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Biomedical subjects

Kazuro Sugimura

Publications and source records attributed to Kazuro Sugimura.

At least 19 recordsLinked to original sources
PubMed2003

Prospective trial of combined transcatheter arterial chemoembolization and three-dimensional conformal radiotherapy for portal vein tumor thrombus in patients with unresectable hepatocellular carcinoma.

PURPOSE: We conducted a prospective trial of combined transarterial chemoembolization (TACE) and three-dimensional conformal radiotherapy (3D-CRT) for portal vein tumor thrombus (PVTT) in unresectable hepatocellular carcinoma (HCC). The aim of the present study was to investigate the efficacy and toxicity of this trial regime. METHODS AND MATERIALS: Patients with unresectable HCC complicated with tumor thrombus in the first branch of portal vein were selected as eligible for this study. TACE was performed using Lipiodol, epirubicin hydrochloride, and mitomycin, followed by gelatin sponge cubes. The 3D-CRT was performed targeting the clinical target volume (CTV) defined as PVTT only to a total dose of 60 Gy using 10-MV accelerator. RESULTS: A total of 19 patients were enrolled in this study. Survival rates at 1 and 2 years were 40.6% and 10.2%, respectively. The median survival time was 7.0 months. An objective response was observed in 11 of 19 cases (57.9%). Recanalization of the first portal branches was not observed; however, the protrusion of PVTT into the main portal trunk decreased in all cases. Growth of intrahepatic metastasis outside the 3D-CRT field was observed in 12 cases (63%). Deterioration of the Child-Pugh Score was observed in 5 of 6 cases with the percent volume of the total liver receiving a dose exceeding 30 Gy (V(30)) > or =40%, vs. 2 of 13 cases with a V(30) <40% (p < 0.01). CONCLUSION: This combined therapy was feasible. Our results indicate that V(30) was a predictive test for deterioration of liver function. Further investigation of treatment modalities is needed to prevent the growth of intrahepatic metastasis.

Aged↗
PubMed2003

Three-dimensional treatment planning using electrocardiographically gated multi-detector row CT.

PURPOSE: Information concerning the amount and nature of target motion is essential for the determination of internal margin size. However, there are few published reports outlining the motion with heart and aortic pulsation. We introduce a method for three-dimensional radiation treatment planning (3D-RTP) by using electrocardiographically (ECG) gated spiral scanning with a four-section CT system. We describe a new approach to visualize internal organ motion resulting from cardiac motion with ECG gated multidetector row CT. MATERIALS AND METHODS: Five patients with lung or liver tumors were studied with a multidetector row CT system under shallow inspiration breath-holding. With retrospective ECG gating, only data acquired within a predefined interval of the cardiac cycle are used for image reconstruction. All reconstructed image data at diastolic and systolic phases of the cardiac cycle were transferred to the 3D-RTP system. The shift of the internal organs between the cardiac cycles was evaluated. RESULTS: Cardiac contraction influences anterior thorax, pulmonary peripheral vessels, and liver position, in addition to locations near the heart. Apparent movements more than 5 mm between diastolic and systolic phases were observed in the left ventricle, right atrium, and superior vena cava. Two-phase imaging was useful for showing the movement of internal organs during cardiac contraction under breath-holding. CONCLUSIONS: Spatial information using ECG-gated CT has the potential to determine the planning target volume of moving lung and liver tumors more precisely than conventional CT planning.

Computer Systems↗
PubMed2003

Radiographic pulmonary and pleural changes after carbon ion irradiation.

PURPOSE: For the treatment of Stage I non-small-cell lung cancers, a Phase I/II study of carbon ion irradiation was undertaken. In the present study, we focus on posttreatment radiographic lung damage: specifically, its timing, features, and relation to dose-volume factors. MATERIALS AND METHODS: Forty-three patients with 44 Stage I non-small-cell lung cancers were treated with carbon ion irradiation ranging from 59.4 to 95.4 photon Gy equivalent dose (GyE) in 18 fractions over 6 weeks, according to our dose escalation protocols. Primary lesions were irradiated by 2-4 portals. Follow-up evaluation with computed tomography (CT) was sequentially performed to assess changes in the lung. CT findings were classified into two categories: pulmonary reaction and pleural reaction. A dose-volume histogram for each patient was calculated, using a three-dimensional CT planning system. Statistical analysis was conducted using Spearman's rank test. RESULTS: The median appearance period of pulmonary reactions was 3 months after the start of carbon ion irradiation, whereas the maximum period was 6 months. The severity of pulmonary reactions statistically correlated with lung volumes irradiated no less than 20 GyE (vol. 20) and 40 GyE (vol. 40) (p = 0.017 and p = 0.0089). Geometrically unique findings in the irradiated fields were observed in 7 patients (16%). The median appearance period of pleural reactions was 4 months after the start of carbon ion irradiation. The occurrence of pleural reactions significantly correlated with planning target volume (p = 0.000098), vol. 20 (p = 0.00011), and vol. 40 (p = 0.00097). CONCLUSIONS: Lung damage after carbon ion irradiation was observed in the parenchyma and in the pleura. The severity of pulmonary reactions was correlated with dose-volume factors. These findings might provide useful information in the planning and management of carbon ion irradiation.

Aged↗
PubMed2003

Time-resolved contrast-enhanced pulmonary MR angiography using sensitivity encoding (SENSE).

PURPOSE: To evaluate the relationship between gadolinium concentration and signal-to-noise ratio (SNR) on sensitivity encoding (SENSE) images, and determine the appropriate bolus injection protocol for visualizing pulmonary circulation. MATERIALS AND METHODS: Eighteen different gadolinium concentration phantoms (0, 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.5, 2.0, 5.0, 10.0, 20.0, 30.0, 50.0, and 100.0 mmol/L) were analyzed to determine the relationship between gadolinium concentration and SNR on SENSE images in a phantom study. In an in vivo study, 3 mL (protocol A) or 6 mL (protocol B) of Gd-DTPA BMA at 3 mL/second, and 5 mL of Gd-DTPA BMA at 5 mL/second (protocol C) were administered to eight normal volunteers for contrast-enhanced (CE) pulmonary MR angiography (MRA) with SENSE. The peak SNRs of pulmonary parenchyma and the difference in SNR between pulmonary artery (PA) and pulmonary vein (PV) at peak SNR in the PA were statistically evaluated. RESULTS: For each flip angle at each gadolinium concentration, the SNRs and contrast-to-noise ratios (CNRs) of the SENSE images were significantly lower than those acquired with a nonparallel imaging technique (P < 0.05). The peak SNR of the pulmonary parenchyma, and differences in SNR between the PA and PV at the peak SNR of the PA obtained with a 5-mL/second bolus injection protocol were found to be significantly higher than those obtained with other protocols (P < 0.05). CONCLUSION: 3D-CE-MRA using SENSE demonstrated linearity between gadolinium concentration and SNR, and resulted in MRA with high spatial and temporal resolution with the aid of a sharp bolus injection protocol.

Adult↗
PubMed2003

Clinical oxygen-enhanced magnetic resonance imaging of the lung.

SUMMARY: Oxygen-enhanced magnetic resonance (MR) ventilation imaging is a new technique, and the full extent of its physiologic significance has not been elucidated. This review article includes (1) theory of oxygen enhancement; (2) respiratory physiology; (3) oxygen-enhanced MR imaging (MRI) sequence design; (4) basic study of oxygen-enhanced MRI in animal models and humans; (5) clinical study of oxygen-enhanced MRI; and (6) merits and demerits of the technique in comparison with hyperpolarized noble gas MR ventilation imaging. Oxygen-enhanced MRI provides not only ventilation-related information but also respiration-related information. Although application of oxygen-enhanced MR ventilation imaging to patients with pulmonary diseases has been limited, oxygen-enhanced MRI offers the possibility of demonstrating regional pulmonary function and substituting for nuclear medicine ventilation-perfusion study, when combined with MR perfusion imaging. We believe that further basic studies and clinical applications of this new technique will define the real significance of oxygen-enhanced MR ventilation imaging in the future of pulmonary functional imaging and its usefulness for diagnostic radiology.

Animals↗
PubMed2003

CT-guided transthoracic needle aspiration biopsy of small (< or = 20 mm) solitary pulmonary nodules.

OBJECTIVE: The purpose of our study was to determine the diagnostic accuracy and to analyze the factors influencing the diagnostic accuracy and incidences of pneumothorax and chest tube insertion rates for percutaneous CT-guided needle biopsy of small (< or = 20 mm) solitary pulmonary nodules. SUBJECTS AND METHODS: One hundred sixty-two patients with 162 small solitary pulmonary nodules underwent CT-guided transthoracic needle aspiration biopsy. The overall diagnostic accuracy, pneumothorax rate, and chest tube insertion rate were calculated. Factors influencing the diagnostic accuracy and pneumothorax rate were statistically evaluated. Influencing factors, diagnostic accuracies, pneumothorax rates, and chest tube insertion rates were statistically compared. RESULTS: Overall diagnostic accuracy, pneumothorax rate, and chest tube insertion rate were 77.2%, 28.4%, and 2.5%, respectively. Diagnostic accuracy was significantly affected by length of needle path and lesion size (p < 0.05). The pneumothorax rate was significantly affected by the percentage of predicted forced expiratory volume in 1 sec, the number of punctures, and the needle path length (p < 0.05). The chest tube insertion rate was significantly affected by the number of punctures (p < 0.05). For diagnostic accuracy, needle path lengths of 40 mm or less and lesion sizes greater than 10 mm were significantly more accurate than other factors (p < 0.05). For pneumothorax rates, a percentage of predicted forced expiratory volume in 1 sec of greater than 70%, a single puncture, and a needle path length of 40 mm or less were significantly lower than other factors (p < 0.05). CONCLUSION: CT-guided transthoracic needle aspiration biopsy is a useful diagnostic tool for small solitary pulmonary nodules smaller than 20 mm in diameter. The diagnostic accuracy is significantly improved for large (> 10 mm) lesion size and short (< or = 40 mm) needle path length.

Adult↗
PubMed2003

[Diagnostic imaging--recent progress].

Current advances in the diagnostic imaging for lung cancer includes multidetector-row CT (MDCT), lung cancer screening using low-dose MDCT and fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. There is no question about the clinical usefulness of MDCT, and the further development of the hardware and the software of MDCT will open new horizons for CT diagnosis. PET is not an alternative modality to CT but a supplementary one, which adds metabolic information to the morphology. Recently, experimental research on the refraction imaging of human lung specimens has been performed with synchrotron radiation. With progressive refinement, this technique may come to have some practical purpose in diagnosing lung cancer in vivo.

Carcinoma, Squamous Cell↗
PubMed2002

Percutaneous transluminal angioplasty of malfunctioning Brescia-Cimino arteriovenous fistula: analysis of factors adversely affecting long-term patency.

Our objective was to identify the factors adversely affecting long-term patency after percutaneous transluminal angioplasty (PTA) for hemodialysis Brescia-Cimino arteriovenous fistulas. Between November 1995 and March 2000, 91 PTA procedures were performed on 50 patients with 57 Brescia-Cimino fistulas. A retrospective study based on the chart review was performed. The initial technical success rate for all procedures and the primary and secondary patency rates for all fistulas were calculated. Regarding fistulas successfully maintained by the primary PTA, the primary and secondary patency rates were compared using the Kaplan-Meier method between two patient groups. They were classified on the basis of several factors, including age (older, over 70 years, and younger group), age of the fistulas (older, over 6 months, and younger group), with or without diabetes mellitus (DM), solitary or multiple lesions, long or short segment lesion, stenosis or occlusion, and with or without arterial and/or anastomotic lesions. Initial technical success rates for all procedures and fistulas were 91.2 and 89.5%, respectively. Cumulative primary and secondary patency rates at 1 year were 47.3 and 67.3%, respectively. In the comparative study, the secondary patency rate for the older group was lower than that of the younger group with statistical significance ( p=0.029). The higher age is the only factor that reduces the long-term patency rate after PTA.

Aged↗
PubMed2002

Improvement of three-dimensional treatment planning models of small lung targets using high-speed multi-slice computed tomographic imaging.

PURPOSE: To improve the reliability of the patient model and reduce treatment volume by acquiring multi-slice computed tomographic (CT) data with the patients' single holding of breath at normal inhalation and exhalation. METHODS AND MATERIALS: Seven patients with nine small peripheral lung cancer tumors underwent CT scanning under three respiration conditions using multi-slice CT: free breathing (FB), shallow inspiration (SI), and shallow expiration (SE). To compare the treatment plan created using the two-respiratory-phase images (SI + SE) with the plans created using only SE images or using only FB images, we attempted to calculate the true dosimetric characteristics for three-dimensional treatment planning taking respiratory movement into consideration. Minimum dose to the gross tumor volume (GTV) and ipsilateral lung dose-volume histogram (DVH) were calculated for the inhalation and exhalation positions of shallow breathing. RESULTS: There was no significant difference between minimum doses of the GTV in the three treatment plans when using anteroposterior/posteroanterior parallel-opposed fields. However, there was a significant difference between the minimum doses of the GTV in the two-phase treatment plan and the minimum dose in the other treatment plans when using the four-field technique, consisting of shaped anterior, posterior, right and left lateral fields (p = 0.03, 0.04). Comparison of the percent volume of ipsilateral lung receiving a dose exceeding 20 Gy (V(20)) based on inhalation and exhalation CT data revealed that the V(20) of the two-phase plan was the smallest of the three treatment planning fields (p < 0.001). CONCLUSION: Two-phase planning using multi-slice CT provides an immediate reduction in the amount of normal tissue treated and improved reliability of patient data for DVH modeling.

Humans↗
PubMed2002

A prospective survey of delayed adverse reactions to iohexol in urography and computed tomography.

We investigated 7505 inpatients who underwent intravenous urography or contrast-enhanced computed tomography to assess risk factors for delayed adverse drug reactions to iohexol, a non-ionic iodinated contrast medium. Focusing on delayed adverse reactions, all adverse events were prospectively investigated for 7 days after injection of iohexol. To explore the relevant risk factors, the relationship between occurrence of adverse reactions to iohexol and 17 different variables was evaluated by logistic regression analysis. To assess the influence of seasonal factors, adverse reactions were separately evaluated during two periods: February to April (the pollinosis period in Japan) and July to September (the non-pollinosis period). The prevalence of delayed adverse events and delayed adverse reactions was 3.5 and 2.8%, respectively, whereas the prevalence of adverse events and adverse reactions was 5.7 and 5.0%, respectively. Multivariate analysis showed that six parameters had a significant influence on delayed adverse reactions to iohexol, including (a) a history of allergy, (b) season, (c) radiographic procedure, (d) age, (e) concomitant surgery or other invasive procedures, and (f) concomitant medication. The prevalence of delayed reactions was lower than in previous large-scale studies. Significant risk factors included a history of allergy and performance of radiography during the pollinosis period, suggesting that allergy was involved in delayed adverse reactions. The type of radiographic procedure also had an influence.

Contrast Media↗
PubMed2002

MR imaging of diffuse adenomyosis changes after GnRH analog therapy.

PURPOSE: To evaluate uterine changes on MRI before and after GnRH analog (GnRHa) treatment in diffuse adenomyosis. MATERIALS AND METHODS: Thirty-one patients with MRI features suggestive of diffuse adenomyosis received GnRHa for 6 months. Diffuse adenomyosis was sub-classified as: symmetric (symmetric/ entire widening of the junctional zone [JZ]) and asymmetric (asymmetric/ partial widening of JZ). Pre- and post-high signal intensity (SI) foci and JZ width, and post-demarcated change (interface of adenomyosis with the myometrium became more discrete with a concomitant decrease in JZ width) were analyzed. RESULTS: Before therapy, 15 of 18 asymmetric contained high SI foci compared to none of symmetric. After therapy, JZ width decreased (P < 0.0001). Eight asymmetric and none of symmetric showed demarcated change with resolved high SI foci. CONCLUSION: Our results suggest the use of GnRHa is associated with a decrease of JZ width in adenomyosis. Asymmetric adenomyosis with high SI foci appears to be the most sensitive to hormonal therapy.

Adult↗
PubMed2002

Proton two-dimensional chemical shift imaging for evaluation of prostate cancer: external surface coil vs. endorectal surface coil.

PURPOSE: To compare the diagnostic ability of proton magnetic resonance spectroscopy (MRS) using an external surface coil with that using an endorectal surface coil in patients with prostate cancer. MATERIALS AND METHODS: MR imaging (MRI) and two-dimensional chemical shift imaging (2D CSI) were performed in 5 healthy volunteers and in 35 patients with prostate cancer. The receiver coil was the anterior lower part of a phased-array coil or an endorectal surface coil. RESULTS: Receiver-operating characteristic analysis for diagnosing prostate cancer showed no significant difference (P = 0.784) between the area under the curve of phased-array coil CSI and that of endorectal surface coil CSI. CONCLUSION: The phased-array coil CSI could provide comparable detection accuracy to endorectal surface coil CSI. In patients with rectal diseases or patients who could not tolerate the discomfort with insertion of an endorectal surface coil, we recommend the phased-array coil CSI.

Adult↗
PubMed2002

Dynamic oxygen-enhanced MRI reflects diffusing capacity of the lung.

The purpose of this study was to demonstrate the feasibility of dynamic oxygen-enhanced MRI in a clinical setting. We hypothesized that dynamic oxygen enhancement can reflect the regional diffusing capacity of the lung. Ten patients with pulmonary emphysema and seven healthy volunteers were examined with a respiratory-synchronized inversion recovery single-shot turbo spin-echo sequence (TR = 3200-5000 ms, TE = 16 ms, TI = 720 ms, ETS = 4 ms) following 100% oxygen inhalation, using a 1.5 T whole-body scanner. Maximum mean relative enhancement ratios calculated by averaging six defined regions of interest (ROIs) in both lungs were statistically compared between healthy volunteers and patients, and were correlated with diffusing lung capacity (%DL(CO)). In patients with pulmonary emphysema, maximum mean relative enhancement ratios were significantly decreased compared to those in healthy volunteers (P = 0.0008). Maximum mean relative enhancement ratio had excellent correlation with % DL(C0) (r(2) = 0.83). Dynamic oxygen-enhanced MRI may reflect the diffusing capacity of the lung; therefore, imaging of oxygen enhancement with MRI may provide maps of the diffusing capacity.

Adult↗
PubMed2002

Postsurgical pelvis: treatment follow-up.

Imaging for recurrence and complications of gynecologic malignancies following treatment with radical hysterectomy, chemotherapy, and radiation therapy has become an important determinant for treatment options available to patients. MR imaging and computed tomography can be used to provide evidence of limited local disease recurrence and thereby identify disease that is still potentially curable with adjuvant treatments. This article examines the imaging modalities currently used to detect recurrence and assist in making treatment changes for gynecologic malignancies and presents specific patient findings following definitive primary treatment of uterine cancer and ovarian cancer with radical hysterectomy, radiation therapy, or chemotherapy.

Endometrial Neoplasms↗
PubMed2002

A case with primary amyloidosis of the liver and spleen: radiologic findings.

A case with primary amyloidosis of the liver and spleen is presented. In the liver, ultrasonography showed heterogeneous echogenicity. Portal phase CT showed heterogeneous enhancement, and delayed phase CT showed delayed enhancement with focal hypoattenuating areas. Bone scintigraphy showed diffuse accumulation. In the spleen, arterial phase CT showed the lack of parenchymal enhancement, and T2-weighted MR imaging showed decreased signal intensity. The combination of imaging findings of the liver and spleen was suggestive of amyloidosis.

Aged↗
PubMed2002

Contrast-enhanced MR perfusion imaging and MR angiography: utility for management of pulmonary arteriovenous malformations for embolotherapy.

OBJECTIVE: The purpose of this study was to assess the capability of MR perfusion imaging and angiography (MRA) for management of pulmonary arteriovenous malformation (PAVM). METHODS AND PATIENTS: Eight patients, having 15 PAVMs underwent pulmonary angiography (PAG), CT, MR perfusion imaging and MRA. For the pretherapeutic management, MRA was compared with PAG and CT regarding detectability and diameter of vasculature. For post-therapeutic management, the change in size of aneurysmal sac, any residual contrast-enhancement and the blood supply within the sac were evaluated. RESULTS: All PAVMs with aneurysmal sac, feeding artery and draining vein diameters of equal to or more than 3 mm, were identified and measured with similar results by all modalities. On follow-up studies, 7 (58.4%) out of 12 treated PAVMs showed a decrease in size and residual contrast-enhancement. The residual contrast-enhancement was considered as bronchial artery-to-pulmonary artery collateral flow by MR perfusion imaging. CONCLUSION: MR perfusion imaging and MRangiography are useful for management of PAVMs over 3 mm in diameter.

Adolescent↗