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Biomedical subjects

Tatsuo Kumazaki

Publications and source records attributed to Tatsuo Kumazaki.

At least 37 records · Page 2Linked to original sources
PubMed2005

A case of dermoid cyst of the ovary with malignant transformation complicated with small intestinal fistula formation.

A 54-year-old woman complained of abdominal pain and watery diarrhea that had begun two days before admission. Physical examination revealed abdominal distention and tenderness throughout the abdomen, but there was no muscle guarding or rebound tenderness. The leukocyte count was 27.0 x 10(3)/microl, and CRP was 28.5 mg/dl. A plain film of the abdomen revealed the shadow of a huge gas-containing mass with an air-fluid level and a dilated small intestine with air-fluid level. CT showed a huge gas-containing cystic mass with fatty component and solid structure. Omental thickening was also noted. Emergency surgery was performed, and an enlarged left ovary that was adherent to the small intestine was removed. Microscopic examination revealed a squamous cell carcinoma in the dermoid cyst wall. The carcinoma had directly invaded the small intestine and a fistula between the cyst and the intestine was noted. Thickened omentum showed granulomatous inflammation in the fatty tissue, but no metastases were detected. The histopathological diagnosis was dermoid cyst with malignant transformation and invasion of the small intestine. Chemotherapy was performed, but the patient died of progression of peritoneal metastases 10 months after the operation.

Carcinoma, Squamous Cell↗
PubMed2004

Magnetic resonance portography using contrast-enhanced fat-saturated three-dimensional steady-state free precession imaging.

PURPOSE: To assess the feasibility of contrast-enhanced fat-saturated three-dimensional steady-state free precession (FIESTA) imaging for contrast-enhanced magnetic resonance (MR) portography. MATERIALS AND METHODS: Contrast-enhanced fat-saturated three-dimensional fast spoiled gradient-echo (SPGR) and FIESTA were performed as MR portography. In 10 cases, fat-saturated three-dimensional FIESTA was first performed and followed by fast SPGR, and the order of post-contrast imaging was reversed in the other 10 cases. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were estimated for portal and visceral veins on the source images. The visualization of portal vein was scored on three-dimensional MR portography. Portal venous system disorders were assessed using three-dimensional MR portography. RESULTS: The SNRs, CNRs, and visual assessment of portal and visceral veins were significantly higher in contrast-enhanced fat-saturated three-dimensional FIESTA than contrast-enhanced fat-saturated three-dimensional fast SPGR (P < 0.05). The contrast-enhanced fat-saturated three-dimensional FIESTA provided high venous signals even at 8 minutes after gadolinium injection. The abnormalities of portal venous system were well visualized with MR portography using contrast-enhanced fat-saturated three-dimensional FIESTA. CONCLUSION: Contrast-enhanced fat-saturated three-dimensional FIESTA was valuable for MR portography, with flexible time window and high vascular signals. This imaging may allow for other post-contrast imaging options before portography and release patients from consecutive breath-holds.

Adult↗
PubMed2004

Three-dimensional display in staging hemodynamic brain ischemia for JET study: objective evaluation using SEE analysis and 3D-SSP display.

The Japanese EC-IC bypass trial (JET study) was established to evaluate the validity of MCA-STA anastomosis in intracranial arterial occlusive disease aiming at stroke prevention. This study must use an objective method to reliably estimate hemodynamic brain ischemia. We devised a method of objectively classifying the severity of hemodynamic ischemia using quantitatively analytical and display software, stereotactic extraction estimation for stereotactic brain coordinates and three-dimensional stereotactic surface projections (3D-SSP). We analyzed data from 16 patients registered in the JET study. Our method offers quantitative information and 3-dimensional displays of the CBF at rest and after Diamox challenge, vascular reserve and the severity of the hemodynamic brain ischemia. We compared the maximal projection counts with ROI data from tomographic images in the anterior commissure-posterior commissure plane. The maximal counts data correlated closely with the ROI data of rest and with Diamox SPECT images (both p < 0.0001). The slopes of the linear regression line were 1.15 and 1.12, respectively. The results of this study indicated that our method could simply and objectively evaluate the severity of impaired brain circulation. This procedure should support the evaluation of hemodynamic ischemia in the JET study although validation is required by several institutions using more study subjects.

Aged↗
PubMed2004

A comparative study of the microcirculatory changes in the developing liver cirrhosis between the central and peripheral parts of the main lobe in mice.

A comparative study of the microcirculatory changes in the developing liver cirrhosis between the central and peripheral parts of the main lobe in mice. INTRODUCTION: To investigate whether a difference in microvascular vascular changes occurring in the peripheral and the central area of the main liver lobe exists and if, it can explain the liver atrophy observed predominantly in the peripheral part of the main liver lobe. MATERIALS AND METHODS: Liver cirrhosis was induced in mice and the microvascular changes asserted using an intravital microscopy system after 1, 2, 3 and 8 weeks of treatment. RESULTS: The mean blood velocity increased in the sinusoids; intrahepatic shunts appeared predominantly in the peripheral area and larger sized afferent terminal portal venules were rarefied in the peripheral area, with the central area being not affected. DISCUSSION: The difference between the peripheral and central area shows a decreased direct and indirect reduction of the blood flow to the periphery of the main lobe, through the reduced number of afferent terminal portal venules and the development of intrahepatic shunting.

Journal Article↗
PubMed2004

Radio-guided brain tumorectomy using a gamma detecting probe and a mobile solid-state gamma camera.

BACKGROUND: We herein report a technique to distinguish brain tumors from normal brain tissue during surgery using a gamma probe and a solid-state mobile gamma camera after (99m)Tc-hexakis-2-methoxy-isobutyl-isonitrile ((99m)Tc-MIBI) is administered to patients immediately before operation. METHODS: We examined 13 patients with brain tumors. Before the operation, (99m)Tc-MIBI single photon emission computed tomography (SPECT) was performed to assess accumulation in the tumors. On the day of the operation, (99m)Tc-MIBI was administered intravenously and craniotomy for tumor resection was performed. During the operation, the tumor was localized with a gamma probe and preremoval scintigraphy images were taken with a mobile gamma camera. After tumor resection was completed, residual tumors were confirmed using it again. We compared accumulation found in the preoperative SPECT images and intraoperative scintigraphy images, performed a histologic examination of adjacent tissues, and measured the dose the personnel was exposed to per operation. RESULTS: In all patients, tumors were confirmed by a gamma probe and scintigraphy during the operation. Intraoperative accumulation in tumors was significantly related to accumulation found in the preoperative (99m)Tc-MIBI SPECT images. In 9 out of 13 patients, accumulation disappeared in the postremoval scintigraphy images, and no tumor tissue was found by histologic examination. Residual tumor tissue was found in 4 patients. Average exposure of the personnel per operation was 22.9 +/- 4.0 microSv. CONCLUSION: Resection of brain tumors with a gamma probe and a mobile gamma camera was very useful since the area to be removed was easily identified and residual tumors could be detected.

Adult↗
PubMed2004

Interaction between iopamidol and gadopentetate dimeglumine: an in-vitro experimental study of direct mixing.

OBJECTIVE: To determine whether or not there is any interaction between iopamidol and gadopentetate dimeglumine (Gd-DTPA) in test tubes using the direct mixing manner. MATERIALS AND METHODS: The test solution was prepared by mixing iopamidol (Iopamiron 300) and Gd-DTPA (Magnevist) at a ratio of 1:1. The color, viscosity, and pH of the mixed solutions were assessed immediately after mixing and 1,3,6, and 24 hours after mixing. The concentration of aromatic primary amines, content of iopamidol, concentration of free iodine ion, and content of Gd-DTPA in the mixed solution were determined, and the presence or absence of spots, other than those resulting from iopamidol and Gd-DTPA, was determined using thin layer chromatography. These tests were carried out immediately, and 24 hours after mixing. Using iopamidol alone and Gd-DTPA alone as controls, the same items were examined. RESULTS: There was no significant change in the appearance or pH of the mixed iopamidol and Gd-DTPA solution immediately and 1, 3, 6, and 24 hours after direct mixing. The study of iopamidol alone or Gd-DTPA alone showed no apparently abnormal values or findings. CONCLUSION: The direct mixing of iopamidol and Gd-DTPA in a test tube results in no significant interaction.

Contrast Media↗
PubMed2004

Hepatic pseudoaneurysm ruptured into the jejunal limb after hepatectomy for the treatment of gall bladder carcinoma.

A 74-year-old woman with advanced carcinoma of the gall bladder underwent anterior and medial segmentectomies, extrahepatic bile duct resection, lymph node dissection, and hepaticojejunostomy with retrograde transhepatic biliary drainage. On the sixteenth postoperative day, bleeding was noted through the biliary drain, but it stopped spontaneously. Two days later, the biliary drain showed bleeding again. Ultrasonography revealed mild dilatation of the intrahepatic bile duct. Cholangiography via the drain disclosed a defect in the jejunal limb. Emergency angiography revealed an aneurysm, 2 cm in diameter, in the posterior branch of the right hepatic artery. Contrast medium demonstrated extravasation into the jejunal limb. The pseudoaneurysm was embolized with coils. No further hemorrhage was noted, and the patient was discharged 30 days after operation.

Aged↗
PubMed2004

MRI of cardiac morphology and function after percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy.

OBJECTIVE: The objective of our study was to use MRI to show the cardiac morphology and function of patients with hypertrophic obstructive cardiomyopathy after percutaneous transluminal septal myocardial ablation. CONCLUSION: Black blood T2-weighted and contrast-enhanced fast inversion recovery gradient-echo images displayed ablated septal myocardium until 35 weeks after percutaneous transluminal septal myocardial ablation. Central hypointense areas were observed on MRI in patients until 4 weeks after ablation. Black blood and cine steady-state free precession MRI were used to assess the decreased septal wall thickness and diameter of the left atrium after ablation as well as the reduced motion of the ablated region. MRI may be useful for evaluation of cardiac structural, signal, and functional changes associated with percutaneous transluminal septal myocardial ablation.

Adolescent↗
PubMed2004

Hybrid treatment of acute massive pulmonary thromboembolism: mechanical fragmentation with a modified rotating pigtail catheter, local fibrinolytic therapy, and clot aspiration followed by systemic fibrinolytic therapy.

OBJECTIVE: We sought to evaluate the efficacy and safety of a hybrid treatment for acute massive pulmonary thromboembolism in patients with hemodynamic impairment by combining mechanical fragmentation, local thrombolysis, and clot aspiration. SUBJECTS AND METHODS: Within a period of 35 months, 25 patients with hemodynamic impairment (eight men and 17 women; age range, 35-77 years) were treated with mechanical thrombus fragmentation using a modified rotating pigtail catheter. After embolus fragmentation, all patients received an intrapulmonary injection of recombinant human-tissue plasminogen activator and then underwent manual clot aspiration with a large-lumen percutaneous transluminal coronary angioplasty guide catheter. RESULTS: All the patients survived, and their clinical status improved. Posttreatment angiography showed an improvement in pulmonary perfusion in all patients (mean Miller score before treatment, 22.2; after treatment, 13.6; p < 0.01). Mean pulmonary artery pressure decreased from 32.6 to 23.4 mm Hg (p < 0.01). Mean treatment time was 124.6 min. CONCLUSION: Hybrid treatment with mechanical fragmentation using a rotating pigtail catheter combined with local fibrinolysis and manual clot aspiration resulted in a rapid and safe improvement in the hemodynamic condition of patients with acute massive pulmonary thromboembolism. This hybrid treatment appears to be especially useful in patients at high risk for right ventricular failure and is a minimally invasive alternative to surgical embolectomy.

Acute Disease↗
PubMed2004

[Practice and future aspects of nuclear cardiology].

The field of nuclear cardiology has demonstrated sustained growth in recent years owing to its increasingly recognized value for clinical applications and patient management. Computer advances in this field have allowed the technology of ECG-gated SPECT to become a routine part of nuclear cardiology. In our laboratory, myocardial perfusion and left ventricular function during stress (bicycle exercise or dobutamine infusion) were analyzed in a single examination by means of gated SPECT. This procedure has the potential to provide comprehensive information with which to evaluate patients with ischemic heart disease. 123I-BMIPP is a branched-chain free fatty acid, and its distribution could provide useful information about metabolic function in patients with ischemic heart disease (including minor infarction). The solid-state gamma camera 2020 tc Imager is now commercially available and has been clinically applied. The lightweight and compact design of the camera allows mobility of the unit between departments and floors. This technique would be useful for assessing left ventricular function under emergency conditions. In this paper, the techniques of examinations are described, and potential assessments are addressed. We look forward to further advances in nuclear cardiology for the accurate diagnosis and management of patients with various cardiac diseases.

Electrocardiography↗
PubMed2003

Staging of malignant lymphoma with three-station black-blood fast short-inversion time inversion recovery (STIR).

PURPOSE: The purpose of this study was to assess the usefulness of three-station black-blood fast short-inversion time inversion recovery (STIR) imaging in detecting and staging malignant lymphoma. METHODS: Seventeen patients with malignant lymphoma were examined with a 1.5T imager. The findings and stagings determined with three-station black-blood fast STIR imaging were compared with reference standards (e.g., computed tomography [CT] findings and clinical stagings). RESULTS: Three-station black-blood fast STIR imaging provided a fat-suppressed T2-weighted imaging contrast with fewer flow artifacts and revealed nodal involvement as well as bone marrow and spleen involvement to an extent comparable with CT. Especially notable was the excellent specificity (94%) of this imaging technique. Regarding disease staging, significant agreement was observed between clinical staging (k=0.60) and staging as evaluated by three-station black-blood fast STIR, although the detection of lymphadenopathy in the thorax was relatively poor. The average time required for this imaging was approximately 30 min. CONCLUSION: Three-station black-blood fast STIR MR imaging may be useful as a staging tool for malignant lymphoma because this imaging technique reveals lymphoma lesions, which determine the staging, without radiation exposure or the use of contrast agents.

Adult↗
PubMed2003

Centrally fat-saturated three-dimensional magnetic resonance angiography of the abdomen using selective central fat-saturation of k-space.

PURPOSE: To assess the usefulness of centrally fat-saturated three-dimensional magnetic resonance (MR) angiography of the abdomen using an elliptical centric view order and selective placement of fat-saturation pulses in the central 30% portion of the k-space in terms of fat signal reduction, image contrast of post-contrast images, and breath-holding time. METHODS: Fat signal in abdomen and breath-holding time were compared between centrally fat-saturated three-dimensional sequence and partially fat-saturated three-dimensional sequence or conventional fat-saturated three-dimensional sequence. Abdominal contrast-enhanced centrally fat-saturated three-dimensional MR angiography was obtained at arterial and equilibrium phases, and image quality was quantitatively and visually evaluated. RESULTS: Centrally fat-saturated three-dimensional sequence suppressed fat signal, as did the conventional fat-saturated three-dimensional sequence, and the breath-hold was prolonged only by 1.5 seconds compared to the partially fat-saturated three-dimensional sequence. Contrast-enhanced centrally fat-saturated three-dimensional MR angiography provided abdominal MR arteriography with large signal difference between vessels and fat, while venous signal was insufficient at equilibrium phase. CONCLUSION: Abdominal contrast-enhanced centrally fat-saturated three-dimensional MR angiography using an elliptical centric view order and selective central fat-saturation of k-space reduced fat signal comparable to conventional fat-saturated three-dimensional sequence, and provided contrast-enhanced MR arteriography with high vascular contrast and minimum prolongation of breath-hold.

Abdomen↗
PubMed2003

Development of quantitative analysis method for stereotactic brain image: assessment of reduced accumulation in extent and severity using anatomical segmentation.

Through visual assessment by three-dimensional (3D) brain image analysis methods using stereotactic brain coordinates system, such as three-dimensional stereotactic surface projections and statistical parametric mapping, it is difficult to quantitatively assess anatomical information and the range of extent of an abnormal region. In this study, we devised a method to quantitatively assess local abnormal findings by segmenting a brain map according to anatomical structure. Through quantitative local abnormality assessment using this method, we studied the characteristics of distribution of reduced blood flow in cases with dementia of the Alzheimer type (DAT). Using twenty-five cases with DAT (mean age, 68.9 years old), all of whom were diagnosed as probable Alzheimer's disease based on NINCDS-ADRDA, we collected I-123 iodoamphetamine SPECT data. A 3D brain map using the 3D-SSP program was compared with the data of 20 cases in the control group, who age-matched the subject cases. To study local abnormalities on the 3D images, we divided the whole brain into 24 segments based on anatomical classification. We assessed the extent of an abnormal region in each segment (rate of the coordinates with a Z-value that exceeds the threshold value, in all coordinates within a segment), and severity (average Z-value of the coordinates with a Z-value that exceeds the threshold value). This method clarified orientation and expansion of reduced accumulation, through classifying stereotactic brain coordinates according to the anatomical structure. This method was considered useful for quantitatively grasping distribution abnormalities in the brain and changes in abnormality distribution.

Aged↗
PubMed2003

Assessment of left ventricular function using solid-state gamma camera equipped with a highly-sensitive collimator.

PURPOSE: The solid-state gamma camera 2020tc Imager (Digirad, CA) is now commercially available and has been clinically applied. The present study evaluates the feasibility of equilibrium radionuclide ventriculography (ERNV) within a 3 min period using this camera equipped with a highly sensitive collimator. MATERIALS AND METHODS: ERNV was performed from the best septal position (left anterior oblique view) in 20 patients with cardiac disease using a single detector anger-type gamma camera equipped with a low-energy, high-resolution collimator. Immediately thereafter, we performed a second ERNV using the solid-state gamma camera equipped with a highly sensitive collimator. Acquisition periods were 10 and 3 min, respectively. RESULTS: Significantly more counts were collected from over the left ventricle with the solid-state gamma camera over 3 min than those with the anger-type gamma camera over 10 min (817.1 +/- 387.8 k counts vs. 668.2 +/- 327.4 k counts, p < 0.01). The left ventricular ejection fraction obtained from ERNV data using the solid-state gamma camera correlated closely with those acquired by the anger-type gamma camera (r = 0.94, p < 0.0001, SEE = 5.93%). CONCLUSION: The results showed that the solid-state gamma camera could assess left ventricular function with excellent data collection efficiency and high reliability.

Equipment Failure Analysis↗
PubMed2003

Ultrasonographic demonstration of retropharyngeal lymph nodes: preliminary report.

The aim of this study was to describe the results of ultrasonography of upper retropharyngeal lymph node (RPN) metastasis in patients with pharyngeal carcinomas. A total of 10 patients with metastatic RPN were examined using percutaneous ultrasound (US) with 3.5-MHz probes. Primary cancer sites were the nasopharynx in two patients, the oropharynx in three and the hypopharynx in five. Metastatic RPNs lay in the level of occipital bone in five patients, C1 in nine, and C2 in five. US images were compared with previously obtained computerized tomography (CT) images based on size and depth. In all of the 10 patients, metastatic RPNs were ultrasonographically demonstrated as hypoechoic masses. Nodal sizes ranged from 1.5 cm to 3.5 cm both in CT and in US. Depths of the RPN centers were from 3.5 cm to 7.0 cm in CT, and from 3.5 cm to 6.5 cm in US. Differences of sizes and depths between CT and US were from -0.5 cm to 0.5 cm and from 0.0 cm to 1.0 cm, respectively. RPNs that are 1.5 cm or more in size can be demonstrated with percutaneous US using CT guidance. This technique should be utilized for the purpose of monitoring in a radiation therapy setting.

Aged↗