Cardiac Computed Tomography Scans Research Articles

Cardiac CT Scan for Preoperative Planning in a Patient with Bilateral Subclavian Stenosis Needing Coronary Artery Bypass

A 61-year-old male vasculopath presented for coronary revascularization and was found to have high-grade bilateral subclavian artery stenosis. The adequacy of the left internal mammary artery for bypass to the left anterior descending artery was in question. Rather than assessing the left internal mammary artery intraoperatively, we performed a preoperative cardiac computed tomography (CT) angiogram. This showed that the free left internal mammary artery was a suitable conduit and the procedure was performed expeditiously. Therefore, cardiac CT angiography is a noninvasive tool for preoperative planning in coronary revascularization.

Unique Capability of Aquilion One 320 Slice Cardiac Computed Tomography Scanning to Emulate Conventional Angiography

Unique Capability of Aquilion One 320 Slice Cardiac Computed Tomography Scanning to Emulate Conventional Angiography

Incidental Pulmonary Nodules on Cardiac Computed Tomography: Prognosis and Use

Background Small asymptomatic lung nodules are found frequently in the course of cardiac computed tomography (CT) scanning. However, the utility of assessing and reporting incidental findings in healthy, asymptomatic subjects is unknown. Methods The sample comprised 1023 60- to 69-year-old subjects free of clinical cardiovascular disease and cancer who participated in the Atherosclerotic Disease, VAscular functioN and genetiC Epidemiology Study. All subjects underwent cardiac CT for determination of coronary calcium between 2001 and 2004, and the first 459 subjects were assessed for incidental pulmonary findings. We used health plan clinical databases to ascertain 24-month health care use and clinical outcomes. Results Noncalcified pulmonary nodules were reported in 81 of 459 subjects (18%). Chest CT was performed on 78% of participants in the 24 months after notification, compared with 2.5% in the previous 24 months. Chest x-ray use increased from 28% to 49%. The mean number of chest CT scans per subject was 1.3 (range, 0-5). Although no malignant lesions were diagnosed in the group who had pulmonary findings read, 1 lung cancer case was diagnosed in the group who did not have lung findings read. Among the 63 participants followed up by CT, the original lesion was not identified in 22 participants (35%), the lesion had decreased or remained stable in 39 participants (62%), and there was interval growth in 2 participants (3%). Conclusion Reporting noncalcified pulmonary nodules resulted in substantial rescanning that overwhelmingly revealed resolution or stability of pulmonary nodules, arguing for benign processes.

Association between non-subcutaneous adiposity and calcified coronary plaque: a substudy of the Multi-Ethnic Study of Atherosclerosis

BackgroundExcessive non-subcutaneous fat deposition may impair the functions of surrounding tissues and organs through the release of inflammatory cytokines and free fatty acids. ObjectiveWe examined the cross-sectional association between non-subcutaneous adiposity and calcified coronary plaque, a noninvasive measure of coronary artery disease burden. DesignParticipants in the Multi-Ethnic Study of Atherosclerosis underwent computed tomography (CT) assessment of calcified coronary plaque. We measured multiple fat depots in 398 white and black participants (47% men, 43% black), aged 47–86 y, from Forsyth County, NC, during 2002–2005, with the use of cardiac and abdominal CT scans. In addition to examining each depot separately, we also created a non-subcutaneous fat index with the standard scores of non-subcutaneous fat depots. ResultsA total of 219 participants (55%) were found to have calcified coronary plaque. After adjusting for demographics, lifestyle factors, and height, calcified coronary plaque was associated with a 1 SD increment in the non-subcutaneous fat index [odds ratio (OR): 1.41; 95% CI: 1.08, 1.84], pericardial fat (OR: 1.38; 95% CI: 1.04, 1.84), abdominal visceral fat (OR: 1.35; 95% CI: 1.03, 1.76) but not with fat content in the liver, intermuscular fat, or abdominal subcutaneous fat. The relation between non-subcutaneous fat index and calcified coronary plaque remained after further adjustment for abdominal subcutaneous fat (OR: 1.40; 95% CI: 1.00, 1.94). The relation did not differ by sex and ethnicity. ConclusionsThe overall burden of non-subcutaneous fat deposition, but not abdominal subcutaneous fat, may be a correlate of coronary atherosclerosis.

Electron beam computed tomography: Challenges and opportunities

In computed tomography (CT), a cross-sectional view is developed by measuring and analyzing the x-ray attenuation of a thin x-ray fan that rotates around the subject. There are two ways to make the x-ray fan. One is to physically rotate an x-ray tube around the subject. The other way is to scan an electron beam around a fixed tungsten anode ring that surrounds the subject. The medical application we address is to non-invasively determine risk of coronary disease in subjects who are symptom-free. Subjects lie still, holding their breath and drugs to lower heart rate are administered in order to reduce image blur. The advantage of electron beam CT imaging is speed. In addition to higher cost, the disadvantage is low x-ray source brightness so scan speed is limited by signal strength. We explore the possible improvement of using electrostatic rather than magnetic beam deflection incorporating a new method that provides little or no deflection aberrations even at large deflection angles. Since shielding electrical fields is very efficient, it is possible to operate a multitude of electron guns in close proximity each scanning a short segment of the anode ring. By modulating each gun at a signature frequency, all guns could operate simultaneously and x-ray signals can be separated by the modulation frequency. This idea should allow increasing x-ray scan speed by at least 10-fold. This would allow a cardiac CT scan to be made on a subject at elevated heartbeat while on a treadmill – a condition well known to accentuate heart malfunctions.

Preoperative Visualization of a Muscular Ventricular Septal Defect by 64-Slice Cardiac Computed Tomography

A 21-year-old man presented to a primary care physician for a general evaluation. He had a past medical history of a “heart murmur” present since childhood. His only complaint was mild increased fatigability with exertion; he had no dyspnea at rest. Physical examination was remarkable for a 2/6 systolic ejection murmur heard throughout the precordium. A transthoracic echocardiogram showed a muscular ventricular septal defect (VSD) with a mildly dilated right ventricle and an elevated right ventricular systolic pressure of 80 mm Hg. The patient was evaluated for an elective repair of the VSD. Preoperative assessment included a cardiac computed tomography (CT) angiogram (Lightspeed VCT, GE Healthcare) to rule out coronary disease. The CT scan clearly demonstrated the muscular VSD (Figure) and showed normal coronary arteries.

A heart within the heart: double-chambered left ventricle

We describe a rare congenital anomaly in a 49-year-old woman who presented with palpitations and slightly reduced exercise capacity. A double-chambered left ventricle was suspected on echocardiography and confirmed by cardiac computed tomography scanning, cardiac magnet resonance imaging, and invasive angiography.

Left Ventricular Diverticulosis

Cardiac computed tomography scanning is rapidly emerging as the noninvasive modality of choice for assessment of coronary artery disease. Secondary to the exquisite resolution of the modality, left ventricular diverticula can be well demonstrated. Left ventricular diverticula are rare, and in the past, the terms diverticula and aneurysm have been used interchangeably. The differentiation of diverticula and aneurysm is crucial for appropriate management. To the best of our knowledge, this is the first report of left ventricular diverticula seen on cardiac computed tomography examination.

The Cleveland Clinic PediPump: Virtual Fitting Studies in Children Using Three-Dimensional Reconstructions of Cardiac Computed Tomography Scans

The fitting of implantable ventricular assist devices (VADs) is a particular challenge for pediatric patients and patients with small body surface area. The purpose of this study was to determine optimal placement of the PediPump, a pediatric VAD currently under development at the Cleveland Clinic, using virtual three-dimensional (3D) on-screen models. Digital models were created from computed tomographic datasets of pediatric hearts using commercially available 3D image processing software. Pixels representing the myocardium, great vessels, sternum, and rib cage were selected and rendered as on-screen models (n = 13) from pediatric patients with or without congenital heart disease (median age 42 months; range 2 days to 13 years 11 months). Using 3D model manipulation software, virtual models of the PediPump (70 x 10 mm) were combined on-screen with the anatomic models. A variety of virtual fitting options were created, which allowed easy detection of device interference with surrounding tissues. Generation of 3D on-screen models of cardiac structures in relation to PediPump placement has provided useful preliminary fitting information, which is being used to guide further development of this device.

Analysis of Heart Rate and Heart Rate Variation During Cardiac CT Examinations

We sought to examine heart rate and heart rate variability during cardiac computed tomography (CT). Ninety patients (59.0 +/- 13.5 years) underwent coronary CT angiography (CTA), with 52 patients also undergoing coronary artery calcium scanning (CAC). Forty-two patients with heart rate greater than 70 bpm were pretreated with oral beta-blockers (in five patients, use of beta-blocker was not known). Sixty-four patients were given sublingual nitroglycerin. Mean heart rate and percentage of beats outside a +/-5 bpm region about the mean were compared between baseline (free breathing), prescan hyperventilation, and scan acquisition (breath-hold). Mean scan acquisition time was 13.1 +/- 1.5 seconds for CAC scanning and 14.2 +/- 2.9 seconds for coronary CTA. Mean heart rate during scan acquisition was significantly lower than at baseline (CAC 58.2 +/- 8.5 bpm; CTA 59.2 +/- 8.8 bpm; baseline 62.8 +/- 8.9 bpm; P < .001). The percentage of beats outside a +/-5 bpm about the mean were not different between baseline and CTA scanning (3.5% versus 3.3%, P = .87). The injection of contrast had no significant effect on heart rate (58.2 bpm versus 59.2 bpm, P = .24) or percentage of beats outside a +/-5 bpm about the mean (3.0% versus 3.3%, P = .64). No significant difference was found between gender and age groups (P > .05). Breath-holding during cardiac CT scan acquisition significantly lowers the mean heart rate by approximately 4 bpm, but heart rate variability is the same or less compared with normal breathing.

New Frontiers in the Evaluation of Cardiac Patients for Noncardiac Surgery

New Frontiers in the Evaluation of Cardiac Patients for Noncardiac Surgery

Instructions for Obtaining Journal CME Credit

Anesthesiology's journal-based CME program is open to all readers. Members of the American Society of Anesthesiologists participate at a preferred rate, but you need not be an ASA member or a journal subscriber to take part in this CME activity. Please complete the following steps:The American Society of Anesthesiologists is approved by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing medical education programs for physicians.The American Society of Anesthesiologists designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit ™. Physicians should only claim credit commensurate with the extent of their participation in the activity.Purpose: The focus of the journal-based CME program, and the articles chosen for the program, is to educate readers on current developments in the science and clinical practice of the specialty of Anesthesiology.Target Audience: Physicians and other medical professionals whose medical specialty is the practice of anesthesia.Learning Objectives: After reading this article, participants should have a better understanding of emerging approaches to evaluating patients and determining their risk for cardiac complications after surgery.Authors – Ronit Lavi, M.D., Shahar Lavi, M.D., Elena Daghini, M.D., and Lilach O. Lerman, M.D., Ph.D. Grants or research support: Supported in part by grant Nos. HL77131 and DK73608 from the National Institutes of Health, Bethesda, Maryland. Consultantships or honoraria: NoneQuestion Writers – Peter L. Bailey, M.D., and Leslie C. Jameson, M.D. Drs. Bailey and Jameson have no grants, research support, or consultant positions, nor do they receive any honoraria from outside sources, which may create conflicts of interest concerning this CME program.Based on the article by Lavi et al. entitled “New frontiers in the evaluation of cardiac patients for noncardiac surgery” in the December issue of Anesthesiology, choose the one correct answer for each question: http://content.wkhealth.com/linkback/openurl?issn=0003–3022&amp;volume=107&amp;issue=6&amp;spage=1018∂=fulltext1. Which of the following statements concerning perioperative cardiac risk is most likely true?A. The lower limit of functional capacity consistent with an adequate cardiac reserve is 7 metabolic equivalents.B. Congestive heart failure does not predict increased perioperative cardiac complications.C. Type of surgical procedure does not influence cardiac risk.D. The outcomes used to quantify cardiac risk are cardiac death and nonfatal myocardial infarction.2. Which of the following statements concerning the evaluation of coronary arteries by computed tomography is most likely true?A. Its negative predictive value is too low for clinical use.B. Respiratory movement does not reduce image quality.C. Coronary stents can result in imaging artifacts.D. It cannot be used to detect coronary artery graft problems after bypass surgery.3. Which of the following statements concerning echocardiography and the evaluation of patients for cardiac conditions is most likely true?A. It is not recommended for the preoperative evaluation of suspected aortic stenosis.B. The specificity of dobutamine stress echocardiography is excellent (&gt; 95%).C. Quality of dobutamine stress echocardiography is operator dependent to a significant degree.D. Its cost relative to other cardiac tests is high.4. Which of the following statements concerning myocardial nuclear studies and the evaluation of patients with suspected cardiac conditions is most likely true?A. Testing with myocardial single-photon emission computed tomography with thallium dipyridamole is the best predictor of postoperative adverse cardiac events.B. Positron emission tomography with F-18 fluorodeoxyglucose can predict functional recovery of viable myocardium.C. Positron emission tomography scanning is very cost effective.D. Single-photon emission computed tomography technetium-99m imaging is not a useful preoperative assessment tool.5. Which of the following statements about cardiac computed tomography scanning is most likely true?A. It is associated with less risk than coronary angiography.B. It has been demonstrated to be a cost-effective strategy in reducing perioperative risk.C. It is not useful for assessing left ventricular function.D. It is not useful for assessing coronary plaques.

Relation of Retinopathy to Coronary Artery Calcification: The Multi-Ethnic Study of Atherosclerosis

Microvascular disease, reflected by retinal vascular changes, has been shown to predict clinical coronary heart disease. Whether retinal vascular changes are associated with subclinical coronary artery disease is unclear and was examined in this study. The authors conducted a multiethnic, population-based study of 6,147 persons aged 45-84 years, sampled from six US communities in 2002-2004, who were free of clinical cardiovascular disease. Coronary artery calcification (CAC), a noninvasive measure of subclinical coronary artery disease, was assessed by cardiac computed tomography scanning and categorized into three groups of increasing severity: none (average CAC score = 0), mild (1-100), and moderate-to-severe (>100). Retinopathy signs and retinal vascular caliber were graded from retinal photographs following standardized protocols. After adjustment for age, gender, race/ethnicity, blood pressure, diabetes, lipid profile, smoking, and other risk factors, retinopathy was associated with having a moderate-to-severe CAC score (odds ratio = 1.43, 95% confidence interval: 1.18, 1.75). This association remained significant in both men and women and in persons with and without diabetes or hypertension. Variations in retinal vascular caliber were not significantly associated with CAC score. This study shows that retinopathy signs are independently associated with CAC, supporting the concept that common pathophysiologic processes may underlie both micro- and macrovascular disease.

Technologic Advances in Multidetector CT with a Focus on Cardiac Imaging

Cardiac computed tomography (CT) is emerging as an important tool for the diagnosis and monitoring of heart disease. The prevalence of heart disease in the United States is already quite high and is expected to increase as the "baby boomer" segment of the population ages. To use complex multiple-row detector CT scanners most efficiently for cardiac examinations, it is important to understand many of the technical components. New developments in CT technology provide the ability to examine the structure of the heart with a level of detail that was not previously possible. In general, detector configurations have improved, the number of channels has increased, and rotation speed has increased, resulting in better quality of cardiac images. However, radiation dose for cardiac CT is fairly high and demands constant vigilance. Several steps can be taken to reduce the dose, including lowering the tube current as the x-ray beam crosses over certain areas of the body, decreasing the tube current during certain phases of the cardiac cycle, and using a higher pitch. Cardiac CT examination dose (for a coronary artery study) is approximately equivalent to that of an abdominal-pelvic CT examination or a dual-phase chest CT examination.

Left Pulmonary Artery Sling Complex: Computed Tomography and Hypothesis of Embryogenesis

We retrospectively reviewed cases of left pulmonary artery (LPA) sling complex with computed tomography to explore its possible meaning in embryogenesis. Eighteen children (6 girls and 12 boys aged 5 days to 17.5 years; mean, 1.5 years) were identified as having LPA sling during the period of October 1996 to March 2006. Another 2,364 cardiac computed tomography scans that had no LPA sling were included as control. The associated bronchopulmonary and vascular anomalies were identified. Chi-square tests were used to compare the probabilities of coexistence of these anomalies, with or without LPA sling. All patients with LPA sling presented with tracheal stenosis (100%), and there was a high incidence of combined right tracheal bronchus (22%), underdeveloped right lung (22%), persistent left superior vena cava (22%), and left patent ductus arteriosus (39%). These associated anomalies were more highly associated with subjects who had LPA sling than with those who did not (p < 0.01). Owing to the spatial coexistence of LPA sling with the associated anomalies in the embryonic foregut mesoderm, we propose that a "space available" hypothesis in the local environment appears to be important in the embryogenesis of an LPA sling complex.

Abstract 999: Gated Micro Computed Tomography Scanning: An Emerging Tool for Longitudinal Assessment of Murine Cardiac Remodeling.

Background: Recent advances in high energy X-ray source computed tomography (CT) technology have made it possible to accurately image murine cardiac structure and function. We describe the use of a gated Micro CT system to assess cardiac remodeling in a murine model of myocardial infarction (MI). Methods: Adult FVB mice (n = 10) were randomized to surgically induced MI by left coronary artery ligation or sham procedure. Dual gated cardiac and respiratory Micro CT scans were performed pre-operatively and at weeks 4, 8 and 12 post-procedure. End-diastolic and end-systolic images were acquired by gating on the ECG P-and S’-waves, respectively. Post-acquisition analysis was performed using image analysis software and the following parameters were quantified: left ventricular (LV) volume and mass, right ventricular volume and mass, right and left atrial volumes, and ventricular ejection fraction (EF). Results: Images were successfully acquired with a resolution of 100 microns allowing for identification and quantification of key cardiac structures (Fig 1A ). Following MI, animals exhibited left ventricular failure with significantly increased* end systolic and diastolic volumes by week 4. Ventricular dilation continued through week 8, plateauing by week 12. Left ventricular mass increased steadily over 12 weeks*, with a significantly decreased* LVEF of 28.0 ± .05% by week 12 (pre-MI: 66.7 ± .06%,*p &lt; 0.01). Post-MI left ventricular change is detailed in Fig 1B . Conclusions: MicroCT scanning can be successfully used to characterize murine myocardial structure and function, making it a useful tool to assess cardiac phenotypes and models of cardiovascular disease.

Esophagus imaging for radiofrequency ablation of atrial fibrillation using a dual-source computed tomography system: Preliminary observations

The very recent introduction of dual-source computed tomography (DSCT) has significantly improved the temporal resolution of ECG-gated multidetector-row cardiac computed tomography (CT). The aim of the present study was to evaluate whether with a DSCT visualization of the esophagus is feasible without any use of contrast in the esophagus. A total of 20 patients were evaluated. Ten patients underwent examination with a DSCT scanner without a gastric tube. In another ten patients, which served as control group, a CT scan was performed with a radio-opaque gastric tube prior to circumferential pulmonary vein isolation (in seven patients with a 16-slice CT and in three patients with a DSCT). In the control group the gastric tube and the left atrium were reconstructed and were well visualized in all ten patients in the electro-anatomic mapping system, independently whether 16-row CT or DSCT scan was used. In the study group integration of the esophagus into the electro-anatomic mapping system was not feasible, due to the lacking contrast counterpart the surrounding tissue. Even with the newest generation of DSCT scanner it is not possible to integrate the esophagus image into the 3-D electroanatomic mapping system without contrast by whatever means. However placing a conventional gastric tube before performing the CT scan allowed visualization and integration of the esophagus into the 3-D electro-anatomical map in all patients.

Papillary fibroelastoma of the pulmonary valve

A papillary fibroelastoma is rare, but it is the most common primary tumor of the cardiac valves. Most papillary fibroelastomas affect the left-sided heart valves, such as the aortic and mitral valves; however, they also rarely affect the pulmonary valve. Generally, surgical removal is strongly recommended to prevent its potential thromboembolic risks, especially in cases of left-sided cardiac involvement. However, there are few reports on the treatment of asymptomatic, small, right-sided cardiac fibroelastomas. We present a rare case of an asymptomatic papillary fibroelastoma occurring on the pulmonary valve, which was detected by transthoracic echocardiography, transesophageal echocardiography, and a 64-slice cardiac computed tomography scan, and which was surgically removed.

Unusual systemic venous return with absence of superior caval veins

Unusual systemic venous return with absence of superior caval veins

Assessment of Coronary Artery Disease by Cardiac Computed Tomography

This scientific statement reviews the scientific data for cardiac computed tomography (CT) related to imaging of coronary artery disease (CAD) and atherosclerosis. Cardiac CT is a CT imaging technique that accounts for cardiac motion, typically through the use of ECG gating. The utility and limitations of generations of cardiac CT systems are reviewed in this statement with emphasis on CT measurement of CAD and coronary artery calcified plaque (CACP) and noncalcified plaque. Successive generations of CT technology have been applied to cardiac imaging beginning in the early 1980s with conventional CT, electron beam CT (EBCT) in 1987, and multidetector CT (MDCT) in 1999. Compared with other imaging modalities, cardiac CT has undergone an accelerated …