A new compressed sensing cine cardiac MRI sequence with free-breathing real-time acquisition and fully automated motion-correction: A comprehensive evaluation.

PURPOSE: The purpose of this study was to compare a new free-breathing compressed sensing cine (FB-CS) cardiac magnetic resonance imaging (CMR) to the standard reference multi-breath-hold segmented cine (BH-SEG) CMR in an unselected population. MATERIALS AND METHODS: From January to April 2021, 52 consecutive adult patients who underwent both conventional BH-SEG CMR and new FB-CS CMR with fully automated respiratory motion correction were retrospectively enrolled. There were 29 men and 23 women with a mean age of 57.7 ± 18.9 (standard deviation [SD]) years (age range: 19.0-90.0 years) and a mean cardiac rate of 74.6 ± 17.9 (SD) bpm. For each patient, short-axis stacks were acquired with similar parameters providing a spatial resolution of 1.8 × 1.8 × 8.0 mm3 and 25 cardiac frames. Acquisition and reconstruction times, image quality (Likert scale from 1 to 4), left and right ventricular volumes and ejection fractions, left ventricular mass, and global circumferential strain were assessed for each sequence. RESULTS: FB-CS CMR acquisition time was significantly shorter (123.8 ± 28.4 [SD] s vs. 267.2 ± 39.3 [SD] s for BH-SEG CMR; P < 0.0001) at the penalty of a longer reconstruction time (271.4 ± 68.7 [SD] s vs. 9.9 ± 2.1 [SD] s for BH-SEG CMR; P < 0.0001). In patients without arrhythmia or dyspnea, FB-CS CMR provided subjective image quality that was not different from that of BH-SEG CMR (P = 0.13). FB-CS CMR improved image quality in patients with arrhythmia (n = 18; P = 0.002) or dyspnea (n = 7; P = 0.02), and the edge sharpness was improved at end-systole and end-diastole (P = 0.0001). No differences were observed between the two techniques in ventricular volumes and ejection fractions, left ventricular mass or global circumferential strain in patients in sinus rhythm or with cardiac arrhythmia. CONCLUSION: This new FB-CS CMR addresses respiratory motion and arrhythmia-related artifacts without compromising the reliability of ventricular functional assessment.

Compressed Sensing Real-Time Cine Reduces CMR Arrhythmia-Related Artifacts.

BACKGROUND AND OBJECTIVE: Cardiac magnetic resonance (CMR) is a key tool for cardiac work-up. However, arrhythmia can be responsible for arrhythmia-related artifacts (ARA) and increased scan time using segmented sequences. The aim of this study is to evaluate the effect of cardiac arrhythmia on image quality in a comparison of a compressed sensing real-time (CSrt) cine sequence with the reference prospectively gated segmented balanced steady-state free precession (Cineref) technique regarding ARA. METHODS: A total of 71 consecutive adult patients (41 males; mean age = 59.5 ± 20.1 years (95% CI: 54.7-64.2 years)) referred for CMR examination with concomitant irregular heart rate (defined by an RR interval coefficient of variation >10%) during scanning were prospectively enrolled. For each patient, two cine sequences were systematically acquired: first, the reference prospectively triggered multi-breath-hold Cineref sequence including a short-axis stack, one four-chamber slice, and a couple of two-chamber slices; second, an additional single breath-hold CSrt sequence providing the same slices as the reference technique. Two radiologists independently assessed ARA and image quality (overall, acquisition, and edge sharpness) for both techniques. RESULTS: The mean heart rate was 71.8 ± 19.0 (SD) beat per minute (bpm) (95% CI: 67.4-76.3 bpm) and its coefficient of variation was 25.0 ± 9.4 (SD) % (95% CI: 22.8-27.2%). Acquisition was significantly faster with CSrt than with Cineref (Cineref: 556.7 ± 145.4 (SD) s (95% CI: 496.7-616.7 s); CSrt: 23.9 ± 7.9 (SD) s (95% CI: 20.6-27.1 s); p < 0.0001). A total of 599 pairs of cine slices were evaluated (median: 8 (range: 6-14) slices per patient). The mean proportion of ARA-impaired slices per patient was 85.9 ± 22.7 (SD) % using Cineref, but this was figure was zero using CSrt (p < 0.0001). The European CMR registry artifact score was lower with CSrt (median: 1 (range: 0-5)) than with Cineref (median: 3 (range: 0-3); p < 0.0001). Subjective image quality was higher in CSrt than in Cineref (median: 3 (range: 1-3) versus 2 (range: 1-4), respectively; p < 0.0001). In line, edge sharpness was higher on CSrt cine than on Cineref images (0.054 ± 0.016 pixel-1 (95% CI: 0.050-0.057 pixel-1) versus 0.042 ± 0.022 pixel-1 (95% CI: 0.037-0.047 pixel-1), respectively; p = 0.0001). CONCLUSION: Compressed sensing real-time cine drastically reduces arrhythmia-related artifacts and thus improves cine image quality in patients with arrhythmia.

60-S Retrogated Compressed Sensing 2D Cine of the Heart: Sharper Borders and Accurate Quantification.

BACKGROUND AND OBJECTIVE: Real-time compressed sensing cine (CSrt) provides reliable quantification for both ventricles but may alter image quality. The aim of this study was to assess image quality and the accuracy of left (LV) and right ventricular (RV) volumes, ejection fraction and mass quantifications based on a retrogated segmented compressed sensing 2D cine sequence (CSrg). METHODS: Thirty patients were enrolled. Each patient underwent the reference retrogated segmented steady-state free precession cine sequence (SSFPref), the real-time CSrt cine and the segmented retrogated prototype CSrg sequence providing the same slices. Functional parameters quantification and image quality rating were performed on SSFPref and CSrg images sets. The edge sharpness, which is an estimate of the edge spread function, was assessed for the three sequences. RESULTS: The mean scan time was: SSFPref = 485.4 ± 83.3 (SD) s (95% CI: 454.3-516.5) and CSrg = 58.3 ± 15.1 (SD) s (95% CI: 53.7-64.2) (p < 0.0001). CSrg subjective image quality score (median: 4; range: 2-4) was higher than the one provided by CSrt (median: 3; range: 2-4; p = 0.0008) and not different from SSFPref overall quality score (median: 4; range: 2-4; p = 0.31). CSrg provided similar LV and RV functional parameters to those assessed with SSFPref (p > 0.05). Edge sharpness was significantly better with CSrg (0.083 ± 0.013 (SD) pixel-1; 95% CI: 0.078-0.087) than with CSrt (0.070 ± 0.011 (SD) pixel-1; 95% CI: 0.066-0.074; p = 0.0004) and not different from the reference technique (0.075 ± 0.016 (SD) pixel-1; 95% CI: 0.069-0.081; p = 0.0516). CONCLUSIONS: CSrg cine provides in one minute an accurate quantification of LV and RV functional parameters without compromising subjective and objective image quality.

Right Ventricular Volume and Function Assessment in Congenital Heart Disease Using CMR Compressed-Sensing Real-Time Cine Imaging.

BACKGROUND AND OBJECTIVE: To evaluate the reliability of compressed-sensing (CS) real-time single-breath-hold cine imaging for quantification of right ventricular (RV) function and volumes in congenital heart disease (CHD) patients in comparison with the standard multi-breath-hold technique. METHODS: Sixty-one consecutive CHD patients (mean age = 22.2 ± 9.0 (SD) years) were prospectively evaluated during either the initial work-up or after repair. For each patient, two series of cine images were acquired: first, the reference segmented multi-breath-hold steady-state free-precession sequence (SSFPref), including a short-axis stack, one four-chamber slice, and one long-axis slice; then, an additional real-time compressed-sensing single-breath-hold sequence (CSrt) providing the same slices. Two radiologists independently assessed the image quality and RV volumes for both techniques, which were compared using the Wilcoxon test and paired Student's t test, Bland-Altman, and linear regression analyses. The visualization of wall-motion disorders and tricuspid-regurgitation-related signal voids were also analyzed. RESULTS: The mean acquisition time for CSrt was 22.4 ± 6.2 (SD) s (95% CI: 20.8-23.9 s) versus 442.2 ± 89.9 (SD) s (95% CI: 419.2-465.2 s) for SSFPref (p < 0.001). The image quality of CSrt was diagnostic in all examinations and was mostly rated as good (n = 49/61; 80.3%). There was a high correlation between SSFPref and CSrt images regarding RV ejection fraction (49.8 ± 7.8 (SD)% (95% CI: 47.8-51.8%) versus 48.7 ± 8.6 (SD)% (95% CI: 46.5-50.9%), respectively; r = 0.94) and RV end-diastolic volume (192.9 ± 60.1 (SD) mL (95% CI: 177.5-208.3 mL) versus 194.9 ± 62.1 (SD) mL (95% CI: 179.0-210.8 mL), respectively; r = 0.98). In CSrt images, tricuspid-regurgitation and wall-motion disorder visualization was good (area under receiver operating characteristic curve (AUC) = 0.87) and excellent (AUC = 1), respectively. CONCLUSIONS: Compressed-sensing real-time cine imaging enables, in one breath hold, an accurate assessment of RV function and volumes in CHD patients in comparison with standard SSFPref, allowing a substantial improvement in time efficiency.

Single breath-hold compressed sensing real-time cine imaging to assess left ventricular motion in myocardial infarction.

PURPOSE: To evaluate the reliability of a real-time compressed sensing (CS) cine sequence for the detection of left ventricular wall motion disorders after myocardial infarction in comparison with the reference steady-state free precession cine sequence. MATERIALS AND METHODS: One hundred consecutive adult patients referred for either initial work-up or follow-up by cardiac magnetic resonance (CMR) in the context of myocardial infarction were prospectively included. There were 77 men and 23 women with a mean age of 63.12±11.3 (SD) years (range: 29-89 years). Each patient underwent the reference segmented multi-breath-hold steady-state free precession cine sequence including one short-axis stack and both vertical and horizontal long-axis slices (SSFPref) and the CS real-time single-breath-hold evaluated sequence (CSrt) providing the same slices. Wall motion disorders were independently and blindly assessed with both sequences by two radiologists, using the American Heart Association left ventricle segmentation. Paired Wilcoxon signed-rank test was used to search for differences in wall motion disorders conspicuity between both sequences and receiver operating characteristic curve (ROC) analysis was performed to assess the diagnosis performance of CSrt sequence using SSFPref as the reference method. RESULTS: Each patient had at least one cardiac segment with wall motion abnormality on SSFPref and CSrt images. The 1700 segments analyzed with SSFPref were classified as normokinetic (360/1700; 21.2%), hypokinetic (783/1700; 46.1%), akinetic (526/1700; 30.9%) or dyskinetic (31/1700; 1.8%). Sensitivity and specificity of the CS sequence were 99.6% (95% CI: 99.1-99.9%) and 99.7% (95% CI: 98.5-100%), respectively. Area under ROC of CSrt diagnosis performance was 0.997 (95% CI: 0.993-0.999). CONCLUSION: CS real-time cine imaging significantly reduces acquisition time without compromising the conspicuity of left ventricular -wall motion disorders in the context of myocardial infarction.

Perirenal PEComa: Computed Tomography Findings and Differential Diagnosis.

The World Health Organization defines perivascular epithelioid cell tumors (PEComas) as mesenchymal tumors and tumor-like conditions composed of epithelioid cells with a perivascular distribution. These tumors may show benign or malignant histology and/or biological behavior. However, the pathological features of malignancy may not correlate with biologic aggressiveness, and the criteria for malignancy are not clearly defined. Abdominopelvic PEComas are very rare and have been reported in various locations, including kidney, liver, pancreas, gastrointestinal tract, genitourinary tract, peritoneum, and retroperitoneum. Cross-sectional imaging techniques, including computed tomography (CT) may play an important role in the accurate detection and characterization of these tumors. We present the third case of an extremely rare PEComa with perirenal location, discuss CT findings and differential diagnosis.