1
|
Dong H, Leach JR, Kao E, Zhou A, Chitiboi T, Zhu C, Ballweber M, Jiang F, Lee YJ, Iannuzzi J, Gasper W, Saloner D, Hope MD, Mitsouras D. Measurement of Abdominal Aortic Aneurysm Strain Using MR Deformable Image Registration: Accuracy and Relationship to Recent Aneurysm Progression. Invest Radiol 2024; 59:425-432. [PMID: 37855728 PMCID: PMC11026303 DOI: 10.1097/rli.0000000000001035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
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.
Collapse
Affiliation(s)
- Huiming Dong
- From the Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA (H.D., J.L., E.K., A.Z., C.Z., M.B., Y.J.L., D.S., M.H., D.M.); Vascular Imaging Research Center, San Francisco Veteran Affairs Medical Center, San Francisco, CA (H.D., J.L., E.K., A.Z., C.Z., M.B., D.S., M.H., D.M.); Siemens Healthineers (T.C.); Department of Radiology, University of Washington, Seattle, WA (C.Z.); Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA (F.J.); Department of Surgery, University of California, San Francisco, San Francisco, CA (J.I., W. G.); and Department of Vascular Surgery, San Francisco Veteran Affairs Medical Center, San Francisco, CA (J.I., W.G.)
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Zamirpour S, Xuan Y, Wang Z, Gomez A, Leach JR, Mitsouras D, Saloner DA, Guccione JM, Ge L, Tseng EE. Height and body surface area versus wall stress for stratification of mid-term outcomes in ascending aortic aneurysm. Int J Cardiol Heart Vasc 2024; 51:101375. [PMID: 38435381 PMCID: PMC10909604 DOI: 10.1016/j.ijcha.2024.101375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/13/2024] [Accepted: 02/23/2024] [Indexed: 03/05/2024]
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: p = 0.15; longitudinal: p = 0.18), but did differ for diameter/height (circumferential: p = 0.003; longitudinal: p = 0.048). All-cause mortality was independently associated with peak longitudinal stresses (p = 0.04). Peak longitudinal stresses were best predicted by diameter (c-statistic = 0.66), followed by diameter/height (c-statistic = 0.59), and diameter/BSA (c-statistic = 0.55). 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.
Collapse
Affiliation(s)
- Siavash Zamirpour
- Department of Surgery, Division of Adult Cardiothoracic Surgery, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
- School of Medicine, University of California, San Francisco, USA
| | - Yue Xuan
- Department of Surgery, Division of Adult Cardiothoracic Surgery, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - Zhongjie Wang
- Department of Surgery, Division of Adult Cardiothoracic Surgery, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - Axel Gomez
- Department of Surgery, Division of Adult Cardiothoracic Surgery, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - Joseph R. Leach
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - Dimitrios Mitsouras
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - David A. Saloner
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - Julius M. Guccione
- Department of Surgery, Division of Adult Cardiothoracic Surgery, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - Liang Ge
- Department of Surgery, Division of Adult Cardiothoracic Surgery, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| | - Elaine E. Tseng
- Department of Surgery, Division of Adult Cardiothoracic Surgery, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, USA
| |
Collapse
|
3
|
Zamirpour S, Boskovski MT, Pirruccello JP, Pace WA, Hubbard AE, Leach JR, Ge L, Tseng EE. Sex differences in ascending aortic size reporting and growth on chest computed tomography and magnetic resonance imaging. Clin Imaging 2024; 105:110021. [PMID: 37992628 DOI: 10.1016/j.clinimag.2023.110021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 10/16/2023] [Accepted: 11/02/2023] [Indexed: 11/24/2023]
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.
Collapse
Affiliation(s)
- Siavash Zamirpour
- Division of Adult Cardiothoracic Surgery, Department of Surgery, University of California San Francisco, San Francisco Veterans Affairs Health Care System, San Francisco, CA, USA; School of Medicine, University of California San Francisco, CA, USA
| | - Marko T Boskovski
- Division of Adult Cardiothoracic Surgery, Department of Surgery, University of California San Francisco, San Francisco Veterans Affairs Health Care System, San Francisco, CA, USA
| | - James P Pirruccello
- Division of Cardiology, Department of Medicine, University of California San Francisco, USA; Institute for Human Genetics, University of California San Francisco, USA
| | - William A Pace
- Division of Adult Cardiothoracic Surgery, Department of Surgery, University of California San Francisco, San Francisco Veterans Affairs Health Care System, San Francisco, CA, USA; School of Medicine, University of California San Francisco, CA, USA
| | - Alan E Hubbard
- Division of Biostatistics, School of Public Health, University of California Berkeley, USA
| | - Joseph R Leach
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco Veterans Affairs Health Care System, San Francisco, CA, USA
| | - Liang Ge
- Division of Adult Cardiothoracic Surgery, Department of Surgery, University of California San Francisco, San Francisco Veterans Affairs Health Care System, San Francisco, CA, USA
| | - Elaine E Tseng
- Division of Adult Cardiothoracic Surgery, Department of Surgery, University of California San Francisco, San Francisco Veterans Affairs Health Care System, San Francisco, CA, USA.
| |
Collapse
|
4
|
Zhou A, Leach JR, Zhu C, Dong H, Jiang F, Lee YJ, Iannuzzi J, Gasper W, Saloner D, Hope MD, Mitsouras D. Dynamic Contrast-Enhanced MRI in Abdominal Aortic Aneurysms as a Potential Marker for Disease Progression. J Magn Reson Imaging 2023; 58:1258-1267. [PMID: 36747321 DOI: 10.1002/jmri.28640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Abdominal aortic aneurysms (AAAs) may rupture before reaching maximum diameter (Dmax ) thresholds for repair. Aortic wall microvasculature has been associated with elastin content and rupture sites in specimens, but its relation to progression is unknown. PURPOSE To investigate whether dynamic contrast-enhanced (DCE) MRI of AAA is associated with Dmax or growth. 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 Dmax . We measured slope to 1-minute and area under the curve (AUC) to 1 minute and 4 minutes of the signal intensity change postcontrast relative to that precontrast arrival, and, Ktrans , a measure of microvascular permeability, using the Patlak model. These were averaged over all wall voxels for association to Dmax and growth rate, and, over left/right and anterior/posterior quadrants for testing circumferential homogeneity. Dmax was measured orthogonal to the aortic centerline and growth rate was calculated by linear fit of Dmax measurements. STATISTICAL TESTS Pearson correlation and linear mixed effects models. A P value <0.05 was considered statistically significant. RESULTS In 44 DCE MRIs, mean Dmax was 45 ± 7 mm and growth rate in 1.5 ± 0.4 years of prior follow-up was 1.7 ± 1.2 mm per year. DCE measurements correlated with each other (Pearson r = 0.39-0.99) and significantly differed between anterior/posterior versus left/right quadrants. DCE measurements were not significantly associated with Dmax (P = 0.084, 0.289, 0.054 and 0.255 for slope, AUC at 1 minute and 4 minutes, and Ktrans , respectively). Slope and 4 minutes AUC significantly associated with growth rate after controlling for Dmax . 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 Dmax . EVIDENCE LEVEL 3. TECHNICAL EFFICACY Stage 2.
Collapse
Affiliation(s)
- Ang Zhou
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Joseph R Leach
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Chengcheng Zhu
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Huiming Dong
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Fei Jiang
- Department of Biostatistics, University of California San Francisco, San Francisco, California, USA
| | - Yoo Jin Lee
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - James Iannuzzi
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
- Department of Surgery, University of California San Francisco, San Francisco, California, USA
| | - Warren Gasper
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
- Department of Surgery, University of California San Francisco, San Francisco, California, USA
| | - David Saloner
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Michael D Hope
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Dimitrios Mitsouras
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| |
Collapse
|
5
|
Leach JR, Zhu C, Burris N, Hope MD. Editorial: Advances in aortic imaging. Front Cardiovasc Med 2023; 10:1137949. [PMID: 36818356 PMCID: PMC9929938 DOI: 10.3389/fcvm.2023.1137949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 01/16/2023] [Indexed: 02/04/2023] Open
Affiliation(s)
- Joseph R. Leach
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States,*Correspondence: Joseph R. Leach ✉
| | - Chengcheng Zhu
- Department of Radiology, University of Washington, Seattle, WA, United States
| | - Nicolas Burris
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States
| | - Michael D. Hope
- California Advanced Imaging Medical Associates, San Francisco, CA, United States
| |
Collapse
|
6
|
Leach JR, Shen H, Huo E, Hope TA, Mitsouras D, Whooley MA, Hope MD. Impact of Implicit Abdominal Aortic Aneurysm Screening in the Veterans Affairs Health Care System Over 10 Years. J Am Heart Assoc 2022; 11:e024571. [PMID: 35348001 PMCID: PMC9075479 DOI: 10.1161/jaha.121.024571] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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; P<0.001). AAA rupture rates were similar between those unscreened and screened‐negative individuals. Conclusions Accounting for both explicit and implicit screening, AAA screening in the Veterans Affairs population has moderate reach. Efforts to expand explicit AAA screening are not likely to impact either all‐cause mortality or AAA rupture on the population scale as significantly as a careful accounting for and use of implicit screening data.
Collapse
Affiliation(s)
- Joseph R. Leach
- Department of Radiology and Biomedical Imaging University of CaliforniaSan Francisco, and San Francisco Veterans Affairs Medical Center San Francisco CA
| | - Hui Shen
- San Francisco Veterans Affairs Medical Center San Francisco CA
| | - Eugene Huo
- Department of Radiology and Biomedical Imaging University of CaliforniaSan Francisco, and San Francisco Veterans Affairs Medical Center San Francisco CA
| | - Thomas A. Hope
- Department of Radiology and Biomedical Imaging University of CaliforniaSan Francisco, and San Francisco Veterans Affairs Medical Center San Francisco CA
| | - Dimitrios Mitsouras
- Department of Radiology and Biomedical Imaging University of CaliforniaSan Francisco, and San Francisco Veterans Affairs Medical Center San Francisco CA
| | - Mary A. Whooley
- San Francisco Veterans Affairs Medical Center San Francisco CA
- Department of Medicine University of California San Francisco CA
| | - Michael D. Hope
- Department of Radiology and Biomedical Imaging University of CaliforniaSan Francisco, and San Francisco Veterans Affairs Medical Center San Francisco CA
| |
Collapse
|
7
|
Leach JR, Zhu C, Mitsouras D, Saloner D, Hope MD. Abdominal aortic aneurysm measurement at CT/MRI: potential clinical ramifications of non-standardized measurement technique and importance of multiplanar reformation. Quant Imaging Med Surg 2021; 11:823-830. [PMID: 33532280 DOI: 10.21037/qims-20-888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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.
Collapse
Affiliation(s)
- Joseph R Leach
- University of California, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Chengcheng Zhu
- University of California, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Dimitrios Mitsouras
- University of California, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - David Saloner
- University of California, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Michael D Hope
- University of California, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| |
Collapse
|
8
|
Mitsouras D, Leach JR. Expanding the Radiologist's Arsenal against Abdominal Aortic Aneurysms, a Versatile Adversary. Radiology 2020; 295:730-732. [PMID: 32233921 PMCID: PMC7263282 DOI: 10.1148/radiol.2020200531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 02/22/2020] [Accepted: 02/24/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Dimitrios Mitsouras
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, Calif; and Department of Radiology, Veterans Affairs Medical Center, 4150 Clement St, 114D, San Francisco, CA 94121
| | - Joseph R. Leach
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, Calif; and Department of Radiology, Veterans Affairs Medical Center, 4150 Clement St, 114D, San Francisco, CA 94121
| |
Collapse
|
9
|
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]; P < .001) and faster growth rates (median, 2.0 mm/y [IQR, 1.3-3.2 mm/y] vs 1.0 mm/y [IQR, 0.4-1.8 mm/y]; P < .001). Small AAAs (size range, 3-4 cm) with ILT grew 1.9-fold faster than did those without ILT (median, 1.5 mm/y [IQR, 0.9-2.7 mm/y] vs 0.8 mm/y [IQR, 0.3-1.5 mm/y]; P < .001). Medium AAAs (size range, 4-5 cm) with ILT had 1.2-fold faster growth than did those without ILT (median growth, 2.1 mm/y [IQR, 1.4, 3.7 mm/y] vs 1.8 mm/y [IQR, 0.9, 2.0 mm/y]; P = .06). In multivariable analysis, baseline diameter and ILT were independently positively related to aneurysm growth rate (standardized regression coefficient, 0.43 [P < .001] and 0.15 [P = .02], respectively). Conclusion Both maximal cross-sectional aneurysm diameter and the presence of intraluminal thrombus are independent predictors of abdominal aortic aneurysm growth. © RSNA, 2020 Online supplemental material is available for this article.
Collapse
Affiliation(s)
- Chengcheng Zhu
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Joseph R Leach
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Yuting Wang
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Warren Gasper
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - David Saloner
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Michael D Hope
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| |
Collapse
|
10
|
Haraldsson H, Leach JR, Kao EI, Wright AG, Ammanuel SG, Khangura RS, Ballweber MK, Chin CT, Shah VN, Meisel K, Saloner DA, Amans MR. Reduced Jet Velocity in Venous Flow after CSF Drainage: Assessing Hemodynamic Causes of Pulsatile Tinnitus. AJNR Am J Neuroradiol 2019; 40:849-854. [PMID: 31023664 DOI: 10.3174/ajnr.a6043] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 03/18/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND PURPOSE Idiopathic intracranial hypertension is commonly associated with transverse sinus stenosis, a venous cause of pulsatile tinnitus. In patients with idiopathic intracranial hypertension, CSF drainage via lumbar puncture decreases intracranial pressure, which relieves the stenosis, and may provide at least temporary cessation of pulsatile tinnitus. The objective of this study was to evaluate changes in venous blood flow caused by lowered intracranial pressure in patients with pulsatile tinnitus to help identify the cause of pulsatile tinnitus. MATERIALS AND METHODS Ten patients with suspected transverse sinus stenosis as a venous etiology for pulsatile tinnitus symptoms underwent MR imaging before and after lumbar puncture in the same session. The protocol included flow assessment and rating of pulsatile tinnitus intensity before and after lumbar puncture and MR venography before lumbar puncture. Post-lumbar puncture MR venography was performed in 1 subject. RESULTS There was a lumbar puncture-induced reduction in venous peak velocity that correlated with the opening pressure (r = -0.72, P = .019) without a concomitant reduction in flow rate. Patients with flow jets had their peak velocity reduced by 0.30 ± 0.18 m/s (P = .002), correlating with a reduction in CSF pressure (r = 0.82, P = .024) and the reduction in subjectively scored pulsatile tinnitus intensity (r = 0.78, P = .023). The post-lumbar puncture MR venography demonstrated alleviation of the stenosis. CONCLUSIONS Our results show a lumbar puncture-induced reduction in venous peak velocity without a concomitant reduction in flow rate. We hypothesize that the reduction is caused by the expansion of the stenosis after lumbar puncture. Our results further show a correlation between the peak velocity and pulsatile tinnitus intensity, suggesting the flow jet to be instrumental in the development of sound.
Collapse
Affiliation(s)
- H Haraldsson
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - J R Leach
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - E I Kao
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - A G Wright
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - S G Ammanuel
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - R S Khangura
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - M K Ballweber
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - C T Chin
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - V N Shah
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| | - K Meisel
- Neurology (K.M.), University of California, San Francisco, San Francisco, California
| | - D A Saloner
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.).,Radiology Service (D.A.S.), VA Medical Center, San Francisco, California
| | - M R Amans
- From the Departments of Radiology and Biomedical Imaging (H.H., J.R.L., E.I.K., A.G.W., S.G.A., R.S.K., M.K.B., C.T.C., V.N.S., D.A.S., M.R.A.)
| |
Collapse
|
11
|
Zhu C, Leach JR, Tian B, Cao L, Wen Z, Wang Y, Liu X, Liu Q, Lu J, Saloner D, Hope MD. Evaluation of the distribution and progression of intraluminal thrombus in abdominal aortic aneurysms using high-resolution MRI. J Magn Reson Imaging 2019; 50:994-1001. [PMID: 30694008 DOI: 10.1002/jmri.26676] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Intraluminal thrombus (ILT) signal intensity on MRI has been studied as a potential marker of abdominal aortic aneurysm (AAA) progression. PURPOSE 1) To characterize the relationship between ILT signal intensity and AAA diameter; 2) to evaluate ILT change over time; and 3) to assess the relationship between ILT features and AAA growth. STUDY TYPE Prospective. SUBJECTS Eighty AAA patients were imaged, and a subset (n = 41) were followed with repeated MRI for 16 ± 9 months. FIELD STRENGTH/SEQUENCE 3D black-blood fast-spin-echo sequence at 3 T. ASSESSMENT ILT was designated as "bright" if the signal was greater than 1.2 times that of adjacent psoas muscle. AAAs were divided into three groups based on ILT: Type 1: bright ILT; Type 2: isointense ILT; Type 3: no ILT. During follow-up, an active ILT change was defined as new ILT formation or an increase in ILT signal intensity to bright; stable ILT was defined as no change in ILT type or ILT became isointense from bright previously. STATISTICAL TESTS Shapiro-Wilk test; Mann-Whitney U-test; Fisher's exact test; Kruskal-Wallis test; Spearman's r; intraclass correlation coefficient (ICC), Cohen's kappa. RESULTS AAAs with Type 1 ILT were larger than those with Types 2 and 3 ILT (5.1 ± 1.1 cm, 4.4 ± 0.9 cm, 4.2 ± 0.8 cm, P = 0.008). The growth rate of AAAs with Type 1 ILT was significantly greater than that of AAAs with Types 2 and 3 ILT (2.6 ± 2.5, 0.6 ± 1.3, 1.5 ± 0.6 mm/year, P = 0.01). During follow-up, AAAs with active ILT changes had a 3-fold increased growth rate compared with AAAs with stable ILT (3.6 ± 3.0 mm/year vs. 1.2 ± 1.5 mm/year, P = 0.008). DATA CONCLUSION AAAs with bright ILT are larger in diameter and grow faster. Active ILT change is associated with faster AAA growth. Black-blood MRI can characterize ILT features and monitor their change over time, which may provide new insights into AAA risk assessment. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2019;50:994-1001.
Collapse
Affiliation(s)
- Chengcheng Zhu
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Joseph R Leach
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Bing Tian
- Department of Radiology, Changhai Hospital, Shanghai, China
| | - Lizhen Cao
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Zhaoying Wen
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA.,Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Disease, Beijing, China
| | - Yan Wang
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Xinke Liu
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA.,Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Qi Liu
- Department of Radiology, Changhai Hospital, Shanghai, China
| | - Jianping Lu
- Department of Radiology, Changhai Hospital, Shanghai, China
| | - David Saloner
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Michael D Hope
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| |
Collapse
|
12
|
Rayz VL, Abla A, Boussel L, Leach JR, Acevedo-Bolton G, Saloner D, Lawton MT. Computational modeling of flow-altering surgeries in basilar aneurysms. Ann Biomed Eng 2014; 43:1210-22. [PMID: 25348846 DOI: 10.1007/s10439-014-1170-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 10/16/2014] [Indexed: 11/29/2022]
Abstract
In cases where surgeons consider different interventional options for flow alterations in the setting of pathological basilar artery hemodynamics, a virtual model demonstrating the flow fields resulting from each of these options can assist in making clinical decisions. In this study, image-based computational fluid dynamics (CFD) models were used to simulate the flow in four basilar artery aneurysms in order to evaluate postoperative hemodynamics that would result from flow-altering interventions. Patient-specific geometries were constructed using MR angiography and velocimetry data. CFD simulations carried out for the preoperative flow conditions were compared to in vivo phase-contrast MRI measurements (4D Flow MRI) acquired prior to the interventions. The models were then modified according to the procedures considered for each patient. Numerical simulations of the flow and virtual contrast transport were carried out in each case in order to assess postoperative flow fields and estimate the likelihood of intra-aneurysmal thrombus deposition following the procedures. Postoperative imaging data, when available, were used to validate computational predictions. In two cases, where the aneurysms involved vital pontine perforator arteries branching from the basilar artery, idealized geometries of these vessels were incorporated into the CFD models. The effect of interventions on the flow through the perforators was evaluated by simulating the transport of contrast in these vessels. The computational results were in close agreement with the MR imaging data. In some cases, CFD simulations could help determine which of the surgical options was likely to reduce the flow into the aneurysm while preserving the flow through the basilar trunk. The study demonstrated that image-based computational modeling can provide guidance to clinicians by indicating possible outcome complications and indicating expected success potential for ameliorating pathological aneurysmal flow, prior to a procedure.
Collapse
Affiliation(s)
- V L Rayz
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA,
| | | | | | | | | | | | | |
Collapse
|
13
|
Rayz VL, Boussel L, Ge L, Leach JR, Martin AJ, Lawton MT, McCulloch C, Saloner D. Flow residence time and regions of intraluminal thrombus deposition in intracranial aneurysms. Ann Biomed Eng 2010; 38:3058-69. [PMID: 20499185 PMCID: PMC2940011 DOI: 10.1007/s10439-010-0065-8] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 05/05/2010] [Indexed: 10/31/2022]
Abstract
Thrombus formation in intracranial aneurysms, while sometimes stabilizing lesion growth, can present additional risk of thrombo-embolism. The role of hemodynamics in the progression of aneurysmal disease can be elucidated by patient-specific computational modeling. In our previous work, patient-specific computational fluid dynamics (CFD) models were constructed from MRI data for three patients who had fusiform basilar aneurysms that were thrombus-free and then proceeded to develop intraluminal thrombus. In this study, we investigated the effect of increased flow residence time (RT) by modeling passive scalar advection in the same aneurysmal geometries. Non-Newtonian pulsatile flow simulations were carried out in base-line geometries and a new postprocessing technique, referred to as "virtual ink" and based on the passive scalar distribution maps, was used to visualize the flow and estimate the flow RT. The virtual ink technique clearly depicted regions of flow separation. The flow RT at different locations adjacent to aneurysmal walls was calculated as the time the virtual ink scalar remained above a threshold value. The RT values obtained in different areas were then correlated with the location of intra-aneurysmal thrombus observed at a follow-up MR study. For each patient, the wall shear stress (WSS) distribution was also obtained from CFD simulations and correlated with thrombus location. The correlation analysis determined a significant relationship between regions where CFD predicted either an increased RT or low WSS and the regions where thrombus deposition was observed to occur in vivo. A model including both low WSS and increased RT predicted thrombus-prone regions significantly better than the models with RT or WSS alone.
Collapse
Affiliation(s)
- V L Rayz
- Department of Radiology, University of California San Francisco, 4150 Clement Street, San Francisco, CA 94121, USA.
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Leach JR, Rayz VL, Soares B, Wintermark M, Mofrad MRK, Saloner D. Carotid atheroma rupture observed in vivo and FSI-predicted stress distribution based on pre-rupture imaging. Ann Biomed Eng 2010; 38:2748-65. [PMID: 20232151 PMCID: PMC2900591 DOI: 10.1007/s10439-010-0004-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 03/04/2010] [Indexed: 11/13/2022]
Abstract
Atherosclerosis at the carotid bifurcation is a major risk factor for stroke. As mechanical forces may impact lesion stability, finite element studies have been conducted on models of diseased vessels to elucidate the effects of lesion characteristics on the stresses within plaque materials. It is hoped that patient-specific biomechanical analyses may serve clinically to assess the rupture potential for any particular lesion, allowing better stratification of patients into the most appropriate treatments. Due to a sparsity of in vivo plaque rupture data, the relationship between various mechanical descriptors such as stresses or strains and rupture vulnerability is incompletely known, and the patient-specific utility of biomechanical analyses is unclear. In this article, we present a comparison between carotid atheroma rupture observed in vivo and the plaque stress distribution from fluid–structure interaction analysis based on pre-rupture medical imaging. The effects of image resolution are explored and the calculated stress fields are shown to vary by as much as 50% with sub-pixel geometric uncertainty. Within these bounds, we find a region of pronounced elevation in stress within the fibrous plaque layer of the lesion with a location and extent corresponding to that of the observed site of plaque rupture.
Collapse
Affiliation(s)
- Joseph R Leach
- UC Berkeley/UC San Francisco Joint Graduate Group in Bioengineering, Berkeley, CA, USA.
| | | | | | | | | | | |
Collapse
|
15
|
Haglund RV, Robards VL, Leach JR, Miller JS, Forrest JB. Nephrostolithotomy. A new operation. J Okla State Med Assoc 1984; 77:315-7. [PMID: 6502292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
16
|
Abstract
Herein we review our 6-year experience with operative and non-operative treatment of bladder ruptures. Many ruptured bladders with extraperitoneal and intraperitoneal extravasation of urine can be treated without an operation and with less patient morbidity.
Collapse
|
17
|
Leach JR. Safety means savings. Hospitals 1972; 46:74-5. [PMID: 5055142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
18
|
Gigax JH, Leach JR. Uric acid calculi associated with ileostomy for ulcerative colitis. J Urol 1971; 105:777-9. [PMID: 5091707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
19
|
Johnson AJ, Leach JR. Pediatric diagnostic methods in adult urology. Mich Med 1966; 65:820-8. [PMID: 5916920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|