Shawn D. Teague

ACCF/ACR/AHA/ASE/ASNC/HRS/NASCI/RSNA/SAIP/SCAI/SCCT/SCMR 2008 Health Policy Statement on Structured Reporting in Cardiovascular Imaging

Joseph P. Drozda, Jr, MD, FACC, Chair Vincent J. Bufalino, MD, FACC Joseph G. Cacchione, MD, FACC Christopher P. Cannon, MD, FACC W. Don Creighton, MD Pamela S. Douglas, MD, MACC T. Bruce Ferguson, Jr, MD, FACC Raymond J. Gibbons, MD, FACC Harlan M. Krumholz, MD, FACC Frederick A. Masoudi

Fundamentals of multichannel CT

Multichannel computed tomography (MCCT) has created a technical revolution in CT scanning. Following the introduction of single-channel helical scanning in 1989, 4-channel systems were introduced in 1998 and 16-channel systems in 2002. The core of this new technique is the X-ray detector array design, which allows for multiple simultaneous registration of slice information during gantry rotation. This design allows for faster scanning and acquisition of thinner slice widths. The high-speed scanning also minimizes motion artifacts. The ability to scan with very thin slice thickness creates a scanned volume with isotropic voxels. This allows for two- and three-dimensional reconstructions with similar resolution as the source images. MCCT also allows for higher X-ray tube currents, which create better penetration of metallic orthopedic fixation devices. Musculoskeletal imaging benefits from MCCT because large anatomic areas may be covered with thin slices. When needed, high tube currents can be applied for scanning areas of interest in the presence of metal. Thin slice acquisition allows isotropic viewing, which we use routinely.

Rate of Progression of Transthyretin Amyloidosis

Hereditary transthyretin (TTR) amyloidosis is an adult-onset disease characterized mainly by peripheral neuropathy and cardiomyopathy. Although disease progression is usually 5 to 15 years from time of diagnosis to death, no specific measurements of disease progression have been identified. The present study was designed to identify objective parameters to measure progression of hereditary TTR amyloidosis and determine if these parameters would show significant change within 1 year. Nine patients with biopsy-proved TTR amyloidosis and evidence of cardiac involvement were studied at baseline, 6 months, and 12 months by cardiac magnetic resonance imaging (MRI), electrocardiogram, and echocardiogram. Neurologic impairment score and electromyogram were determined at baseline and 12 months. Left ventricular mass determined by MRI and echocardiogram showed significant change at 12-month examination (p = 0.005 and p = 0.0009, respectively). Electrocardiogram and neurologic impairment score did not show significant change at 12 months. Measurement of left ventricular mass by MRI and echocardiographic techniques showed significant change in hereditary TTR cardiac amyloidosis within 1 year. In conclusion, these methods provide a means to clinically monitor progression of hereditary TTR amyloidosis and determine efficacy of therapeutic interventions.

Structured Reporting: Coronary CT Angiography A White Paper from the American College of Radiology and the North American Society for Cardiovascular Imaging

With the growing use of electronic medical records, the trend of diagnostic imaging reporting is toward a more structured format. Advantages include improved quality and consistency of the reporting and ease of data mining. The essential elements of a structured report are provided and illustrated for coronary artery computed tomographic angiograms.

Imaging of the Coronary Sinus: Normal Anatomy and Congenital Abnormalities

Knowledge of the anatomy of the coronary sinus (CS) and cardiac venous drainage is important because of its relevance in electrophysiologic procedures and cardiac surgeries. Several procedures make use of the CS, such as left ventricular pacing, mapping and ablation of arrhythmias, retrograde cardioplegia, targeted drug delivery, and stem cell therapy. As a result, it is more important for physicians interpreting the results of computed tomographic (CT) examinations dedicated to the heart or including the heart to be able to identify normal variants and congenital anomalies and to understand their clinical importance. Abnormalities of the CS range from anatomic morphologic variations to hemodynamically significant anomalies such as an unroofed CS, anomalous pulmonary venous connection to the CS, and coronary artery-CS fistula. It can be important to identify some anatomic variations, even though they are clinically occult, to ensure appropriate preprocedural planning. Both CT and magnetic resonance imaging provide excellent noninvasive depiction of the anatomy and anomalies of the CS. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.324105220/-/DC1.

Reconstruction of myocardial tissue motion and strain fields from displacement-encoded MR imaging

A quantitative analysis of myocardial mechanics is fundamental to understanding cardiac function, diagnosis of heart disease, and assessment of therapeutic intervention. Displacement encoding with stimulated-echo (DENSE) magnetic resonance imaging (MRI) technique was developed to track the three-dimensional (3D) displacement vector of discrete material grid points in the myocardial tissue. Despite the wealth of information gained from DENSE images, the current software only provides two-dimensional in-plane deformation. The objective of this study is to introduce a postprocessing method to reconstruct and visualize continuous dynamic 3D displacement and strain fields in the ventricular wall from DENSE data. An anatomically accurate hexagonal finite-element model of the left ventricle (LV) is reconstructed by fitting a prolate spheroidal primitive to contour points of the epi- and endocardial surfaces. The continuous displacement field in the model is described mathematically based on the discrete DENSE vectors using a minimization method with smoothness regularization. Based on the displacement, heart motion and myocardial stretch (or strain) are analyzed. Illustratory computations were conducted with DENSE data of three infarcted and one normal sheep ventricles. The full 3D results show stronger overall axial shortening, wall thickening, and twisting of the normal LV compared with the infarcted hearts. Local myocardial stretches show a dyskinetic LV in the apical region, dilation of apex in systole, and a compensatory increase in strain in the healthy basal region as a compensatory mechanism. We conclude that the proposed postprocessing method significantly extends the utility of DENSE MRI, which may provide a patient-specific 3D model of cardiac mechanics.

Training, competency, and certification in cardiac CT: A summary statement from the Society of Cardiovascular Computed Tomography

Training and competency criteria in cardiac CT were developed to guide practitioners in the process of achieving and maintaining skills in performing and interpreting cardiac CT studies. Appropriate training and eventual certification in cardiac CT angiography may be obtained by adhering to the recommendations for competency as set forth by either the American College of Cardiology Foundation (ACCF) or the American College of Radiology (ACR). Competency under either pathway requires both knowledge and experience-based components, with benchmarks set for level of experience on the basis of the extent of training experience. Although these recommended parameters are substantial, meeting these training criteria does not guarantee competence or expertise, which is the responsibility of the individual practitioner and may require further training and experience. Separate from satisfying initial training for the achievement of competency, certification in cardiac CT may be achieved through formal certification under the Certification Board of Cardiovascular Computed Tomography. Eligibility for certification generally follows the ACCF/American Heart Association Level 2 or ACR competency pathways. The ACR also conducts a certificate program related to advanced proficiency in cardiac CT. This official document of the Society of Cardiovascular Computed Tomography summarizes the present criteria for competency and certification in the field of cardiac CT.

CT-based Diagnosis of Diffuse Coronary Artery Disease on the Basis of Scaling Power Laws

PURPOSE To provide proof of concept for a diagnostic method to assess diffuse coronary artery disease (CAD) on the basis of coronary computed tomography (CT) angiography. MATERIALS AND METHODS The study was approved by the Cleveland Clinic Institutional Review Board, and all subjects gave informed consent. Morphometric data from the epicardial coronary artery tree, determined with CT angiography in 120 subjects (89 patients with metabolic syndrome and 31 age- and sex-matched control subjects) were analyzed on the basis of the scaling power law. Results obtained in patients with metabolic syndrome and control subjects were compared statistically. RESULTS The mean lumen cross-sectional area (ie, lumen cross-sectional area averaged over each vessel of an epicardial coronary artery tree) and sum of intravascular volume in patients with metabolic syndrome (0.039 cm(2) ± 0.015 [standard deviation] and 2.71 cm(3) ± 1.75, respectively) were significantly less than those in control subjects (0.054 cm(2)± 0.015 and 3.29 cm(3)± 1.77, respectively; P < .05). The length-volume power law showed coefficients of 27.0 cm(-4/3) ± 9.0 (R(2) = 0.91 ± 0.08) for patients with metabolic syndrome and 19.9 cm(-4/3) ± 4.3 (R(2) = 0.92 ± 0.07) for control subjects (P < .05). The probability frequency shows that more than 65% of patients with metabolic syndrome had a coefficient of 23 or more for the length-volume scaling power law, whereas approximately 90% of the control subjects had a coefficient of less than 23. CONCLUSION The retrospective scaling analysis provides a quantitative rationale for diagnosis of diffuse CAD.

Low radiation dose ECG-gated chest CT angiography on a 256-slice multidetector CT scanner

Computed tomography angiography (CTA) of the thorax other than cardiac CTA, is utilized for a multitude of conditions and ranges in application from a diagnostic test, to presurgical planning and postsurgical follow-up. Helical CTA without electrocardiogram (ECG) gating has been routinely utilized for the evaluation of thoracic vasculature. However, its applicability can be limited in the evaluation of the thoracic aorta and pulmonary vasculature because of the artifacts resulting from cardiac motion. Traditional retrospective ECG-gated helical scans address this issue but at the price of a high radiation dose to the patient. In this paper we review CTA dose reduction strategies for non-coronary indications, examine field of view requirements, and discuss breath hold challenges for ECG-gated acquisitions. In addition, we present clinical examples performed using low-dose prospective gating technique for evaluation of the aorta acquired on a 256-slice multidetector computed tomography system.

ACCF/ACR/AHA/ASE/ASNC/HRS/NASCI/RSNA/SAIP/SCAI/SCCT/SCMR 2008 Health Policy Statement on Structured Reporting in Cardiovascular Imaging. Endorsed by the Society of Nuclear Medicine [added].

WRITING COMMITTEE MEMBERS Pamela S. Douglas, MD, MACC, FAHA, FASE, Chair; Robert C. Hendel, MD, FACC, FAHA, Co-Chair; Jennifer E. Cummings, MD, FACC*; John M. Dent, MD, FACC, FASE†; John McB. Hodgson, MD, FACC, FSCAI‡; Udo Hoffmann, MD, MPH§; Robert J. Horn III ; W. Gregory Hundley, MD, FACC, FAHA¶; Charles E. Kahn, Jr, MD, MS#; Gerard R. Martin, MD, FACC; Frederick A. Masoudi, MD, MSPH, FACC; Eric D. Peterson, MD, MPH, FACC, FAHA; Geoffrey L. Rosenthal, MD, PhD, FACC; Harry Solomon**; Arthur E. Stillman, MD, PhD, FAHA††; Shawn D. Teague, MD‡‡; James D. Thomas, MD, FACC, FAHA§§; Peter L. Tilkemeier, MD, MMM, FACC, FAHA, FASNC ; Wm. Guy Weigold, MD, FACC¶¶