Performance of two Methods for Cardiac MRI Edema Mapping: Dual-Contrast Fast Spin-Echo and T2 Prepared Balanced Steady State Free Precession.

PURPOSE: To compare true positive and false negative results of myocardial edema mapping in two methods. Myocardial edema may be difficult to detect on cardiac MRI. MATERIALS AND METHODS: 76 patients (age 59 ±â€Š11 years, 15 female) with acute myocardial infarction (MI) and 10 healthy volunteers were prospectively included in this single-center study. 1.5 T cardiac MRI was performed in patients 2.5 days after revascularization (median) for edema mapping: Steady State Free Precession (SSFP) mapping sequence with T2-preparation pulses (T2prep); and dual-contrast Fast Spin-Echo (dcFSE) signal decay edema mapping. Late gadolinium enhancement (LGE) was used as the reference for expected edema in acute MI. RESULTS: 311 myocardial segments in patients were acutely infarcted with mean T2 73 ms for T2prep SSFP vs. 87 ms for dcFSE edema mapping. In healthy volunteers the mean T2 was 56 ms for T2prep SSFP vs. 50 ms for dcFSE edema mapping. Receiver operating characteristic (ROC) curve for T2prep SSFP show area under the curve (AUC) 0.962, p < 0.0001, Youden index J 0.8266, associated criterion > 60 ms, sensitivity 94 %, specificity 89 %. dcFSE ROC AUC 0.979, p < 0.0001, J 0.9219, associated criterion > 64 ms, sensitivity 93 %, specificity 99 %. CONCLUSION: Both edema mapping methods indicate high-grade edema with high sensitivity. Nevertheless, edema in acute infarction may be focally underestimated in both mapping methods. KEY POINTS: · Sensitivity for edema detection is high for both methods.. · Edema may be focally underestimated by T2prep SSFP edema mapping and dcFSE mapping.. CITATION FORMAT: · Krumm P, Martirosian P, Rath D et al. Performance of two Methods for Cardiac MRI Edema Mapping: Dual-Contrast Fast Spin-Echo and T2 Prepared Balanced Steady State Free Precession. Fortschr Röntgenstr 2020; 192: 669 - 677.

Cardiac MRI left ventricular global function index and quantitative late gadolinium enhancement in unrecognized myocardial infarction.

PURPOSE: To compare left ventricular global function index (LVGFI) and quantitative late gadolinium enhancement (LGE) in patients with unrecognized myocardial infarction (UMI), recognized myocardial infarction (RMI) and without myocardial infarction (MI). MATERIAL AND METHODS: Under waiver of the Institutional Review Board 235 patients (age 63.5±10.5years, 57 female) were retrospectively evaluated. All patients had undergone cardiac MRI at 1.5T for symptoms of CAD. 67 patients (29%) had suffered a known RMI before. Functional imaging and full-intensity late gadolinium enhancement (LGE) imaging were evaluated for LVGFI and quantitative LGE mass. RESULTS: Of 168 patients without history of RMI, 48 patients (29%) had UMI, 120 patients had no MI. LVGFI was lower in RMI patients (34±8% [range 16;52]), and UMI patients (35±8% [range 10;51]), compared to patients with no MI (38±7% [range 16;55]) respectively and similar between RMI and UMI patients. RMI patients had full-intensity LGE in 11±6% of left ventricular myocardial mass (LVMM). UMI patients had LGE in 9±5% of LVMM. RMI patients had significantly more LGE than UMI patients (p=0.0096). CONCLUSION: LGE quantification is effective to assess infarction scar size in RMI and UMI patients. LVGFI provides information on cardiac function and morphology but does not allow for a reliable differentiation between patients with and without history of MI, due small differences and wide overlap of LVGFI values for all three patient groups. This may be a reason why LVGFI is not applied in clinical routine.

Signal decay mapping of myocardial edema using dual-contrast fast spin-echo MRI.

PURPOSE: To introduce a dual-contrast fast spin-echo (dcFSE) sequence for signal decay mapping of myocardial edema. MATERIALS AND METHODS: After consultation with the Institutional Review Board, 22 acute myocardial infarction (MI) patients were examined with magnetic resonance imaging (MRI) at 1.5T 2 days after revascularization. Edema was evaluated in 16 myocardial segments with an exponential fit for signal decay time (SDT) in dcFSE mapping and T2 signal intensity ratio for single-contrast FSE. Myocardial viability was evaluated in late gadolinium enhancement (LGE). A control group of 10 volunteers was examined for edema imaging. SDT was compared in segment groups: 1) with LGE in MI, 2) penumbra, 3) remote from LGE, 4) controls. Groups 1/3 and 3/4 were tested on difference. Three phantoms providing similar T2 but different T1 relaxation times (low, intermediate, high) were examined with dcFSE and multicontrast spin echo sequence as a reference. RESULTS: The SDT/T2 ratio for segment groups was 1) 82msec/1.7 in segments with LGE; 2) 65msec/1.6 for penumbra, 3) 62msec/1.7 for remote segments, and 4) 50msec/1.6 in controls. In dcFSE group 1/3 (P < 0.0001) and in group 3/4 (P = 0.0002) SDT was significantly different. In single-contrast FSE the T2 ratio was not significantly different for both tests: 1/3 P = 0.1889; 3/4 P = 0.8879. T2 -overestimation of dcFSE was 23% in low, 29% in intermediate, and 35% in highly T1 contaminated phantoms. CONCLUSION: dcFSE signal decay edema mapping is feasible in volunteers and patients. DcFSE SDT is superior to T2 ratio for detection of high-grade and diffuse myocardial edema. J. Magn. Reson. Imaging 2016;44:186-193.

Preoperative assessment of peritoneal carcinomatosis: intraindividual comparison of 18F-FDG PET/CT and MRI.

OBJECTIVE: Exact determination of localization and extent of peritoneal carcinomatosis (PC) before peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) is crucial for the clinical outcome. Our study compares dynamic contrast enhanced 3D MRI (T1wDCE) and 18F-FDG PET/CT regarding diagnostic accuracy in correlation with surgical exploration (SE) and histological (HI) results. MATERIALS AND METHODS: 15 patients with PC were examined on a 1.5T MRI and 16 slice PET/CT. MRI: coronal T1wDCE covering the complete abdomen (0.15 mmol Gd-chelate/kg BW, 2000 mL mannitol solution p.o., 40 mg buscopan i.v.). PET-CT: contrast enhanced 16slice CT (120 mL ultravist 370 i.v., 1000 mL mannitol solution p.o., 40 mg buscopan i.v.), PET: 350 MBq 18-FDG i.v., 3 min acquisition time/bed, 60 min after tracer injektion). Assessment by two independent, experienced observers in correlation with results of SE and HI for each abdominal segment based on the peritoneal cancer index (PCI) proposed by Sugarbaker and co-authors. RESULTS: MRI and PET/CT provided reliable detection of PC. One patient had to be excluded from statistical analysis. In summary, 182 segments were assessed (13/patient, 14 patients, one patient excluded from statistical analysis). PC was found in 118 by MRI, 124 by PET/CT. 4 segments were classified false positive for MRI, 2 for PET/CT. False negative segments (MRI: 17, PET/CT: 9) did not result in irresectability. Positive predictive value for PC/segment was 97/98%, negative predictive value 73/84%, sensitivity 87/93%, specificity 92/96%, and diagnostic accuracy 88/94% (MRI/PET/CT). CONCLUSION: With high diagnostic accuracy for PC of both, MRI and PET/CT, PET/CT provides better diagnostic accuracy and especially better NPV.

Peritoneal carcinomatosis: comparison of dynamic contrast-enhanced magnetic resonance imaging with surgical and histopathologic findings.

OBJECTIVE: In patients with peritoneal carcinomatosis (PC) accurate preoperative assessment is essential to determine indication and surgical procedure to ensure optimal outcome. Purpose of our study was to assess the diagnostic accuracy (DA) of multiphasic dynamic contrast-enhanced MRI to determine the extent of PC in correlation with surgical and histopathological findings. MATERIALS AND METHODS: 14 Patients with proven PC were examined on a 1.5T system before peritonectomy and hyperthermic intraperitoneal chemotherapy. Patient preparation included oral application of 2000 mL mannitol solution and 40 mg butylscopolaminiumbromid i.v. Coronal contrast-enhanced multiphasic dynamic T1w 3D gre sequences (T1W DCE) (0.15 mmol Gd-chelate/kg bw) covering the whole abdomen were acquired (TR 2.9 ms, TE 1.1 ms, resolution 2.0 × 2.0 × 1.8 mm, FOV 400 × 400 mm). MRI was assessed by two radiologists and correlated with surgical exploration (SE) and histopathology for each segment based on the peritoneal cancer index proposed by Sugarbaker et al. RESULTS: In total, 182 segments were evaluated. PC was found in 118/121 of 182 segments (reader 1/2) by MRI and in 131 segments by SE. In 4/7 segments MRI was false positive. False negative segments 17/17 in MRI did not result in irresectability. The positive predictive value for PC per segment of MRI was 97%/94%, the negative predictive value 73%/72%, the sensitivity 87%/87% and the specificity 92%/86%. The DA was 88%/87%. CONCLUSION: T1W DCE is an accurate and clinical valuable tool for the preoperative assessment of peritoneal tumor spread.