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Biomedical subjects

T Kozuka

Publications and source records attributed to T Kozuka.

At least 91 records · Page 5Linked to original sources
PubMed1993

[Transthoracic percutaneous ethanol injection for the liver].

Fourteen normal rats were received with percutaneous ethanol injection (PEI) in the subphrenic region of the liver, using a 22G fine needle, via the thoracic cage. The procedure was successful in all rats. Minor complications were observed in 3 rats: these included pneumothorax, hemorrhage, and pleural effusion. However all complications had disappeared in the follow up CT one week after the procedure. The transthoracic approach is a useful and safe method of PEI for the subphrenic region of the liver.

Animals↗
PubMed1993

[An experimental study of a new embolic material--Lipiodol suspension of water-absorbent particle].

A water-absorbent particle (a polymer of polyacrylic acid soda) was investigated as a new embolic material. The size of a single particle is 200 microns (N-100) or 10 microns (NP-1010). A particle absorbs 100 times its own weight of physiologic NaCl solution within a few seconds. The particles have no acute or chronic toxicity or immunogenicity. This material suspended by Lipiodol was evaluated in an in vitro study using an AVM model composed of a plastic syringe and polyurethane sponge. The AVM model was perfused by physiological NaCl solution at a pressure of 150 mmHg. The swollen polymer worked as an adequate embolic material in the AVM model, using a minimum quantity. The embolic effect depended upon the quantity and concentration of the suspension. Restoration of flow was not observed within a period of ten minutes. The embolized part was clearly visualized due to the retention of Lipiodol. This material is a promising agent for arterial embolization.

Absorption↗
PubMed1993

Peliosis of the spleen with intraperitoneal hemorrhage.

We encountered a patient with steroid-related peliosis of the spleen, a rare disease characterized by multiple blood-filled cavities in the splenic parenchyma, with spontaneous intraperitoneal hemorrhage. The ultrasonographic, computed tomographic, and angiographic images were compared with pathologic findings of the material obtained surgically.

Aged↗
PubMed1993

Display of MR angiograms: maximum intensity projection versus three-dimensional rendering.

OBJECTIVE: The purpose of this study is to clarify the most useful technique of MR imaging in demonstrating the collateral venous pathways due to portal hypertension. SUBJECTS: Twenty-eight cirrhotic patients with collateral venous pathways due to portal hypertension and three patients without them were studied. We evaluated the detectability of collateral vessels of flow-enhanced transverse MR images by time of flight effect, projection MR angiography using the maximum intensity projection technique and three-dimensional (3D) computer graphic images, by using the arterial portography as the standard. RESULTS: Flow-enhanced transverse MR images showed 98% of the collateral vessels detected by angiography, however, the connection of each vessel was obscure. Fully 81% of the collateral vessels were seen by projection MR angiography, and 98% of them by the 3D computer graphic images. CONCLUSION: The detectability of collateral vessels of 3D computer graphic imaging was better than that of the projection MR angiography and was as accurate as that of transverse MR imaging. 3D Computer graphic images provided complex anatomical information in a more easily understood fashion than either transverse MR images or projection MR angiography.

Adolescent↗
PubMed1993

Treatment of indolent non-Hodgkin's lymphoma localized in the head and neck.

A total of 25 patients with indolent non-Hodgkin's lymphoma localized in the head and neck region was analyzed. Of these, 21 patients were classified as clinical Stage I, and 4 as Stage II. In 22 patients the extranodal site was involved, and it was a remarkable characteristic of this series of patients. Overall treatment results were as follows: survival rate 100% at 5 years, and relapse-free survival rate 81% at 2 and 5 years. There was only 1 death at 6 years and 2 months after treatment, and 4 relapses occurred by 2 years after treatment. Relapse was observed in 3 of 8 patients with follicular mixed/follicular medium type, which was in contrast to the other indolent histologies (SL, DSCl, ILL) with very few relapses.

Adult↗
PubMed1993

Metastasis of hepatocellular carcinoma to the colon demonstrated by Tc-99m PMT scintigraphy.

A 57-year-old man was found to have a tumor in the ascending colon after hepatic segmentectomy for ruptured hepatocellular carcinoma. Colonoscopy was performed, and metastasis of the hepatocellular carcinoma to the ascending colon was suspected based on the biopsy specimens obtained from the tumor. On hepatobiliary scintigraphy using Tc-99m PMT performed to confirm this diagnosis, Tc-99m PMT was clearly observed to accumulate in the tumor. Thus, the tumor was diagnosed as metastasis of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1993

Pulsed Doppler echocardiographic assessment of portal venous flow patterns in patients after the Fontan operation.

OBJECTIVE: To assess the effect of the condition of the right heart after the Fontan operation on portal venous flow, and to determine whether the characteristics of portal venous flow were different when there was an atriopulmonary connection with atrial septal closure rather than an atriopulmonary or total cavopulmonary connection with intra-atrial routing. PATIENTS AND METHODS: After the Fontan operation six patients with an atriopulmonary connection (group 1), three patients with an atriosubpulmonary connection (group 2), four patients with intra-atrial routing and an atriopulmonary connection (group 3), and five patients with a total cavopulmonary connection (group 4) were studied by pulsed Doppler echocardiography. The flow signals were recorded for the pulmonary artery, hepatic vein, and intrahepatic portal vein in each patient. Postoperative cardiac catheterisation was performed in 16 of the 18 patients. The Doppler findings were compared with those of 14 controls. RESULTS: The portal flow was pulsatile in 13 patients and constant in five patients. Reversed flow was shown at or just after the QRS wave after hepatic venous regurgitation in two group 1 patients. The flow signal was interrupted in two group 1 patients and two group 2 patients. Decrease in velocity of flow was recorded in two group 1 patients, one group 2 patients, three group 3 patients, and one group 4 patient. Portal flow was constant in one group 3 patient and four group 4 patients. The pulsatility ratio ranged from -0.46 to 0.49 (mean (SD), 0.03 (0.32)) in the patients from group 1 and 2, from 0.41 to 0.76 (0.54 (0.15)) in group 3, and from 0.70 to 0.80 (0.75 (0.04)) in group 4. The ratio in the controls ranged from 0.29 to 0.83 (0.61 (0.13)). The ratio was significantly lower in groups 1 and 2 than in group 3 (p < 0.01), group 4 (p < 0.01), or the controls (p < 0.005). There was no significant difference in the ratio between group 3 and group 4 and no correlation between the pulsatility ratio and the cardiac index (r = 0.26), mean right atrial pressure (r = 0.25), or pulmonary vascular resistance (r = 0.17). CONCLUSION: The larger hepatic venous regurgitation caused by atrial contraction in patients with an atriopulmonary connection correlated with the higher portal pulsatility and a total cavopulmonary connection reduced portal pulsatility.

Atrial Function, Right↗
PubMed1993

Focal organizing pneumonia: CT appearance.

PURPOSE: To clarify the computed tomographic (CT) features of focal organizing pneumonia. MATERIALS AND METHODS: The authors retrospectively studied CT scans of 18 patients with histologically proved focal organizing pneumonia. Chest radiographs in all 18 patients suggested bronchogenic carcinoma. RESULTS: Seventeen of the 18 lesions (94%) had an irregular margin, 10 (56%) had satellite lesions, nine (50%) had a pleural tag, and nine (50%) had an air bronchogram. The pneumonia could be classified into three types: Type A (n = 5) was a small round mass (pleural tag, n = 4). Type B (n = 7) was an oval mass with broad contact with the pleura (satellite lesions and convergence of peripheral vessels, n = 6). Type C (n = 6) was an oval mass along the bronchovascular bundle (satellite lesions, n = 3; pleural tag, n = 4). CONCLUSION: The CT features of focal organizing pneumonia show wide variation, and some type B and C lesions are suggestive of benign lesions. However, other lesions may be difficult to differentiate from bronchogenic carcinoma even with CT.

Adult↗
PubMed1993

Treatment of hepatocellular carcinoma by chemoembolization: evaluation with 3DFT MR imaging.

OBJECTIVE: We evaluated the usefulness of an MR imaging technique that used dynamic three-dimensional Fourier transformation (3DFT) fast imaging with steady-state precession (FISP) with gadopentetate dimeglumine for detecting viable regions of hepatocellular carcinoma following transcatheter arterial chemoembolization with iodized oil (Lipiodol). Images obtained with the 3DFT FISP technique were directly correlated with hepatectomy specimens. SUBJECTS AND METHODS: Dynamic 3DFT FISP MR imaging was performed after transcatheter arterial chemoembolization and before partial hepatectomy in 10 patients with 10 tumors of hepatocellular carcinoma. Imaging parameters were 20/8/30 degrees (TR/TE/flip angle) with a slab thickness of 21-75 mm and seven or 15 partitions. 3DFT FISP images were obtained at the slice level where a tumor had been detected on T1- and/or T2-weighted spin-echo MR images before, just after (early phase), and 1 and 2 min after (late phase) IV administration of gadopentetate dimeglumine (0.1 mmol/kg). We directly compared the dynamic MR images of the 10 patients with the gross and microscopic findings. RESULTS: On early-phase images, tumors of hepatocellular carcinoma showed no enhancement in three patients and partial intense enhancement in seven. Viable regions of the tumor showed intense enhancement relative to the surrounding liver parenchyma in the early phase, whereas necrotic regions showed no enhancement in either the early or the late phase. Both viable and necrotic regions had lower signal intensities than did the surrounding liver parenchyma in the late phase. By using dynamic 3DFT MR imaging, we were able to accurately assess the effect of transcatheter arterial chemoembolization with iodized oil in nine of the 10 patients. However, in one patient in whom microscopically viable cells were seen in the capsule of the carcinoma, viable regions could not be detected with our technique. CONCLUSION: Dynamic 3DFT MR imaging was useful in differentiating viable regions of hepatocellular carcinoma from necrotic regions following transcatheter arterial chemoembolization with iodized oil.

Aged↗
PubMed1993

Imaging of peritoneal pseudocysts: value of MR imaging compared with sonography and CT.

OBJECTIVE: Peritoneal pseudocysts are created when fluid arising from the ovary is trapped by peritoneal adhesions. We studied the value of MR imaging, compared with sonography and CT, for detecting these abnormalities. SUBJECTS AND METHODS: Nine women, 27 to 49 years old, who had surgically proved peritoneal pseudocysts were included in the study. All nine patients were premenopausal, and eight had a history of pelvic surgery. All patients were examined with MR imaging and sonography, and five were also examined with CT. Imaging findings were analyzed and compared with the surgical findings. RESULTS: Sonograms in all nine patients showed a thick-walled cyst that contained focal echoes indicating nodules, making it difficult to differentiate these lesions from cystic ovarian tumors. In eight of the nine patients, the fluid in the pseudocysts had low signal intensity on T1-weighted MR images and high signal intensity on T2-weighted spin-echo MR images, suggesting that the fluid was serous. The pseudocyst had an irregular shape on MR images in seven patients and on CT scans in three patients. However, MR provided more information than CT did about the nature of the fluid within the pseudocyst. CONCLUSION: Our study suggests that MR imaging is more useful than sonography and CT for determining the characteristic findings of peritoneal pseudocysts.

Adult↗
PubMed1993

[Relationship between reduced myocardial uptake of beta-methyl-p-(123I)- iodophenyl-pentadecanoic acid (123I-BMIPP) and regional diastolic ventricular dysfunction in patients with hypertrophic cardiomyopathy].

To assess whether regionally depressed myocardial uptake of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP), is related to regional ventricular diastolic dysfunction in patients (pts) with hypertrophic cardiomyopathy (HCM), we carried out 123I-BMIPP myocardial SPECT and radionuclide ventriculography (RNV) at rest in 9 HCM pts (eight pts with asymmetric septal hypertrophy (ASH), and one patient with apical hypertrophy). The defects of 123I-BMIPP were semiquantitatively estimated by segmental analysis. Regional LV function was determined by sector analysis in RNV: regional peak filling rate (rPFR), regional time to peak filling rate (rTPFR), and early 1/3 filling rate (1/3 fil) were estimated in the LV septal and posterior sectors. Wall thickness was evaluated with M-mode echocardiography. As results, the defects of 123I-BMIPP myocardial SPECT, were found frequently in septal wall, but any defect was not recognized in all septum with significant hypertrophy. Also, the degree of septal hypertrophy was not significantly related to BMIPP defect score. However, the regional diastolic function (rPFR, rTPFR, 1/3 fil) in the septal lesions with 123I-BMIPP defects was decreased more than those without 123I-BMIPP defect in HCM. Furthermore, the relative regional diastolic dysfunction (the differences between rTPFR and 1/3 fil in the septum and in the posterior wall) was significantly related to BMIPP defect score. In conclusion, this results suggest that the decreased uptake of 123I-BMIPP is related to regional diastolic dysfunction more than wall hypertrophy.

Aged↗
PubMed1993

Hyperparathyroidism--comparison of flash imaging with spin echo MR imaging.

MR images of the neck were prospectively studied in 19 patients with hyperparathyroidism. Fast low angle shot (FLASH) sequence was performed in addition to T1- and T2-weighted spin echo (SE) sequences. FLASH images were obtained with 320/12/20 degrees (TR/TE/flip angle) using presaturation technique. TE of 12 ms was chosen to eliminate high signal of fat tissue. In the evaluation of detectability, a combination of T1-weighted SE and FLASH images (T1WI + FLASH) was compared with a combination of T1- and T2-weighted SE images (T1WI + T2WI). MR imaging correctly depicted 20 of 30 abnormal glands on both T1WI + FLASH and T1WI + T2WI. FLASH imaging effectively eliminated high signal of fat tissue. Nineteen abnormal glands demonstrated higher signal than surrounding tissues on FLASH images, whereas 12 glands were high-intense on T2-weighted SE images. We conclude that FLASH imaging provides improved tissue contrast and anatomic delineation and, thus, may replace T2-weighted SE imaging in the neck.

Adenoma↗
PubMed1993

Evaluation of effective portal venous flow in chronic liver diseases using echo-Doppler flowmetry combined with per jejunal portal scintigraphy.

Portal circulation changes due to the progression of chronic liver disease and portal venous flow are also affected by pharmacotherapy. Thus, noninvasive measurement of effective portal venous flow (EPVF) is highly desirable. We evaluated EPVF under steady-state conditions using echo-Doppler flowmetry combined with per jejunal portal scintigraphy in 32 patients with chronic liver disease. After introduodenal administration of 37 MBq (1 mCi) of 123I-iodoamphetamine, scintigraphy of the pulmonary and hepatic regions was performed and a portosystemic shunt index (SI) calculated. EPVF was calculated as follows: EPVF = PVFx (1-SI/100). EPVF in chronic hepatitis, compensated cirrhosis and decompensated cirrhosis was 12.0 +/- 1.8 ml/min/kg, 10.3 +/- 1.6 ml/min/kg and 8.0 +/- 2.5 ml/min/kg, respectively. There were significant differences in EPVF between all groups, although PVF was similar in each group. EPVF correlated with liver function tests and was a better indicator of liver function than PVF. Measurement of EPVF may provide useful information in the management of patients with chronic liver disease.

Adult↗
PubMed1993

Angiomyolipoma of the liver. Ultrasound, CT, MR imaging and angiography.

Angiomyolipoma, a rare benign liver tumor, was observed in a 50-year-old woman examined with US, CT, MR imaging and angiography. Dynamic studies using CT and MR imaging were valuable in differentiating the disease from hepatocellular carcinoma with fat deposits.

Angiography, Digital Subtraction↗
PubMed1993

Single-exposure dual-energy chest images with computed radiography. Evaluation with simulated pulmonary nodules.

RATIONALE AND OBJECTIVES: Dual-energy subtraction radiography using computed radiography (CR) can aid in the detection of pulmonary abnormalities such as nodules, but the subtracted image requires higher x-ray exposure than usual to reduce quantum mottle. To reduce quantum mottle without increasing x-ray exposure, a new dual-energy subtraction algorithm was investigated that included an edge-adaptive smoothing process and a subtraction process. The signal-to-noise ratio and the image quality of this new subtracted image was significantly superior to that of conventional subtracted images. METHODS: Observer performance of the subtracted digital radiography in detecting simulated pulmonary nodules was compared with original CR images and conventional subtracted digital radiography of 50 patients. RESULTS: A combination of an original CR image and a new subtracted CR image was significantly superior to a single original CR image or a combination of an original CR image and a conventional subtracted CR image (P < .01). DISCUSSION: The single-exposure dual-energy subtraction method is superior to the conventional subtraction method in the detection of pulmonary nodules.

Humans↗
PubMed1993

[Quantitative assessment of cerebral blood flow by 123I-IMP SPECT: venous sampling method with hand warming in the water bath].

In order to establish a noninvasive, quantitative method for measuring regional cerebral blood flow (rCBF) by N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) SPECT, we attempted to employ continuous venous sampling instead of arterial sampling. Forty two patients with cerebrovascular diseases were classified into two groups, with (group II: n = 35) and without (group I: n = 7) hand warming. In group II, either hand was warmed, wrapping in a hot blanket (group IIA) or immersed in a 44 degrees C water bath (group IIB). In each patient, immediately after intravenous bolus injection of 222 MBq IMP, arterial and venous blood samples were collected continuously for 5 min from the radial artery and the cubital vein, respectively. By octanol extraction, IMP was divided into the unmetabolized and metabolized fraction. The ratio of 123I-IMP radioactivity of venous blood compared to arterial blood (pass ratio, referred as %PR) was calculated in three fractions, whole blood, unmetabolized, and metabolized fraction. By using these parameters, we assessed the possibility to estimate the amount of unmetabolized IMP fraction of arterial blood, usually used as an input function, from venous samples. In group I, %PR demonstrated a considerable variation between individuals (whole IMP, 47.5 +/- 24.6% (mean +/- SD): unmetabolized IMP, 46.0 +/- 24.5%: metabolized IMP, 51.8 +/- 27.4%). In group II, especially in group IIB, both increase of %PR value and the decrease in variation (whole, 77.9 +/- 5.6%: unmetabolized, 75.7 +/- 5.7%: metabolized, 86.7 +/- 8.7%) were observed, which permitted the further calculation based on the assumption that %PR value was constant in each IMP fraction (whole blood and unmetabolized fraction).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Mechanism of gravity-dependent atelectasis. Analysis by nonradioactive xenon-enhanced dynamic computed tomography.

RATIONALE AND OBJECTIVES: The physiologic mechanism of gravity-dependent atelectasis (GDA), a common finding identified during anesthesia, is not well understood. The purpose of this study was to determine whether an inherent reduction in alveolar volume or a reduction in alveolar ventilation is the more important causative factor for the development of GDA in an experimental animal model. METHODS: After uniform reduction of lung volume in ten rabbits by artificially induced pneumoperitoneum, dynamic inhalation computed tomography (CT) was performed using 50% nonradioactive xenon in oxygen. Time-CT attenuation value curves were fitted to an exponential function, CT value = a - b x e(-kt), and K value, which is proportional to the alveolar ventilation/alveolar volume ratio, was calculated by regression analysis. RESULTS: Gravity-dependent atelectasis occurred only in 5 of 10 rabbits. In this group, K values in the dorsal regions increased before the appearance of GDA. No significant change in K values in the ventral regions was observed. CONCLUSION: One mechanism of GDA may be a preferential reduction in alveolar volume without small airway collapse rather than alveolar volume loss secondary to decreased ventilation.

Animals↗