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Tatsuo Kumazaki

Publications and source records attributed to Tatsuo Kumazaki.

At least 19 recordsLinked to original sources
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

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↗
PubMed2003

Effects of view ordering and dummy pulse rate on two-dimensional and three-dimensional steady-state free precession imaging.

RATIONALE AND OBJECTIVE: To assess the effects of view ordering and dummy pulse rate on the image quality of steady-state free precession (SSFP) imaging. MATERIAL AND METHODS: Two- and three-dimensional (2D and 3D) SSFP imaging with various view orderings (eg, centric, sequential, reverse centric) and dummy pulse rates were performed in the phantom including several concentrations of gadolinium and patients. RESULTS: Centric view orderings increased the noise in 3D SSFP images in the phantom. In the patients studied, the centric view ordering increased the signals obtained from abdominal organs in 2D and 3D SSFP and the background signal in 3D images, without changing the vascular signals. An increased dummy pulse rate reduced the background signal in 2D SSFP, but not in 3D SSFP. CONCLUSION: Sequential ordering is recommended for both 2D and 3D SSFP, and centric view ordering combined with an increase in dummy pulse rate can be used for 2D imaging.

Aged↗
PubMed2003

The role of interventional radiology in patients requiring damage control laparotomy.

BACKGROUND: Interventional angiography has been used as a less invasive alternative to surgery to control hemorrhage resulting from trauma. This retrospective study analyzed the role of interventional radiology in patients requiring damage control laparotomy. METHODS: Twenty patients underwent damage control laparotomy between January 1994 and May 2001. Eight of the 20 patients also underwent angiographic evaluation and treatment before or after the damage control laparotomy. RESULTS: Three patients underwent angiography before damage control laparotomy, because a large, pelvic retroperitoneal hematoma was seen on computed tomographic scan, and the amount of intraperitoneal blood seemed insufficient to account for the magnitude of the patient's hemodynamic instability. Five patients underwent angiography after damage control laparotomy. The indication was a nonexpanding retroperitoneal hematoma in three patients, a nonexpanding hepatic hilar hematoma in one patient, and a hepatic injury associated with cirrhosis in one patient. Lumbar artery injuries were identified and treated by embolization in three patients. Four of the eight patients who underwent both damage control laparotomy and angiography survived. CONCLUSION: Angiography before damage control laparotomy may be indicated to control retroperitoneal pelvic hemorrhage in hemodynamically unstable patients who have insufficient intraperitoneal blood loss to account for their hemodynamic instability. Angiography after damage control laparotomy should be considered when a nonexpanding, inaccessible hematoma is found at operation in a patient with a coagulopathy.

Abdominal Injuries↗
PubMed2003

Effect of the surface potential of the hemodialysis membrane and the electrical charge of the gadolinium contrast medium on dialyzability.

PURPOSE: To search for methods of improving the excretion of injected gadolinium contrast medium (GdCM) in hemodialysis (HD) patients, we investigated the effect of the surface potential of HD membranes and the electrical charge of GdCM on the dialyzability of GdCM. MATERIALS AND METHODS: Ionic (Gd-DTPA) or non-ionic (Gd-DO3A) GdCM solutions were dialyzed using a clinical HD unit. Two types of HD membranes, AN69 with a surface potential and PMMA without, were used. GdCM clearance was then calculated. RESULTS: Gd-DTPA clearance was significantly higher for PMMA membranes than for AN69 membranes. Gd-DO3A clearance was slightly higher for AN69 membranes than for PMMA membranes. The difference in Gd-DTPA and Gd-DO3A clearance values was not significant when PMMA membranes were used. CONCLUSION: These data indicate that non-ionic GdCM is preferable to ionic GdCM in patients receiving dialysis through an electrically positive membrane. Either ionic or non-ionic GdCM can be used when a normal dialysis membrane is being used.

Contrast Media↗
PubMed2003

[Strategy to reduce esophageal cancer by dietary reformation].

BACKGROUND AND OBJECTIVE: From 1920 to 1940, many people were affected by esophageal carcinoma in villages in the mountains of Nara Prefecture in Japan. However, a movement for the improvement of living conditions, especially concerning food, diminished the incidence of cancer of the esophagus. Today Xinjiang in China, esophageal cancer is also one of the main causes of death. Therefore, we analyzed in Xinjiang whether the improvement of dietary habits can reduce mortality of esophageal cancer. METHODS: The mortality of esophageal cancer and related matters obtained from the Japanese Literature and Governmental Information, Xinjiang Medical School Cancer Center Hospital, and the Chinese Literature were analyzed. RESULTS: The Kazaks have a higher incidence of esophageal cancer and a lower male/female ratio than other ethnic groups and Japanese people. Kazaks eat very hot meals rapidly, and male Kazaks are more likely to drink hard liquors. In Japan, people in regions with high alcohol consumption tend to have increased mortality of esophageal cancer, but regions with high smoking rates show no correlation with esophageal cancer mortality. There were no data relevant to the incidence of esophageal cancer and alcohol consumption or smoking rates in Xinjiang. The male mortality rate in Nara Prefecture was much higher than that in other areas in the 1930s, but it decreased gradually and eventually reached national levels. The female mortality rate in Nara decreased at a sluggish pace, but retained a several-fold incidence rate until the 1980s. In 1995, women in Nara reached the national level at last. The male/female ratio was low in Nara all the time, and alcohol consumption in Nara was low, too. CONCLUSION: Recently, it has been indicated that alcohol consumption is strongly related to esophageal cancer. However, women in Xinjiang do not drink strong liquor at all. One of their causes of esophageal cancer is dietary habits, which concerns both genders. Therefore, the incidence of esophageal carcinoma could be reduced by dietary reform in Xinjiang, where women as well as the overall population have a high incidence of esophageal carcinoma.

Adult↗
PubMed2003

Effect of prostaglandin E1 on contrast enhanced CT of the liver: statistical analysis during arterial portography.

PURPOSE: To determine the diagnostic effect of prostaglandin E(1) on contrast enhancement quality of CT during arterial portography (CTAP). MATERIALS AND METHODS: Our patients population included 30 patients (11 women, 19 men; age range, 41 approximately 81 years) with liver tumors (23 hepatocellular carcinoma and 7 metastatic liver tumor) who had undergone angiography. We divided the 30 patients, who had undertaken CTAP twice, into two groups at random (group A; n=15, group B; n=15). In group A, first CTAP was performed without prostaglandin E(1). Approximately 5 minutes later, a second CTAP was again initiated 30 seconds after injection of prostaglandin E(1) under the same conditions. In group B, prostaglandin E(1) was injected before the first CTAP only. We measured the mean CT numbers and standard deviation (SD) numbers of anterior, posterior, medial and lateral segments in the liver at the same section of the CTAP using the same size and location of the regions of interest, and these values with and without prostaglandin E(1) were compared. RESULTS: 1) CT numbers: The CT numbers were significantly increased in the medial segment after the injection of prostaglandin E(1) (p<0.05) in all cases of both groups. On the other hand, they were clearly decreased in the posterior segment after the injection of prostaglandin E(1) (p<0.05) in both groups. There were no statistical differences in the CT numbers in the anterior and lateral segments in all patients. In addition, the CT numbers of anterior and posterior segments showed high attenuation compared with the medial and lateral segments in group A without prostaglandin E(1). 2) SD numbers: The SD numbers, which are an index of the homogeneous enhancement, were significantly decreased in the posterior, medial and lateral segments after the injection of prostaglandin E(1) (p<0.01, p<0.05, p<0.01, respectively) in both groups. There were no significant differences in the SD numbers in the anterior segment regardless of the injection of prostaglandin E(1) in all cases. CONCLUSION: CTAP with injection of prostaglandin E(1) makes contrast enhancement of liver parenchyma more homogeneously than the conventional procedure, and it may be a useful technique for the detection of liver tumors.

Adult↗
PubMed2002

Fat-suppressed three-dimensional MR angiography technique with elliptical centric view order and no prolonged breath-holding time.

PURPOSE: To determine the appropriate rate of fat-suppression pulses (using spec IR-spectral selective inversion recovery) for fat-suppressed 3D magnetic resonance angiography (MRA) with an elliptical centric view order. MATERIALS AND METHODS: In abdominal 3D fast spoiled gradient echo (fast SPGR) with an elliptical centric view order, the spec IR pulse rate was changed from zero to one every 15 repetitions (in nine steps) in eight volunteers. In the equilibrium phase, abdominal contrast-enhanced 3D MRA was obtained by 3D fast SPGR using an elliptical centric view order without fat-suppression and with two spec IR, and by fat-suppressed 3D fast SPGR with a sequential-centric view order (efgre3D) in 18 cases. Fat and vascular signals were estimated. RESULTS: Although 3D fast SPGR using an elliptical centric view order with spec IR placed every 15 TR and efgre3D effectively decreased fat signals, these sequences lengthened the breath-hold by 4-6 seconds compared with non-fat-suppressed sequence. 3D fast SPGR using an elliptical centric view order and two spec IR reduced the fat signal by 30% and provided good 3D MR angiography without substantial prolongation of breath-hold. CONCLUSION: Two spec IR can be used for generation of partially fat-suppressed abdominal 3D MRA without prolongation of the breath-hold when performing 3D fast SPGR using an elliptical centric view order.

Abdomen↗
PubMed2002

Serial assessment of left ventricular performance at rest and during bicycle exercise by ECG-gated myocardial perfusion SPECT.

UNLABELLED: The present study evaluates left ventricular performance during exercise by ECG-gated myocardial perfusion SPECT with short-time data collection. METHODS: The study population consisted of 10 healthy volunteers (Group N) and 9 patients with ischemic heart disease (Group I). Seven patients in Group I had a history of prior myocardial infarction. Rest ECG-gated SPECT was performed 40 min after an injection of Tc-99m-tetrofosmin (555-740 MBq). After resting data acquisition, Group N underwent up to two 5-min stages of exercise (75 and 125 watts) on a detachable bicycle ergometer. The Group I patients all underwent symptom-limited, maximal testing on the ergometer. ECG-gated SPECT data were acquired from both groups for 3 min at rest and during the last 3 min of each exercise stage. RESULTS: Significant increases occurred in LVEF from rest to peak stress in both groups (from 55.4 +/- 5.8 to 66.6 +/- 4.1% in group N, p < 0.0001; from 49.0 +/- 12.8 to 56.7 +/- 13.8% in Group I, p < 0.001). The LVESV values significantly decreased to peak stress in Group N (from 49.9 +/- 13.1 to 37.8 +/- 10.0 ml, p < 0.0001), whereas LVEDV did not change (from 110.6 +/- 18.9 to 112.0 +/- 19.0 ml). In contrast, the LVESV values at rest and under peak stress were similar in Group I (from 52.6 +/- 23.9 to 51.7 +/- 31.4 ml) and LVEDV in Group I at peak exercise tended to increase (from 102.8 +/- 36.7 to 111.3 +/- 39.0 ml). The changes in LVESV from rest to peak stress were significantly different between Groups N and I (-12.1 +/- 6.3 vs. -0.9 +/- 11.6 ml, p < 0.02). CONCLUSION: ECG-gated SPECT with short-time data collection can assess left ventricular function during exercise and may offer useful information for evaluating patients with ischemic heart disease.

Adult↗
PubMed2002

Assessment of myocardial washout of Tc-99m-sestamibi in patients with chronic heart failure: comparison with normal control.

BACKGROUND: In contrast to 201TlCl, 99mTc-sestamibi shows very slow myocardial clearance after its initial myocardial uptake. In the present study, myocardial washout of 99mTc-sestamibi was calculated in patients with non-ischemic chronic heart failure (CHF) and compared with biventricular parameters obtained from first-pass and ECG-gated myocardial perfusion SPECT data. METHODS AND RESULTS: After administration of 99mTc-sestamibi, 25 patients with CHF and 8 normal controls (NC) were examined by ECG-gated myocardial perfusion SPECT and planar data acquisition in the early and delayed (interval of 3 hours) phase. Left ventricular ejection fraction (LVEF, %), peak filling rate (PFR, sec(-1)), end-diastolic volume (LVEDV, ml) and end-systolic volume (LVESV, ml) were automatically calculated from the ECG-gated SPECT data. Myocardial washout rates over 3 hours were calculated from the early and delayed planar images. Myocardial washout rates in the CHF group (39.6+/-5.2%) were significantly higher than those in the NC group (31.2+/-5.5%, p < 0.01). The myocardial washout rates for the 33 subjects showed significant correlations with LVEF (r = -0.61, p < 0.001), PFR (r = -0.47, p < 0.01), LVEDV (r = 0.45, p < 0.01) and LVESV (r = 0.48, p < 0.01). CONCLUSION: The myocardial washout rate of 99Tc-sestamibi is considered to be a novel marker for the diagnosis of myocardial damage in patients with chronic heart failure.

Adult↗
PubMed2002

Breast-conserving therapy in the management of early stage breast cancer: Our experience in 103 cases.

PURPOSE: The aim of this study is to determine whether our results in breastconserving therapy of 103 patients with earlystage breast cancer are comparable to those of other facilities or not. MATERIALS AND METHODS: From January 1990 to October 1999, 103 patients with earlystage breast cancer were treated by breastconserving surgery and whole breast irradiation. All patients were of Stages I or II, and the greatest dimensions of primary tumor were less than 3 cm. The median followup time was 47 months from the completion of postoperative radiotherapy. Local, regional and distant failure rates, and survival rate were presumed using the KaplanMeyer method. RESULTS: One patient suffered from local recurrence 30 months later. She was followed by simple mastectomy and kept from further recurrence. No regional relapse occurred. Distant metastases were seen in three patients:two patients in bones, and one patient in a bone and the liver after 19, 35, and 32 months, respectively. One patient died from disseminated cancer in 41 months. Only one patient died due to intercurrent disease. Both 5year and 10year diseasefree survival rates were 94.2%, and both 5year and 10year causespecific survival rates were 98.3%. CONCLUSION: Our results were comparable to previously reported data. In this stage although the followup time was too short to define the longterm outcome, it suggested that breast conserving therapy was acceptable and effective in the management of earlystage breast cancer.

Adult↗
PubMed2002

Clinical application of a CT-guided lung biopsy system: core needle biopsy at the IVR center.

Prior reports of CT-guided lung biopsy of the small lung nodules of less than 2 cm have been unsatisfactory. In January 1998, we began a preliminary study of CT-guided lung biopsy in our conventional CT room. With the basic results achieved, we constructed a novel CT-guided lung biopsy system. Together with Hitachi Corporation we have developed CT, the Radix Prima, exclusive for interventional procedures especially for CT-guided lung biopsy. As reconstruction delay time of the procedures has been shortened from 1.0 sec. to 0.6 sec., real time CT fluoroscopy monitoring is possible on the Cathode Ray Tube (CRT) monitor in the CT room, very closed to the patient. Multiple confirmations of the tip of the biopsy needle have been possible with this specially equipped CT. A semi-automatic-type needle have been selected for reliable biopsy, because the old fully-automatic-type needle was very heavy and easily misfired. Multiple punctures have been also used, because single punctures have a greater risk of obtaining inadequate specimens. In our clinical study at our IVR center, the subjects comprised 41 patients (26 males, 15 females, ranging in age from 34 to 79, mean 64 years old). The mean nodule diameter was 1.9 cm, the mean distance from skin surface to lesion was 5.5 cm, and the mean number of punctures was 3.0. The biopsy results included 23 malignancies. In 13 patients the results were benign tumors or specific inflammation. In 4 patients the results were nonspecific inflammation. In only 1 patient was the specimen inadequate. There was no false negative. The correct rate of benign/malignant diagnoses was 98%. A complication of pneumothorax was observed in 22 patients, but all were improved by conservative treatment. Pulmonary hemorrhage was observed in 21 patients, 7 of whom also had hemoptysis. Each of these patients also responded to conservative treatment from specialist medical staff at the IVR center. The 98%accuracy of our results indicates that multiple punctures using a semi-automatic-type biopsy needle and multiple confirmations of the needle tip on our method of real time CT fluoroscopy are extremely important for CT-guided lung biopsy of small lung nodules of less than 2 cm.

Adult↗