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.

Microcatheter collateral channel tracking failure in retrograde percutaneous coronary intervention for chronic total occlusion: incidence, predictors, and management.

AIMS: This study sought to demonstrate the incidence, predictors, and management of microcatheter collateral channel (CC) tracking failure in retrograde percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions. METHODS AND RESULTS: Prospectively collected data from 371 consecutive retrograde CTO-PCI procedures between March 2015 and January 2018 were retrospectively analysed. The incidence of initial microcatheter CC tracking failure was 22.5% in 280 procedures with wire CC tracking success. For septal collaterals, CC grade 0-1 collaterals (odds ratio [OR]: 8.3; p<0.001), channel entry angle <90° (OR: 13.0; p=0.001), channel exit angle <90° (OR: 44.3; p=0.004), and Finecross MG as initial microcatheter (OR: 2.7; p=0.032) were independently related to initial microcatheter CC tracking failure. Meanwhile, the only predictor for epicardial collaterals was CC 1 collaterals (OR: 26.9; p<0.001). Frequently applied solutions included microcatheter switching (61.9%), and microcatheter switching combined with GUIDEZILLA (14.3%) or anchoring balloon technique (6.3%). CONCLUSIONS: Initial microcatheter CC tracking failure was found in nearly one quarter of procedures after wire CC tracking success. Independent angiographic predictors of initial microcatheter CC tracking failure included CC 0-1 collaterals, channel entry angle <90°, and channel exit angle <90° for septal collaterals, and CC 1 collaterals for epicardial collaterals.

Assessment of the acute effects of glucocorticoid treatment on coronary microembolization using cine, first-pass perfusion, and delayed enhancement MRI.

PURPOSE: To assess the acute effects of methylprednisone treatment (MPT) on coronary microembolization (CME) by cardiac cine, first-pass perfusion, and delayed gadolinium enhancement magnetic resonance imaging (DE-MRI) in an experimental swine model. MATERIALS AND METHODS: Microembolization was established by intracoronary infusion of microspheres into the left anterior artery. Swine received placebo (n = 12) or methylprednisolone (n = 10, 30 mg/kg) intravenously 30 minutes before microembolization. Perfusion and DE-MRI was performed 6 hours after microembolization. Cine MR images of pre-/post-CME were obtained using 1.5T scanner. RESULTS: Cine MRI demonstrated relative amelioration of the post-CME myocardial contractile dysfunction in the glucocorticoid-treated group compared to the placebo group (P < 0.001). Post-CME target myocardial perfusion parameters decreased in both groups after microembolization. The extent of these decreases were the same for the embolized-to-control area ratio of maximum upslope (P = 0.245; 95% confidence interval of the difference [CID], -0.041/0.148) and time to peak ratio (P = 0.122; 95% CID, -0.201/0.026); however, the maximum signal intensity was higher in the glucocorticoid-treated group (P = 0.012; 95% CID, 0.023/0.156). DE-MRI revealed patchy hyperenhancement in all placebo pigs (n = 12/12) after microembolization, but no hyperenhanced regions in the glucocorticoid-pretreated pigs (n = 0/10). CONCLUSION: Standard, readily available, cardiac MRI techniques are useful in demonstrating post-CME myocardial dysfunction and the acute effects of glucocorticoid treatment on CME. Glucocorticoid pretreatment improves myocardial contractile dysfunction, prevents hyperenhancement, and partially ameliorates the decline of myocardial perfusion in the embolized area.

Quantitative and qualitative assessment of non-obstructive left main coronary artery plaques using 64-multislice computed tomography compared with intravascular ultrasound.

BACKGROUND: There are few reports of quantitative and qualitative measuring of left main coronary artery (LMCA) plaques by multislice computed tomography coronary angiography (MSCTA), especially when compared with intravascular ultrasound (IVUS) as reference standard. The aim of this study was to evaluate the use of 64-MSCTA in the diagnosis of LMCA disease, and the accuracy of MSCTA in the quantitative and qualitative assessment of the LMCA lesion as compared with IVUS. METHODS: A total of 91 patients (53 men, 38 women, mean age (64.78 +/- 9.19) years) were examined by 64-MSCTA and IVUS. Compared with the IVUS, the sensitivity, specificity, positive and negative predictive values (PPV and NPV) of the MSCTA on the diagnosis of LMCA diseases were calculated. Also, kappa index (kappa) for the agreement between MSCTA and IVUS was calculated. Minimal lumen area (MLA), external elastic membrane cross-sectional area (EEM-CSA) and plaque burden were measured by two blinded and independent operators on MSCTA cross-sectional reconstruction and compared with the parameters measured from IVUS by manually tracing. The CT value of soft, fibrous and calcific plaques was measured using IVUS classification of the plaques. RESULTS: The sensitivity, specificity, PPV and NPV of MSCTA for detecting LMCA plaques were 93.1%, 84.2%, 95.7%, 76.2%, respectively. Kappa index (kappa = 0.744, P < 0.001) indicated excellent agreement between MSCTA and IVUS. The Pearson index between MLA on IVUS and MLA on MSCTA was 0.815 (P < 0.01). The Pearson index of plaque burden and EEM-CSA between IVUS and MSCTA was 0.736 and 0.740 respectively (both P < 0.01). The CT value of soft plaque, fibrous plaque and calcific plaque compared with IVUS were (52.52 +/- 15.71) HU, (108.32 +/- 43.44) HU and (604.16 +/- 377.67) HU (P < 0.001). Receiver operating characteristic curve analysis of CT value of non-calcific plaques for predicting soft plaques showed the cutpoint was 54.35 HU, with a sensitivity of 83.3% and specificity of 94.4%. CONCLUSIONS: Sixty-four section MSCTA is an effective diagnostic tool for the detection of LMCA plaques with higher sensitivity and specificity. The correlation of quantitative and qualitative analysis between MSCTA and IVUS was excellent. The CT value of plaques can help the diagnosis of plaque composition.