Ryota Shimofusa

Chiba University, Tiba, Chiba, Japan

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Publications (17)21.28 Total impact

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    ABSTRACT: PURPOSE We compared non-cardiac findings, in particular lung findings, by a cardiologist with those by a radiologist in 320 slice CT heart images. METHOD AND MATERIALS Non-cardiac findings using full field view electrocardiogram gated 320 slice CT (Aquilion one, Toshiba Medical) heart images acquired from 96 consecutive subjects (55 male; mean age, 63.8 yrs) were analyzed retrospectively by a cardiologist and by a radiologist team without any clinical data, and the findings of each examiner were compared. Of the subjects, 48 underwent only heart imaging (Group 1), and 48 underwent whole thorax imaging for additional evaluation of thoracic aorta or pulmonary embolism (Group 2). RESULTS Of the 96 subjects, non-cardiac findings were reported in 31 subjects by the cardiologist and 51 subjects by the radiologists. In Group 1, suspected lung cancer, interstitial pneumonia, benign or inflammation lung disease, findings that should be followed up, and previously known non-cardiac findings were reported in 0, 0, 4, 10 and 1 subject, respectively, by the cardiologist and 1, 5, 13, 2 and 1 subjects, respectively, by the radiologists. In Group 2, suspected lung cancer, interstitial pneumonia, benign or inflammation lung disease, findings that should be followed up, and previously known non-cardiac findings were reported in 0, 0, 6, 9 and 1 subject, respectively, by the cardiologist and 2, 5, 19, 1 and 2 subjects, respectively, by the radiologists. In three subjects who were diagnosed as lung cancer by radiologists, only two were diagnosed as findings that should be followed by the cardiologist. CONCLUSION Among 97 subjects, 3 were de novo lung cancer diagnosed by radiologists. Of these, one was diagnosed using only heart images, and two were diagnosed by the cardiologist as findings that should be followed up. One lung cancer subject was missed when analysis was performed only by the cardiologist, and, therefore, non-cardiac findings should be evaluated by radiologists. CLINICAL RELEVANCE/APPLICATION Even when using only heart images, non-cardiac and lung findings on CT should be evaluated by radiologists, and cardiologists should examine full field thoracic images when possible.
    International journal of cardiology 01/2014; · 6.18 Impact Factor
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    ABSTRACT: We present a case of unusual gas embolism in a 73-year-old man who was found in a state of cardiopulmonary arrest with an oxygen-supply tube connected to an intravenous catheter inserted into his median cubital vein. Postmortem computed tomography (PMCT) performed 27h after death showed systemic gas distribution including intravascular gas, pneumothorax, pneumoperitoneum, pneumomediastinum, pneumoretroperitoneum and gastric emphysema. A second PMCT scan performed 116h after death showed a marked decrease of air inside the body. The current case shows the importance of PMCT for visualization, quantification, and preservation of evidence for establishment of the cause of death in cases with suspected gas embolism. Our findings also indicate that performance of two PMCT examinations may be useful for differentiation of embolized gas from gas produced by putrefaction.
    Forensic science international 06/2013; · 2.10 Impact Factor
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    ABSTRACT: PURPOSE: To assess the value of gadoxetic acid-enhanced magnetic resonance imaging (MRI) for the pre-therapeutic detection of hepatocellular carcinoma (HCC) using receiver operating characteristic (ROC) analysis with the combination of computed tomography (CT) arterial portography and CT hepatic arteriography (CTAP/CTHA). MATERIALS AND METHODS: A total of 54 consecutive patients with 87 nodular HCCs were retrospectively analyzed. All HCC nodules were confirmed pathologically. Three blinded readers independently reviewed 432 hepatic segments, including 78 segments with 87 HCCs. Each reader read two sets of images: Set 1, CTAP/CTHA; Set 2, gadoxetic acid-enhanced MRI including a gradient dual-echo sequence and diffusion-weighted imaging (DWI). The ROC method was used to analyze the results. The sensitivity, specificity, positive predictive value, negative predictive value and sensitivity according to tumor size were evaluated. RESULTS: For each reader, the area under the curve was significantly higher for Set 2 than for Set 1. The mean area under the curve was also significantly greater for Set 2 than for Set 1 (area under the curve, 0.98 vs. 0.93; P=.0009). The sensitivity was significantly higher for Set 2 than for Set 1 for all three readers (P=.012, .013 and .039, respectively). The difference in the specificity, positive predictive values and negative predictive values of the two modalities for each reader was not significant (P>.05). CONCLUSION: Gadoxetic acid-enhanced MRI including a gradient dual-echo sequence and DWI is recommended for the pre-therapeutic evaluation of patients with HCC.
    Magnetic Resonance Imaging 12/2012; · 2.06 Impact Factor
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    ABSTRACT: The purpose of our study was to describe the MR appearance of Kimura disease and to interpret the differences in appearance from malignant parotid gland tumours. MR studies of seven patients with Kimura disease were reviewed. The MR studies included T(1) weighted, T(2) weighted, short tau inversion-recovery, diffusion-weighted (DW) and dynamic contrast-enhanced imaging. Typical Kimura disease featured subcutaneous lesions, continuously infiltrated parotid lesions from the subcutaneous lesions with or without intraparotid lymphadenopathies, and reactive cervical lymphadenopathies. The subcutaneous lesions showed gradual upward enhancement on dynamic contrast-enhanced MR images. Reactive lymph nodes showed early enhancement on contrast-enhanced MR images and marked high intensity and low apparent diffusion coefficient values on DW images. An indication for making the diagnosis of Kimura disease should be the subcutaneous tissue of the head and neck showing gradual upward enhancement on dynamic contrast-enhanced MRI and a lack of high intensity on DW images, associated with reactive lymph nodes.
    The British journal of radiology 09/2011; 84(1005):800-4. · 2.11 Impact Factor
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    ABSTRACT: PURPOSE Postmortem imaging using computed tomography (CT) or magnetic resonance imaging is called “autopsy imaging” in Japan. Postmortem CT is widely used for detecting causes of death, because autopsy rate is low in Japan. Diseases, which postmortem CT can diagnose, are mainly limited to intracranial hemorrhage and aortic lesions. The purpose of this study is to determine efficacy of postmortem contrast enhancement with cardiac massage. METHOD AND MATERIALS Materials: The series included 48 cases (mean age, 70.6 years; 33 men and 15 women) of non-traumatic death with out-of-hospital cardiopulmonary arrest. All subjects received cardiopulmonary resuscitation (intubation, chest compression and administration of cardiotonic drugs). No case underwent autopsy. Radiological method: Iodinated contrast material (100 ml iohexol, 300 mg iodine/ml) was injected at 1.5 ml/sec from a peripheral intravenous catheter in the upper limb. Immediately after the injection, closed-chest compression was commenced at the rate of 100 times per minute. Using 64-row multidetector CT (Aquilion64, Toshiba Medical Systems), whole-body images were obtained after 200-800 chest compressions. Evaluation: The diagnoses of precontrast images were compared with that of postcontrast images. RESULTS Precontrast images diagnosed causes of death as aortic dissection in six cases and abdominal aortic aneurysm rupture in one case. In two cases, postcontrast images could additionally diagnose pulmonary thromboembolism. Four cases of cardiac rupture and one case of leaking penetrating atherosclerotic ulcer were revealed, which were showed as hemomediastinum, hemorrhagic pericardial effusion or hemorrhagic pleural effusion of unknown causes in precontrast images. In total, postcontrast images obtained new diagnoses in seven cases. CONCLUSION Postmortem contrast-enhanced CT is useful for diagnosis of pulmonary thromboembolism , cardiac rupture and leaking penetrating atherosclerotic ulcer. CLINICAL RELEVANCE/APPLICATION Postmortem contrast-enhanced CT can be performed easily and improve the detectability of causes of death.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting; 11/2010
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    ABSTRACT: Postmortem computed tomography (CT) images can show internal findings related to the cause of death, and it can be a useful method for forensic diagnosis. In this study, we scanned a ready-made box by helical CT on 2-mm slices in a mobile CT scanner and measured each side of the box to assess whether reconstructed images are useful for superimposition. The mean difference between the actual measurements and the measurements on the three-dimensional (3D) reconstructed images (3D-CT images) is 0.9 mm; we regarded it as having no effect on reconstruction for the superimposition method. Furthermore, we could get 3D-CT images of the skull, which were consistent with the actual skull, indicating that CT images can be applied to superimposition for identification. This study suggested that postmortem CT images can be applied as superimpositions for unidentified cases, and thinner slices or cone beam CT can be a more precise tool.
    Journal of Forensic Sciences 11/2010; 55(6):1624-9. · 1.24 Impact Factor
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    ABSTRACT: Although the pathological categorization system advocated by the International Working Party (IWP) on Terminology has been helpful in categorizing benign hepatocellular lesions, the diverse clinicopathological features of the lesions still cause confusion of diagnosis in clinical settings. Recently, an integrated disease concept termed "anomalous portal tract syndrome" (APTS) has been proposed as a congenital anomaly of the portal tract, being a single unifying etiological factor underlying the disorder. In this article, we discuss the radiological features of benign nodular hepatocellular lesions incorporated in the concept of APTS. We systematically reviewed the literature on benign hepatocellular lesions based on the concept of APTS, as well as standard IWP terminology. For this pictorial review, we selected six representative cases and assessed the radiological features of the cases based on the concept of APTS. The comprehensive assessment based on APTS enabled the systematic categorization of benign hepatocellular lesions, including nodular regenerative hyperplasia, large regenerative nodules, partial nodular transformation, focal nodular hyperplasia, and hepatocellular adenoma, and was helpful in understanding the overlapping features of these lesions. Although the disease concept of APTS is still evolving, it is nonetheless helpful in comprehensively understanding the clinicopathological and radiological features of various benign hepatocellular lesions.
    Journal of hepato-biliary-pancreatic sciences. 11/2010; 18(3):386-96.
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    ABSTRACT: CONCLUSION Fusion of DWI and ADC map may help to identify and characterize many lesions in the brain and body. BACKGROUND The usefulness of diffusion-weighted images (DWI) in the brain and cancer detection in the body has been reported. The DWIs are inherently T2-weighted, changes in tissue T2 can influence the appearance of DWI independent of tissue diffusibility. In order to exclude T2 shine-through effect, apparent diffusion coefficient (ADC) is calculated. However, because the organs are often heterogeneous in signal intensity, localization of possible lesions on ADC maps is not easy on ordinary viewer. Further, ADC values of cancers are ranged in specific values, for example 0.6-1.4x1 x 10-3mm2 /second in breast cancer when b-factor values are 800s/mm2. However, the gray-scale ADC maps don’t provide ADC value visually. Colored ADC maps may be necessary. Hence we have developed a fusion software, in which ADC maps are colored according to ADC values, and the colored ADC maps and DWI are fused automatically. The purpose of this study is to examine the usefulness of fusion of DWI and colored ADC maps. EVALUATION Diffusion weighted images of the brain, breast, and abdomen were obtained with various b factors. ADC maps were made. All images were exported by DICOM protocol and transferred to a personal computer. Using the special fusion software, ADC maps were colored and fused with DWI . In brain disorders such as carbon monoxide poisoning, lacunar infarcts, we examined if exact localization of lesions help to detect ADC changes. In mass lesions in the body such as hepatic hamangiomas, cysts, metastatic liver tumors, pancreas cancers, pancreatitis, and breast cancers, we examined if coloring of ADC maps helps to differentiate these lesions. DISCUSSION In all of the patients fusion images provide useful information. In patients with breast cancer and patients with carbon monoxide poisoning, fusion images helped to identify ADC changes in the lesions. In patients with pancreas cancer or patients with liver tumors, all malignant tumors, inflammation, and hemangiomas are hyperintense on DWI, on the other hand, they are differentiated by colored ADC maps.
    Radiological Society of North America 2009 Scientific Assembly and Annual Meeting; 12/2009
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    ABSTRACT: Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Magnetic resonance (MR) imaging is one of the most powerful modalities for the assessment of HCC with sufficient sensitivity and specificity. In addition to its capacity for lesion detection, MR imaging delineates some unique in vivo pathophysiological features of tumors, which cannot be assessed by other modalities. Chemical shift imaging may depict steatosis of the tumor. Dynamic contrast-enhanced MR imaging is the most powerful tool to assess the vascularity of the tumor, which is closely related to malignant transformation in hepatocarcinogenesis. Diffusion-weighted imaging illustrates the cellularity of the tumor. Super-paramagnetic iron oxide, a liver-specific MR contrast agent accumulating in Kupffer cells, enables detection of the hepatocellular architecture in the lesion. Recently, a new liver-specific MR contrast agent, gadoxetic acid [gadolinium-ethoxybenzyl (Gd-EOB)-diethylenetriaminopentoacetic acid (DTPA)], has been introduced for clinical imaging. Gd-EOB-DTPA has a significant impact on the imaging of HCC, with potential capacity for the concurrent assessment of vascularity of the tumor and hepatocellular-specific properties within the tumor. Understanding the characteristics of MR imaging methods and contrast agents is essential for the optimal diagnosis and characterization of HCCs.
    Journal of hepato-biliary-pancreatic sciences. 10/2009; 17(5):583-9.
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    ABSTRACT: Intravascular gas is frequently demonstrated on postmortem computed tomography (PMCT). The purpose of this study is to classify the distribution patterns of intravascular gas and to determine its developmental mechanism. The series included 43 cases (mean age, 62 years). All causes of death were non-traumatic (14 cases, sudden death; 29 cases, death caused by known disease). Using a 16-row multi-detector CT, whole body images were obtained with 1.25-mm collimation. Gas in veins, right heart was classified as venous gas. Gas in arteries, left heart was classified as arterial gas. PMCT showed intravascular gas in 20 cases. Distribution of gas was divided into 2 patterns; pattern 1 (11 cases): a small volume of venous gas (superior and inferior vena cava, right heart, subclavian veins and brachiocephalic veins) and no arterial gas; pattern 2 (9 cases): both venous (same positions of pattern 1 plus hepatic veins) and arterial gas (left heart, ascending aorta, vertebral arteries and cerebral arteries). Since imaging findings of pattern 1 are similar to those frequently demonstrated after intravenous contrast-enhanced CT, this gas is presumed to be of exogenous origin from intravenous catheters. In contrast, the gas in pattern 2 may be of endogenous origin, such as decompression disease. Bubbles should move through the ventral side of vessels in the supine position, and subsequently must be trapped by extruded anatomical structures to the ventral side, for example, right ventricle, vertebral and cerebral arteries, hepatic veins and renal veins.
    Legal Medicine 04/2009; 11 Suppl 1:S252-5. · 1.08 Impact Factor
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    ABSTRACT: The purpose of this study is to assess the applicability of facial soft tissue measurements using 3-dimensional reconstructed MDCT and to compare the results with previously reported Japanese data. This study included 50 Japanese cadavers who underwent postmortem whole body 16-detector CT within 0-3 days after death. Using 3-D workstation, 10 anthropological measuring points were located and the soft tissue thicknesses were measured. The differences between the acquired thickness and the previously reported Japanese average thickness were statistically analyzed. All measuring points were readily determined on the 3-dimensional reconstructed images. Previous Japanese cadaveric data was thinner than our data in almost all sites except for 1 measuring point (mid-philtrum). Previous living Japanese data was thicker than ours except for 1 measuring point (end of nasal). Facial soft tissue thickness was easily assessed using 3-D reconstructed MDCT images. At many measuring points, our results were thicker than previously reported cadaveric data and were thinner than the data from live persons.
    Legal Medicine 04/2009; 11 Suppl 1:S256-9. · 1.08 Impact Factor
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    ABSTRACT: We set out to retrospectively review the clinical and imaging features of patients with post-radiation sarcoma, especially in the head and neck region. We reviewed the records of 4194 patients with carcinoma of the head and neck region who had a history of radiation. They had undergone CT and/or MRI. Medical records were reviewed for the primary diagnosis, radiation history and latency period to the development of sarcoma. The patients included four men and two women with a mean age of 64.5 years. The mean latency period for the development of sarcoma was 11.5 years. Primary diagnoses were maxillary carcinoma, nasopharyngeal carcinoma, adenoid cystic carcinoma of the oral floor, tonsilar carcinoma, soft palate carcinoma and tongue carcinoma. Histopathological examinations revealed osteosarcoma, spindle cell sarcoma, chondrosarcoma, malignant peripheral nerve sheath tumour, spindle cell carcinoma and malignant fibrous histiocytoma, respectively. Common findings were a heterogeneous and well-enhanced soft tissue mass and bone destruction. There is at present little or no prospect for the effective prevention of radiation-induced sarcoma of the head and neck. This emphasizes the importance of the earliest possible diagnosis for such patients. The imaging findings are not diagnosis specific, but strict follow-up within the radiation field by CT and MRI and an appreciation of the expected latency period may help to provide the diagnosis. When radiotherapy is performed for head and neck neoplasms, periodic follow-up observations may be necessary for many years.
    The British journal of radiology 11/2007; 80(958):790-7. · 2.11 Impact Factor
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    ABSTRACT: A 61-year-old woman complained of a subcutaneous mass in her right knee. MR images revealed a well-defined subcutaneous mass in the prepatellar region, containing some fluid and foci of short T2. The lesion showed some marginal contrast uptake after an administration of meglumine gadopentetate (Gd-DTPA), consistent with prepatellar bursitis. The pathological specimen, however, revealed subcutaneous sarcoidosis involving the bursa.
    Skeletal Radiology 02/2006; 35(1):58-60. · 1.74 Impact Factor
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    ABSTRACT: The purpose of this study was to assess whether T2-weighted (T2W) imaging with diffusion-weighted (DW) imaging could improve prostate cancer detection as compared with T2W imaging alone. The subjects consisted of 37 patients with prostate cancer and 23 without cancer undergoing magnetic resonance (MR) imaging. Using a 1.5-T superconducting magnet, all patients underwent T2W and DW imaging with parallel imaging. Images were independently reviewed by 3 readers to determine the detectability of prostate cancer. The detectability of T2W imaging without and with DW imaging was assessed by means of receiver operating characteristic analysis. Mean areas under the receiver operating characteristic curve for T2W imaging alone and for T2W imaging with DW imaging were 0.87 and 0.93, respectively. The receiver operating characteristic analysis showed that the addition of DW imaging to conventional T2W imaging significantly improved tumor detection (P = 0.0468) compared with T2W imaging alone. The addition of DW imaging to conventional T2W imaging provides better detection of prostate cancer.
    Journal of Computer Assisted Tomography 01/2005; 29(2):149-53. · 1.58 Impact Factor
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    ABSTRACT: PURPOSE/AIM The purpose is to understand the anatomy and lymphatic drainage of the pleura and also understand the imaging findigs of the pleural tumors. Learnig Objectives i) To understand the anatomy and lymphatic drainage of the pleura. ii) To describe the imaging findings of benign and malignant pleural tumors. CONTENT ORGANIZATION We review the anatomy and lymphatic drainage of the pleura on CT, and present CT and MR images of benign (chronic expanding hematoma, solitary fibrous tumor, etc.) and malignant (pyothorax-associated lymphoma, malignant mesothelioma and metastases from lung carcinoma, breast carcinoma, lymphoma, other primary sites including thymoma, etc.) pleural tumors. SUMMARY The inferior margins of the pleura extend lower than the corresponding border of the lung. Although the lymphatic drainage of the visceral pleura shows same pattern of drainage as the lung, that of parietal pleura is very different. It is important to appreciate the anatomy and lymphatic drainage of the pleura in definig the location and extent of the tumors.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM To present CT and MR imaging appearance of Solitary fibrous tumors (SFTs) of various anatomic sites from head to toe. To review imaging characteristics and to correlate them with pathological features. CONTENT ORGANIZATION 1. Introduction 2. Epidemiology and pathology 3. Review of the radiological findings of SFTs occurred in CNS, head and neck, thorax, liver, retroperitoneum, pelvic and extremities 4. Correlation between the radiological findings and pathological features 5. Summary SUMMARY Solitary fibrous tumor (SFT) is an uncommon mesenchymal tumor. SFT was reported as a localized fibrous tumor occurring in the pleura and has been recently reported with increasing frequency in various anatomic sites. We present SFTs originated in various anatomic sites and developed metastases and recurrences, and review the radiological findings of them with their pathological features. Surely this exhibit will help the radiologists to better understand SFT.
    Radiological Society of North America 2010 Scientific Assembly and Annual Meeting;
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    ABSTRACT: PURPOSE/AIM Locations and degree of brain atrophy are important indexes on degenerative diseases. Brain atrophy is evaluated by subjective decisions of sophisticated neuroradiologists on routine work, so learning evaluation methods is difficult for beginners. We review evaluation methods of brain atrophy and present cases with characteristic atrophy. CONTENT ORGANIZATION 1. MRI protocol 2. Evaluation methods A. Cerebrum, B. Basal ganglia B. Brain Stem, C. Cerebellum 3. Case-based illustration of various diseases: Quiz format -Alzheimer disease -frontotemporal lobar degeneration -multiple system atrophy -progressive supranuclear palsy -corticobasal degeneration -spinocerebellar degeneration etc. SUMMARY Volume of brain is affected by various factors; aging, vascular disorders, drugs, etc. In addition, radiologists are bad at detecting diffuse abnormal findings. Correct evaluation of brain atrophy requires: 1. Selecting appropriate sequences and sections 2. Learning various evaluation methods 3. Unifying findings of each location We present how to evaluate brain atrophy and help you to come up to a sophisticated neuroradiologist.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting;

Publication Stats

127 Citations
21.28 Total Impact Points

Institutions

  • 2005–2014
    • Chiba University
      • • Graduate School of Medicine
      • • Department of Radiology
      Tiba, Chiba, Japan
  • 2007–2011
    • Chiba University Hospital
      Tiba, Chiba, Japan