To address the sensitive and uncertain limitations of single-energy computed tomography(CT)calibration methods in computing proton stopping power ratio during treatment planning,different methods have been proposed us...To address the sensitive and uncertain limitations of single-energy computed tomography(CT)calibration methods in computing proton stopping power ratio during treatment planning,different methods have been proposed using a dual energy CT approach.This paper reviews the most recent dual-energy CT approaches for computing proton stopping power ratio.These include image domain and projection domain methods.The advantages and uncertainties of these methods are analyzed based on existing studies.This paper highlights recent advances in dual energy CT,discussing their implementation,advantages,limitations,and potential for clinical adoption.展开更多
BACKGROUND No study on dual energy computed tomography(DECT)has been found in the literature to evaluate possibly fatal cardiac/myocardial problems in corona virus disease 2019(COVID-19)patients.Myocardial perfusion d...BACKGROUND No study on dual energy computed tomography(DECT)has been found in the literature to evaluate possibly fatal cardiac/myocardial problems in corona virus disease 2019(COVID-19)patients.Myocardial perfusion deficits can be found in COVID-19 patients even without any significant coronary artery occlusion,and these deficits can be shown via DECT with a perfect interrater agreement.AIM To assess lung perfusion alterations in COVID-19 patients.To our knowledge,no study using DECT has been performed to evaluate possibly fatal cardiac/myocardial problems in COVID-19 patients.The purpose of this study is to evaluate the role of DECT in the detection of COVID-19-related cardiac diseases.METHODS Two blinded independent examiners evaluated CT images using the 17-segment model according to the American Heart Association’s classification of the segmentation of the left ventricular myocardium.Additionally,intraluminal diseases and abnormalities in the main coronary arteries and branches were investigated.Following segment-by-segment analysis,perfusion deficiencies identified on the iodine map pictures on DECT were identified.RESULTS The study enrolled a total of 87 patients.Forty-two of these individuals were classified as COVID-19 positive,and 45 were classified as controls.Perfusion deficits were identified in 66.6%(n=30)of the cases.All control patients had a normal iodine distribution map.Perfusion deficits were found on DECT iodine map images with subepicardial(n=12,40%),intramyocardial(n=8,26.6%),or transmural(n=10,33.3%)anatomical locations within the left ventricular wall.There was no subendocardial involvement in any of the patients.CONCLUSION Myocardial perfusion deficits can be found in COVID-19 patients even without any significant coronary artery occlusion.These deficits can be shown via DECT with a perfect interrater agreement.Additionally,the presence of perfusion deficit is positively correlated with D-dimer levels.展开更多
Gastroenteropancreatic neuroendocrine neoplasms comprise a heterogeneous group of tumors that differ in their pathogenesis,hormonal syndromes produced,biological behavior and consequently,in their requirement for and/...Gastroenteropancreatic neuroendocrine neoplasms comprise a heterogeneous group of tumors that differ in their pathogenesis,hormonal syndromes produced,biological behavior and consequently,in their requirement for and/or response to specific chemotherapeutic agents and molecular targeted therapies.Various imaging techniques are available for functional and morphological evaluation of these neoplasms and the selection of investigations performed in each patient should be customized to the clinical question.Also,with the increased availability of cross sectional imaging,these neoplasms are increasingly being detected incidentally in routine radiology practice.This article is a review of the various imaging modalities currently used in the evaluation of neuroendocrine neoplasms,along with a discussion of the role of advanced imaging techniques and a glimpse into the newer imaging horizons,mostly in the research stage.展开更多
The radiological differential diagnosis of acute pancreatitis includes diffuse pancreatic lymphoma,diffuse autoimmune pancreatitis and groove located mass lesions that may mimic groove pancreatitis.Dual energy compute...The radiological differential diagnosis of acute pancreatitis includes diffuse pancreatic lymphoma,diffuse autoimmune pancreatitis and groove located mass lesions that may mimic groove pancreatitis.Dual energy computed tomography and diffusion weighted magnetic resonance imaging are useful in the early diagnosis of acute pancreatitis,and dual energy computed tomography is also useful in severity assessment and prognosis prediction.Walled off necrosis is an important complication in terms of prognosis,and it is important to know its radiological findings and distinguish it from pseudocyst.展开更多
The relationship between coronavirus disease-19(COVID-19)and cardiovascular diseases has been an important issue.Therefore,cardiac biomarkers and cardiac imaging have an important place in the diagnostic phase.It is i...The relationship between coronavirus disease-19(COVID-19)and cardiovascular diseases has been an important issue.Therefore,cardiac biomarkers and cardiac imaging have an important place in the diagnostic phase.It is important to know the relationship of biomarkers in COVID-19 so that we can understand the diagnosis of the disease,the predicted course and results after diagnosis.展开更多
BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data o...BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data on radiation dose in this group of children undergoing CTCA.AIM To audit the radiation dose of CTCA in children with KD.METHODS Study(December 2013-February 2018)was performed on dual source CT scanner using adaptive prospective electrocardiography-triggering.The dose length product(DLP in milligray-centimeters-mGy.cm)was recorded.Effective radiation dose(millisieverts-mSv)was calculated by applying appropriate age adjusted conversion factors as per recommendations of International Commission on Radiological Protection.Radiation dose was compared across the groups(0-1,1-5,5-10,and>10 years).RESULTS Eighty-five children(71 boys,14 girls)with KD underwent CTCA.The median age was 5 years(range,2 mo-11 years).Median DLP and effective dose was 21 mGy.cm,interquartile ranges(IQR)=15(13,28)and 0.83 mSv,IQR=0.33(0.68,1.01)respectively.Mean DLP increased significantly across the age groups.Mean effective dose in infants(0.63 mSv)was significantly lower than the other age groups(1-5 years 0.85 mSv,5-10 years 1.04 mSv,and>10 years 1.38 mSv)(P<0.05).There was no significant difference in the effective dose between the other groups of children.All the CTCA studies were of diagnostic quality.No child required a repeat examination.CONCLUSION CTCA is feasible with submillisievert radiation dose in most children with KD.Thus,CTCA has the potential to be an important adjunctive imaging modality in children with KD.展开更多
A patient with insulinoma diagnosed by clinical features and localized preoperatively using a combination of contrast-enhanced ultrasonography （CEUS）, dual phase contrast enhanced spiral computed tomography （DPSCT...A patient with insulinoma diagnosed by clinical features and localized preoperatively using a combination of contrast-enhanced ultrasonography （CEUS）, dual phase contrast enhanced spiral computed tomography （DPSCT） and arterial stimulation and venous sampling （ASVS） was reported. A 37-year-old man was admitted to our hospital because of hypoglycemic attacks, palpitations, and muscular weakness. Fajans＇ ratio reported to be an index for insulinoma was positive. Transabdominal computed tomography and ultrasonography failed to detect any abnormalities. CEUS showed a small low echoic lesion in the pancreatic body with blood flow and the early arterial phase of DPSCT revealed a small strengthening focus, which mimicked a pancreatic tumor in the pancreatic body. ASVS showed that the insulin levels in the hepatic vein were extremely increased by calcium injection to the gastroduodenal artery. An open intra-abdominal operation was performed and an insulinoma was confirmed in the pancreatic body. Enucleation of tumor was undertaken and histopathological examination showed an adenoma, insulin expression was positive in immunofluorescence staining.Symptomatic hypoglycemia never happened even without glucose infusion since the operation. His blood glucose level improved to within the normal range.展开更多
文摘To address the sensitive and uncertain limitations of single-energy computed tomography(CT)calibration methods in computing proton stopping power ratio during treatment planning,different methods have been proposed using a dual energy CT approach.This paper reviews the most recent dual-energy CT approaches for computing proton stopping power ratio.These include image domain and projection domain methods.The advantages and uncertainties of these methods are analyzed based on existing studies.This paper highlights recent advances in dual energy CT,discussing their implementation,advantages,limitations,and potential for clinical adoption.
文摘BACKGROUND No study on dual energy computed tomography(DECT)has been found in the literature to evaluate possibly fatal cardiac/myocardial problems in corona virus disease 2019(COVID-19)patients.Myocardial perfusion deficits can be found in COVID-19 patients even without any significant coronary artery occlusion,and these deficits can be shown via DECT with a perfect interrater agreement.AIM To assess lung perfusion alterations in COVID-19 patients.To our knowledge,no study using DECT has been performed to evaluate possibly fatal cardiac/myocardial problems in COVID-19 patients.The purpose of this study is to evaluate the role of DECT in the detection of COVID-19-related cardiac diseases.METHODS Two blinded independent examiners evaluated CT images using the 17-segment model according to the American Heart Association’s classification of the segmentation of the left ventricular myocardium.Additionally,intraluminal diseases and abnormalities in the main coronary arteries and branches were investigated.Following segment-by-segment analysis,perfusion deficiencies identified on the iodine map pictures on DECT were identified.RESULTS The study enrolled a total of 87 patients.Forty-two of these individuals were classified as COVID-19 positive,and 45 were classified as controls.Perfusion deficits were identified in 66.6%(n=30)of the cases.All control patients had a normal iodine distribution map.Perfusion deficits were found on DECT iodine map images with subepicardial(n=12,40%),intramyocardial(n=8,26.6%),or transmural(n=10,33.3%)anatomical locations within the left ventricular wall.There was no subendocardial involvement in any of the patients.CONCLUSION Myocardial perfusion deficits can be found in COVID-19 patients even without any significant coronary artery occlusion.These deficits can be shown via DECT with a perfect interrater agreement.Additionally,the presence of perfusion deficit is positively correlated with D-dimer levels.
文摘Gastroenteropancreatic neuroendocrine neoplasms comprise a heterogeneous group of tumors that differ in their pathogenesis,hormonal syndromes produced,biological behavior and consequently,in their requirement for and/or response to specific chemotherapeutic agents and molecular targeted therapies.Various imaging techniques are available for functional and morphological evaluation of these neoplasms and the selection of investigations performed in each patient should be customized to the clinical question.Also,with the increased availability of cross sectional imaging,these neoplasms are increasingly being detected incidentally in routine radiology practice.This article is a review of the various imaging modalities currently used in the evaluation of neuroendocrine neoplasms,along with a discussion of the role of advanced imaging techniques and a glimpse into the newer imaging horizons,mostly in the research stage.
文摘The radiological differential diagnosis of acute pancreatitis includes diffuse pancreatic lymphoma,diffuse autoimmune pancreatitis and groove located mass lesions that may mimic groove pancreatitis.Dual energy computed tomography and diffusion weighted magnetic resonance imaging are useful in the early diagnosis of acute pancreatitis,and dual energy computed tomography is also useful in severity assessment and prognosis prediction.Walled off necrosis is an important complication in terms of prognosis,and it is important to know its radiological findings and distinguish it from pseudocyst.
文摘The relationship between coronavirus disease-19(COVID-19)and cardiovascular diseases has been an important issue.Therefore,cardiac biomarkers and cardiac imaging have an important place in the diagnostic phase.It is important to know the relationship of biomarkers in COVID-19 so that we can understand the diagnosis of the disease,the predicted course and results after diagnosis.
文摘BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data on radiation dose in this group of children undergoing CTCA.AIM To audit the radiation dose of CTCA in children with KD.METHODS Study(December 2013-February 2018)was performed on dual source CT scanner using adaptive prospective electrocardiography-triggering.The dose length product(DLP in milligray-centimeters-mGy.cm)was recorded.Effective radiation dose(millisieverts-mSv)was calculated by applying appropriate age adjusted conversion factors as per recommendations of International Commission on Radiological Protection.Radiation dose was compared across the groups(0-1,1-5,5-10,and>10 years).RESULTS Eighty-five children(71 boys,14 girls)with KD underwent CTCA.The median age was 5 years(range,2 mo-11 years).Median DLP and effective dose was 21 mGy.cm,interquartile ranges(IQR)=15(13,28)and 0.83 mSv,IQR=0.33(0.68,1.01)respectively.Mean DLP increased significantly across the age groups.Mean effective dose in infants(0.63 mSv)was significantly lower than the other age groups(1-5 years 0.85 mSv,5-10 years 1.04 mSv,and>10 years 1.38 mSv)(P<0.05).There was no significant difference in the effective dose between the other groups of children.All the CTCA studies were of diagnostic quality.No child required a repeat examination.CONCLUSION CTCA is feasible with submillisievert radiation dose in most children with KD.Thus,CTCA has the potential to be an important adjunctive imaging modality in children with KD.
文摘A patient with insulinoma diagnosed by clinical features and localized preoperatively using a combination of contrast-enhanced ultrasonography （CEUS）, dual phase contrast enhanced spiral computed tomography （DPSCT） and arterial stimulation and venous sampling （ASVS） was reported. A 37-year-old man was admitted to our hospital because of hypoglycemic attacks, palpitations, and muscular weakness. Fajans＇ ratio reported to be an index for insulinoma was positive. Transabdominal computed tomography and ultrasonography failed to detect any abnormalities. CEUS showed a small low echoic lesion in the pancreatic body with blood flow and the early arterial phase of DPSCT revealed a small strengthening focus, which mimicked a pancreatic tumor in the pancreatic body. ASVS showed that the insulin levels in the hepatic vein were extremely increased by calcium injection to the gastroduodenal artery. An open intra-abdominal operation was performed and an insulinoma was confirmed in the pancreatic body. Enucleation of tumor was undertaken and histopathological examination showed an adenoma, insulin expression was positive in immunofluorescence staining.Symptomatic hypoglycemia never happened even without glucose infusion since the operation. His blood glucose level improved to within the normal range.
