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  1. Article: Editorial: Advances in aortic imaging.

    Leach, Joseph R / Zhu, Chengcheng / Burris, Nicolas / Hope, Michael D

    Frontiers in cardiovascular medicine

    2023  Volume 10, Page(s) 1137949

    Language English
    Publishing date 2023-02-01
    Publishing country Switzerland
    Document type Editorial
    ZDB-ID 2781496-8
    ISSN 2297-055X
    ISSN 2297-055X
    DOI 10.3389/fcvm.2023.1137949
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  2. Article ; Online: Expanding the Radiologist's Arsenal against Abdominal Aortic Aneurysms, a Versatile Adversary.

    Mitsouras, Dimitrios / Leach, Joseph R

    Radiology

    2020  Volume 295, Issue 3, Page(s) 730–732

    MeSH term(s) Aortic Aneurysm, Abdominal ; Disease Progression ; Humans ; Radiologists ; Tomography, X-Ray Computed
    Language English
    Publishing date 2020-03-31
    Publishing country United States
    Document type Editorial ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S. ; Comment
    ZDB-ID 80324-8
    ISSN 1527-1315 ; 0033-8419
    ISSN (online) 1527-1315
    ISSN 0033-8419
    DOI 10.1148/radiol.2020200531
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  3. Article ; Online: Sex differences in ascending aortic size reporting and growth on chest computed tomography and magnetic resonance imaging.

    Zamirpour, Siavash / Boskovski, Marko T / Pirruccello, James P / Pace, William A / Hubbard, Alan E / Leach, Joseph R / Ge, Liang / Tseng, Elaine E

    Clinical imaging

    2023  Volume 105, Page(s) 110021

    Abstract: Purpose: Diameter-based guidelines for prophylactic repair of ascending aortic aneurysms have led to routine aortic evaluation in chest imaging. Despite sex differences in aneurysm outcomes, there is little understanding of sex-specific aortic growth ... ...

    Abstract Purpose: Diameter-based guidelines for prophylactic repair of ascending aortic aneurysms have led to routine aortic evaluation in chest imaging. Despite sex differences in aneurysm outcomes, there is little understanding of sex-specific aortic growth rates. Our objective was to evaluate sex-specific temporal changes in radiologist-reported aortic size as well as sex differences in aortic reporting.
    Method: In this cohort study, we queried radiology reports of chest computed tomography or magnetic resonance imaging at an academic medical center from 1994 to 2022, excluding type A dissection. Aortic diameter was extracted using a custom text-processing algorithm. Growth rates were estimated using mixed-effects modeling with fixed terms for sex, age, and imaging modality, and patient-level random intercepts. Sex, age, and modality were evaluated as predictors of aortic reporting by logistic regression.
    Results: This study included 89,863 scans among 46,622 patients (median [interquartile range] age, 64 [52-73]; 22,437 women [48%]). Aortic diameter was recorded in 14% (12,722/89,863 reports). Temporal trends were analyzed in 7194 scans among 1998 patients (age, 68 [60-75]; 677 women [34%]) with ≥2 scans. Aortic growth rate was significantly higher in women (0.22 mm/year [95% confidence interval 0.17-0.28] vs. 0.09 mm/year [0.06-0.13], respectively). Aortic reporting was significantly less common in women (odds ratio, 0.54; 95% CI, 0.52-0.56; p < 0.001).
    Conclusions: While aortic growth rates were small overall, women had over twice the growth rate of men. Aortic dimensions were much less frequently reported in women than men. Sex-specific standardized assessment of aortic measurements may be needed to address sex differences in aneurysm outcomes.
    MeSH term(s) Humans ; Male ; Female ; Middle Aged ; Aged ; Cohort Studies ; Sex Characteristics ; Tomography, X-Ray Computed/methods ; Magnetic Resonance Imaging ; Aneurysm ; Aortic Aneurysm, Thoracic/diagnostic imaging ; Risk Factors
    Language English
    Publishing date 2023-11-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1028123-x
    ISSN 1873-4499 ; 0899-7071
    ISSN (online) 1873-4499
    ISSN 0899-7071
    DOI 10.1016/j.clinimag.2023.110021
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  4. Article: Height and body surface area versus wall stress for stratification of mid-term outcomes in ascending aortic aneurysm.

    Zamirpour, Siavash / Xuan, Yue / Wang, Zhongjie / Gomez, Axel / Leach, Joseph R / Mitsouras, Dimitrios / Saloner, David A / Guccione, Julius M / Ge, Liang / Tseng, Elaine E

    International journal of cardiology. Heart & vasculature

    2024  Volume 51, Page(s) 101375

    Abstract: Objectives: Current diameter-based guidelines for ascending thoracic aortic aneurysms (aTAA) do not consistently predict risk of dissection/rupture. ATAA wall stresses may enhance risk stratification independent of diameter. The relation of wall ... ...

    Abstract Objectives: Current diameter-based guidelines for ascending thoracic aortic aneurysms (aTAA) do not consistently predict risk of dissection/rupture. ATAA wall stresses may enhance risk stratification independent of diameter. The relation of wall stresses and diameter indexed to height and body surface area (BSA) is unknown. Our objective was to compare aTAA wall stresses with indexed diameters in relation to all-cause mortality at 3.75 years follow-up.
    Methods: Finite element analyses were performed in a veteran population with aortas ≥ 4.0 cm. Three-dimensional geometries were reconstructed from computed tomography with models accounting for pre-stress geometries. A fiber-embedded hyperelastic material model was applied to obtain wall stress distributions under systolic pressure. Peak wall stresses were compared across guideline thresholds for diameter/BSA and diameter/height. Hazard ratios for all-cause mortality and surgical aneurysm repair were estimated using cause-specific Cox proportional hazards models.
    Results: Of 253 veterans, 54 (21 %) had aneurysm repair at 3.75 years. Indexed diameter alone would have prompted repair at baseline in 17/253 (6.7 %) patients, including only 4/230 (1.7 %) with diameter < 5.5 cm. Peak wall stresses did not significantly differ across guideline thresholds for diameter/BSA (circumferential:
    Conclusions: Diameter/height improved stratification of peak wall stresses compared to diameter/BSA. Peak longitudinal stresses predicted all-cause mortality independent of age and indexed diameter and may aid risk stratification for aTAA adverse events.
    Language English
    Publishing date 2024-02-28
    Publishing country Ireland
    Document type Journal Article
    ZDB-ID 2818464-6
    ISSN 2352-9067
    ISSN 2352-9067
    DOI 10.1016/j.ijcha.2024.101375
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  5. Article: Abdominal aortic aneurysm measurement at CT/MRI: potential clinical ramifications of non-standardized measurement technique and importance of multiplanar reformation.

    Leach, Joseph R / Zhu, Chengcheng / Mitsouras, Dimitrios / Saloner, David / Hope, Michael D

    Quantitative imaging in medicine and surgery

    2021  Volume 11, Issue 2, Page(s) 823–830

    Abstract: Accurate and reproducible measurement of abdominal aortic aneurysm (AAA) size is an essential component of patient management, and most reliably performed at CT using a multiplanar reformat (MPR) strategy. This approach is not universal, however. This ... ...

    Abstract Accurate and reproducible measurement of abdominal aortic aneurysm (AAA) size is an essential component of patient management, and most reliably performed at CT using a multiplanar reformat (MPR) strategy. This approach is not universal, however. This study aims to characterize the measurement error present in routine clinical assessment of AAAs and the potential clinical ramifications. Patients were included if they had AAA assessed by CT and/or MRI at two time points at least 6 months apart. Clinical maximal AAA diameter, assessed by non-standardized methods, was abstracted from the radiology report at each time point and compared to the reference aneurysm diameter measured using a MPR strategy. Discrepancies between clinical and reference diameters, and associated aneurysm enlargement rates were analyzed. Two hundred thirty patients were included, with average follow-up 3.3±2.5 years. When compared to MPR-derived diameters, clinical aneurysm measurement inaccuracy was, on average, 3.3 mm. Broad limits of agreement were found for both clinical diameters [-6.7 to +6.5 mm] and aneurysm enlargement rates [-4.6 to +4.2 mm/year] when compared to MPR-based measures. Of 78 AAAs measuring 5-6 cm by the MPR method, 21 (26.9%) were misclassified by the clinical measurement with respect to a common repair threshold (5.5 cm), of which 5 were misclassified as below, and 16 were misclassified as above the threshold. The clinical use of non-standardized AAA measurement strategies can lead to incorrect classification of AAAs as larger or smaller than the commonly accepted repair threshold of 5.5 cm and can induce large errors in quantification of aneurysm enlargement rate.
    Language English
    Publishing date 2021-01-16
    Publishing country China
    Document type Journal Article
    ZDB-ID 2653586-5
    ISSN 2223-4306 ; 2223-4292
    ISSN (online) 2223-4306
    ISSN 2223-4292
    DOI 10.21037/qims-20-888
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  6. Article ; Online: Impact of Implicit Abdominal Aortic Aneurysm Screening in the Veterans Affairs Health Care System Over 10 Years.

    Leach, Joseph R / Shen, Hui / Huo, Eugene / Hope, Thomas A / Mitsouras, Dimitrios / Whooley, Mary A / Hope, Michael D

    Journal of the American Heart Association

    2022  Volume 11, Issue 7, Page(s) e024571

    Abstract: Background Abdominal aortic aneurysm (AAA) screening programs have been active in the United States since 2005, but are not the only way AAAs are detected. AAA management and outcomes have not been investigated broadly in the context of "implicit AAA ... ...

    Abstract Background Abdominal aortic aneurysm (AAA) screening programs have been active in the United States since 2005, but are not the only way AAAs are detected. AAA management and outcomes have not been investigated broadly in the context of "implicit AAA screening," whereby radiologic examinations not intended for focused screening can identify AAAs. Methods and Results We examined the association between imaging-based AAA screening, both explicit and implicit, and various outcomes for ≈1.6 million veterans in the Veterans Affairs health care system from 2005 to 2015. Screened-positive, screened-negative, and unscreened veterans were identified in the overall cohort and within a subgroup of veterans aged 65 years in 2005. The yearly composite screening rate increased over 10 years, from 11.7% to 18.3%, whereas the screened-positive rate decreased from 7.3% to 4.9%. Only 12.9% of screening examinations were explicit AAA screening ultrasounds. The subgroup's composite screening rate was 74% within its 10-year eligibility window, with implicit screening accounting for 91.8% of examinations. In the 2005 subgroup, all-cause mortality and Charlson comorbidity scores were higher for veterans who underwent screening compared with those unscreened (31.2% versus 23.1% and 0.47 versus 0.25, respectively;
    MeSH term(s) Aged ; Aortic Aneurysm, Abdominal/diagnostic imaging ; Aortic Aneurysm, Abdominal/epidemiology ; Delivery of Health Care ; Humans ; Mass Screening/methods ; Risk Factors ; Ultrasonography ; United States/epidemiology ; Veterans
    Language English
    Publishing date 2022-03-29
    Publishing country England
    Document type Journal Article
    ZDB-ID 2653953-6
    ISSN 2047-9980 ; 2047-9980
    ISSN (online) 2047-9980
    ISSN 2047-9980
    DOI 10.1161/JAHA.121.024571
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  7. Article ; Online: Intraluminal Thrombus Predicts Rapid Growth of Abdominal Aortic Aneurysms.

    Zhu, Chengcheng / Leach, Joseph R / Wang, Yuting / Gasper, Warren / Saloner, David / Hope, Michael D

    Radiology

    2020  Volume 294, Issue 3, Page(s) 707–713

    Abstract: Background Intraluminal thrombus (ILT) within abdominal aortic aneurysms (AAAs) may be a potential marker for subsequent aneurysm growth. Purpose To investigate the role of ILT in AAA progression as assessed with CT and MRI. Materials and Methods This ... ...

    Abstract Background Intraluminal thrombus (ILT) within abdominal aortic aneurysms (AAAs) may be a potential marker for subsequent aneurysm growth. Purpose To investigate the role of ILT in AAA progression as assessed with CT and MRI. Materials and Methods This was a retrospective study, with patient data included from January 2004 to December 2018 at a Veteran Affairs medical center. Male patients with AAA who underwent contrast material-enhanced CT at baseline and CT or black-blood MRI at follow-up (minimal follow-up duration of 6 months) were included. The maximal AAA diameter was measured with multiplanar reconstruction, and the annual growth rate of aneurysms was calculated. Uni- and multivariable linear regression analyses were used to determine the relationship between demographic and imaging factors and aneurysm growth. Results A total of 225 patients (mean age, 72 years ± 9 [standard deviation]) were followed for a mean of 3.3 years ± 2.5. A total of 207 patients were followed up with CT, and 18 were followed up with MRI. At baseline, the median size of the AAA was 3.8 cm (interquartile range [IQR], 3.3-4.3 cm); 127 of 225 patients (54.7%) had ILT. When compared with AAAs without ILT, AAAs with ILT had larger baseline diameters (median, 4.1 cm [IQR, 3.6-4.8 cm] vs 3.4 cm [IQR, 3.2-3.9 cm];
    MeSH term(s) Aged ; Aged, 80 and over ; Aortic Aneurysm, Abdominal/complications ; Aortic Aneurysm, Abdominal/diagnostic imaging ; Aortic Aneurysm, Abdominal/pathology ; Disease Progression ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Risk Factors ; Thrombosis/complications ; Thrombosis/diagnostic imaging ; Thrombosis/pathology ; Tomography, X-Ray Computed
    Language English
    Publishing date 2020-01-28
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 80324-8
    ISSN 1527-1315 ; 0033-8419
    ISSN (online) 1527-1315
    ISSN 0033-8419
    DOI 10.1148/radiol.2020191723
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  8. Article ; Online: Dynamic Contrast-Enhanced MRI in Abdominal Aortic Aneurysms as a Potential Marker for Disease Progression.

    Zhou, Ang / Leach, Joseph R / Zhu, Chengcheng / Dong, Huiming / Jiang, Fei / Lee, Yoo Jin / Iannuzzi, James / Gasper, Warren / Saloner, David / Hope, Michael D / Mitsouras, Dimitrios

    Journal of magnetic resonance imaging : JMRI

    2023  Volume 58, Issue 4, Page(s) 1258–1267

    Abstract: Background: Abdominal aortic aneurysms (AAAs) may rupture before reaching maximum diameter (D: Purpose: To investigate whether dynamic contrast-enhanced (DCE) MRI of AAA is associated with D: Study type: Prospective.: Population: A total of 27 ... ...

    Abstract Background: Abdominal aortic aneurysms (AAAs) may rupture before reaching maximum diameter (D
    Purpose: To investigate whether dynamic contrast-enhanced (DCE) MRI of AAA is associated with D
    Study type: Prospective.
    Population: A total of 27 male patients with infrarenal AAA (mean age ± standard deviation = 75 ± 5 years) under surveillance with DCE MRI and 2 years of prior follow-up intervals with computed tomography (CT) or MRI.
    Field strength/sequence: A 3-T, dynamic three-dimensional (3D) fast gradient-echo stack-of-stars volumetric interpolated breath-hold examination (Star-VIBE).
    Assessment: Wall voxels were manually segmented in two consecutive slices at the level of D
    Statistical tests: Pearson correlation and linear mixed effects models. A P value <0.05 was considered statistically significant.
    Results: In 44 DCE MRIs, mean D
    Conclusion: Contrast uptake may be increased in lateral aspects of the AAA. Contrast enhancement 1-minute slope and 4-minutes AUC may be associated with a period of recent AAA growth that is independent of D
    Evidence level: 3.
    Technical efficacy: Stage 2.
    MeSH term(s) Humans ; Male ; Prospective Studies ; Aortic Aneurysm, Abdominal/diagnostic imaging ; Aortic Aneurysm, Abdominal/complications ; Aorta ; Disease Progression ; Magnetic Resonance Imaging/methods
    Language English
    Publishing date 2023-02-06
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1146614-5
    ISSN 1522-2586 ; 1053-1807
    ISSN (online) 1522-2586
    ISSN 1053-1807
    DOI 10.1002/jmri.28640
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  9. Article ; Online: Measurement of Abdominal Aortic Aneurysm Strain Using MR Deformable Image Registration: Accuracy and Relationship to Recent Aneurysm Progression.

    Dong, Huiming / Leach, Joseph R / Kao, Evan / Zhou, Ang / Chitiboi, Teodora / Zhu, Chengcheng / Ballweber, Megan / Jiang, Fei / Lee, Yoo Jin / Iannuzzi, James / Gasper, Warren / Saloner, David / Hope, Michael D / Mitsouras, Dimitrios

    Investigative radiology

    2023  Volume 59, Issue 6, Page(s) 425–432

    Abstract: Background: Management of asymptomatic abdominal aortic aneurysm (AAA) based on maximum aneurysm diameter and growth rate fails to preempt many ruptures. Assessment of aortic wall biomechanical properties may improve assessment of progression and ... ...

    Abstract Background: Management of asymptomatic abdominal aortic aneurysm (AAA) based on maximum aneurysm diameter and growth rate fails to preempt many ruptures. Assessment of aortic wall biomechanical properties may improve assessment of progression and rupture risk. This study aimed to assess the accuracy of AAA wall strain measured by cine magnetic resonance imaging (MRI) deformable image registration (MR strain) and investigate its relationship with recent AAA progression.
    Methods: The MR strain accuracy was evaluated in silico against ground truth strain in 54 synthetic MRIs generated from a finite element model simulation of an AAA patient's abdomen for different aortic pulse pressures, tissue motions, signal intensity variations, and image noise. Evaluation included bias with 95% confidence interval (CI) and correlation analysis. Association of MR strain with AAA growth rate was assessed in 25 consecutive patients with >6 months of prior surveillance, for whom cine balanced steady-state free-precession imaging was acquired at the level of the AAA as well as the proximal, normal-caliber aorta. Univariate and multivariate regressions were used to associate growth rate with clinical variables, maximum AAA diameter (D max ), and peak circumferential MR strain through the cardiac cycle. The MR strain interoperator variability was assessed using bias with 95% CI, intraclass correlation coefficient, and coefficient of variation.
    Results: In silico experiments revealed an MR strain bias of 0.48% ± 0.42% and a slope of correlation to ground truth strain of 0.963. In vivo, AAA MR strain (1.2% ± 0.6%) was highly reproducible (bias ± 95% CI, 0.03% ± 0.31%; intraclass correlation coefficient, 97.8%; coefficient of variation, 7.14%) and was lower than in the nonaneurysmal aorta (2.4% ± 1.7%). D max ( β = 0.087) and MR strain ( β = -1.563) were both associated with AAA growth rate. The MR strain remained an independent factor associated with growth rate ( β = -0.904) after controlling for D max .
    Conclusions: Deformable image registration analysis can accurately measure the circumferential strain of the AAA wall from standard cine MRI and may offer patient-specific insight regarding AAA progression.
    MeSH term(s) Aortic Aneurysm, Abdominal/diagnostic imaging ; Humans ; Disease Progression ; Male ; Female ; Aged ; Magnetic Resonance Imaging, Cine/methods ; Reproducibility of Results ; Image Interpretation, Computer-Assisted/methods ; Aorta, Abdominal/diagnostic imaging ; Aorta, Abdominal/pathology ; Middle Aged ; Computer Simulation ; Sensitivity and Specificity
    Language English
    Publishing date 2023-10-19
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural
    ZDB-ID 80345-5
    ISSN 1536-0210 ; 0020-9996
    ISSN (online) 1536-0210
    ISSN 0020-9996
    DOI 10.1097/RLI.0000000000001035
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  10. Article ; Online: On the Relative Impact of Intraluminal Thrombus Heterogeneity on Abdominal Aortic Aneurysm Mechanics.

    Leach, Joseph R / Kao, Evan / Zhu, Chengcheng / Saloner, David / Hope, Michael D

    Journal of biomechanical engineering

    2019  Volume 141, Issue 11

    Abstract: Intraluminal thrombus (ILT) is present in the majority of abdominal aortic aneurysms (AAA) of a size warranting consideration for surgical or endovascular intervention. The rupture risk of AAAs is thought to be related to the balance of vessel wall ... ...

    Abstract Intraluminal thrombus (ILT) is present in the majority of abdominal aortic aneurysms (AAA) of a size warranting consideration for surgical or endovascular intervention. The rupture risk of AAAs is thought to be related to the balance of vessel wall strength and the mechanical stress caused by systemic blood pressure. Previous finite element analyses of AAAs have shown that ILT can reduce and homogenize aneurysm wall stress. These works have largely considered ILT to be homogeneous in mechanical character or have idealized a stiffness distribution through the thrombus thickness. In this work, we use magnetic resonance imaging (MRI) to delineate the heterogeneous composition of ILT in 7 AAAs and perform patient-specific finite element analysis under multiple conditions of ILT layer stiffness disparity. We find that explicit incorporation of ILT heterogeneity in the finite element analysis is unlikely to substantially alter major stress analysis predictions regarding aneurysm rupture risk in comparison to models assuming a homogenous thrombus, provided that the maximal ILT stiffness is the same between models. Our results also show that under a homogeneous ILT assumption, the choice of ILT stiffness from values common in the literature can result in significantly larger variations in stress predictions compared to the effects of thrombus heterogeneity.
    Language English
    Publishing date 2019-05-28
    Publishing country United States
    Document type Journal Article
    ZDB-ID 243094-0
    ISSN 1528-8951 ; 0148-0731
    ISSN (online) 1528-8951
    ISSN 0148-0731
    DOI 10.1115/1.4044143
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