The Experts below are selected from a list of 10203 Experts worldwide ranked by ideXlab platform
Tae Kyun Kim - One of the best experts on this subject based on the ideXlab platform.
-
the use of navigation in medial opening wedge high tibial osteotomy can improve tibial slope maintenance and Reduce Radiation Exposure
International Orthopaedics, 2016Co-Authors: Sang Hwa Eom, Seok Kim, Moon Jong Chang, Tae Kyun KimAbstract:We sought to determine the usefulness and the disadvantages of the navigation in medial opening wedge high tibial osteotomy (MOWHTO) compared to the conventional technique, in terms of target coronal alignment achievement, tibial slope maintenance, Radiation Exposure and operative time. We retrospectively compared 40 knees treated with navigated MOWHTO by one surgeon with 20 knees treated with conventional MOWHTO by another surgeon. Screw length of the plate was predetermined using validated simple algorithms only in the navigation group to facilitate the operation. The acceptable range of the postoperative coronal alignment was defined as 2°–6° of the mechanical tibiofemoral angle (mTFA) and 55 %–70 % of the weight loading line coordinate (WLL). The proportion of the coronal alignment outlier, posterior tibial slope change, fluoroscopy time and operative time were compared. The coronal alignment outliers were fewer in the navigation group, but the differences were not significant (mTFA outlier 18 % vs. 30 %, p = 0.326; WLL outlier 20 % vs. 30 %, p = 0.519). Tibial slope was maintained in the navigation group (+0.3°, p = 0.732), whereas increased in the conventional group (+3°, p < 0.001). The fluoroscopy time was shorter in the navigation group (10.4 seconds vs. 24.8 seconds, p < 0.001). The operative time was comparable in both groups (41.3 minutes vs. 39.2 minutes, p = 0.232). The use of navigation can improve tibial slope maintenance and Reduce Radiation Exposure in MOWHTO, without considerable extension of operative time by optimising the surgical technique. Level III, retrospective comparative study.
Susanne Wienbeck - One of the best experts on this subject based on the ideXlab platform.
-
pre and post contrast versus post contrast cone beam breast ct can we Reduce Radiation Exposure while maintaining diagnostic accuracy
European Radiology, 2019Co-Authors: Johannes Uhlig, Uwe Fischer, Lorenz Biggemann, Joachim Lotz, Susanne WienbeckAbstract:To evaluate whether post-contrast cone-beam breast CT (CBBCT) alone is comparable to the current standard of combined pre- and post-contrast CBBCT regarding diagnostic accuracy and superior regarding Radiation Exposure. This study included 49 women (61 breasts) with median age 57.9 years and BI-RADS 4/5 lesions diagnosed on mammography/ultrasound in density type c/d breasts. Two radiologists rated post-contrast CBBCT and pre- and post-contrast CBBCT with subtraction images on the BI-RADS scale separately for calculation of inter- and intra-observer agreement and in consensus for diagnostic accuracy assessment. Sensitivity, specificity, and area under the curve (AUC) were compared via McNemar test and DeLong method, respectively. Subtraction imaging misregistration were measured from 1 (no artifacts) to 4 (artifacts with width > 4 mm). A total of 100 lesion (51 malignant; 6 high risk; 43 benign) were included. AUC, sensitivity, and specificity showed no significant differences comparing post-contrast CBBCT alone versus pre- and post-contrast CBBCT (AUC 0.84 vs. 0.83, p = 0.643; sensitivity 0.89 vs. 0.85, p = 0.158; specificity 0.73 vs. 0.76, p = 0.655). Inter- and intra-observer agreement was excellent (intra-class correlation coefficient ICC = 0.76, ICC = 0.83, respectively). Radiation dose was significantly lower for post-contrast CBBCT alone versus pre- and post-contrast CBBCT (median average glandular Radiation dose 5.9 mGy vs. 11.7 mGy, p < 0.001). High-degree misregistrations were evident in the majority of subtraction images (level 1/2/3/4 16.9%/27.1%/16.9%/39%), in particular for bilateral exams (3.2%/29.2%/8.3%/58.3%). Diagnostic accuracy of post-contrast CBBCT alone is comparable to pre- and post-contrast CBBCT in type c/d breasts, while yielding a significant twofold Radiation dose reduction. • The diagnostic accuracy of post-contrast CBBCT alone is comparable to dual acquisition of pre- and post-contrast CBBCT. • Acquisition of the post-contrast CBBCT scan alone Reduces Radiation Exposure compared to pre- and post-contrast CBBCT, thus countering one of the main limitations of CBBCT. • High-degree misregistration artifacts limit the interpretation of subtraction images from pre- and post-contrast CBBCT studies.
-
Pre- and post-contrast versus post-contrast cone-beam breast CT: can we Reduce Radiation Exposure while maintaining diagnostic accuracy?
European radiology, 2018Co-Authors: Johannes Uhlig, Uwe Fischer, Lorenz Biggemann, Joachim Lotz, Susanne WienbeckAbstract:To evaluate whether post-contrast cone-beam breast CT (CBBCT) alone is comparable to the current standard of combined pre- and post-contrast CBBCT regarding diagnostic accuracy and superior regarding Radiation Exposure. This study included 49 women (61 breasts) with median age 57.9 years and BI-RADS 4/5 lesions diagnosed on mammography/ultrasound in density type c/d breasts. Two radiologists rated post-contrast CBBCT and pre- and post-contrast CBBCT with subtraction images on the BI-RADS scale separately for calculation of inter- and intra-observer agreement and in consensus for diagnostic accuracy assessment. Sensitivity, specificity, and area under the curve (AUC) were compared via McNemar test and DeLong method, respectively. Subtraction imaging misregistration were measured from 1 (no artifacts) to 4 (artifacts with width > 4 mm). A total of 100 lesion (51 malignant; 6 high risk; 43 benign) were included. AUC, sensitivity, and specificity showed no significant differences comparing post-contrast CBBCT alone versus pre- and post-contrast CBBCT (AUC 0.84 vs. 0.83, p = 0.643; sensitivity 0.89 vs. 0.85, p = 0.158; specificity 0.73 vs. 0.76, p = 0.655). Inter- and intra-observer agreement was excellent (intra-class correlation coefficient ICC = 0.76, ICC = 0.83, respectively). Radiation dose was significantly lower for post-contrast CBBCT alone versus pre- and post-contrast CBBCT (median average glandular Radiation dose 5.9 mGy vs. 11.7 mGy, p
Moon Jong Chang - One of the best experts on this subject based on the ideXlab platform.
-
the use of navigation in medial opening wedge high tibial osteotomy can improve tibial slope maintenance and Reduce Radiation Exposure
International Orthopaedics, 2016Co-Authors: Sang Hwa Eom, Seok Kim, Moon Jong Chang, Tae Kyun KimAbstract:We sought to determine the usefulness and the disadvantages of the navigation in medial opening wedge high tibial osteotomy (MOWHTO) compared to the conventional technique, in terms of target coronal alignment achievement, tibial slope maintenance, Radiation Exposure and operative time. We retrospectively compared 40 knees treated with navigated MOWHTO by one surgeon with 20 knees treated with conventional MOWHTO by another surgeon. Screw length of the plate was predetermined using validated simple algorithms only in the navigation group to facilitate the operation. The acceptable range of the postoperative coronal alignment was defined as 2°–6° of the mechanical tibiofemoral angle (mTFA) and 55 %–70 % of the weight loading line coordinate (WLL). The proportion of the coronal alignment outlier, posterior tibial slope change, fluoroscopy time and operative time were compared. The coronal alignment outliers were fewer in the navigation group, but the differences were not significant (mTFA outlier 18 % vs. 30 %, p = 0.326; WLL outlier 20 % vs. 30 %, p = 0.519). Tibial slope was maintained in the navigation group (+0.3°, p = 0.732), whereas increased in the conventional group (+3°, p < 0.001). The fluoroscopy time was shorter in the navigation group (10.4 seconds vs. 24.8 seconds, p < 0.001). The operative time was comparable in both groups (41.3 minutes vs. 39.2 minutes, p = 0.232). The use of navigation can improve tibial slope maintenance and Reduce Radiation Exposure in MOWHTO, without considerable extension of operative time by optimising the surgical technique. Level III, retrospective comparative study.
-
The use of navigation in medial opening wedge high tibial osteotomy can improve tibial slope maintenance and Reduce Radiation Exposure
International Orthopaedics, 2016Co-Authors: Young Gon Na, Moon Jong ChangAbstract:Purposes We sought to determine the usefulness and the disadvantages of the navigation in medial opening wedge high tibial osteotomy (MOWHTO) compared to the conventional technique, in terms of target coronal alignment achievement, tibial slope maintenance, Radiation Exposure and operative time. Methods We retrospectively compared 40 knees treated with navigated MOWHTO by one surgeon with 20 knees treated with conventional MOWHTO by another surgeon. Screw length of the plate was predetermined using validated simple algorithms only in the navigation group to facilitate the operation. The acceptable range of the postoperative coronal alignment was defined as 2°–6° of the mechanical tibiofemoral angle (mTFA) and 55 %–70 % of the weight loading line coordinate (WLL). The proportion of the coronal alignment outlier, posterior tibial slope change, fluoroscopy time and operative time were compared. Results The coronal alignment outliers were fewer in the navigation group, but the differences were not significant (mTFA outlier 18 % vs. 30 %, p = 0.326; WLL outlier 20 % vs. 30 %, p = 0.519). Tibial slope was maintained in the navigation group (+0.3°, p = 0.732), whereas increased in the conventional group (+3°, p
David J Hak - One of the best experts on this subject based on the ideXlab platform.
-
leaded eyeglasses substantially Reduce Radiation Exposure of the surgeon s eyes during acquisition of typical fluoroscopic views of the hip and pelvis
Orthopaedic Proceedings, 2018Co-Authors: David J Hak, Raymond H Thornton, Lawrence T Dauer, B Quinn, Daniel MiodownikAbstract:IntroductionRadiation Exposure to the eye causes cataracts. Few orthopaedists wear leaded glasses when using fluoroscopy despite regulatory limits for maximum annual eye Exposure.MethodsUsing anthropomorphic patient and surgeon phantoms, Radiation dose at the surgeon phantom's lens was measured with and without leaded glasses during fluroscopic acquisition of 16 common pelvic and hip views. The magnitude of lens dose reduction was calculated by dividing the unprotected dose by the dose measured behind leaded glasses.ResultsThe unprotected lens dose varied considerably among the different views, ranging from 0 μRem for a single obturator oblique pelvic view, to 257 μRem for a single lateral sacral view with the image intensifier opposite the surgeon. On average, use of leaded glassess Reduced Radiation to the surgeon phantom's eye by 90%. The greatest reduction was seen with a crosstable lateral radiograph of the hip (22 μRem unprotected lens dose vs. 1 μRem with leaded glasses).ConclusionsThe use of leade...
-
leaded eyeglasses substantially Reduce Radiation Exposure of the surgeon s eyes during acquisition of typical fluoroscopic views of the hip and pelvis
Journal of Bone and Joint Surgery American Volume, 2013Co-Authors: Sean Burns, Raymond H Thornton, Lawrence T Dauer, Brian T Quinn, Daniel Miodownik, David J HakAbstract:Background Despite recommendations to do so, few orthopaedists wear leaded glasses when performing operative fluoroscopy. Radiation Exposure to the ocular lens causes cataracts, and regulatory limits for maximum annual occupational Exposure to the eye continue to be revised downward. Methods Using anthropomorphic patient and surgeon phantoms, Radiation dose at the surgeon phantom's lens was measured with and without leaded glasses during fluoroscopic acquisition of sixteen common pelvic and hip views. The magnitude of lens dose reduction from leaded glasses was calculated by dividing the unprotected dose by the dose measured behind leaded glasses. Results On average, the use of leaded glasses Reduced Radiation to the surgeon phantom's eye by tenfold, a 90% reduction in dose. However, there was widespread variation in the amount of Radiation that reached the phantom surgeon's eye among the various radiographic projections we studied. Without leaded glasses, the dose measured at the surgeon's lens varied more than 250-fold among these sixteen different views. Conclusions In addition to protecting the surgeon's eye from the deleterious effects of Radiation, the use of leaded glasses could permit an orthopaedist to perform fluoroscopic views on up to ten times more patients before reaching the annual dose limit of 20 mSv of Radiation to the eye recommended by the International Commission on Radiological Protection. Personal safety and adherence to limits of occupational Radiation Exposure should compel orthopaedists to wear leaded glasses for fluoroscopic procedures if other protective barriers are not in use. Clinical relevance Leaded glasses are a powerful tool for reducing the orthopaedic surgeon's lens Exposure to Radiation during acquisition of common intraoperative fluoroscopic views.
-
leaded eyeglasses substantially Reduce Radiation Exposure of the surgeon s eyes during acquisition of typical fluoroscopic views of the hip and pelvis
Journal of Bone and Joint Surgery-british Volume, 2013Co-Authors: David J Hak, Raymond H Thornton, Lawrence T Dauer, B Quinn, Daniel MiodownikAbstract:Introduction Radiation Exposure to the eye causes cataracts. Few orthopaedists wear leaded glasses when using fluoroscopy despite regulatory limits for maximum annual eye Exposure. Methods Using anthropomorphic patient and surgeon phantoms, Radiation dose at the surgeon phantom9s lens was measured with and without leaded glasses during fluroscopic acquisition of 16 common pelvic and hip views. The magnitude of lens dose reduction was calculated by dividing the unprotected dose by the dose measured behind leaded glasses. Results The unprotected lens dose varied considerably among the different views, ranging from 0 μRem for a single obturator oblique pelvic view, to 257 μRem for a single lateral sacral view with the image intensifier opposite the surgeon. On average, use of leaded glassess Reduced Radiation to the surgeon phantom9s eye by 90%. The greatest reduction was seen with a crosstable lateral radiograph of the hip (22 μRem unprotected lens dose vs. 1 μRem with leaded glasses). Conclusions The use of leaded glasses could permit an orthopaedist to perform up to 10 times more cases before reaching the annual limit of 20 mSv (20 mSv = 2×10 6 mRem). A large number of images are often required during a single operative procedure and varies greatly between cases. The number of cases which a surgeon can safely perform without leaded glasses is dependent on the number and type of images, and location of the surgeon with respect to the image intensifier.
Johannes Uhlig - One of the best experts on this subject based on the ideXlab platform.
-
pre and post contrast versus post contrast cone beam breast ct can we Reduce Radiation Exposure while maintaining diagnostic accuracy
European Radiology, 2019Co-Authors: Johannes Uhlig, Uwe Fischer, Lorenz Biggemann, Joachim Lotz, Susanne WienbeckAbstract:To evaluate whether post-contrast cone-beam breast CT (CBBCT) alone is comparable to the current standard of combined pre- and post-contrast CBBCT regarding diagnostic accuracy and superior regarding Radiation Exposure. This study included 49 women (61 breasts) with median age 57.9 years and BI-RADS 4/5 lesions diagnosed on mammography/ultrasound in density type c/d breasts. Two radiologists rated post-contrast CBBCT and pre- and post-contrast CBBCT with subtraction images on the BI-RADS scale separately for calculation of inter- and intra-observer agreement and in consensus for diagnostic accuracy assessment. Sensitivity, specificity, and area under the curve (AUC) were compared via McNemar test and DeLong method, respectively. Subtraction imaging misregistration were measured from 1 (no artifacts) to 4 (artifacts with width > 4 mm). A total of 100 lesion (51 malignant; 6 high risk; 43 benign) were included. AUC, sensitivity, and specificity showed no significant differences comparing post-contrast CBBCT alone versus pre- and post-contrast CBBCT (AUC 0.84 vs. 0.83, p = 0.643; sensitivity 0.89 vs. 0.85, p = 0.158; specificity 0.73 vs. 0.76, p = 0.655). Inter- and intra-observer agreement was excellent (intra-class correlation coefficient ICC = 0.76, ICC = 0.83, respectively). Radiation dose was significantly lower for post-contrast CBBCT alone versus pre- and post-contrast CBBCT (median average glandular Radiation dose 5.9 mGy vs. 11.7 mGy, p < 0.001). High-degree misregistrations were evident in the majority of subtraction images (level 1/2/3/4 16.9%/27.1%/16.9%/39%), in particular for bilateral exams (3.2%/29.2%/8.3%/58.3%). Diagnostic accuracy of post-contrast CBBCT alone is comparable to pre- and post-contrast CBBCT in type c/d breasts, while yielding a significant twofold Radiation dose reduction. • The diagnostic accuracy of post-contrast CBBCT alone is comparable to dual acquisition of pre- and post-contrast CBBCT. • Acquisition of the post-contrast CBBCT scan alone Reduces Radiation Exposure compared to pre- and post-contrast CBBCT, thus countering one of the main limitations of CBBCT. • High-degree misregistration artifacts limit the interpretation of subtraction images from pre- and post-contrast CBBCT studies.
-
Pre- and post-contrast versus post-contrast cone-beam breast CT: can we Reduce Radiation Exposure while maintaining diagnostic accuracy?
European radiology, 2018Co-Authors: Johannes Uhlig, Uwe Fischer, Lorenz Biggemann, Joachim Lotz, Susanne WienbeckAbstract:To evaluate whether post-contrast cone-beam breast CT (CBBCT) alone is comparable to the current standard of combined pre- and post-contrast CBBCT regarding diagnostic accuracy and superior regarding Radiation Exposure. This study included 49 women (61 breasts) with median age 57.9 years and BI-RADS 4/5 lesions diagnosed on mammography/ultrasound in density type c/d breasts. Two radiologists rated post-contrast CBBCT and pre- and post-contrast CBBCT with subtraction images on the BI-RADS scale separately for calculation of inter- and intra-observer agreement and in consensus for diagnostic accuracy assessment. Sensitivity, specificity, and area under the curve (AUC) were compared via McNemar test and DeLong method, respectively. Subtraction imaging misregistration were measured from 1 (no artifacts) to 4 (artifacts with width > 4 mm). A total of 100 lesion (51 malignant; 6 high risk; 43 benign) were included. AUC, sensitivity, and specificity showed no significant differences comparing post-contrast CBBCT alone versus pre- and post-contrast CBBCT (AUC 0.84 vs. 0.83, p = 0.643; sensitivity 0.89 vs. 0.85, p = 0.158; specificity 0.73 vs. 0.76, p = 0.655). Inter- and intra-observer agreement was excellent (intra-class correlation coefficient ICC = 0.76, ICC = 0.83, respectively). Radiation dose was significantly lower for post-contrast CBBCT alone versus pre- and post-contrast CBBCT (median average glandular Radiation dose 5.9 mGy vs. 11.7 mGy, p
