Comparison of compressed sensing and conventional coronary magnetic resonance angiography for detection of coronary artery stenosis

Optimization of the acceleration of compressed sensing in whole-heart contrast-free coronary magnetic resonance angiography

BACKGROUND

This study aims to identify optimal acceleration factors (AFs) for compressed sensing (CS) technology to enhance its clinical application for suspected coronary artery disease (CAD) in whole-heart non-contrast coronary magnetic resonance angiography (CMRA).

METHODS

Two hundred and seventeen individuals with suspected CAD underwent whole-heart non-contrast CMRA on a 1.5T CMR scanner with CS AFs of 2, 4, and 6 (CS2, CS4, and CS6). Two radiologists independently and blindly scored the image quality. The overall image scores, coronary artery segment scores, signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR), and scan times were compared. The scores for the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX), and right coronary artery (RCA) were assessed. Of the 217 patients, 37 (37/217, 17.1%) underwent x-ray coronary angiography (CAG). The images from CS2, CS4, and CS6 were evaluated by two radiologists blinded to CAG results to identify significant luminal narrowing. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated.

RESULTS

The CS2 group exhibited higher overall scores, coronary artery segment scores, SNR, and CNR, but longer scan times compared to the CS4 and CS6 groups (overall score: 24.5 vs 22.0 vs 21.0, p < 0.001; SNR: 127 vs 112 vs 99, p < 0.001; CNRcor-fat: 118 vs 101 vs 84, p < 0.001; CNRcor-myo: 69.7 vs 62.8 vs 53.5, p < 0.001; scan time: 884 ± 308 s vs 473 ± 163 s vs 331 ± 146 s, p < 0.001). Proximal and middle segments received higher scores compared to their corresponding distal segments, and the RCA exhibited higher image quality than LAD and LCX in all groups (p < 0.05). In the subgroup analysis, 19 (19/37, 51.3%) were diagnosed with CAD by CAG. The sensitivity, specificity, PPV, NPV, and accuracy were as follows: CS2 (94.7%, 88.9%, 90.0%, 94.1%, and 91.9%), CS4 (89.5%, 94.4%, 94.4%, 89.5%, and 91.9%), and CS6 (89.5%, 66.7%, 73.9%, 85.7%, and 78.4%), respectively, in patient-based analysis.

CONCLUSION

Image quality showed a decreasing trend with increasing CS AFs, while scan time decreased in non-contrast CMRA. A scanning protocol using CS4 provided high-quality images with relatively short scan times and showed potential for detecting significant coronary stenosis, making it an optimal protocol for coronary magnetic resonance imaging.

Deep Learning-Based Acceleration of Compressed Sensing for Noncontrast-Enhanced Coronary Magnetic Resonance Angiography in Patients With Suspected Coronary Artery Disease

BACKGROUND

The clinical application of coronary MR angiography (MRA) remains limited due to its long acquisition time and often unsatisfactory image quality. A compressed sensing artificial intelligence (CSAI) framework was recently introduced to overcome these limitations, but its feasibility in coronary MRA is unknown.

PURPOSE

To evaluate the diagnostic performance of noncontrast-enhanced coronary MRA with CSAI in patients with suspected coronary artery disease (CAD).

STUDY TYPE

Prospective observational study.

POPULATION

A total of 64 consecutive patients (mean age ± standard deviation [SD]: 59 ± 10 years, 48.4% females) with suspected CAD.

FIELD STRENGTH/SEQUENCE

A 3.0-T, balanced steady-state free precession sequence.

ASSESSMENT

Three observers evaluated the image quality for 15 coronary segments of the right and left coronary arteries using a 5-point scoring system (1 = not visible; 5 = excellent). Image scores ≥3 were considered diagnostic. Furthermore, the detection of CAD with ≥50% stenosis was evaluated in comparison to reference standard coronary computed tomography angiography (CTA). Mean acquisition times for CSAI-based coronary MRA were measured.

STATISTICAL TESTS

For each patient, vessel and segment, sensitivity, specificity, and diagnostic accuracy of CSAI-based coronary MRA for detecting CAD with ≥50% stenosis according to coronary CTA were calculated. Intraclass correlation coefficients (ICCs) were used to assess the interobserver agreement.

RESULTS

The mean MR acquisition time ± SD was 8.1 ± 2.4 minutes. Twenty-five (39.1%) patients had CAD with ≥50% stenosis on coronary CTA and 29 (45.3%) patients on MRA. A total of 885 segments on the CTA images and 818/885 (92.4%) coronary MRA segments were diagnostic (image score ≥3). The sensitivity, specificity, and diagnostic accuracy were as follows: per patient (92.0%, 84.6%, and 87.5%), per vessel (82.9%, 93.4%, and 91.1%), and per segment (77.6%, 98.2%, and 96.6%), respectively. The ICCs for image quality and stenosis assessment were 0.76-0.99 and 0.66-1.00, respectively.

DATA CONCLUSION

The image quality and diagnostic performance of coronary MRA with CSAI may show good results in comparison to coronary CTA in patients with suspected CAD.

EVIDENCE LEVEL

1.

TECHNICAL EFFICACY

2.

3.0 T unenhanced Dixon water-fat separation whole-heart coronary magnetic resonance angiography: compressed-sensing sensitivity encoding imaging versus conventional 2D sensitivity encoding imaging

This study was aimed to investigate 3.0 T unenhanced Dixon water-fat whole-heart CMRA (coronary magnetic resonance angiography) using compressed-sensing sensitivity encoding (CS-SENSE) and conventional sensitivity encoding (SENSE) in vitro and in vivo. The key parameters of CS-SENSE and conventional 1D/2D SENSE were compared in vitro phantom study. In vivo study, fifty patients with suspected coronary artery disease (CAD) completed unenhanced Dixon water-fat whole-heart CMRA at 3.0 T using both CS-SENSE and conventional 2D SENSE methods. We compared mean acquisition time, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and the diagnostic accuracy between two techniques. In vitro study, CS-SENSE achieved better effectiveness between higher SNR/CNR and shorter scan times using the appropriate acceleration factor compared with conventional 2D SENSE. In vivo study, CS-SENSE CMRA had better performance than 2D SENSE in terms of the mean acquisition time, SNR and CNR (7.4 ± 3.2 min vs. 8.3 ± 3.4 min, P = 0.001; SNR: 115.5 ± 35.4 vs. 103.3 ± 32.2; CNR: 101.1 ± 33.2 vs. 90.6 ± 30.1, P < 0.001 for both). The diagnostic accuracy between CS-SENSE and 2D SENSE had no significant difference on a patient-based analysis (sensitivity: 97.3% vs. 91.9%; specificity: 76.9% vs. 61.5%; accuracy: 92.0% vs. 84.0%; P > 0.05 for each). Unenhanced CS-SENSE Dixon water-fat separation whole-heart CMRA at 3.0 T can improve the SNR and CNR, shorten the acquisition time while providing equally satisfactory image quality and diagnostic accuracy compared with 2D SENSE CMRA.

Non-contrast enhancement of brachial plexus magnetic resonance imaging with compressed sensing

PURPOSE

To observe the quality of brachial plexus (BP) images obtained from magnetic resonance imaging (MRI) with 3D T2 STIR SPACE sequence and compressed sensing (CS) and to compare the results with BP images from the same sequence without CS.

METHODS

In this study, compressed sensing was applied to acquire non-contrast BP images from ten healthy volunteers with 3D T2 STIR SPACE sequence to shorten acquisition time without sacrificing image quality. The acquisition time of scanning with CS was compared to that without CS. The quantitative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared using paired t-test to determine the quality of images with and without CS. The qualitative assessment by three experienced radiologists was performed using a scoring scale from 1 (poor) to 5 (excellent) and analyzed for interobserver agreement on image quality.

RESULTS

The increasing SNR and CNR of images with CS were found in nine regions of BP images (p < 0.001) with faster acquisition time. The result of paired t-test (p < 0.001) illustrates the significant difference between images with CS compared to images without CS. The assessment of observers also shows higher scores for images with CS compared to images without CS.

CONCLUSIONS

This study demonstrates that CS can effectively increase the visibility of images and image boundaries, SNR, and CNR of BP images obtained with 3D T2 STIR SPACE sequence with the good interobserver agreement and within clinically optimal acquisition time compared to images from similar sequence without CS.

3D whole-heart noncontrast coronary MR angiography based on compressed SENSE technology: a comparative study of conventional SENSE sequence and coronary computed tomography angiography

OBJECTIVE

The relatively long scan time has hampered the clinical use of whole-heart noncontrast coronary magnetic resonance angiography (NCMRA). The compressed sensitivity encoding (SENSE) technique, also known as the CS technique, has been found to improve scan times. This study aimed to identify the optimal CS acceleration factor for NCMRA.

METHODS

Thirty-six participants underwent four NCMRA sequences: three sequences using the CS technique with acceleration factors of 4, 5, and 6, and one sequence using the conventional SENSE technique with the acceleration factor of 2. Coronary computed tomography angiography (CCTA) was considered as a reference sequence. The acquisition times of the four NCMRA sequences were assessed. The correlation and agreement between the visible vessel lengths obtained via CCTA and NCMRA were also assessed. The image quality scores and contrast ratio (CR) of eight coronary artery segments from the four NCMRA sequences were quantitatively evaluated.

RESULTS

The mean acquisition time of the conventional SENSE was 343 s, while that of CS4, CS5, and CS6 was 269, 215, and 190 s, respectively. The visible vessel length from the CS4 sequence showed good correlation and agreement with CCTA. The image quality score and CR from the CS4 sequence were not statistically significantly different from those in the other groups (p > 0.05). Moreover, the image score and CR showed a decreasing trend with the increase in the CS factor.

CONCLUSIONS

The CS technique could significantly shorten the acquisition time of NCMRA. The CS sequence with an acceleration factor of 4 was generally acceptable for NCMRA in clinical settings to balance the image quality and acquisition time.

Free-breathing cardiovascular cine magnetic resonance imaging using compressed-sensing and retrospective motion correction: accurate assessment of biventricular volume at 3T

PURPOSE

We applied a combination of compressed-sensing (CS) and retrospective motion correction to free-breathing cine magnetic resonance (MR) (FBCS cine MoCo). We validated FBCS cine MoCo by comparing it with breath-hold (BH) conventional cine MR.

MATERIALS AND METHODS

Thirty-five volunteers underwent both FBCS cine MoCo and BH conventional cine MR imaging. Twelve consecutive short-axis cine images were obtained. We compared the examination time, image quality and biventricular volumetric assessments between the two cine MR.

RESULTS

FBCS cine MoCo required a significantly shorter examination time than BH conventional cine (135 s [110-143 s] vs. 198 s [186-349 s], p < 0.001). The image quality scores were not significantly different between the two techniques (End-diastole: FBCS cine MoCo; 4.7 ± 0.5 vs. BH conventional cine; 4.6 ± 0.6; p = 0.77, End-systole: FBCS cine MoCo; 4.5 ± 0.5 vs. BH conventional cine; 4.5 ± 0.6; p = 0.52). No significant differences were observed in all biventricular volumetric assessments between the two techniques. The mean differences with 95% confidence interval (CI), based on Bland-Altman analysis, were - 0.3 mL (- 8.2 - 7.5 mL) for LVEDV, 0.2 mL (- 5.6 - 5.9 mL) for LVESV, - 0.5 mL (- 6.3 - 5.2 mL) for LVSV, - 0.3% (- 3.5 - 3.0%) for LVEF, - 0.1 g (- 8.5 - 8.3 g) for LVED mass, 1.4 mL (- 15.5 - 18.3 mL) for RVEDV, 2.1 mL (- 11.2 - 15.3 mL) for RVESV, - 0.6 mL (- 9.7 - 8.4 mL) for RVSV, - 1.0% (- 6.5 - 4.6%) for RVEF.

CONCLUSION

FBCS cine MoCo can potentially replace multiple BH conventional cine MR and improve the clinical utility of cine MR.

Clinical impact of noncontrast percutaneous coronary intervention in patients with acute coronary syndrome

PURPOSE

Contrast-induced acute kidney injury (CI-AKI) is one of the common serious complications of percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). This study aimed to assess the significance of noncontrast strategy in the setting of ACS.

METHODS

CI-AKI was defined as an increase in serum creatinine of ?0.5 mg/dL or ?1.25 times from the baseline. One-year worsening renal function (WRF) was defined as an increase of ?0.3mg/dL in serum creatinine from the baseline after PCI.

RESULTS

Of 250 ACS patients, 81 were treated with noncontrast PCI. The average doses of contrast medium in the noncontrast and conventional groups were 17 (9?22) ml and 150 (120?200) ml, respectively. CI-AKI was observed in 4 patients (5%) in the noncontrast group and 29 patients (17%) in the conventional group. Noncontrast PCI was associated with a lower incidence of CI-AKI (adjusted odds ratio, 0.26;95% confidence interval [CI], 0.08?0.82). The bootstrap method and inverse probability weighting led to similar results. CI-AKI was associated with a higher incidence of 1-year WRF (adjusted hazard ratio, 2.30;95% CI, 1.12?4.69), while noncontrast PCI was not.

CONCLUSIONS

Noncontrast PCI was associated with the lower incidence of CI-AKI in ACS patients. J. Med. Invest. 69 : 57-64, February, 2022.

Assessment of Non-contrast-enhanced Dixon Water-fat Separation Compressed Sensing Whole-heart Coronary MR Angiography at 3.0 T: A Single-center Experience

RATIONALE AND OBJECTIVES

The clinical utility of Dixon water-fat separation coronary MR angiography (CMRA) with compressed sensing (CS) reconstruction has not been determined in a patient population. This study was designed to evaluate the performance of 3.0 T non-contrast-enhanced Dixon water-fat separation CS whole-heart CMRA sequence in vitro and in vivo.

MATERIALS AND METHODS

In vitro phantom MRI, we compared key parameters of the SENSE and CS images. And in this prospective in vivo study, from November 2019 to October 2020, 94 participants were recruited for 3.0 T non-contrast-enhanced Dixon water-fat separation CS whole-heart CMRA. The accuracy of CMRA for detecting a ≥ 50% reduction in diameter was determined using X-ray coronary angiography (CA) as the reference method.

RESULTS

Compared with SENSE, CS with an appropriate acceleration factor offers both higher SNR/CNR (p < 0.05) and a shortened acquisition. Fifty-eight patients successfully completed the CMRA and CA. The sensitivity, specificity, positive predictive values, negative predictive values, and accuracy of 3.0 T non-contrast-enhanced Dixon water-fat separation CS whole-heart CMRA according to a patient-based analysis were 96.4%, 66.7%, 73.0%, 95.2% and 81.0%, respectively. The area under the receiver-operator characteristic (ROC) curve (AUC) of 3.0 T non-contrast-enhanced Dixon water-fat separation CS whole-heart CMRA for detecting significant coronary artery stenosis is 0.908, 0.895, and 0.904 in patient-, vessel-, and segment-based analyses respectively.

CONCLUSION

3.0 T non-contrast-enhanced Dixon water-fat separation whole-heart CMRA using appropriate CS is a promising noninvasive and radiation-free technique to detect clinically significant coronary stenosis on patients with suspected CAD.

Clinical Application of Non-Contrast-Enhanced Dixon Water-Fat Separation Compressed SENSE Whole-Heart Coronary MR Angiography at 3.0 T With and Without Nitroglycerin

BACKGROUND

3.0 T non-contrast-enhanced nitroglycerin (NTG)-assisted whole-heart coronary magnetic resonance angiography (MRA) employing Dixon water-fat separation and compressed SENSE (CS-SENSE) acceleration is a promising method for diagnosing coronary artery disease (CAD).

PURPOSE

To evaluate the diagnostic performance of this technique for detecting clinically-relevant (≥50% diameter reducing) CAD and to evaluate the difference in NTG-induced coronary vasodilation between patients with and without clinically-relevant CAD.

STUDY TYPE

Prospective.

POPULATION

Sixty-six patients with suspected CAD.

FIELD STRENGTH/SEQUENCE

3.0 T; CSSENSE, Dixon water-fat separation, three-dimensional segmented turbo field gradient-echo sequence for whole-heart coronary MRA.

ASSESSMENT

Overall image quality of coronary MRA was calculated on the basis of all visible coronary segments. The diagnostic performance of coronary MRA for detecting a ≥50% reduction in coronary artery diameter with and without NTG was compared using X-ray coronary angiography (CAG) as the reference. According to CAG, patients were divided into a non-clinically-relevant CAD group and clinically-relevant CAD group, and the difference in NTG-induced vasodilation between the groups was evaluated.

STATISTICAL TESTS

Unpaired/paired Student's t-test, Mann-Whitney U test, paired Wilcoxon signed-rank test, χ² test, McNemar test. A two-tailed P value <0.05 was considered significant.

RESULTS

Overall image quality was increased significantly in the coronary MRA images after NTG. The diagnostic performance of the non-NTG vs. NTG-assisted coronary MRA was as follows on a per-patient basis: sensitivity 94.3% vs. 94.3%, specificity 64.5% vs. 83.9%, positive predictive value 75.0% vs. 86.8%, negative predictive value 90.9% vs. 92.9%, and accuracy 80.3% vs. 89.4%, respectively. NTG-induced vasodilation was significantly lower in the clinically-relevant CAD group than in the non-clinically-relevant CAD group (13.7 ± 8.1% vs. 24.1 ± 16.3%).

DATA CONCLUSION

Non-contrast Dixon water-fat separation CS-SENSE coronary MRA at 3.0 T can noninvasively detect clinically-relevant CAD and sublingual NTG improved performance. Combining pre- and post-NTG coronary MRA may provide a simple noninvasive and nonionizing test to evaluate coronary vasodilation function.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 2.