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T Kozuka

Publications and source records attributed to T Kozuka.

At least 145 records · Page 8Linked to original sources
PubMed1991

Prediction of severe adverse reactions to ionic and nonionic contrast media in Japan: evaluation of pretesting. A report from the Japanese Committee on the Safety of Contrast Media.

In a nationwide prospective study of adverse reactions to intravenous contrast media (CM), the Japanese Committee on the Safety of Contrast Media compared high-osmolar ionic CM with low-osmolar nonionic CM. A total of 337,647 cases were analyzed. The reliability of pretesting with an intravenous injection of a small amount of CM as a means of predicting severe or fatal reactions was also evaluated. The predictive values of the pretest were 1.2% for ionic and 0.0% for nonionic CM, and the sensitivity values were 3.7% and 0.0%, respectively. Such low values render this test meaningless for predicting which patients are at risk of a severe adverse reaction. A comparison of the incidence of severe adverse reactions between the nonpretested and pretested patients, as well as between the nonpretested and pretested patients with negative results, disclosed no statistically significant differences. Also, no beneficial effects of premedication in patients with a positive pretest were proved. The authors therefore conclude that pretesting with an intravenous injection of a small amount of CM is not useful in predicting severe reactions to ionic or nonionic CM.

Contrast Media↗
PubMed1991

Early asbestosis: evaluation with high-resolution CT.

To determine the earliest stage at which lesions in asbestosis can be diagnosed and to assess their progression, 23 asbestos-exposed patients with minimal or no abnormalities at plain radiography were examined with high-resolution computed tomography (HRCT) twice, with an interval of 12-37 months between examinations. In 21 of the patients, parenchymal abnormalities were found. Major parenchymal features seen at CT included thickened intralobular and interlobular lines, subpleural curvilinear lines, pleural-based nodular irregularities, hazy patches of increased attenuation, small cystic spaces, and small areas of low attenuation. At paired serial CT, subpleural isolated dots or branching structures connected with the most peripheral branch of the pulmonary artery started to appear in lower subpleural zones and then became confluent to create pleural-based nodular irregularities. CT-pathologic correlation led to the conclusion that the confluence of subpleural peribronchiolar fibrosis creates subpleural fibrosis.

Adult↗
PubMed1991

Nerve root avulsion of birth palsy: comparison of myelography with CT myelography and somatosensory evoked potential.

Findings at myelography and computed tomographic (CT) myelography were reviewed in 21 patients (22 limbs) with birth palsy; nerve root shadows were the focus of this study. Myelography demonstrated 51 completely avulsed roots (78%) and 14 incompletely avulsed roots (22%). A traumatic meningocele was detected at 38 roots on myelograms and 51 roots on CT myelograms. Thirteen avulsed roots (eight completely and five incompletely avulsed roots) (20%) were not associated with a meningocele. In nine patients who underwent brachial plexus exploration, myelographic findings were compared with root somatosensory evoked potential (SEP). SEP was not induced at 22 of 25 completely avulsed roots and was induced at all seven incompletely avulsed roots. Myelography and SEP were consistent in 29 of 32 roots (91%). It is concluded that myelography is indispensable for preoperative evaluation of cervical nerve root avulsion of birth palsy, because CT myelography is not sensitive to nerve root avulsion without a traumatic meningocele, and SEP cannot enable one to discriminate incomplete avulsion from intact roots.

Brachial Plexus↗
PubMed1991

Carcinoma of the esophagus: CT vs MR imaging in determining resectability.

MR imaging and CT were performed prospectively in 35 patients with esophageal carcinoma to determine the resectability of the primary tumors, because at our institution patients with resectable tumors have surgery regardless of the presence of distant metastases. Tumors with evidence of aortic or tracheobronchial invasion on MR or CT were considered to be unresectable. Tracheobronchial invasion was diagnosed when the tumor extended into the lumen of the airway, and aortic invasion was diagnosed when the triangular fat space between the esophagus, aorta, and spine adjacent to the primary tumor was obliterated. Two patients were excluded because of suboptimal MR images produced by motion artifacts. Pathologic proof was obtained from either surgery or autopsy in 31 patients. Of these, six patients (19%) had proved unresectable tumors (three aortic invasion and three tracheobronchial invasion). In all six cases, these features were correctly detected with both MR and CT. One patient had false-positive findings on MR and CT. An indeterminate diagnosis was obtained with MR in three patients and with CT in four patients. These incorrect or indeterminate results were all related to the diagnosis of aortic invasion. No patient had a false-negative result. When indeterminate diagnoses were considered false-positive, sensitivity, specificity, and accuracy for resectability were 100%, 84%, and 87%, respectively, for MR and 100%, 80%, and 84%, respectively, for CT. We conclude that MR and CT have nearly the same accuracy in predicting resectability of tumors in patients with esophageal carcinoma.

Adenocarcinoma↗
PubMed1991

CT findings of endobronchial metastasis.

One hundred and sixty-one patients with pulmonary metastases were studied with CT. Six of them proved to have endobronchial (intraluminal) metastatic lesions by bronchoscopy. Retrospective analysis of the CT studies showed obstruction and/or narrowing of the bronchi in 5 cases while no lesion was observed in one patient. Although CT can not always demonstrate intraluminal lesions, it should be performed when an endobronchial metastasis from extrathoracic malignancy is seen by bronchoscopy because it will show hilar or mediastinal lymphadenopathy, or single or multiple pulmonary metastases other than the endobronchial lesion.

Adult↗
PubMed1991

[A comparative clinical study of adjuvant chemotherapy of tumors in the head and neck areas by means of HCFU].

In order to evaluate the efficacy of HCFU as an adjuvant chemotherapy agent for squamous cell carcinoma of the head and neck areas, a randomized comparative study was performed with cooperative facilities. 191 patients who had undergone radical therapy were randomly assigned to the following two groups: Group A was the control group, which underwent radical therapy only, and Group B was a group which received long-term HCFU administration (300-600 mg/day x 12 weeks or more). In the comparison of non-recurrence rate in both groups, Group B had better results among patients who were at the advanced clinical stages such as N1 through N3, Stage II (p = 0.0583) and Stage III (p = 0.0970). The adverse reactions to HCFU included pollakiuria, feverishness, and digestive symptoms, but these were mild and the recovery was possible.

Adult↗
PubMed1991

Sonographic staging of cancer of the mobile tongue.

In order to determine the value of sonography (US), in staging cancer of the mobile tongue, 57 patients were studied prospectively. Real-time sector scanners (5 and 7.5 MHz) were used with a submental approach. The findings by US were compared with those obtained by inspection and palpation and in 13 operated patients with the surgical results. US failed to visualize the tumor in 3 of the 57 patients (5%); in 30 patients (53%), the tumor was considered to be of nearly the same size by US and by palpation, but in 17 cases (30%), to be larger by US than by palpation, and in the remaining 7 cases (12%), to be smaller by US. Extension across the midline (8/8), and depth of tumor penetration, or extension to adjacent structures (5/5) were more correctly evaluated by US. We conclude that US is useful for staging work-up of tumors of the mobile tongue.

Adult↗
PubMed1990

[Dynamic MRI of liver tumors--evaluation by inversion recovery snap shot FLASH MR imaging].

We have studied 20 patients with liver tumor (hepatoma 12, hemangioma 6, metastatic tumor 2) using inversion recovery snap shot FLASH dynamic MR imaging. After intravenous injection of Gd-DTPA, serial 17 images were obtained during 7 minutes. Hepatoma showed central enhancement on early phase (0-20 sec) in 11 patients and absent or less enhancement than surrounding liver parenchyma on late phase (1-3 min) in 12 patients. Hemangioma showed peripheral enhancement on early phase in 6 patients, and slight to moderate enhancement on late phase in 5 patients. Peripheral slight enhancement were seen on late and delayed (5-7 min) phase in two patients with metastatic liver tumor. These characteristic enhancement patterns should facilitate differential diagnosis of liver tumors.

Aged↗
PubMed1990

[Usefulness of ioversol (MP-328) in angiocardiography--a multicenter comparative study with iopamidol].

A randomized, controlled study was conducted to compare the radiographic efficacy, safety and usefulness of ioversol and iopamidol in 146 patients undergoing angiocardiography at six institutions. The hemodynamic and electrocardiographic effects were clinically insignificant and comparable for both agents. Ioversol demonstrated lower incidence of adverse reactions and less heat sensation in left coronary arteriography than those with iopamidol. Overall radiographic efficacy with ioversol was slightly better than with iopamidol, according to the evaluation by both investigators and committee members. Ioversol appears to be very useful for angiocardiography. This comparative study demonstrated the value of safety and efficacy evaluation criteria suggested by the preceding clinical trial with ioversol.

Adult↗
PubMed1990

[Effects of sampling bandwidth in MR imaging].

Phantom and volunteer study was performed with spin-echo sequences of different sampling bandwidths to evaluate the narrow bandwidth signal acquisition technique. Our results demonstrated the characteristics of the narrow bandwidth sequence as follows: SNR improvement, sensitive to the field inhomogeneity and motion, loss of edge definition for short T2 tissues, and prominent chemical shift artifacts. Narrow bandwidth sequence with flow compensation was suitable for brain T2 weighted images because of its high SNR and less artifacts. In spite of the improvement of SNR, the narrow bandwidth technique may be inappropriate for short T2 tissues such as muscle, because of prominent chemical shift artifacts and loss of edge definition. Consequently, sampling bandwidth is one of the parameters which can be manipulated to improve MR image quality.

Brain↗
PubMed1990

[A short TE gradient-echo sequence using asymmetric sampling].

We have developed a gradient-echo pulse sequence with a short TE less than 4 msec using a data set of asymmetric off-center sampling with a broad bandwidth. The use of such a short TE significantly reduces T2* de-phasing effect even in a two-dimensional mode, and by collecting an off-center echo, motion-induced phase dispersion is also considerably decreased. High immunity of this sequence to these dephasing effects permits clear visualization of anatomical details near the skull base where large local field inhomogeneities and rapid blood flow such as in the internal carotid artery are present.

Brain↗
PubMed1990

[Myelography for nerve root avulsion in birth palsy].

Myelography and CT myelography (CTM) were reviewed in 18 cases of birth palsy with clinically suspected avulsion injury. Root-somatosensory evoked potential (root-SEP) was also reviewed for myelographic evaluation of the nerve root avulsion in birth palsy. Root-SEP is not induced in case of avulsed nerve roots, but is induced in case of both normal and incompletely avulsed roots. Myelography demonstrated 58 abnormal nerve roots in 18 cases (19 limbs); 45 (78%) complete and 13 (22%) incomplete nerve root avulsions. Each of complete and incomplete avulsions was defined as total absence and partial presence of rootlets on myelography, respectively. Traumatic meningoceles were detected at 46 roots (79%) on myelography and/or CTM; 35 roots on myelography and 45 roots on CTM. CTM could not detect only a very small meningocele at one root. At 11 roots CTM was superior to myelography in delineating a meningocele because CTM is sensitive to a poorly enhanced meningocele. CTM, however, could not diagnose nerve root avulsions so accurately as myelography, since myelography detected 12 (7 completely and 5 incompletely) avulsed roots without meningocele, whereas CTM could not delineate the nerve roots clearly. Thus, myelography is indispensable to evaluate nerve root avulsions without meningocele. Root-SEP was examined in 9 patients who underwent brachial plexus exploration. SEP was negative at 22/25 roots with complete avulsion and was positive at 7/7 roots with myelographically incomplete avulsion, regardless of presence or absence of any traumatic meningocele.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1990

Assessment of the intrapulmonary ventilation-perfusion distribution after the Fontan procedure for complex cardiac anomalies: relation to pulmonary hemodynamics.

In 12 patients who underwent the Fontan procedure for complex cardiac anomalies, lung scanning with xenon-133 was performed to assess the intrapulmonary ventilation-perfusion distribution, and comparison was made with a control group. All data were then analyzed in relation to either pre- or postoperative pulmonary hemodynamic data. In ventilation scans, the intrapulmonary distribution in the right lung was almost normal. In perfusion scans, an abnormal increased upper to lower lobe perfusion ratio greater than the normal value found in the control group was noted in seven patients (58.3%). There was a significant correlation (p less than 0.02) between the upper to lower lobe perfusion ratio and postoperative pulmonary vascular resistance. Furthermore, this perfusion ratio correlated inversely with the preoperative (p less than 0.005) and postoperative (p less than 0.02) right pulmonary artery area index, defined as the ratio of cross-sectional area to the normal value. Of five patients with less than 90% arterial oxygen saturation, four showed an abnormal distribution of pulmonary blood flow greater than the normal perfusion ratio. No patient had evidence of a pulmonary arteriovenous fistula by the echocardiographic contrast study. These results suggest that abnormal distribution of pulmonary blood flow to the upper lung segment may develop in patients after the Fontan procedure, and that insufficient size of the pulmonary artery before operation and the consequent postoperative elevation of pulmonary vascular resistance may be responsible for this perfusion abnormality.

Child↗
PubMed1990

[Mn-TPPS4; a potential MRI contrast agent for localizing the normal aortic wall in rabbits].

The localizing potential of the Mn (III) complex of tetrakis (4-sulfonatophenyl) porphyrin (Mn-TPPS4) for the normal aortic wall was investigated in nine male New Zealand White rabbits by means of 2.0 T magnetic resonance imaging system. Fortyeight hours after intravenous administration of 0.25-0.50 mmol/kg body weight (b.w.) of Mn-TPPS4, the selective contrast enhancing effects in the normal aortic wall were observed using ECG-gated T1 weighted sequence. An intense brownish internal surface was also observed in the post-mortem aorta. These preliminary results indicate that Mn-TPPS4 might be a suitable MRI contrast agent for the localization of the normal aorta. Acute cardio-toxic effects were observed in one animal after 0.25 mmol/kg b.w. of Mn-TPPS4.

Animals↗
PubMed1990

[Diffusion imaging using three orthogonal diffusion encoding gradients].

A new pulse sequence for in vivo diffusion measurements by magnetic resonance imaging is introduced. The proposed sequence employed gradient sensitization in three orthogonal directions to accentuate the effects of diffusion. The amplitudes and durations of the diffusion encoding gradients were carefully selected to achieve optimal signal-to-noise ratio in diffusion imaging. The pulse sequence was implemented on a superconducting whole body imager operating at 1.5 T. The self-diffusion coefficient of water in a bottle was measured to be 2.17 +/- 0.089 X 10(-9) m2/sec at 23 degrees C consistent with other previous measurements. A preclinical study with a human volunteer was also performed and results were presented.

Brain↗
PubMed1990

[A case of recessive dystrophic epidermolysis bullosa associated with dwarfism with special reference to pathophysiological role of growth hormone].

Epidermolysis bullosa is a group of disorders whose common primary feature is the formation of blisters following trivial trauma. Recessive dystrophic epidermolysis bullosa (RDEB), a subtype of epidermolysis bullosa, is frequently associated with growth retardation. This growth retardation has been reported to be caused by trophopathy following protein loss through skin lesions. Endocrine disorders as the cause of growth retardation in RDEB have not been clearly described. An 11-year-old female had a typical RDEB with dwarfism. Her height was 125 cm and weight was 21 kg, both of which were 2.5 SD below the average. The skin lesions were generalized and probably caused by undernourishment, infection, and blood loss through the skin. However, her serum albumin was at the lower normal limit, and the rapid turnover proteins were slightly decreased. Endocrinological examinations revealed that all the basal levels of pituitary, thyroid, and adrenal hormones were normal. Results of the exercise test, the insulin tolerance test, and the growth hormone-releasing factor test indicated the presence of hypothalamic disorder in secretion of growth hormone. This is the first report of RDEB in which hypothalamic disorder in growth hormone secretion was investigated. On the other hand, growth hormone is known to be involved in collagen metabolism, and a decrease in collagen fibrils and an increase in collagenase activities are found in the skin of RDEB. This implies that this hypothalamic disorder in growth hormone secretion may be involved in the pathophysiology of both dwarfism and the skin lesions in RDEB.

Child↗
PubMed1990

Computed tomographic findings of nasopharyngeal carcinoma with skull base and intracranial involvement.

Twenty-nine patients with nasopharyngeal carcinoma (NPC) with skull base or intracranial involvement were analyzed by high-resolution computed tomography (CT). We divided the path of the primary tumor spread into six directions from the nasopharynx. The most common direction of spread was the anterior region, and the second most common was the posterolateral region. Recently, high resolution CT has been used for the diagnosis of the nasopharynx. T-staging of NPC was made according to the International Union Against Cancer (UICC) TNM classification system, depending on clinical findings and conventional radiograph examinations (not including CT). CT images were valuable for detection of the primary tumor involvement of the skull base region in NPC. Furthermore, bone target CT images were better for searching for subtle bony changes. Therefore, we recommend that CT should be used in T-staging of NPC systematically. When CT is used as one of the staging criteria, some patients with NPC with subtle bony changes will be upstaged.

Adolescent↗