9 results on '"Saho Irahara"'
Search Results
2. Value of parametric indexes to identify tracheal atresia with or without fistula on fetal magnetic resonance imaging
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Hidekazu Aoki, Shunsuke Nosaka, Yutaka Kanamori, Yasuyuki Suzuki, Saho Irahara, Reiko Okamoto, Mikiko Miyasaka, Yoshiyuki Tsutsumi, Noriko Morimoto, Haruhiko Sago, and Osamu Miyazaki
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Fistula ,Tracheoesophageal fistula ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Esophageal Atresia ,medicine.diagnostic_test ,business.industry ,Ultrasound ,Magnetic resonance imaging ,respiratory system ,Airway obstruction ,medicine.disease ,Magnetic Resonance Imaging ,Diaphragm (structural system) ,Airway Obstruction ,Trachea ,Tracheal atresia ,Pediatrics, Perinatology and Child Health ,Respiratory System Abnormalities ,Airway ,business ,Nuclear medicine ,030217 neurology & neurosurgery ,Tracheoesophageal Fistula - Abstract
Tracheal atresia causes some secondary changes (dilated trachea, flattened/inverted diaphragm, hyperintense and hyperinflated lungs). They can be reduced if a high airway fistula is present. This study evaluated fetal MR images of tracheal atresia and the secondary changes, focusing on the presence of a fistula. We assessed fetal MR images of tracheal atresia without fistula (n=4, median 26 weeks), tracheal atresia with fistula (n=4, median 33 weeks) and controls (n=30, median 32 weeks). We evaluated airway obstruction using true-positive rate in tracheal atresia and false-positive rate in controls indicating they are likely normal variants. Tracheal diameter, craniocaudal-anteroposterior ratio of the right hemidiaphragm, lung-to-liver signal intensity ratio, and cardiothoracic ratio were compared among the three groups using the Kruskal-Wallis test followed by pairwise comparison using the Mann-Whitney U test. True-positive rate was 100% in tracheal atresia, while false-positive rate was 20% in controls. The Kruskal-Wallis test showed differences among groups in craniocaudal-anteroposterior ratio and cardiothoracic ratio (P
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- 2021
3. Clinical application of dynamic 18F-fluorodeoxyglucose positron-emission tomography / computed tomography in the differential diagnoses of musculoskeletal lesions
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Michiko Kubo, Yoshimi Bando, Yoichi Otomi, Saho Irahara, Takayoshi Shinya, Koichi Sairyo, Toshihiko Nishisho, Bettina Beuthien-Baumann, Masafumi Harada, and Hideki Otsuka
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sarcoma ,dynamic scan ,Computed tomography ,General Biochemistry, Genetics and Molecular Biology ,Fluorodeoxyglucose positron emission tomography ,Diagnosis, Differential ,03 medical and health sciences ,0302 clinical medicine ,Fluorodeoxyglucose F18 ,musculoskeletal lesion ,medicine ,Humans ,Medical diagnosis ,Fluorodeoxyglucose ,Dynamic Scan ,Receiver operating characteristic ,medicine.diagnostic_test ,business.industry ,bone and soft tissue tumors ,General Medicine ,medicine.disease ,positron emission tomography computed tomography ,030228 respiratory system ,ROC Curve ,Positron emission tomography ,030220 oncology & carcinogenesis ,Positron-Emission Tomography ,Sarcoma ,Radiopharmaceuticals ,business ,Nuclear medicine ,medicine.drug - Abstract
We aimed to assess the differential diagnostic efficacy of dynamic F-18 fluorodeoxyglucose (FDG) positron emission tomography / computed tomography (PET / CT) and to evaluate the appropriate scan timings for diagnosis of musculoskeletal lesions (MSLs). Dynamic scans (5-15 [phase 1], 15-25 [phase 2], and 25-35 [phase 3] min after F-18 FDG injection) and dual-time-point scans (1 and 2 h after injection) were acquired for 23 MSLs [4 benign MSLs (BMSLs). 10 primary malignant musculoskeletal tumors (PMMSTs), and 9 metastatic musculoskeletal tumors (MMSTs)]. We compared the maximum standardized uptake values (SUVmax) and corresponding retention indices for dynamic (RI-SUVdyn) and dual-time-point (RI-SUVdual) scans and evaluated diagnostic efficacy using receiver operating characteristic (ROC) curve analyses. The SUVmax gradually decreased or was almost identical with minimal fluctuation in 3 BMSLs and 1 PMMST. SUVmax increased over time after phase 2 in 18 malignant MSLs (MMSLs). There were significant differences in SUVmax (for all time phases) and RI-SUV dual between BMSLs and MMSLs and between PMMSTs and MMSTs. In the ROC analyses, the areas under the curve for SUV in phases 2 and 3 were highest for differentiating BMSLs from MMSLs and PMMSTs from MMSTs, respectively. Dynamic F-18 FDG PET / CT is valuable for diagnosis of musculoskeletal lesions. J. Med. Invest. 68 : 96-104, February, 2021.
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- 2021
4. Diagnostic Performance of Arterial Spin Labeling for Grading Nonenhancing Astrocytic Tumors
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Seiji Iwamoto, Youichi Otomi, Delgerdalai Khashbat, Takashi Abe, Teruyoshi Kageji, Mungunbagana Ganbold, Saho Irahara, Shinji Nagahiro, Masafumi Harada, and Naoto Uyama
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Perfusion scanning ,Astrocytoma ,perfusion ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,medicine.diagnostic_test ,Receiver operating characteristic ,astrocytoma grading ,business.industry ,Brain Neoplasms ,Magnetic resonance imaging ,Blood flow ,medicine.disease ,nonenhancing ,arterial spin labeling ,Cerebral blood flow ,Cerebrovascular Circulation ,Mann–Whitney U test ,Spin Labels ,Nuclear medicine ,business ,Perfusion ,030217 neurology & neurosurgery ,Major Paper ,Magnetic Resonance Angiography - Abstract
Purpose: We evaluated the utility of arterial spin labeling (ASL) imaging of tumor blood flow (TBF) for grading non-enhancing astrocytic tumors. Materials and Methods: Thirteen non-enhancing astrocytomas were divided into high-grade (n = 7) and low-grade (n = 6) groups. Both ASL and conventional sequences were acquired using the same magnetic resonance machine. Intratumoral absolute maximum TBF (TBFmax), absolute mean TBF (TBFmean), and corresponding values normalized to cerebral blood flow (TBFmax and TBFmean ratios) were measured. The Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis were used to assess the accuracy of TBF variables for tumor grading. Results: Compared with low-grade astrocytoma, high-grade astrocytoma exhibited significantly greater absolute TBFmax (90.93 ± 24.96 vs 46.94 ± 20.97 ml/100 g/min, P < 0.001), TBFmean (58.75 ± 19.89 vs 31.16 ± 17.63 ml/100 g/min, P < 0.001), TBFmax ratio (3.34 ± 1.22 vs 1.35 ± 0.5, P < 0.001), and TBFmean ratio (2.15 ± 0.94 vs 0.88 ± 0.41, P < 0.001). The TBFmax ratio yielded the highest diagnostic accuracy (sensitivity 100%, specificity 86.3%), while absolute TBFmean yielded the lowest accuracy (sensitivity 85.7%, specificity 70.1%) by ROC analysis. Conclusion: Parameters from ASL perfusion imaging, particularly TBFmax ratio, may be useful for distinguishing high-grade from low-grade astrocytoma in cases with equivocal conventional MRI findings.
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- 2017
5. The diagnostic ability of SPECT/CT fusion imaging for gastrointestinal bleeding : a retrospective study
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Yuki Obama, Michiko Kubo, Kaori Terazawa, Maki Arase, Naoto Uyama, Takashi Abe, Moriaki Yamanaka, Hideki Otsuka, Masafumi Harada, Saho Irahara, Maki Otomo, and Yoichi Otomi
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Adult ,Male ,Gastrointestinal bleeding ,Planar Imaging ,Single Photon Emission Computed Tomography Computed Tomography ,Scintigraphy ,Sensitivity and Specificity ,030218 nuclear medicine & medical imaging ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Capsule endoscopy ,law ,Spect imaging ,Medicine ,Humans ,lcsh:RC799-869 ,Technetium Tc 99m Aggregated Albumin ,Aged ,Retrospective Studies ,Gastrointestinal tract ,medicine.diagnostic_test ,business.industry ,Gastroenterology ,Tc-99 m HSA-DTPA ,Tc-99m HSA-DTPA ,Retrospective cohort study ,Gastrointestinal bleeding scintigraphy ,General Medicine ,SPECT/CT ,Middle Aged ,medicine.disease ,Endoscopy ,Technetium Tc 99m Pentetate ,lcsh:Diseases of the digestive system. Gastroenterology ,030211 gastroenterology & hepatology ,Female ,Radiopharmaceuticals ,business ,Nuclear medicine ,Gastrointestinal Hemorrhage ,Research Article - Abstract
Background Blood loss from the gastrointestinal tract can be an acute and life-threatening event. For the treatment of gastrointestinal bleeding, it is important to accurately detect gastrointestinal bleeding and to localize the sites of bleeding. The purpose of this study was to retrospectively assess the capabilities of SPECT/CT in the diagnosis of gastrointestinal bleeding by a comparison with planar imaging alone as well as planar and SPECT. Methods We conducted a retrospective analysis of 20 patients (21 examinations) who underwent gastrointestinal bleeding scintigraphy in the past 7 years and in whom the bleeding site was identified by endoscopy or capsule endoscopy, or in whom no evidence of gastrointestinal bleeding was identified during the clinical course. Five patients (5 examinations) were diagnosed by planar imaging (planar group). Eight patients (9 examinations) were diagnosed by planar imaging and SPECT (planar + SPECT group). Seven patients (7 examinations) were diagnosed by planar imaging and SPECT/CT (planar + SPECT/CT group). We calculated the diagnostic ability of each method in detecting the presence of bleeding, as well as the ability of each method to identify the sites of bleeding. The sensitivity, specificity, and accuracy of the methods were compared. Results The diagnostic ability of the three imaging methods in detecting the presence of gastrointestinal bleeding was as follows. Planar imaging showed 100% sensitivity (3/3), 100% specificity (2/2), and 100% accuracy (5/5). Planar + SPECT imaging showed 85.7% sensitivity (6/7), 100% specificity (2/2), and 88.9% accuracy (8/9). Planar + SPECT/CT imaging showed 100% sensitivity (6/6), 100% specificity (1/1), and 100% accuracy (7/7). The diagnostic ability of the three modalities in detecting the site of bleeding was as follows: planar, 33.3% (1/3); planar + SPECT, 71.4% (5/7); and planar + SPECT/CT, 100% (6/6). Conclusions All 3 imaging methods showed good accuracy in detecting the presence of gastrointestinal bleeding. The addition of SPECT or SPECT/CT made the anatomical position of the uptake clear and contributed to the localization of the site of gastrointestinal bleeding. Planar + SPECT/CT imaging therefore showed the highest diagnostic ability for detecting the site of gastrointestinal bleeding.
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- 2018
6. Correlation of 3D Arterial Spin Labeling and Multi-Parametric Dynamic Susceptibility Contrast Perfusion MRI in Brain Tumors
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Masafumi Harada, Shinji Nagahiro, Saho Irahara, Naoto Uyama, Takashi Abe, Youichi Otomi, Seiji Iwamoto, Delgerdalai Khashbat, Teruyoshi Kageji, and Mungunbagana Ganbold
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Adult ,Male ,medicine.medical_specialty ,media_common.quotation_subject ,Perfusion Imaging ,Contrast Media ,Perfusion scanning ,General Biochemistry, Genetics and Molecular Biology ,030218 nuclear medicine & medical imaging ,Correlation ,03 medical and health sciences ,0302 clinical medicine ,Vascularity ,Nuclear magnetic resonance ,otorhinolaryngologic diseases ,medicine ,Contrast (vision) ,Humans ,media_common ,Aged ,Chemistry ,Brain Neoplasms ,technology, industry, and agriculture ,General Medicine ,Middle Aged ,Magnetic Resonance Imaging ,Cerebral blood flow ,Cerebrovascular Circulation ,Dynamic contrast-enhanced MRI ,Arterial spin labeling ,Female ,Spin Labels ,Radiology ,medicine.symptom ,Perfusion ,030217 neurology & neurosurgery ,circulatory and respiratory physiology - Abstract
Purpose : Arterial spin labeling (ASL) is an alternative method to Dynamic susceptibility contrast (DSC) perfusion MRI for brain tumors. However, ASL cerebral blood flow (CBF) can be easily affected by transit time. DSC MRI derived time to maximum of the residue function (Tmax) is possible to assess the transit time on ASL. Methods : Thirty patients with brain tumors were studied using ASL and DSC MRI. The relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), Tmax, and mean transit time (MTT) were obtained from DSC MRI. The ratios of the parameters were analyzed. Results : ASL CBF ratio correlated with the DSC rCBF ratio (r=0.78, p
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- 2016
7. Increased (18)F-fluorodeoxyglucose accumulation in bilateral adrenal glands of the patients suffering from vasovagal reaction due to blood vessel puncture
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Kaori Terazawa, Saho Irahara, Yoichi Otomi, Ayaka Takahashi, Masafumi Harada, Saki Nagase, Hideki Otsuka, Takayoshi Shinya, and Michiko Kubo
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Adult ,Male ,Pathology ,medicine.medical_specialty ,Punctures ,030204 cardiovascular system & hematology ,030218 nuclear medicine & medical imaging ,Vasovagal Reaction ,03 medical and health sciences ,0302 clinical medicine ,Fluorodeoxyglucose F18 ,Positron Emission Tomography Computed Tomography ,Adrenal Glands ,medicine ,Syncope, Vasovagal ,Humans ,Radiology, Nuclear Medicine and imaging ,Bilateral adrenal glands ,PET-CT ,Vagovagal reflex ,Adrenal gland ,business.industry ,Biological Transport ,General Medicine ,medicine.anatomical_structure ,Female ,18 f fluorodeoxyglucose ,business ,Vascular Surgical Procedures ,Blood vessel - Abstract
The purpose of the study was to evaluate the hypothesis that patients having a vasovagal reaction (VVR) after blood vessel puncture show increased FDG accumulation in bilateral adrenal glands.Over the past 8 years, 26 patients experienced a VVR after blood vessel puncture following intra-venous injection of FDG at our institution. Of the 26 patients, 16 underwent multiple-occasion FDG-PET/CT scans while suffering a VVR at only one examination. All 16 patients had no morphological abnormality in the adrenal glands on FDG-PET/CT and follow-up examination. For the 16, we retrospectively reviewed the FDG-PET/CT scan with respect to the adrenal glands and compared the result to that for the FDG-PET/CT scan of the same patient when there was no VVR event. We used both visual analysis and semi-quantitative analysis employing either maximum standardized uptake value (SUVmax) or adrenal-to-liver (A/L) SUVmax ratio.On visual analysis of the FDG-PET/CT with VVR, accumulations in both of the adrenal glands was judged positive, defined as higher than the hepatic accumulation, in 84 % of the cases. The SUVmax in the right adrenal gland was 2.79 ± 0.69 with VVR and 1.92 ± 0.33 without VVR; this value in the left adrenal gland was 3.07 ± 0.71 with VVR and 2.05 ± 0.39 without. Mean SUVmax of both adrenal glands was 2.93 ± 0.66 with VVR and 1.98 ± 0.35 without. The A/L SUVmax ratio in the right adrenal gland was 1.02 ± 0.26 with VVR and 0.69 ± 0.11 without; this value in the left was 1.11 ± 0.23 with VVR and 0.74 ± 0.15 without. The mean A/L SUVmax ratio of both adrenal glands was 1.06 ± 0.24 with VVR and 0.72 ± 0.13 without. Each parameter with VVR was significantly higher than that without. For the two adrenal glands, the mean SUVmax with VVR was 48 % higher than that without VVR.We confirmed the hypothesis that patients having a VVR after blood vessel puncture show increased FDG accumulation in their bilateral adrenal glands. This may reflect hyper-metabolism of the adrenal glands in synthesizing and secreting catecholamine.
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- 2016
8. Clinical Significance of Discrepancy between Arterial Spin Labeling Images and Contrast-enhanced Images in the Diagnosis of Brain Tumors
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Yoshifumi Mizobuchi, Mungunkhuyag Majigsuren, Saho Irahara, Teruyoshi Kageji, Delgerdalai Khashbat, Wataru Sako, Kohei Nakajima, Masafumi Harada, Shinji Nagahiro, Takashi Abe, Yoichi Otomi, and Yuki Obama
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Adult ,Gadolinium DTPA ,Male ,medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,Oligodendroglioma ,Brain tumor ,Contrast Media ,Neuroimaging ,Astrocytoma ,Gliosarcoma ,Metastasis ,Diagnosis, Differential ,Glioma ,otorhinolaryngologic diseases ,medicine ,Image Processing, Computer-Assisted ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Brain Neoplasms ,Primary central nervous system lymphoma ,Electron Spin Resonance Spectroscopy ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,Image Enhancement ,Magnetic Resonance Imaging ,Neoplasms, Neuroepithelial ,Hyperintensity ,Lymphoma ,Female ,Spin Labels ,Radiology ,Lymphoma, Large B-Cell, Diffuse ,Nuclear medicine ,business ,Glioblastoma ,Brain metastasis ,Follow-Up Studies - Abstract
Purpose In the imaging of intra-axial brain tumors, we sometimes found areas of high signal intensity around the enhanced tumor lesions on arterial spin labeling (ASL) magnetic resonance (MR) imaging. We undertook this study to investigate the relationship between high signal intensity on ASL imaging outside the area of contrast enhancement (CE) and histological diagnosis of intra-axial brain tumors. Methods We examined images from 28 consecutive patients with intra-axial brain tumors who underwent ASL and CE MR imaging-three with low grade glioma (LGG), 13 with high grade glioma (HGG), six with metastasis, and six with primary central nervous system lymphoma (PCNSL)-and divided imaging findings into an "ASL dominant" group when hyperintensity on ASL was found outside the CE area and a "CE dominant" group when hyperintensity on ASL was not found outside the area of enhancement. We then analyzed the relationship between imaging findings and the histological diagnosis of the tumors. Results Four cases were excluded because of poor quality of ASL images, 7 cases were classified as ASL dominant, and 17 cases were classified as CE dominant. The histological diagnoses of ASL dominant cases were LGG in 3 cases, HGG in 3 cases, and PCNSL in one case. Those of CE dominant cases were HGG in 10 cases, metastasis in 5 cases, and PCNSL in 2 cases. All cases with brain metastasis were classified as CE dominant. Conclusion The high signal intensity outside the area of contrast enhancement is probably caused by increased perfusion or vascular proliferation, which indicates the presence of glioma or PCNSL and not metastasis. This finding indicates a new utility for ASL images in the diagnosis of brain tumors as a supplement to the conventional measurement of perfusion obtained from ASL images.
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- 2015
9. Diagnosis of brain tumors using dynamic contrast-enhanced perfusion imaging with a short acquisition time
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Yoshifumi Mizobuchi, Mungunkhuyag Majigsuren, Delgerdalai Khashbat, Takashi Abe, Saho Irahara, Yuki Obama, Masafumi Harada, Yoichi Otomi, Shinji Nagahiro, Kohhei Nakajima, and Teruyoshi Kageji
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Pathology ,medicine.medical_specialty ,Multidisciplinary ,Receiver operating characteristic ,business.industry ,Research ,Brain tumor ,Pharmacokinetic model analysis ,Perfusion scanning ,medicine.disease ,Metastasis ,Glioma ,Two-compartment model analysis ,medicine ,Mann–Whitney U test ,Dynamic contrast enhanced (DCE) perfusion ,Magnetic resonance imaging (MRI) ,Nuclear medicine ,business ,Perfusion ,Brain metastasis - Abstract
This study sought to determine the diagnostic utility of perfusion parameters derived from dynamic contrast-enhanced (DCE) perfusion MRI with a short acquisition time (approximately 3.5 min) in patients with glioma, brain metastasis, and primary CNS lymphoma (PCNSL). Twenty-six patients with 29 lesions (4 low-grade glioma, 13 high-grade glioma, 7 metastasis, and 5 PCNSL) underwent DCE-MRI in a 3 T scanner. A ROI was placed on the hotspot of each tumor in maps for volume transfer contrast K trans , extravascular extracellular volume V e , and fractional plasma volume V p . We analyzed differences in parameters between tumors using the Mann–Whitney U test. We calculated sensitivity and specificity using receiver operating characteristics analysis. Mean K trans values of LGG, HGG, metastasis and PCNSL were 0.034, 0.31, 0.38, 0.44, respectively. Mean Ve values of each tumors was 0.036, 0.57, 0.47, 0.96, and mean Vp value of each tumors was 0.070, 0.086, 0.26, 0.17, respectively. Compared with other tumor types, low-grade glioma showed lower K trans (P
- Published
- 2015
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