Thomas Brady

Publications of Thomas Brady

• Prognostic value of different cardiac MRI parameters for the diagnosis of myocarditis

  Authors: Waleed Ahmed, Daniel Verdini, Uthamalingam Shanmugam, Heidi Lumish, Peerawut Deeprasertkul, Yongkasem Vorasettakarnkij, Hector Medina, Ravi Shah, Thomas Brady, Udo Hoffmann, Gotdfred Holmvang, Brian Ghoshhajra, David Sosnovik

  Journal of Cardiovascular Magnetic Resonance. 01/2011;

• Prevalence of fat by cardiac magnetic resonance imaging stratified by age in 940 patients referred for evaluation of arrhythmogenic (rv) dysplasia

  Authors: Hector Medina-Zuluga, Daniel Verdini, Manavjot Sidhu, Peerawut Deeprasertkul, Yongkasem Vorasettakarnkij, Waleed Ahmed, Thomas Brady, Thomas Neilan, Stephan Danik, Suhny Abbara, David Sosnovik, Gotfred Holmvang, Brian Ghoshhajra

  Journal of Cardiovascular Magnetic Resonance. 01/2011;

• The utility of delayed-enhancement and t2-weighted cardiovascular mri for predicting clinical outcomes in patients at high risk for cardiac sarcoidosis

  Authors: Yongkasem Vorasettakarnkij, Hector Medina, Waleed Ahmed, Godtfred Holmvang, Peerawut Deeprasertkul, Daniel Verdini, Shanmugam Uthamalingam, Thomas Brady, Brian Ghoshhajra, David Sosnovik

  Journal of Cardiovascular Magnetic Resonance. 01/2011;

• Comparison of the accuracy of multidetector computed tomography versus two-dimensional echocardiography to measure left atrial volume.

  Authors: Erick Avelar, Ronen Durst, Guido A Rosito, Molly Thangaroopan, Simi Kumar, Francois Tournoux, Raymond C Chan, Judy Hung, Udo Hoffmann, Suhny Abbara, Thomas Brady, Ricardo C Cury

  The American journal of cardiology. 07/2010; 106(1):104-9.

  Left atrial (LA) volume is an important prognostic factor in cardiovascular disease. Multidetector computed tomography (MDCT) is an emerging cardiac imaging modality; however, its accuracy inLeft atrial (LA) volume is an important prognostic factor in cardiovascular disease. Multidetector computed tomography (MDCT) is an emerging cardiac imaging modality; however, its accuracy in measuring the LA volume has not been well studied. The aim of our study was to determine the accuracy of MDCT in quantifying the LA volume. A total of 48 patients underwent MDCT and 2-dimensional (2D) echocardiography (2DE) on the same day. The area-length and Simpson's methods were used to obtain the 2D echocardiographic LA volume. The LA volume assessment by MDCT was obtained using the modified Simpson's method. Four artificial phantoms were created, and their true volume was assessed by an independent observer using both imaging modalities. The correlation between the LA volume by MDCT and 2DE was significant (r = 0.68). The mean 2D echocardiographic LA volume was lower than the LA volume obtained with MDCT (2DE 79 +/- 37 vs MDCT 103 +/- 32, p <0.05). In the phantom experiment, the volume obtained using MDCT and 2DE correlated significantly with the true volume (r = 0.97, p <0.05 vs r = 0.96, p <0.05, respectively). However, the mean 2D echocardiographic phantom volume was 16% lower than the true volume (2DE, Simpson's method 53 +/- 24 vs the true volume 61 +/- 24, p <0.05). The mean volume calculated using MDCT did not differ from the true volume (MDCT 60 +/- 21 vs true volume 61 +/- 24, p = NS). 2DE appeared to systematically underestimate the LA volume compared to phantom and cardiac MDCT, suggesting that different normal cutoff values should be used for each modality. In conclusion, LA volume quantification using MDCT is an accurate and feasible method.

• Direct comparison of rest and adenosine stress myocardial perfusion CT with rest and stress SPECT.

  Authors: David Okada, Brian Ghoshhajra, Ron Blankstein, Jose Rocha-Filho, Leonid Shturman, Ian Rogers, Hiram Bezerra, Ammar Sarwar, Henry Gewirtz, Udo Hoffmann, Wilfred Mamuya, Thomas Brady, Ricardo Cury

  Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology. 11/2009;

  INTRODUCTION: We have recently described a technique for assessing myocardial perfusion using adenosine-mediated stress imaging (CTP) with dual source computed tomography. SPECT myocardial perfusionINTRODUCTION: We have recently described a technique for assessing myocardial perfusion using adenosine-mediated stress imaging (CTP) with dual source computed tomography. SPECT myocardial perfusion imaging (SPECT-MPI) is a widely utilized and extensively validated method for assessing myocardial perfusion. The aim of this study was to determine the level of agreement between CTP and SPECT-MPI at rest and under stress on a per-segment, per-vessel, and per-patient basis. METHODS: Forty-seven consecutive patients underwent CTP and SPECT-MPI. Perfusion images were interpreted using the 17 segment AHA model and were scored on a 0 (normal) to 3 (abnormal) scale. Summed rest and stress scores were calculated for each vascular territory and patient by adding corresponding segmental scores. RESULTS: On a per-segment basis (n = 799), CTP and SPECT-MPI demonstrated excellent correlation: Goodman-Kruskall gamma = .59 (P < .0001) for stress and .75 (P < .0001) for rest. On a per-vessel basis (n = 141), CTP and SPECT-MPI summed scores demonstrated good correlation: Pearson r = .56 (P < .0001) for stress and .66 (P < .0001) for rest. On a per-patient basis (n = 47), CTP and SPECT-MPI demonstrated good correlation: Pearson r = .60 (P < .0001) for stress and .76 (P < .0001) for rest. CONCLUSIONS: CTP compares favorably with SPECT-MPI for detection, extent, and severity of myocardial perfusion defects at rest and stress.

• Relation of left ventricular mass and concentric remodeling to extent of coronary artery disease by computed tomography in patients without left ventricular hypertrophy: ROMICAT study.

  Authors: Quynh Truong, Michael Toepker, Amir Mahabadi, Fabian Bamberg, Ian Rogers, Ron Blankstein, Thomas Brady, John Nagurney, Udo Hoffmann

  Journal of hypertension. 08/2009;

  OBJECTIVE: Cardiac computed tomography allows for simultaneous assessment of left ventricular mass (LVM) and coronary artery disease (CAD). We aimed to determine whether LVM, LVM index (LVMi), andOBJECTIVE: Cardiac computed tomography allows for simultaneous assessment of left ventricular mass (LVM) and coronary artery disease (CAD). We aimed to determine whether LVM, LVM index (LVMi), and the left ventricular geometric pattern of concentric remodeling are associated with the extent of CAD in patients without left ventricular hypertrophy. METHODS: In 348 patients from the Rule Out Myocardial Infarction Using Computer Assisted Tomography trial, 64-slice computed tomography was performed and LVM measured at end-diastole. We used three LVM indexation criteria to obtain three cohorts: LVM indexed to body surface area by echocardiography (n = 337) and computed tomography criteria (n = 325), and by height (n = 326). The cohorts were subdivided into concentric remodeling and normal geometry. Extent of coronary plaque was classified based on a 17-segment model, treated as a continuous variable, and stratified into three groups: zero segment, one to four segments, and more than four segments. RESULTS: Patients with more than four segments of coronary plaque had higher LVM (Delta12.8-15.1 g) and LVMi (Delta4.0-5.5 g/m and Delta2.2 g/m) than those without CAD (all P </= 0.03). After multivariable adjustment, LVM and LVMi remained independent predictors of extent of coronary plaque, with 0.27-0.29 segments more plaque per 20 g increase of LVM (all P = 0.02), 0.32-0.34 segments more plaque per 10 g/m increase of LVMi (both P = 0.02), and 0.80 segments more plaque per 10 g/m increase of LVMi (P = 0.008). Concentric remodeling patients had 1.1-1.3 segments more plaque than those with normal geometry (all P </= 0.05). Patients with more than four segments of plaque had two-fold increase in odds (all P </= 0.05) of having concentric remodeling as compared with those without CAD. CONCLUSION: Increased LVM, LVMi, and concentric remodeling are associated with a greater degree of coronary plaque burden in patients without left ventricular hypertrophy. These findings could provide an indication to intensify medical therapy in patients with subclinical CAD and hypertension.

• Cardiac myocardial perfusion imaging using dual source computed tomography.

  Authors: Ron Blankstein, David Okada, Jose Rocha-Filho, Frank Rybicki, Thomas Brady, Ricardo Cury

  The international journal of cardiovascular imaging. 03/2009;

  The ability to simultaneously visualize both coronary atherosclerosis and myocardial perfusion may enable the assessment of the anatomical burden and physiological significance of coronary lesions inThe ability to simultaneously visualize both coronary atherosclerosis and myocardial perfusion may enable the assessment of the anatomical burden and physiological significance of coronary lesions in a single exam. In this paper we introduce a novel use of the dual source CT: pharmacologically induced stress myocardial perfusion imaging, (SP-DSCT). We describe an experimental protocol by which we used the DSCT to assess both stress and rest myocardial perfusion in order to identify areas of infarcted and ischemic myocardium. Based on our initial investigations, this protocol is feasible and can be used to identify hemodynamically significant stenosis. Nevertheless, further studies are required to determine the incremental value of this technique to traditional coronary CT angiography and/or nuclear stress myocardial perfusion imaging.

• Contrast-enhanced cine cardiac MR detects impairment of coronary microvascular perfusion in patients after acute myocardial infarct

  Authors: Ricardo Loureiro, Hiram Bezerra, Joalbo Andrade, Chun-Ho Yun, Ammar Sarwar, Michael Bolen, Thomas Brady, Ricardo Cury

  Journal of Cardiovascular Magnetic Resonance. 01/2009;

• Assessment of the presence and extent of coronary collateralization by coronary computed tomographic angiography in patients with total occlusions.

  Authors: Johannes Rieber, Tej Sheth, Eline Mooyaart, Michael Shapiro, Javed Butler, Maros Ferencik, Thomas Brady, Volker Klauss, Udo Hoffmann

  The international journal of cardiovascular imaging. 12/2008;

  Coronary computed tomography angiography (CTA) may be helpful to manage patients with chronic coronary occlusions. The aim of this study was to determine the sensitivity and specificity of CTA toCoronary computed tomography angiography (CTA) may be helpful to manage patients with chronic coronary occlusions. The aim of this study was to determine the sensitivity and specificity of CTA to detect the presence and extent of coronary collaterals as compared to invasive coronary angiography (ICA). We retrospectively evaluated 26 patients who underwent both coronary CTA and ICA within 3 weeks and demonstrated a total coronary occlusion (TIMI grade 0) in one of the major coronary arteries. CTA was performed using a 64-slice multidetector CT. The presence, and extent of collateralization was assessed by two blinded observers using the Rentrop classification for ICA. CTA accurately identified the presence and location of all 26 total occlusions. The presence of any collaterals was accurately detected in 21/23 patients [sensitivity 91% (CI: 71-98%)] and the absence in three patients [specificity 100% (CI: 29%-100%)]. The sensitivity of coronary CTA to identify patients with collateralization increased from 91 to 94% (CI: 71-99%) and 100% (CI: 59-100%) for collaterals Rentrop grade 2 and 3 in ICA, respectively. Coronary CTA accurately detects the presence of any coronary collateralization in patients with total occlusions. Although CT technology is currently limited in the assessment of individual collaterals and smaller vessels, it may be helpful in the management of patients with total occlusions.

• Musculoskeletal applications of flat-panel volume CT.

  Authors: Benjamin Reichardt, Ammar Sarwar, Soenke Bartling, Arnold Cheung, Michael Grasruck, Christianne Leidecker, Miriam Bredella, Thomas Brady, Rajiv Gupta

  Skeletal radiology. 05/2008;

  Flat-panel volume computed tomography (fpVCT) is a recent development in imaging. We discuss some of the musculoskeletal applications of a high-resolution flat-panel CT scanner. FpVCT has four mainFlat-panel volume computed tomography (fpVCT) is a recent development in imaging. We discuss some of the musculoskeletal applications of a high-resolution flat-panel CT scanner. FpVCT has four main advantages over conventional multidetector computed tomography (MDCT): high-resolution imaging; volumetric coverage; dynamic imaging; omni-scanning. The overall effective dose of fpVCT is comparable to that of MDCT scanning. Although current fpVCT technology has higher spatial resolution, its contrast resolution is slightly lower than that of MDCT (5-10HU vs. 1-3HU respectively). We discuss the efficacy and potential utility of fpVCT in various applications related to musculoskeletal radiology and review some novel applications for pediatric bones, soft tissues, tumor perfusion, and imaging of tissue-engineered bone growth. We further discuss high-resolution CT and omni-scanning (combines fluoroscopic and tomographic imaging).

• Images in cardiovascular medicine. Left main coronary artery compression syndrome: evaluation with 64-slice cardiac multidetector computed tomography.

  Authors: Jonathan D Dodd, Andrew Maree, Igor Palacios, Michael M de Moor, Eline A Q Mooyaart, Michael D Shapiro, Maros Ferencik, Thomas Brady, Suhny Abbara, Ricardo C Cury, Udo Hoffmann

  Circulation. 02/2007; 115(1):e7-8.

• A cost-effectiveness analysis of a hypothetical catheter-based strategy for the detection and treatment of vulnerable coronary plaques with drug-eluting stents.

  Authors: Johanna L Bosch, Molly T Beinfeld, James E Muller, Thomas Brady, G Scott Gazelle

  Journal of interventional cardiology. 11/2005; 18(5):339-49.

  AIM: Extensive efforts are underway to develop methods for the detection and treatment of vulnerable/high-risk coronary artery plaques. We utilized decision analysis to evaluate the hypotheticalAIM: Extensive efforts are underway to develop methods for the detection and treatment of vulnerable/high-risk coronary artery plaques. We utilized decision analysis to evaluate the hypothetical clinical benefits and cost-effectiveness of a catheter-based strategy. METHODS AND RESULTS: Currently, stenotic coronary plaques are treated without regard to vulnerability. In a new strategy, vulnerable coronary plaques are detected with a catheter-based test and treated with a drug-eluting stent, regardless of degree of stenosis. A Markov-decision model was developed to compare the new strategy with current practice. Monte Carlo simulations were performed from a societal perspective, costs were converted to year 2003 U.S. dollars, and future costs and outcomes were discounted at 3%. Sensitivity analyses were performed to evaluate the effect of assumptions on variables such as the prevalence of vulnerable plaques and treatment effect. In 60-year-old male patients with coronary stenoses the new strategy would be less expensive and more effective than current practice (37,045 dollars vs 38,257 dollars and 10.23 vs 9.86 quality-adjusted life years (QALYs), respectively). The benefits of the new strategy were robust in sensitivity analyses (e.g., if the prevalence of vulnerable plaques in this patient group was 50% or more and the sensitivity and specificity of the new test were at least 0.80). CONCLUSION: In selected patients with coronary artery stenosis, the detection of vulnerable plaques with a catheter-based test followed by their treatment with a drug-eluting stent could be a less expensive and more effective strategy than current practice. If applied to 1 million such patients in the United States undergoing catheterization, the new strategy would add 370,000 QALYs and save 1.2 billion dollars per year.

• Experimental flat-panel high-spatial-resolution volume CT of the temporal bone.

  Authors: Rajiv Gupta, Soenke H Bartling, Samit K Basu, William R Ross, Hartmut Becker, Armin Pfoh, Thomas Brady, Hugh D Curtin

  AJNR. American journal of neuroradiology. 09/2004; 25(8):1417-24.

  BACKGROUND AND PURPOSE: A CT scanner employing a digital flat-panel detector is capable of very high spatial resolution as compared with a multi-section CT (MSCT) scanner. Our purpose was toBACKGROUND AND PURPOSE: A CT scanner employing a digital flat-panel detector is capable of very high spatial resolution as compared with a multi-section CT (MSCT) scanner. Our purpose was to determine how well a prototypical volume CT (VCT) scanner with a flat-panel detector system defines fine structures in temporal bone. METHODS: Four partially manipulated temporal-bone specimens were imaged by use of a prototypical cone-beam VCT scanner with a flat-panel detector system at an isometric resolution of 150 microm at the isocenter. These specimens were also depicted by state-of-the-art multisection CT (MSCT). Forty-two structures imaged by both scanners were qualitatively assessed and rated, and scores assigned to VCT findings were compared with those of MSCT. RESULTS: Qualitative assessment of anatomic structures, lesions, cochlear implants, and middle-ear hearing aids indicated that image quality was significantly better with VCT (P < .001). Structures near the spatial-resolution limit of MSCT (e.g., bony covering of the tympanic segment of the facial canal, the incudo-stapedial joint, the proximal vestibular aqueduct, the interscalar septum, and the modiolus) had higher contrast and less partial-volume effect with VCT. CONCLUSION: The flat-panel prototype provides better definition of fine osseous structures of temporal bone than that of currently available MSCT scanners. This study provides impetus for further research in increasing spatial resolution beyond that offered by the current state-of-the-art scanners.

• Evaluation of retrospective multisector and half scan ECG-gated multidetector cardiac CT protocols with moving phantoms.

  Authors: Stephan Wicky, Michael Rosol, Leena M Hamberg, Udo Hoffmann, Christian Enzweiler, Mike Graziano, Thomas Brady

  Journal of computer assisted tomography. 26(5):768-76.

  PURPOSE: We evaluated independently retrospective half scan and multisector mode manufacturer's protocols and compared them with modified acquisition protocols to determine optimal imaging parametersPURPOSE: We evaluated independently retrospective half scan and multisector mode manufacturer's protocols and compared them with modified acquisition protocols to determine optimal imaging parameters for cardiac scanning. MATERIALS AND METHODS: Data were acquired using two fabricated gated moving phantoms. In half scan mode, the manufacturer's recommended pitch values were compared with adjacent values at different motion rates. In multisector mode, the manufacturer's protocols were compared with ones with different gantry speeds and pitch values at the same motion rates. Weighted CT dose indexes (CTDI) were obtained for all protocols. Gated and reformatted reconstructed images of the moving phantoms were evaluated. RESULTS: In half scan mode, slightly better image quality was observed by lowering the pitch value, but with an increase of 6.3% of the weighted CTDI. Better results were obtained in multisector mode by lowering the pitch value up to 0.2, but with an increase of 14.3% of the weighted CTDI. Optimal images were obtained with the lowest temporal resolution. CONCLUSIONS: Gated moving phantom studies offer the advantage of testing acquisition protocols of complex motions and of helping to establish appropriate protocols.