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Dive into the research topics where Satoshi Hirasawa is active.

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Featured researches published by Satoshi Hirasawa.


Anatomical Sciences Education | 2014

An Integrated Teaching Method of Gross Anatomy and Computed Tomography Radiology.

Tohru Murakami; Yuki Tajika; Hitoshi Ueno; Sachiko Awata; Satoshi Hirasawa; Maki Sugimoto; Yoshihiko Kominato; Yoshito Tsushima; Keigo Endo; Hiroshi Yorifuji

It is essential for medical students to learn and comprehend human anatomy in three dimensions (3D). With this in mind, a new system was designed in order to integrate anatomical dissections with diagnostic computed tomography (CT) radiology. Cadavers were scanned by CT scanners, and students then consulted the postmortem CT images during cadaver dissection to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld digital imaging and communications in medicine viewers at the bench‐side (OsiriX on iPod touch or iPad), which enabled “pixel‐to‐tissue” direct comparisons of CT images and cadavers. Students had lectures and workshops on diagnostic radiology, and they completed study assignments where they discussed findings in the anatomy laboratory compared with CT radiology findings. This teaching method for gross and radiological anatomy was used beginning in 2009, and it yielded strongly positive student perspectives and significant improvements in radiology skills in later clinical courses. Anat Sci Educ 7: 438–449.


CardioVascular and Interventional Radiology | 2008

Air Embolism Detected During Computed Tomography Fluoroscopically Guided Transthoracic Needle Biopsy

Satoshi Hirasawa; Hiromi Hirasawa; Ayako Taketomi-Takahashi; Hideo Morita; Yoshito Tsushima; Makoto Amanuma; Keigo Endo

Air embolism is a rare but potentially fatal complication of percutaneous needle biopsy of the lung. We report a case of cerebral air embolism which occurred during computed tomography (CT)-guided needle biopsy. Air entering the aorta is depicted on CT-fluoroscopy images of the procedure.


Legal Medicine | 2013

Use of postmortem computed tomography to reveal acute subdural hematoma in a severely decomposed body with advanced skeletonization

Rie Sano; Satoshi Hirasawa; Sachiko Awata; Susumu Kobayashi; Takehiro Shimada; Hiroyuki Takei; Yoichiro Takahashi; Yoshihiko Kominato

An 81-year-old man was found dead 1 month after he had disappeared following a visit to a hot spring resort in early autumn. The body showed severe postmortem changes with advanced skeletonization from the head to the abdomen as well as putrefactive and autolytic changes in the remaining tissues. The thoracic and abdominal organs had been lost. Naked eye examination revealed soft tissue injuries accompanied by ragged edges and characteristic punctures with no signs of vitality, suggesting that these injuries had been due to postmortem animal scavenging. However, bruises were prominent on the anterior parts of both lower extremities. Postmortem computed tomography (PMCT) scan demonstrated subdural hematoma over the right cerebral hemisphere, although the brain itself had undergone putrefactive and autolytic changes. Subsequent autopsy confirmed the presence of a 140 g acute subdural hematoma, which would likely have been fatal. This case illustrates that PMCT is able to yield important information about possible cause of death, even in a partially skeletonized body.


Forensic Science International | 2014

Combination of postmortem mass spectrometry imaging and genetic analysis reveals very long-chain acyl-CoA dehydrogenase deficiency in a case of infant death with liver steatosis

Yoichiro Takahashi; Rie Sano; Tamiko Nakajima; Yoshihiko Kominato; Rieko Kubo; Keiko Takahashi; Noriyasu Ohshima; Tohko Hirano; Susumu Kobayashi; Takehiro Shimada; Hiroyuki Tokue; Sachiko Awata; Satoshi Hirasawa; Takashi Ishige

CASE HISTORY A 3-month-old infant was found dead in his bed. A postmortem computed tomography (CT) scan suggested fatty attenuation in the liver parenchyma, but no other potentially fatal changes were found. To clarify the cause of death, a medicolegal autopsy was carried out. AUTOPSY FINDINGS Internal examination confirmed the presence of liver steatosis as well as hepatomegaly. There were no other significant findings including encephalitis or brain edema. MASS SPECTROMETRY ANALYSIS To clarify the mechanism underlying lipid accumulation in the liver, matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) analysis was conducted. This indicated a significant accumulation of C14:1 acylcarnitine in the liver of the deceased, suggesting very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. GENETIC ANALYSIS To find the cause of the VLCAD deficiency, genetic analysis of the responsible gene, acyl-CoA dehydrogenase, very long chain (ACADVL), was performed. This revealed two novel mutations that may have accounted for the disease. CONCLUSION A combination of these data revealed that the liver steatosis in this case might have been caused by VLCAD deficiency based on genetic mutations of ACADVL. Thus, the deceased might have been vulnerable to energy crisis and sudden infant death. The present findings show that MALDI-IMS analysis as well as genetic analysis can be useful for elucidating the cause of death.


Legal Medicine | 2017

Postmortem computed tomography evaluation of fatal gas embolism due to connection of an intravenous cannula to an oxygen supply

Yoichiro Takahashi; Rie Sano; Akiyuki Yasuda; Eri Kuboya; Keiko Takahashi; Rieko Kubo; Yoshihiko Kominato; Hiroyuki Takei; Susumu Kobayashi; Takehiro Shimada; Sachiko Awata; Hiroyuki Tokue; Satoshi Hirasawa

An 84-year-old man who had suffered from chronic obstructive pulmonary disease accompanied by moderate pneumonia as well as gastric cancer with liver metastasis was found dead by a nurse, who noticed that the patients intravenous catheter in the left forearm had been erroneously connected to an oxygen supply in his hospital room, leading to infusion of oxygen into a vein. Postmortem CT scanning demonstrated multiple accumulations of gas in the pulmonary artery, the right atrium and ventricle, as well as the left subclavian and brachiocephalic veins, corresponding to the route that the infused gas would have taken to the heart and pulmonary artery. Conventional autopsy revealed the presence of gas in the right ventricle. These findings suggested that the immediate cause of death was a gas embolus due to oxygen that had entered the cardiopulmonary circulation via the intravenous catheter. This case highlights the usefulness of postmortem imaging as an aid to conventional autopsy for demonstrating gas embolism.


Legal Medicine | 2016

Use of postmortem coronary computed tomography angiography with water-insoluble contrast medium to detect stenosis of the left anterior descending artery in a case of sudden death

Yoichiro Takahashi; Rie Sano; Keiko Takahashi; Yoshihiko Kominato; Hiroyuki Takei; Susumu Kobayashi; Takehiro Shimada; Hiroyuki Tokue; Sachiko Awata; Satoshi Hirasawa

A 40-year-old man was found dead on a sidewalk in an expressway parking area one hour after he had entered the area on a motorcycle. A medicolegal autopsy was performed to reveal the cause of this sudden and unexpected death. Postmortem coronary CT angiography after introduction of 5% gelatin-barium emulsion as a radiopaque contrast medium into the heart demonstrated a significant arterial luminal filling defect in the left anterior descending (LAD) coronary artery. Macroscopic and microscopic examinations revealed that a thrombus had become deposited on ruptured plaque within the LAD artery, and that a small amount of the contrast medium was present between the thrombus and the vessel endothelium. These histological findings were consistent with incomplete occlusion of the LAD artery in the 3D reconstructed image. The cause of death in this case was definitively determined to be ischemic heart disease. Postmortem angiography played a role in screening of a vascular lesion that was subsequently verified by histology to have been responsible for sudden and unexpected death.


PLOS ONE | 2014

Percutaneous Image-Guided Biopsy for Non-Mass-Forming Isolated Splenomegaly and Suspected Malignant Lymphoma

Hiroyuki Tokue; Satoshi Hirasawa; Hideo Morita; Yoshinori Koyma; Masaya Miyazaki; Kei Shibuya; Azusa Tokue; Sachiko Nakano; Yoshito Tsushima

Background The aim of this study was to evaluate the accuracy, safety, and role of splenic biopsy in the management of patients with non-mass-forming isolated splenomegaly and suspected malignant lymphoma. Methods Between 2001 and 2013, 137 biopsies were performed under computed tomography (CT) fluoroscopic guidance in 39 patients. All patients had splenomegaly based on the CT findings and a suspected diagnosis of malignant lymphoma based on their clinical symptoms. The spleen was the only accessible site to perform a biopsy, and no mass lesions could be identified in the spleen. Results The overall sensitivity, specificity, and diagnostic accuracy of image-guided biopsy for malignant lymphoma were 88%, 100% and 92%, respectively. Major complications occurred in 3 patients. In 1 patient, transcatheter arterial embolization was performed due to hemorrhage, and two patients needed blood transfusion because of hematoma development, without the need for further treatment. Conclusions Image-guided splenic core-needle biopsy is a safe and accurate technique with a high diagnostic accuracy in most patients who with non-mass-forming isolated splenomegaly and suspected underlying malignant lymphoma.


Legal Medicine | 2018

Usefulness of coronary postmortem computed tomography angiography to detect lesions in the coronary artery and myocardium in cases of sudden death

Hiroyuki Takei; Rie Sano; Yoichiro Takahashi; Keiko Takahashi; Yoshihiko Kominato; Hiroyuki Tokue; Takehiro Shimada; Sachiko Awata; Satoshi Hirasawa; Naoya Ohta

Coronary postmortem computed tomography angiography (coronary PMCTA) has been introduced as a routine examination procedure for autopsy at our department. Here, we reviewed eight autopsy cases in which apparent histopathological changes including acute myocardial infarction (AMI), anomalous aortic origin of a coronary artery (AAOCA), hypertrophic obstructive cardiomyopathy (HOCM) and acute myocarditis were involved in the cause of death. For investigation of the coronary artery and shape of the heart, coronary PMCTA was valuable in detecting narrowing or obstruction of coronary artery in AMI, indicating an anomalous aortic origin of the left coronary artery in AAOCA, and demonstrating septal hypertrophy and intracavitary obstruction in HOCM. However, it was debatable whether the hypervascularity demonstrated by coronary PMCTA in the case of acute myocarditis was more prominent than the vascular images obtained in other cases without inflammation. Thus, coronary PMCTA appeared to be useful not only for detection of coronary artery stenosis, but also for indicating other distinctive changes involved in AAOCA and HOCM.


British Journal of Radiology | 2018

Primary postpartum hemorrhage: outcome of uterine artery embolization

Makoto Aoki; Hiroyuki Tokue; Masaya Miyazaki; Kei Shibuya; Satoshi Hirasawa; Kiyohiro Oshima

OBJECTIVE To assess the efficacy of uterine artery embolization (UAE) for the management of primary postpartum hemorrhage (PPH) and to determine the factors associated with clinical outcomes especially in relation to the ovarian artery. METHODS A retrospective analysis of 33 patients who underwent UAE for primary PPH was performed. Clinical data were used regarding maternal characteristics, cause of bleeding, mode of delivery, bleeding onset after delivery, risk factors for PPH, presence of coagulopathy, details regarding the UAE procedure, and types of ovarian artery flow. We defined two types of ovarian artery flow by initial aortography before UAE (Type A: ovarian artery flow arose directly from the aorta to the uterine artery; Type B: ovarian artery flow that did not obviously arise from the aorta). Clinical success was defined as cessation of bleeding after UAE without the need for hysterectomy. Univariate analysis was performed to determine factors related to clinical outcomes. RESULTS The major indication of UAE was uterine atony (82%; 27/33). Extravasation of contrast medium was observed in 15 (45%) patients. The clinical success rate was 85% (28/33). In five patients, embolization failed, and these patients were managed by hysterectomy. Univariate analysis showed that retained placental tissue (p < 0.001), type of ovarian artery (p < 0.001) and the existence of extravasation of contrast medium (p = 0.049) were related to the clinical success rate. CONCLUSION The clinical success rate was 85% (28/33), and some PPH patients were thought to need ovarian artery embolization in addition to UAE. Advances in knowledge: Initial aortography before UAE may be useful to predict the failure of UAE and the need of ovarian artery embolization. Obvious ovarian arterial blood flow to the uterus by aortography could be a warning sign.


Legal Medicine | 2015

Brain fragility can be estimated by its putrefactive signs on postmortem computed tomography.

Kaho Watanabe; Yoichiro Takahashi; Rie Sano; Tamiko Nakajima; Yoshihiko Kominato; Susumu Kobayashi; Takehiro Shimada; Hiroyuki Takei; Sachiko Awata; Satoshi Hirasawa

Along with time after death, postmortem computed tomography (PMCT) of the brain can reveal sequential changes. In the present study, we investigated the relationship between brain rigidity and advanced postmortem changes such as intravascular gas production, cerebral settling or cerebral liquefaction on PMCT. We then examined the findings of PMCT as an indicator of successful macroscopic examination of arbitrary brain slices at classical autopsy. The association between these advanced postmortem changes and the validity of macroscopic brain examination was investigated in 149 cases that were examined by PMCT at our department prior to autopsy in the period from September 2011 to December 2013. We found that the postmortem changes, classified into four stages, generally reflected the fragility of the brain. Thus, it is likely that PMCT findings of advanced postmortem changes are able to indicate decreased brain rigidity ahead of autopsy. These findings support the idea that PMCT could be used as a guide by forensic pathologists for suitable handling of a fragile brain, thus enhancing the quality of autopsy.

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