AimsTo evaluate the feasibility and diagnostic performance of high spatial resolution myocardial perfusion cardiac magnetic resonance (perfusion-CMR).Methods and resultsFifty-four patients underwent adenosine stress perfusion-CMR. An in-plane spatial resolution of 1.4 × 1.4 mm2 was achieved by using 5× k-space and time sensitivity encoding (k–t SENSE). Perfusion was visually graded for 16 left ventricular and two right ventricular (RV) segments on a scale from 0 = normal to 3 = abnormal, yielding a perfusion score of 0–54. Diagnostic accuracy of the perfusion score to detect coronary artery stenosis of >50% on quantitative coronary angiography was determined. Sources and extent of image artefacts were documented.Two studies (4%) were non-diagnostic because of k–t SENSE-related and breathing artefacts. Endocardial dark rim artefacts if present were small (average width 1.6 mm). Analysis by receiver–operating characteristics yielded an area under the curve for detection of coronary stenosis of 0.85 [95% confidence interval (CI) 0.75–0.95] for all patients and 0.82 (95% CI 0.65–0.94) and 0.87 (95% CI 0.75–0.99) for patients with single and multi-vessel disease, respectively. Seventy-four of 102 (72%) RV segments could be analysed.ConclusionHigh spatial resolution perfusion-CMR is feasible in a clinical population, yields high accuracy to detect single and multi-vessel coronary artery disease, minimizes artefacts and may permit the assessment of RV perfusion.

Purpose-To determine the feasibility and diagnostic accuracy of high spatial resolution myocardial perfusion MR at 3.0 Tesla using k-space and time domain undersampling with sensitivity encoding (k-t SENSE).Materials and Methods-The study was reviewed and approved by the local ethic review board. k-t SENSE perfusion MR was performed at 1.5 Tesla and 3.0 Tesla (saturation recovery gradient echo pulse sequence, repetition time/echo time 3.0ms/1.0ms, flip angle 15°, 5x k-t SENSE acceleration, spatial resolution 1.3×1.3×10mm 3 ). Fourteen volunteers were studied at rest and 37 patients during adenosine stress. In volunteers, comparison was also made with standardresolution (2.5×2.5×10mm 3 ) 2x SENSE perfusion MR at 3.0 Tesla. Image quality, artifact scores, signal-to-noise ratios (SNR) and contrast-enhancement ratios (CER) were derived. In patients, diagnostic accuracy of visual analysis to detect >50% diameter stenosis on quantitative coronary angiography was determined by receiver-operator-characteristics (ROC).Results-In volunteers, image quality and artifact scores were similar for 3.0 Tesla and 1.5 Tesla, while SNR was higher (11.6 vs. 5.6) and CER lower (1.1 vs. 1.5, p=0.012) at 3.0 Tesla. Compared with standard-resolution perfusion MR, image quality was higher for k-t SENSE (3.6 vs. 3.1, p=0.04), endocardial dark rim artifacts were reduced (artifact thickness 1.6mm vs. 2.4mm, p<0.001) and CER similar. In patients, area under the ROC curve for detection of coronary stenosis was 0.89 and 0.80, p=0.21 for 3.0 Tesla and 1.5 Tesla, respectively. Address for correspondence: Dr. S. Plein, Academic Unit of Cardiovascular Medicine, University of Leeds, G-floor Jubilee Wing, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, United Kingdom, Tel +44 113 3925404, Fax +44 113 3925405, Email: s.plein@leeds.ac.uk. Advances in knowledge 1. k-space and time domain undersampling with sensitivity encoding (k-t SENSE) can be used to accelerate myocardial perfusion MR imaging at 3.0 Tesla. 2.Compared with 1.5 Tesla, k-t SENSE accelerated perfusion MR imaging at 3.0 Tesla improves SNR and yields similar diagnostic accuracy to detect significant coronary artery stenosis.3. Using the acceleration provided by k-t SENSE to improve spatial resolution yields high image quality and reduces image artifacts compared with perfusion MR at lower resolution. Implications for patient care1. The combination of k-t SENSE acceleration with acquisition at high field strength offers a promising tool for improved detection of coronary artery stenosis by perfusion MR imaging. Conclusions-k-t SENSE accelerated high-resolution perfusion MR at 3.0 Tesla is feasible with similar artifacts and diagnostic accuracy as at 1.5 Tesla. Compared with standard-resolution perfusion MR, image quality is improved and artifacts are reduced. Europe PMC Funders Group

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BackgroundValidation of voltage-based scar delineation has been limited to small populations using mainly endocardial measurements. The aim of this study is to compare unipolar voltage amplitudes (UnipV) with scar on delayed enhancement cardiac magnetic resonance imaging (DE-CMR).MethodsHeart failure patients who underwent DE-CMR and electro-anatomic mapping were included. Thirty-three endocardial mapped patients and 27 epicardial mapped patients were investigated. UnipV were computed peak-to-peak. Electrograms were matched with scar extent of the corresponding DE-CMR segment using a 16-segment/slice model. Non-scar was defined as 0% scar, while scar was defined as 1–100% scar extent.ResultsUnipVs were moderately lower in scar than in non-scar (endocardial 7.1 [4.6–10.6] vs. 10.3 [7.4–14.2] mV; epicardial 6.7 [3.6–10.5] vs. 7.8 [4.2–12.3] mV; both p<0.001). The correlation between UnipV and scar extent was moderate for endocardial (R = -0.33, p<0.001), and poor for epicardial measurements (R = -0.07, p<0.001). Endocardial UnipV predicted segments with >25%, >50% and >75% scar extent with AUCs of 0.72, 0.73 and 0.76, respectively, while epicardial UnipV were poor scar predictors, independent of scar burden (AUC = 0.47–0.56). UnipV in non-scar varied widely between patients (p<0.001) and were lower in scar compared to non-scar in only 9/22 (41%) endocardial mapped patients and 4/19 (21%) epicardial mapped patients with scar.ConclusionUnipV are slightly lower in scar compared to non-scar. However, significant UnipV differences between and within patients and large overlap between non-scar and scar limits the reliability of accurate scar assessment, especially in epicardial measurements and in segments with less than 75% scar extent.

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