Comparison between qualitative and quantitative wall motion analyses using dipyridamole stress breath-hold cine magnetic resonance imaging in patients with severe coronary artery stenosis

CMR publications from China of the last more than 30 years

Cardiovascular magnetic resonance (CMR) is a non-invasive imaging technology, gradually playing an irreplaceable role in the diagnosis and treatment of cardiovascular diseases. This review demonstrates the progress and research highlights of Chinese CMR publications of the last more than 30 years. At initial stage (1988 to 1997), CMR was introduced to evaluate cardiac anatomy, blood flow and ventricular function roughly in China. In the development stage (1998-2007), CMR began to play an important role in the diagnosis of cardiovascular and pericardial disease with the emergence of new techniques, such as myocardial perfusion imaging and magnetic resonance angiography. Since 2008, the development of CMR in China has reached a prosperous period. Cardiovascular disease can be both qualitatively and quantitatively assessment by CMR "one-stop" multi-parameter imaging, including the morphology, function, myocardial perfusion, tissue characteristics, metabolism and even the microstructure of myocardial fibers, which provides comprehensive assessment of the severity, risk stratification and prognosis of cardiovascular disease. Although CMR in China developed very rapidly in recent years, China still needs to put more efforts in CMR research and make greater contributions to the development of CMR in the world.

Diagnostic performance of stress cardiac magnetic resonance imaging in the detection of coronary artery disease: a meta-analysis

OBJECTIVES

The purpose of our study was to conduct an evidence-based evaluation of stress cardiac magnetic resonance imaging (MRI) in the diagnosis of coronary artery disease (CAD).

BACKGROUND

Stress cardiac MRI has recently emerged as a noninvasive method in the detection of CAD, with 2 main techniques in use: 1) perfusion imaging; and 2) stress-induced wall motion abnormalities imaging.

METHODS

We examined studies from January 1990 to January 2007 using MEDLINE and EMBASE. A study was included if it: 1) used stress MRI as a diagnostic test for CAD (> or =50% diameter stenosis); and 2) used catheter X-ray angiography as the reference standard.

RESULTS

Thirty-seven studies (2,191 patients) met the inclusion criteria, with 14 datasets (754 patients) using stress-induced wall motion abnormalities imaging and 24 datasets (1,516 patients) using perfusion imaging. Stress-induced wall motion abnormalities imaging demonstrated a sensitivity of 0.83 (95% confidence interval [CI] 0.79 to 0.88) and specificity of 0.86 (95% CI 0.81 to 0.91) on a patient level (disease prevalence = 70.5%). Perfusion imaging demonstrated a sensitivity of 0.91 (95% CI 0.88 to 0.94) and specificity of 0.81 (95% CI 0.77 to 0.85) on a patient level (disease prevalence = 57.4%).

CONCLUSIONS

In studies with high disease prevalence, stress cardiac MRI, using either technique, demonstrates overall good sensitivity and specificity for the diagnosis of CAD. However, limited data are available regarding use of either technique in populations with low disease prevalence.

Cardiac MRI in ischemic heart disease with severe coronary artery stenosis

RATIONALE AND OBJECTIVES

The aim was to evaluate the left ventricular wall motion abnormalities, perfusion and late contrast enhancement patterns on magnetic resonance imaging (MRI) in patients with 70% or higher degree stenosis or occlusion of coronary arteries on coronary angiography.

MATERIALS AND METHODS

Twenty-four patients (5 women, 19 men, age range 38-78, mean age 59.1) who had 70% or higher degree stenosis or occlusion of coronary arteries on coronary angiography who had been referred for cardiac MRI were included. On coronary angiography, 20 vessels were totally occluded [left anterior descending artery (LAD) 12; left circumflex coronary artery (LCx) 2; right coronary artery 6] and 20 vessels were severely stenotic (70-99%). In 5 patients' three vessels, in 6 patients' two vessels, and in 13 patients' a single vessel was involved. Wall motion, perfusion abnormalities, and late contrast enhancement consistent with nonviable myocardium were analyzed at apical, at midventricular, and basal levels on short-axis images of cardiac MRI in concordance with the segmental irrigation areas of the coronary arteries.

RESULTS

Impaired perfusion was observed on the corresponding irrigation segments of 39 vessels of 40 coronary artery branches. Wall motion abnormalities were present on corresponding irrigation areas of 30 severely stenotic vessels. Combined evaluation of wall motion and perfusion, segments with the decreased left ventricular contraction, and perfusion matched with the corresponding irrigation areas of all of the 40 stenotic or occluded vessels.

CONCLUSION

A correlation was found between the combined assessments of myocardial perfusion, wall motion, and viability on late contrast enhancement on cardiac MRI with the clinical and angiography findings. Thus this combined MRI protocol can be used for the evaluation of ischemic heart disease.

An observer study methodology for evaluating detection of motion abnormalities in gated myocardial perfusion SPECT

To address the task of detecting nonischemic motion abnormalities from animated displays of gated myocardial perfusion single photon emission computed tomography data, we performed an observer study to evaluate the difference in detection performance between gating to 8 and 16 frames. Images were created from the NCAT mathematical phantom with a realistic heart simulating hypokinetic motion in the left lateral wall. Realistic noise-free projection data were simulated for both normal and defective hearts to obtain 16 frames for the cardiac cycle. Poisson noise was then simulated for each frame to create 50 realizations of each heart, All datasets were processed in two ways: reconstructed as a 16-frame set, and collapsed to 8 frames and reconstructed. Ten observers viewed the cardiac images animated with a realistic real-time frame rate. Observers trained on 100 images and tested on 100 images, rating their confidence on the presence of a motion defect on a continuous scale. None of the observers showed a significant difference in performance between the two gating methods. The 95% confidence interval on the difference in areas under the ROC curve (Az8 - Az16) was -0.029-0.085. Our test did not find a significant difference in detection performance between 8-frame gating and 16-frame gating. We conclude that, for the task of detecting abnormal motion, increasing the number of gated frames from 8 to 16 offers no apparent advantage.

Interpreting regional myocardial magnetic resonance imaging data: a new method for collation with angiographic findings in patients with coronary artery disease

The magnetic resonance imaging (MRI) assessment of myocardial function and perfusion is a valuable complementary technique to coronary angiography. We describe a method of presenting and collating regional MRI data with the angiographic findings as annotated by the Green Lane reporting system. Routine clinical use of this approach is likely to increase the accuracy of MRI data interpretation and to influence both medical and interventional treatment strategies.

Factor analysis of medical image sequences improves evaluation of first-pass MR imaging acquisitions for myocardial perfusion

RATIONALE AND OBJECTIVES

Factor analysis of medical image sequences (FAMIS) applied to gadolinium chelate-enhanced subsecond magnetic resonance (MR) imaging was evaluated as a postprocessing method for assessing myocardial perfusion in coronary artery disease (CAD).

MATERIALS AND METHODS

To assess the accuracy of motion correction, five normal volunteers underwent MR imaging at rest. Thirteen patients with well-documented CAD and no myocardial infarction underwent MR imaging at rest and after dipyridamole administration. After motion correction, a single myocardial tissue factor (FAMISt) image was obtained with FAMIS for each raw MR imaging series acquisition. To evaluate how FAMIS could improve the analysis of these acquisitions, five readers visually assessed myocardial perfusion with FAMISt and raw MR images, and a multicase, multireader receiver operating characteristic analysis was performed.

RESULTS

FAMISt images significantly improved detection of the perfusion defects when compared with raw MR images (P = .002). Areas under the receiver operating characteristic curves ranged from 0.84 to 0.93 with FAMISt images and from 0.48 to 0.85 with raw MR images.

CONCLUSION

FAMIS applied to first-pass MR imaging series provided myocardial perfusion images that improve the objective assessment of myocardial perfusion in patients with CAD.