Aortic dissection (AD) is a life-threatening cardiovascular emergency. Non-contrast-enhanced computed tomography (NCE-CT) could provide timely AD screening with fewer contraindications compared to CE-CT imaging. However, NCE-CT examinations lack distinctive imaging characteristics of AD, leading to high rates of missed diagnoses and misdiagnoses, and increased radiologist workload. In this paper, we propose a novel end-to-end multi-task framework for automated aortic segmentation and AD detection using NCE-CT images. The framework comprises three main components: a deformable feature extractor enhancing aorta tubular-feature attention, an adaptive geometric information extraction module to optimize feature sharing between segmentation and classification tasks via the transformer cross-attention mechanism, and a knowledge distillation module transferring diagnostic information from the CE-CT-based teacher model to the NCE-CT-based student model. Multi-center tests across 3 internal and 2 external centers demonstrated that our model outperformed existing methods both for segmenting the aorta and detecting AD. Specifically, for segmenting the aorta, our framework achieved dice of 0.928 and 0.909, Jaccard index (JI) of 0.867 and 0.858, mean intersection over union (MIoU) of 0.932 and 0.913, and frequency-weighted IoU (FWIoU) of 0.995 and 0.994, in internal and external testing datasets, respectively. For identifying AD patients from non-AD patients, our framework achieved accuracies of 0.911 and 0.840, sensitivities of 0.925 and 0.888, andF1-scores of 0.922 and 0.836, in internal and external testing datasets, respectively. Ablation experiment demonstrates the effectiveness of each module. The proposed model may serve as an effective diagnostic assistant for radiologists, acting as a 'second pair of eyes' to assist in AD screening using NCE-CT images.

BackgroundThe Lake Louise Criteria (LLC) were updated in 2018 to improve accuracy in evaluating myocarditis. However, the diagnostic value of combining conventional magnetic resonance imaging (MRI) with contrast-enhanced whole-heart MRI (CE WH-MRI) in the diagnosis of acute myocarditis (AM) has not been determined.PurposeTo assess the diagnostic accuracy of the updated LLC and test the incremental value of CE WH-MRI in diagnosis of AM.Material and MethodsBetween March 2020 and November 2023, a total of 37 patients with clinically suspected AM were prospectively recruited for this study. The cardiac MR (CMR) protocol for myocarditis and controls included T2-STIR, breath-hold steady-state free precession, native T1, T2, CE WH-MRI, late gadolinium enhancement (LGE), and post-contrast T1 mapping.ResultsFor global native T1, the ideal cutoff value was 1308.5 ms (area under the curve [AUC]=0.879, sensitivity=82%, specificity=79%); for global T2, 43.2 ms (AUC=0.889, sensitivity=96%, specificity=75%), for ECV, 30.5% (AUC=0.946, sensitivity=97%, specificity=93%). The CE WH-MRI sequence detected 268 myocardial involvement (MI) segments, whereas 2D-LGE images identified 181 MI segments. Among 37 patients, 34 (91.9%) met the updated LLC definition for diagnosis, the AUC of updated LLC was 0.946.ConclusionThe updated LLC, as a recommended criterion for the diagnosis of AM, had better diagnostic accuracy compared with CMR mapping imaging. Moreover, this study highlighted the additional diagnostic value of CE WH-MRI in the identification of AM. Then, multiparametric CMR imaging can provide a satisfactory diagnostic value to enhance the accuracy of diagnosing AM.

Background:Early gadolinium enhancement (EGE) assessment for myocardial hyperemia is generally considered the least robust of the three Lake Louis Criteria (LLC), which is attributable to the limitations of the technique. The purpose of this study was to assess the feasibility of the contrast-enhanced whole-heart magnetic resonance imaging (CE WH-MRI) as a novel method for the diagnosis of acute myocarditis. Methods:We retrospectively reviewed the data of 54 patients admitted to Fujian Medical University Union Hospital between May 2020 to March 2024 with clinically suspected acute myocarditis. The diagnostic guidelines established by the European Society of Cardiology (ESC) were applied in this study. Additionally, we included 43 healthy individuals as controls. The hyperintense areas in the late gadolinium enhancement (LGE) and CE WH-MRI images were doubtfully or reliably interpreted by the two observers. The left ventricular (LV) myocardium was divided into 17 segments according to American Heart Association (AHA) consensus, which allowed us to evaluate the presence of hyperemia-weighted patterns or LGE. Results:The final population included 43 patients. The acquisition time of CE WH-MRI was 8.2±1.3 min. Myocardial hyperemia-weighted patterns in CE WH-MRI images were found in 41 of 43 (95.35%) participants. LGE was detected in 29 of 43 (67.44%) patients. Comparative analysis between CE WH-MRI and two-dimensional LGE sequences revealed myocardial involvement in 322 and 210 segments, respectively. Conclusions:This study established the viability of CE WH-MRI in identifying myocardial hyperemia-weighted patterns among patients with acute myocarditis. Additionally, through the combination of quantitative cardiac magnetic resonance (CMR) with the established LLC, CE WH-MRI could provide additive value in enhancing the accuracy of acute myocarditis diagnosis.

Background:In liver diffusion-weighted imaging (DWI), single-shot echo-planar imaging (SS-EPI) sequences are susceptible to motion artifacts, resulting in image blurring and decreased lesion detection rates. This study aimed to develop and optimize a motion-corrected (MOCO) technique for liver DWI at 3 Tesla (3T). The technique incorporates motion correction, complex averaging, and a combination of a reparametrized sinc fatsat pulse with an optimized water excitation pulse. Methods:This prospective cross-sectional study performed at Fujian Medical University Union Hospital included 42 healthy volunteers who underwent four SS-EPI DWI sequences on a 3T magnetic resonance imaging (MRI) system between January 2023 and March 2023. The sequences included a navigator-triggered (NT) MOCO-DWI, two free-breathing (FB) MOCO-DWI, and an FB conventional DWI (FB cDWI) sequence. Motion correction and complex averaging were performed for both MOCO-DWI sequences, and fat suppression was achieved using either a sinc fatsat pulse with optimized water excitation or a conventional spectral attenuated inversion recovery (SPAIR) pulse. Liver signal-to-noise ratio (SNR) was measured at b=1,000 s/mm2. Qualitative parameters were independently evaluated by three radiologists using 5-point Likert scales. Quantitative parameters were assessed using the Kolmogorov-Smirnov test, and variance homogeneity was assessed using Levene's test. Regarding the qualitative analysis, the Friedman test was used to compare subjective scores among the four techniques. Results:The SNRs of the liver were significantly higher with FB MOCO-DWI compared to the other EPI DWI sequences at b=1,000 s/mm2 (P<0.05). In the superior-inferior direction, the SNRs of the inferior level of the liver were higher than those of the superior level in NT MOCO-DWI. The qualitative results showed significantly higher ratings for NT MOCO-DWI and FB MOCO-DWI compared to the other EPI DWI sequences at b=1,000 s/mm2 (P<0.05). Regarding the apparent diffusion coefficient (ADC) quantification, the ADC values of the left lobe were higher than those of the right lobe in all four techniques. Conclusions:The proposed EPI DWI technique, incorporating motion correction, complex averaging, and a modified fat suppression scheme using spectral fat saturation and binomial water excitation, was found to be clinically feasible for liver MRI. The FB MOCO-DWI sequence, with its superior SNR and excellent image quality, is recommended for liver DW imaging at 3T in clinical routine.

RATIONALE AND OBJECTIVES:The purpose of the present study was to evaluate the clinical feasibility of the modified 3D breath-hold magnetic resonance cholangiopancreatography with parallel imaging (3D-BH-PI-MRCP) using a spatially selective radiofrequency excitation pulse in patients with suspected pancreaticobiliary diseases. Moreover, we also compared its image quality with those of the original 3D-BH-PI-MRCP with a nonselective exciting pulse and the 3D breath hold compressed sensing magnetic resonance cholangiopancreatography (3D-BH-CS-MRCP).MATERIALS AND METHODS:Between January 2021 and July 2021, 106 patients prospectively underwent modified 3D-BH-PI-MRCP, original 3D-BH-PI-MRCP and 3D-BH-CS-MRCP at 3T in this study. The Friedman test was performed to compare the contrast, signal-to-noise-ratio (SNR), and contrast-noise-ratio, overall image quality, and duct visualization among the three protocols.RESULTS:The contrast ratio, SNR and contrast-to-noise ratio of the common bile duct differed significantly among the three sequences (p < 0.001). Compared to the 3D-BH-CS-MRCP protocol, the overall imaging quality of the two 3D-BH-PI-MRCP was higher but not significantly different. The scores for the anterior and posterior branches visualization were significantly higher in the original 3D-BH-PI-MRCP compared to the 3D-BH-CS-MRCP, but were no significant differences between the modified 3D-BH-PI-MRCP and the 3D-BH-CS-MRCP.CONCLUSION:The modified 3D-BH-PI-MRCP with a spatially selective radiofrequency excitation pulse could provide comparable image quality to the original 3D-BH-PI-MRCP and the 3D-BH-CS-MRCP during a single breath hold (22 seconds), and showed improved SNR and superior visualization of the pancreaticobiliary tree.

Background In recent years, substantial advances have been made in noninvasive cardiac imaging, including cardiac computed tomography (CT) and cardiovascular magnetic resonance (CMR). The purpose of this study was to prospectively compare the diagnostic performance of contrast-enhanced whole heart coronary CMR angiography (CCMRA) to dual-source coronary CT angiography (CCTA) for the diagnosis of significant coronary stenoses (≥50%) in patients with known or suspected coronary artery disease (CAD) referred for conventional x-ray coronary angiography. Methods Our objective was to directly compare the diagnostic accuracy of contrast-enhanced whole-heart CCMRA (CE-CCMRA) to dual-source CCTA (DS-CCTA) for the detection of CAD. We prospectively studied 57 symptomatic patients with suspected or known CAD who were scheduled for conventional x-ray coronary angiography. Significant CAD was defined as an x-ray defined diameter reduction of ≥50% in a coronary artery with a reference diameter of ≥1.5 mm. Results CE-CCMRA and DS-CCTA were completed in 51 (89%) of 57 patients without complications. The acquisition times of CE-CCMRA and DS-CCTA, respectively, were 9.5 ± 3.1 min and 8.3 ± 1.4 s. On patient-based analysis, the sensitivity, specificity, positive and negative predictive value of CE-CCMRA and DS-CCTA were 93.5% versus 93.5%( P > 0.05), 85% versus 90%(P > 0.05), 90.6% versus 93.5%(P > 0.05), and 89.4% versus 90%(P > 0.05), respectively. The area under the curve (AUC) was 0.89 (95% CI: 0.79 to 0.99) for CE-CCMRA and 0.92 (95% CI: 0.83 to 1.00) for DS-CCTA. Conclusions DS-CCTA was found to be superior to CE-CCMRA in the diagnosis of significant coronary stenoses (≥50%) in patients with suspected or known CAD scheduled for conventional x-ray coronary angiography, owing to shorter scanning times and higher spatial resolution. However, CE-CCMRA and DS-CCTA have similar diagnostic accuracies.

The purpose of this study was to compare the proposed rapid NT-MRCP protocol and the conventional NT-MRCP protocol with respect to image quality as well as the acquisition time. Between January 2019 and May 2019, a total number of 67 consecutive patients with suspected pancreaticobiliary diseases were included in this prospective study and underwent 3D rapid MRCP and 3D conventional MRCP sequences. Both acquisition protocols were set from the same navigator-triggered 3D SPACE sequence. The acquisition time was recorded. Two blinded radiologists performed qualitative analyses with respect to overall image quality, motion artifacts, and CBD visibility using a four-point scale. Quantitative evaluation included the contrast, signal-noise ratio (SNR), and contrast-noise ratio (CNR) between the common bile duct (CBD) and periductal tissues. A paired t test was used to assess differences in the qualitative and quantitative evaluations between the two acquisition methods. All MRCP studies were completed successfully. The mean acquisition time of rapid NT-MRCP (96.64 ± 30.55 s) was significantly lower than that of the conventional NT–MRCP (271.42 ± 61.63 s; p < 0.001).The contrast ratio, SNR, and CNR of the CBD were significantly higher for conventional NT-MRCP than with rapid NT-MRCP images (0.95 ± 0.02 vs. 0.93 ± 0.03, p < 0.001; 10.36 ± 4.63 vs. 8.90 ± 4.71, p = 0.011; 14.01 ± 6.02 vs. 12.22 ± 6.36, p = 0.020, respectively). The rapid MRCP depicted the overall image quality, artifacts, CBD visibility, right and left hepatic duct, segment 2 branch, main pancreatic duct, and cystic duct significantly better compared with conventional MRCP (p < 0.05). There were no statistically significant differences between the two methods regarding visibility of anterior, posterior, and segment 3 branches (p > 0.05). In conclusion, the proposed rapid MRCP protocol yielded significantly higher overall image quality and better visualization of the pancreaticobiliary tree with a significantly reduced imaging time without deterioration of image quality compared with the conventional MRCP at 3T.

OBJECTIVE. The purpose of this study was to evaluate the clinical feasibility of breath-hold (BH) MRCP with multichannel receiver coils in comparison with conventional navigator-triggered (NT) MRCP at 3 T. SUBJECTS AND METHODS. We prospectively studied 53 consecutive patients who underwent MRCP with BH sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) and NT SPACE. The acquisition time for each MRCP image was noted. The contrast ratio, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR) between the common bile duct (CBD) and periductal tissues on 3D MRCP images were evaluated quantitatively. The overall image quality, motion artifacts, and CBD visibility were scored on a 4-point scale by two blinded radiologists. A paired t test was used to analyze the differences in the qualitative and quantitative evaluations between the two MRCP acquisition methods. RESULTS. Both MRCP methods were successfully performed for all subjects without any complications. The mean acquisition time of BH MRCP was significantly shorter than that of NT MRCP (18 seconds vs 264.64 ± 89.66 [SD] seconds; p < 0.001). The mean SNR, the contrast ratio, and the CNR of the CBD were significantly higher on NT MRCP images than on BH MRCP images (11.58 ± 6.24 vs 8.71 ± 4.21, 0.93 ± 0.04 vs 0.92 ± 0.03, and 15.42 ± 8.04 vs 12.00 ± 5.76, respectively; p < 0.05). All visual scores were significantly higher with BH MRCP than with conventional NT MRCP (p < 0.001). CONCLUSION. Using 3D BH MRCP with a SPACE sequence at 3 T is feasible in clinical patients, yielding significantly better perceived image quality of the pancreaticobiliary tree in a single BH (mean acquisition time, 18 seconds) without losing image quality compared with the conventional NT MRCP.

To evaluate the accuracy of contrast-enhanced whole-heart magnetic resonance coronary angiography at 3.0T for assessing significant stenosis (>= 50% lumen diameter reduction) in patients with myocardial infarction, by using conventional coronary artery angiography as the reference standard, and also test the performance of that for the detection and assessment of chronic myocardial infarction (MI), compared with standard delayed-enhancement coronary magnetic resonance (DE-CMR) for the determination of infarct size. We studied 42 consecutive patients (37 men, 5 women, mean age 58.5 +/- 10.7 years) with MI scheduled for conventional coronary angiography. Contrast-enhanced whole-heart coronary magnetic resonance angiography (CMRA) was employed after sublingual nitroglycerin (NTG) with the abdominal banding rolled tightly along the side of ribs. Finally, a 3D phase-sensitive inversion-recovery gradient-echo (3D-PSIR-GRE) sequence was performed during free breathing. The assessment of MI sizes on WH-CMRA reconstructed images and 3D-PSIR-GRE images were compared using a paired student t test. The acquisition of CMRA was completed in 40 (95.2%) of 42 patients, with an imaging time averaged at 9.5 +/- 3.1 minutes. The average navigator efficiency was 47%. The sensitivity, specificity, and positive and negative predictive values of whole-heart CMRA for the detection of significant lesions on a segment-by-segment analysis were 91.7% (95% confidence interval [CI] 83.8-96.1), 84.0% (95% CI 80.0-87.4), 57.9% (95% CI 50.0-65.8), 97.7% (95% CI 95.3-98.9), respectively, and on a patient-based analysis 93.5% (95% CI 77.2-98.9), 88.9% (95% CI 50.7-99.4), 96.7% (95% CI 80.9-99.8), and 80.0% (95% CI 44.2-96.5), respectively. Infarcts were generally higher on the CE-CMRA technique compared with the standard technique (18.0 +/- 7.2cm(3) vs 16.1 +/- 6.4cm(3); P<.0001). Contrast-enhanced whole-heart CMRA with 3.0-T not only may permit reliable detection of significant obstructive coronary artery disease in patients with myocardial infarction, but also could identify and quantify the volume of myocardial infarction. This technique could be considered the preferred approach in patients who could not overcome longer scanning times or unable to hold their breath instead of delayed-enhancement magnetic resonance imaging for detection of infarcted myocardium. However, compared with standard imaging, the volume of myocardial infarction is slightly overestimated.

The modified 3D-BH-PI-MRCP technique allowing direct exciting the area of interest, could not only decrease the slice number but also could eliminate folding artifacts.