BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identifica...BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identification of upper and lower GIB and in the prompt treatment of the haemorrhage.AIM To determine whether a volumetric estimation of the extravasated contrast at CTA in GIB may be a predictor of subsequent positive angiographic findings.METHODS In this retrospective single-centre study,35 patients(22 men;median age 69 years;range 16-92 years)admitted to our institution for active GIB detected at CTA and further submitted to catheter angiography between January 2018 and February 2022 were enrolled.Twenty-three(65.7%)patients underwent endoscopy before CTA.Bleeding volumetry was evaluated in both arterial and venous phases via a semi-automated dedicated software.Bleeding rate was obtained from volume change between the two phases and standardised for unit time.Patients were divided into two groups,according to the angiographic signs and their concordance with CTA.RESULTS Upper bleeding accounted for 42.9%and lower GIB for 57.1%.Mean haemoglobin value at the admission was 7.7 g/dL.A concordance between positive CTA and direct angiographic bleeding signs was found in 19(54.3%)cases.Despite no significant differences in terms of bleeding volume in the arterial phase(0.55 mL vs 0.33 mL,P=0.35),a statistically significant volume increase in the venous phase was identified in the group of patients with positive angiography(2.06 mL vs 0.9 mL,P=0.02).In the latter patient group,a significant increase in bleeding rate was also detected(2.18 mL/min vs 0.19 mL/min,P=0.02).CONCLUSION In GIB of any origin,extravasated contrast volumetric analysis at CTA could be a predictor of positive angiography and may help in avoiding further unnecessary procedures.展开更多
AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conforman...AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conformance with HIPAA and IRB Regulations(March 2015-November 2016).A ten blood clot phantom was designed and scanned on a dual-energy CT scanner(SOMATOM Force,Siemens Healthcare Gm BH,Erlangen,Germany)with varying pitch,iterative reconstruction,energy level and slicethickness.A range of clot and tube sizes were used in an attempt to replicate in vivo emboli found within central and segmental branches of the pulmonary arteries in patients with pulmonary emboli.Clot volume was the measured parameter and was analyzed by a single image analyst using a semi-automated region growing algorithm implemented in the FDA-approved Siemens syngo.via image analysis platform.Mixed model analysis was performed on the data.RESULTS On the acquisition side,the continuous factor of energy showed no statistically significant effect on absolute clot volume quantification(P=0.9898).On the other hand,when considering the fixed factor of pitch,there were statistically significant differences in clot volume quantification(P<0.0001).On the reconstruction side,with the continuous factor of reconstruction slice thickness no statistically significant effect on absolute clot volume quantification was demonstrated(P=0.4500).Also on the reconstruction side,with the fixed factor of using iterative reconstructions there was also no statistically significant effect on absolute clot volume quantification(P=0.3011).In addition,there was excellent R^2 correlation between the scale-measured mass of the clots both with respect to the CT measured volumes and with respect to volumes measure by the water displacement method.CONCLUSION Aside from varying pitch,changing CT acquisition parameters and using iterative reconstructions had no significant impact on clot volume quantification with a semi-automated region growing algorithm.展开更多
文摘BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identification of upper and lower GIB and in the prompt treatment of the haemorrhage.AIM To determine whether a volumetric estimation of the extravasated contrast at CTA in GIB may be a predictor of subsequent positive angiographic findings.METHODS In this retrospective single-centre study,35 patients(22 men;median age 69 years;range 16-92 years)admitted to our institution for active GIB detected at CTA and further submitted to catheter angiography between January 2018 and February 2022 were enrolled.Twenty-three(65.7%)patients underwent endoscopy before CTA.Bleeding volumetry was evaluated in both arterial and venous phases via a semi-automated dedicated software.Bleeding rate was obtained from volume change between the two phases and standardised for unit time.Patients were divided into two groups,according to the angiographic signs and their concordance with CTA.RESULTS Upper bleeding accounted for 42.9%and lower GIB for 57.1%.Mean haemoglobin value at the admission was 7.7 g/dL.A concordance between positive CTA and direct angiographic bleeding signs was found in 19(54.3%)cases.Despite no significant differences in terms of bleeding volume in the arterial phase(0.55 mL vs 0.33 mL,P=0.35),a statistically significant volume increase in the venous phase was identified in the group of patients with positive angiography(2.06 mL vs 0.9 mL,P=0.02).In the latter patient group,a significant increase in bleeding rate was also detected(2.18 mL/min vs 0.19 mL/min,P=0.02).CONCLUSION In GIB of any origin,extravasated contrast volumetric analysis at CTA could be a predictor of positive angiography and may help in avoiding further unnecessary procedures.
文摘AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conformance with HIPAA and IRB Regulations(March 2015-November 2016).A ten blood clot phantom was designed and scanned on a dual-energy CT scanner(SOMATOM Force,Siemens Healthcare Gm BH,Erlangen,Germany)with varying pitch,iterative reconstruction,energy level and slicethickness.A range of clot and tube sizes were used in an attempt to replicate in vivo emboli found within central and segmental branches of the pulmonary arteries in patients with pulmonary emboli.Clot volume was the measured parameter and was analyzed by a single image analyst using a semi-automated region growing algorithm implemented in the FDA-approved Siemens syngo.via image analysis platform.Mixed model analysis was performed on the data.RESULTS On the acquisition side,the continuous factor of energy showed no statistically significant effect on absolute clot volume quantification(P=0.9898).On the other hand,when considering the fixed factor of pitch,there were statistically significant differences in clot volume quantification(P<0.0001).On the reconstruction side,with the continuous factor of reconstruction slice thickness no statistically significant effect on absolute clot volume quantification was demonstrated(P=0.4500).Also on the reconstruction side,with the fixed factor of using iterative reconstructions there was also no statistically significant effect on absolute clot volume quantification(P=0.3011).In addition,there was excellent R^2 correlation between the scale-measured mass of the clots both with respect to the CT measured volumes and with respect to volumes measure by the water displacement method.CONCLUSION Aside from varying pitch,changing CT acquisition parameters and using iterative reconstructions had no significant impact on clot volume quantification with a semi-automated region growing algorithm.
