Left ventricular hypertrophy demonstrated by four-dimensional myocardiography by helical computed tomography

Left ventricular outflow tract obstruction by a bioprosthetic mitral valve: diagnosis by cardiac computed tomography

Echocardiography has long been the mainstay of noninvasive cardiac diagnostic imaging; however, newer imaging modalities have proven useful in cases where echocardiography has been nondiagnostic. We present a case of a 42-year-old woman with hypertrophic obstructive cardiomyopathy, who despite septal myectomy and bioprosthetic mitral valve replacement, continued to have persistent symptoms of left ventricular outflow tract obstruction. Transthoracic echocardiographic evaluation did not demonstrate the etiology of the patient's symptoms. The cause of our patient's symptoms was clarified using cardiac computed tomography, which revealed a strut from the bioprosthetic mitral valve protruding into the left ventricular outflow tract. Although this clinical phenomenon has previously been described, we will discuss the role of cardiac imaging with computed tomography in this setting.

Image Fusion of Coronary Tree and Regional Cardiac Function Image Using Multislice Computed Tomography

BACKGROUND

Although trials of image fusion, such as positron emission computed tomography and multislice spiral computed tomography (MSCT), have already demonstrated clinical usefulness, fusion of the coronary artery image and functional image by MSCT alone has not been reported yet. Here, a new idea of data analysis is proposed in which both regional cardiac function and the responsible coronary arteries can be assessed by a fused image.

METHODS AND RESULTS

The study group comprised 5 patients with coronary artery disease. At the first procedure, 3 dimensional (D) volume rendering coronary artery (3D-CTA) was extracted. At the second procedure, the systolic regional wall thickening was calculated and the color 3D functional surface map of systolic wall thickening (3D-SWT) was generated. At the final procedure, 3D-SWT was superimposed on the left ventricular surface with 3D-CTA using a transparency. In all 5 patients, image fusion of the coronary tree and cardiac function was correctly generated. Image fusion can be displayed as clear 3D images, offering better orientation to help assess both the coronary artery and regional function.

CONCLUSIONS

Image fusion of coronary computed tomography angiography and the functional map by MSCT is potentially a new method of assessing both the coronary artery and cardiac function.

Assessment of coronary artery and cardiac function using multidetector CT

Multidetector CT is able to reconstruct artifact-less cardiac images due to improved temporal resolution. In this article, we review the potential benefits of the cardiac application of multidetector CT in the assessment of coronary artery and cardiac function, such as wall motion and systolic thickening. By applying retrospective ECG-gating, 10 phases throughout 1 cardiac cycle are extracted for functional analysis. Animated movies are generated by paging through these 2D and 3D images in cardiac phase order. Left ventricular end-diastolic volume, end-systolic volume, and ejection fraction can also be generated. Using the data acquired during a single breath hold, coronary artery and cardiac function can be assessed by multidetector CT.

Computed tomography assessment of myocardial perfusion, viability, and function

In addition to coronary artery assessment, contrast-enhanced multidetector spiral computed tomography (CE-MDCT) can provide valuable information about myocardial perfusion. Using CE-MDCT, myocardial perfusion defects are often observed in the early phase of the contrast bolus (early defect (ED)), with residual defects (RDs) and late enhancement (LE) observed in the late phase in myocardial infarction (MI). However, the clinical significance of EDs, RDs, and LE has not yet been fully described. This work reviews myocardial viability and function by CE-MDCT based on our prior data by including contrast-enhanced single-slice (detector) CT (CE-SSCT) and CE-MDCT. Recently, equivalent results were obtained, as seen in CE-SSCT with images by CE-MDCT. In this review, images that were acquired by MDCT will be presented. In this work, the following items will be the focus: myocardial enhancement patterns (EDs, LE, and RDs), early perfusion defects and their relationship to wall thickness (WT) and wall motion, early CT perfusion defects vs. Tl-201 single photon emission CT (SPECT), the protocol for performing dual-phase contrast CT, classification of enhancement patterns, enhancement patterns on dual-phase CE-MDCT vs. left ventricular functional recovery and WT, changes in enhancement patterns in conjunction with healing stage, enhancement patterns on dual-phase CE-MDCT vs. 201Tl/99mTc-pyrophosphate (dual-isotope SPECT), the clinical meaning of each enhancement pattern, pitfalls of enhancement patterns and other diseases, and study limitations and the future of MDCT.

Clinical usefulness of the cardiac multi-detector-row CT

Along with improvement of the temporal and special resolution, multi-detector-row CT has become able to generate artifact-less heart images. We discuss the potential benefits of the newly developed cardiac application, demonstrating informative cases.Two- and three-dimensional (2D and 3D) cardiac images were produced throughout one cardiac cycle. By paging 2D and 3D images in cardiac cycle order, animated movies were generated. Cardiac imaging with multi-detector-row CT, acquired during a single breath hold, provides information about: (1) clear morphology of heart chambers and myocardium, (2) wall motion and systolic thickening, (3) myocardial perfusion, (4) volume assessment, and (5) coronary anatomy and pathophysiology.