and angiography using iodinated contrast medium. Our early experience suggested that the less invasive technique of dynamic MRI could replace conventional dynamic CT in assessing the hemodynamics of hepatic tumors.

Carcinoma, Hepatocellular↗