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Biomedical subjects

T Kozuka

Publications and source records attributed to T Kozuka.

At least 55 records · Page 3Linked to original sources
PubMed1996

Acute radiation thyroiditis.

PURPOSE: Radiation-induced thyroid dysfunction is considered a late effect. We prospectively assessed acute reactions of the thyroid to external neck irradiation. METHODS AND MATERIALS: This study included 22 patients in whom the thyroid was incidentally exposed to therapeutic doses of radiation. Thyroid function tests included measurements of serum thyroid stimulating hormone (TSH), free and total triiodothyronine (T3) and thyroxine (T4), thyroglobulin, and antithyroid antibodies. These tests were performed before radiotherapy (baseline values), after approximately 40 Gy had been administrated, 2 weeks after the end of radiotherapy, and 3 and 6 months after the beginning of radiotherapy. RESULTS: Mean serum levels of TSH were 1.53, 0.55, 0.78, 2.14, and 7.57 microU/ml before radiotherapy, after 40 Gy irradiation, 2 weeks after the end of radiotherapy, and 3 and 6 months after radiotherapy, respectively. Thus, levels of TSH exhibited two phases: a significant decrease during radiotherapy (thyrotoxic phase) and an increase after radiotherapy (hypothyroid phase) (baseline vs. 40 Gy: p < 0.0001, baseline vs. 6 months: p = 0.003). Increases of thyroid hormones were subtle during radiotherapy. CONCLUSIONS: We believe that radiation promotes release of excessive amounts of thyroid hormones during radiotherapy owing to suppression of TSH secretion. In addition to the late damage (hypothyroidism), thyrotoxicosis occurs when the thyroid gland receives a therapeutic doses of external radiation.

Acute Disease↗
PubMed1996

Lymphedema due to chronic penile strangulation: a case report.

A 62-year-old man was admitted with swelling of the penis caused by long term use of a penis enlarging ring. For the previous 20 years, he had noticed small pruritic nodules on his penis. He had no micturitional or ejaculatory impairment. The penis had a diameter of 6 cm, a length of 10 cm, and was covered with thickened skin. The penis and the scrotal skin were covered with scattered, small, hemispheric nodules and papules ranging in size from 2 mm to 1 cm. Pathologic examination of the biopsied specimen from a nodule revealed enlargement of the lymphatic vessels of the dermis and fibrosis. This was compatible with lymphedema due to chronic strangulation by the ring. Scar resection and full thickness skin grafting was performed to prevent malignant changes in the lesions.

Chronic Disease↗
PubMed1996

Evaluation of human skin irritation by carboxylic acids, alcohols, esters and aldehydes, with nitrocellulose-replica method and closed patch testing.

Closed patch testing and the nitrocellulose-replica method are performed as useful clinical methods for the evaluation of human skin irritation by cosmetics and topical medicaments. Comparison of the sensitivity between microscopic scoring by nitrocellulose-replica method and visual scoring by closed patch test in the detection of skin irritation, however, has not been well studied with statistical analysis. Here, we evaluated human skin irritation by carboxylic acids, alcohols, esters and aldehydes, with different chain length (C8-C18), using both methods. The results of closed patch testing showed that, although the score of skin irritation for carboxylic acids (C8, C12), alcohols (C8) and aldehydes (C8), tested at a concentration of 0.5 m-2.0 m, significantly increased with increasing concentration of the test compounds, ester compounds scarcely caused any irritation on the surface of the skin occluded. In addition, an increase of carbon chain length in the test compounds made it impossible to detect skin irritation. In contrast, the nitrocellulose-replica method could evaluate skin reactions against very weak irritants that gave no macroscopic alterations on the skin surface in the closed patch test. However, the scoring system is somewhat subjective and should be improved to make the analysis more objective.

Adult↗
PubMed1996

Dynamic range control processing of digital chest images. A clinical evaluation.

PURPOSE: The clinical usefulness of an advanced image-processing system called "dynamic range control processing" was investigated, with which selected parts of the dynamic range of digital chest images could be controlled. MATERIAL AND METHODS: A comparative study of 3 different post-processed formats of storage phosphor (SR) images was performed in 35 patients with abnormalities in the chest. The 3 formats were SR images with standard mode (SR-standard), SR images with strong edge-enhancement (SR-enhanced), and dynamic range controlled SR images (SR-controlled). RESULTS: For lung abnormalities, there was no difference among the 3 SR image formats. For normal mediastinal structures and lung abnormalities covered by the heart or diaphragm, SR-controlled and SR-enhanced images were significantly superior to SR-standard images, while no difference was found between SR-controlled and SR-enhanced images except for the trachea and bony structures. CONCLUSION: Dynamic range control processing appears to be a useful method for displaying SR chest images with an extremely wide dynamic range.

Adolescent↗
PubMed1996

Normal nonuniformity of left ventricular contraction. Assessment by cine MR imaging with presaturation myocardial tagging.

PURPOSE: To identify the normal performance of left ventricular (LV) regional contraction using cine MR imaging with presaturation myocardial tagging. MATERIAL AND METHODS: Sixteen normal volunteers were examined on a 1.5 T MR system with tagging cine sequences. Tags were applied at end-diastole as 2 parallel black lines on short-axis and 4-chamber sections, and the fractional shortenings were calculated at 7 LV locations. RESULTS: The following results were obtained with significance: a transmural gradient of contractility in the short-axis section; prolonged late-systolic endocardial shortening and epicardial early termination in the free wall; initial delay of shortening in the anterior wall; apical predominance of contractility; predominance of circumferential shortening in the free wall and of meridional shortening in the septum. These findings could be associated with myocardial fiber architecture, presumed wall stress and temporal asynergy of excitation. CONCLUSION: Cine MR imaging with myocardial tagging proved to be useful in assessing the nonuniformity of LV contraction.

Adult↗
PubMed1995

Interpretation of subtle interstitial chest abnormalities: conventional radiography versus high-resolution storage-phosphor radiography--a preliminary study.

To evaluate the reliability of digital chest radiography in diagnosing subtle interstitial lung abnormalities, we performed several clinical studies including a comparison of conventional screen-film radiography and storage-phosphor radiography (2 K x 2 K pixels, 10 bit), and a comparison of conventional screen-film radiography and film-digitized radiography (2 K x 2 K pixels, 10 bit). From these previous studies, a spatial resolution of 0.2-mm pixel size was considered inadequate to diagnose subtle interstitial lung diseases. Under these circumstances, the newly developed Fuji Computed Radiography system (FCR 9000; Fuji Photo Film, Tokyo, Japan) has recently become available. This system provides 0.1-mm pixel size (4 K x 5 K pixels, 10-bit depth) and life-size hard copies (14 x 17 inches). To evaluate the reliability of new high-resolution storage-phosphor radiography (FCR 9000) in diagnosing simulated subtle interstitial abnormalities (including simulated lines, micronodules, and groundglass opacities), the differences among radiologists in interpreting conventional screen-film radiographs and life-size high-resolution storage-phosphor radiographs were studied. Observation was made by eight experienced chest radiologists and receiver-operating characteristic (ROC) analysis was performed. There was no significant difference in detecting in subtle simulated interstitial abnormalities between conventional film-screen radiography and high-resolution storage-phosphor radiography. For all three types of abnormalities, there was no significant difference between conventional and storage-phosphor radiography. In conclusion, the high-resolution storage-phosphor chest radiography (0.1-mm pixel size, 10-bit depth) may be substituted for conventional chest radiography in the detection of subtle interstitial abnormalities.

Data Display↗
PubMed1995

Quality of portal verification images using GLP7 film.

RATIONALE AND OBJECTIVES: To improve portal verification radiographs, we tested the application of GLP7 film. METHODS: The quality of the portal verification radiograph using the XV cassette-GLP7 film combination and the XL cassette-GLP7 film combination was investigated. The XV cassette-XV2 film combination and the SA cassette-GS screen-XTL film combination also were used for comparison. RESULTS: The characteristic curves showed that the relative speeds were 0.32 and 0.47 for the XV-GLP7 and XL-GLP7 combinations and that the average gradients were 1.93, 2.14, and 1.32 for the XV-GLP7, XL-GLP7, and XV-XV2 combinations, respectively. In the experiment using Burger's phantom, the smallest visible volumes were 11.8, 11.3, 28.7, and 19.6 mm3 for the XV-GLP7, XL-GLP7, XV-XV2, and SA-GS-XTL combinations, respectively. In the lower dosage treatment in the clinic, there were no marked differences between the GLP7 film and XV2 film. However, in the higher dosage treatment, the GLP7 film had a better quality than did the XV2 film. CONCLUSION: Portal verification radiographs using GLP7 film are of sufficient quality for clinical use.

Humans↗
PubMed1995

Enhancement of hematopoietic uptake by granulocyte colony-stimulating factor in Ga-67 scintigraphy.

The authors report on two non-Hodgkin's lymphoma cases which showed markedly enhanced Ga-67 uptake of granulopoietic area induced by recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration. The rhG-CSF is a newly developed agent for reduction of infections, which stimulates the proliferation and differentiation of granulopoiesis. Use of rhG-CSF is becoming increasingly frequent because the indications are so broad that most patients with intensive chemotherapy for malignancies benefit from undergoing this treatment. In this study, the results of the two cases were: 1) G-CSF enhanced the accumulation of Ga-67 citrate in the granulopoietic area; 2) the marked uptake of red marrow looked like involvement; and 3) in contrast, the involved area became relatively "cold." These findings should be considered in the interpretation of Ga-67 scintigraphy.

Adult↗
PubMed1995

Assessment of right ventricular regional contraction and comparison with the left ventricle in normal humans: a cine magnetic resonance study with presaturation myocardial tagging.

OBJECTIVE: Right ventricular regional contractility has been thought to be difficult to assess precisely. Cine magnetic resonance imaging with presaturation myocardial tagging was employed to quantitate the contraction of the right ventricular free wall and to identify normal performance compared with the left ventricle. METHODS: Nine normal volunteers, aged 27-39 years, were examined in a 1.5 Tesla superconductive magnet, and short axis and four-chamber sections at the mid-ventricular level were imaged with cine magnetic resonance sequences. Tags, applied at end diastole as two parallel black lines, intersected the mid-portion of the free wall, dividing it into upper, centre, and lower segments in the short axis section, and anterior, middle, and posterior segments in the four-chamber section. From a series of cine magnetic resonance images at 50 ms intervals over a cardiac cycle, end diastolic, and early, mid-, and end systolic images were chosen for calculation of the endocardial, epicardial, and mean percent fractional shortening (%FS) in the six segments. RESULTS: There was (1) a gradual increase in %FS in systole in both sections (P < 0.001, < 0.005); (2) a poor transmural gradient of contractility; (3) a predominance of meridional shortening (whole length, mean end systolic %FS (SD): short axis, 17.4 (3.1)%; four-chamber, 30.1 (4.1)%; P < 0.001) in contrast to dominant circumferential shortening in the left ventricular lateral wall; (4) lower predominance of contractility in the short axis section (P < 0.001), and a middle dip of contractility in the four-chamber section (P < 0.005). CONCLUSIONS: Heterogeneity of contractility was closely correlated with the myocardial fibre architecture, and with wall stress determined by its thickness and curvature. It was proved that right ventricular regional function could be analysed non-invasively using cine magnetic resonance imaging with myocardial tagging.

Adult↗
PubMed1995

Clinical evaluation of pulmonary nodules with single-exposure dual-energy subtraction chest radiography with an iterative noise-reduction algorithm.

PURPOSE: To compare the clinical usefulness of the single-exposure dual-energy subtraction method with an iterative noise-reduction algorithm. MATERIALS AND METHODS: Fourteen radiologists read three sets of images from 44 patients: original computed radiographic images only, original computed radiographic images plus conventional bone-subtracted images, and original computed radiographic images plus iterative noise-reduced bone-subtracted images. Twenty-two patients had one or more (maximum, five) pulmonary nodules; 22 had no pulmonary nodules. Observer performance was evaluated by means of calculation of the average area under the alternative free-response receiver operating characteristic curves (A1). RESULTS: Compared with the original computed radiographic image only, detection of nodules was significantly better with both the original computed radiographic image plus iterative bone-subtracted image (A1 = 0.72 +/- 0.02 and 0.66 +/- 0.02, respectively; P = .01) and the original computed radiographic image plus conventional bone-subtracted image (A1 = 0.66 +/- 0.02 and 0.61 +/- 0.01, respectively; P = .03). CONCLUSION: The iterative noise-reduction algorithm is superior to conventional methods in detection of pulmonary nodules.

Adolescent↗
PubMed1995

Detectability of hypervascular hepatocellular carcinoma by arterial phase images of MR and spiral CT.

The ability of arterial phase images of breath-hold MR imaging and spiral CT to detect hypervascular hepatocellular carcinomas (HCCs) was evaluated. Prior to transcatheter arterial chemoembolization (TACE) with iodized oil, MR images and spiral CT during i.v. bolus injection of contrast medium (IV-MR imaging and IV-spiral CT) and spiral CT during intraarterial injection of contrast media through catheter (IA-spiral CT) of the entire liver were obtained in 24 consecutive patients with 93 HCCs. In the detection of HCCs less than 1 cm in diameter, IA-spiral CT (87.3%) was superior to IV-MR imaging (63.5%) and IV-spiral CT (54.0%) (p < 0.001). There was no significant difference in detectability in any tumor size between IV-MR imaging and IV-spiral CT. IA-spiral CT was the best for detecting hypervascular HCCs, and there was no significant difference between IV-MR imaging and IV-spiral CT.

Adult↗
PubMed1995

Cervical invasion of endometrial carcinoma--evaluation by parasagittal MR imaging.

Twenty-seven consecutive patients were examined by T2-(1,800/70 ms) and postcontrast T1-weighted (600/15) spin echo (SE) or dynamic (200/15) SE MR imaging to determine the usefulness of parasagittal MR imaging in assessing cervical invasion of endometrial carcinoma. The images were obtained in a direction parallel to the longitudinal axis of the uterus (parasagittal). The cervical epithelium, being hyperintense on the late phase dynamic and postcontrast T1-weighted SE images, had disappeared partially or totally in all 4 patients with cervical invasion. The enhanced cervical epithelium was completely seen in one patient with the tumor protruding into the cervical canal in a polyp-like form without cervical epithelial invasion. The same was also seen in the 22 patients with the tumor remaining in the corpus cavity. The enhanced parasagittal MR images facilitated the evaluation of the extent of the endometrial carcinoma.

Adenocarcinoma↗
PubMed1995

[Detectability of hypervascular small hepatocellular carcinoma by dynamic spiral CT].

Thirty-one cases of small hepatocellular carcinoma (HCC) under 3 cm in diameter underwent Spiral CT with bolus injection of contrast medium (Dynamic Spiral CT). Dynamic Spiral CT was compared with CT after intra-arterial injection of iodized oil (Lipiodol-CT). The detectability of 79 nodules of small HCC on early phase images of Dynamic Spiral CT was 49.4% (32.6% for those under 1 cm in diameter, 58.3% for 1-2 cm, 91.7% for 2-3 cm). The detectability of small HCCs above the hilum of the liver was better than that below the hilum. Five lesions were detected only on delayed CT images, but not on early phase CT images. Dynamic Spiral CT is useful for detecting hypervascular small HCCs, and both early phase and delayed CT images must be obtained.

Adult↗
PubMed1994

[Usefulness of 3DFT-FISP MR imaging in differential diagnosis of liver tumor].

Dynamic 3-dimensional Fourier transformation (3 DFT)-FISP MR imaging was performed in 30 patients with 49 liver tumors (hepatocellular carcinoma 26, hemangioma 13, cholangiocellular carcinoma 2, metastatic liver tumor 8) to evaluate characteristic enhancement patterns. MR images of 3 DFT-FISP (TR/TE/flip angle/slab thickness/partition/slice thickness, 20 msec/8 msec/30 degree/21-75 mm/7 or 15/3-5 mm) were obtained before, just after (early phase), 1 min after (late phase 1) and 2-4 min after (late phase 2) the administration of 0.1 mmol/kg of Gd-DTPA. Twenty-three of the 26 (88%) hepatocellular carcinomas showed total hyperintense enhancement relative to surrounding liver parenchyma in the early phase, and isointense or total hypointense enhancement in the late phase. Eleven of 13 (85%) hemangiomas showed peripheral hyperintense enhancement in the early phase, and peripheral or total hyperintense enhancement in the late phase. Cholangiocellular carcinomas were enhanced gradually from the early to the late phase. Metastatic liver tumors showed doughnut-like ring enhancement in all 8 lesions in the early phase. We concluded that 3 DFT-FISP dynamic MR imaging was useful in the differential diagnosis of liver tumor.

Adult↗
PubMed1994

Detection of coronary artery disease by dynamic planar and single photon emission tomographic imaging with technetium-99m teboroxime.

To test the clinical significance of technetium-99m teboroxime regional myocardial clearance in the detection of coronary artery disease, 25 patients underwent dynamic planar or single-photon emission tomographic (SPET) myocardial imaging with 99mTc-teboroxime after exercise and again 2 h later at rest. All patients underwent both thallium-201 exercise and redistribution SPET and coronary arteriography. The early phases of exercise 99mTc-teboroxime myocardial clearance determined by dynamic planar imaging showed a significant difference between normal and post-stenotic myocardial regions (clearance rate constant k: 0.047 +/- 0.005 min-1 versus 0.034 +/- 0.003 min-1, P < 0.001). Reflecting this "differential clearance" between myocardial regions, an early redistribution-like phenomenon was observed in a significant number of myocardial segments by comparing serially acquired post-exercise 99mTc-teboroxime SPET images. These results indicated that the analysis of 99mTc-teboroxime myocardial clearance was of potential use in the detection of coronary artery disease, yielding additional information to that provided by the tracer distribution analysis. Although the early redistribution-like phenomenon of 99mTc-teboroxime could be the source of underestimation of ischaemia if acquisition of the initial post-exercise image were delayed, it could also prove useful in the early differentiation of ischaemia from scar because when the phenomenon was observed in delayed post-exercise images, the rest study could be omitted under some circumstances.

Coronary Angiography↗
PubMed1994

Five-year survival after transcatheter chemoembolization for hepatocellular carcinoma.

The 5-year cumulative survival rate of 443 patients who underwent transcatheter chemoembolization (TCE) for non-resectable hepatocellular carcinoma (HCC) before December 1986 was 8.0%, and 29 patients survived for 5 years or more. Of these 29 patients, 25 were men and 4 were women; their mean age was 63.9 years. Macroscopic classification showed lesions of the single nodular type in 16 cases, the multiple nodular type in 10 cases, and the massive type in 3 cases; 12 of the single nodular lesions measured 5 cm or less in size. The TNM classification showed lesions of stage I in 3 cases, stage II in 14 cases, stage III in 6 cases, and stage IV in 6 cases. Lesions classified as Child A were found in 23 patients, and they were thus much more common than Child B lesions (2 patients) and Child C lesions (1 patient). The response was analyzed in relation to the use of iodized oil (Lipiodol). It was used in 215 of the patients, and the 5-year cumulative survival rate of those patients was 12.9% (23 of them survived for 5 years or more). Lipiodol was not used in 228 patients, and they showed a 5-year cumulative survival rate of 3.4%, with 6 patients surviving for 5 years or more. The 6 patients with stage III disease and the 6 with stage IV disease received Lipiodol. TCE with Lipiodol thus contributed greatly in prolonging the survival of patients with HCC complicated by intrahepatic metastases or intraportal tumor thrombi.

Adult↗
PubMed1994

Developing a new picture archiving and communication system for the new Osaka University Hospital.

Osaka University Hospital moved into a new hospital building on the suburban Suita campus in October 1993. A newly developed hospital information system, a new radiologic information system and phase I of a completely new Picture Archiving and Communication System (PACS) also began operating. Work began in 1986 on this PACS. The PACS effort has been guided by one working group and two committees during the last 7 years. A survey of the previous diagnostic and image delivery system was performed as part of the preamble to designing an optimal PACS. Extensive analysis and measurement of pre-existing operational conditions was undertaken. These studies and technical research projects are described in a companion paper in this issue. The phase I hardware installation and initial testing were completed in March 1994. Subsequent phases will build incrementally until the completely new, hospital-wide PACS is realized.

Computer Systems↗