Hu, Chuang M, Kissinger K, Goddu, Goepfert L, Hauser T, Rofsky N, Manning W, Nezafat. Non-Contrast enhanced pulmonary vein MRI with a spatially selective slab inversion preparation sequence. Proc Eighteenth Scientific Meeting of Int Soc Magn Reson Med. 2010.
Publications
2010
Stoeck, Nezafat, Manning W, Kozerke, Peters D. Retrospective bellows-based reconstruction for cardiac MRI: preliminary experience. Proc Eighteenth Scientific Meeting of Int Soc Magn Reson Med. 2010.
Peters D, Nezafat, Hu, Han, Manning W. Comparison of Gd-BOPTA and Gd-DPTA late gadolinium enhancement for visualizing scarusing valve enhancement as a surrogate for scar adjacent to blood. Proc Eighteenth Scientific Meeting of Int Soc Magn Reson Med. 2010.
Peters D, Shaw J, Nezafat, Wit A, Duffy H, Josephson M, Manning W. Comparison of T1 values measured in scar, grey zone and normal myocardium adjacent and remote from scar. Proc Eighteenth Scientific Meeting of Int Soc Magn Reson Med. 2010.
Hu, Moghari H, Goddu, Goepfert, Manning W, Nezafat. Motion correction using coil arrays (MOCCA). Proc Eighteenth Scientific Meeting of Int Soc Magn Reson Med. 2010.
Stoeck, Nezafat, Boesiger, Kozerke. Whole Heart CSPAMM tagging in a single Breath hold using k-t-PCA. Proc Eighteenth Scientific Meeting of Int Soc Magn Reson Med. 2010.
Manning W, Pennell D. Cardiovascular Magnetic Resonance 2nd Edition. 2010.
Hu P, Chuang M, Kissinger K, Goddu B, Goepfert L, Rofsky N, Manning W, Nezafat R. Non-contrast-enhanced pulmonary vein MRI with a spatially selective slab inversion preparation sequence. Magn Reson Med. 2010;63(2):530–6.
We propose a non-contrast-enhanced, three-dimensional, free-breathing, electrocardiogram-gated, gradient recalled echo sequence with a slab-selective inversion for pulmonary vein (PV) MRI. A sagittal inversion slab was applied prior to data acquisition to suppress structures adjacent to the left atrium (LA) and PVs, thereby improving the conspicuity of the PV and LA. Compared with other MR angiography methods using an inversion pulse, the proposed method does not require signal subtraction and the inversion slab is not parallel to the imaging slab. The feasibility of the proposed method was demonstrated in healthy subjects. The inversion slab thickness and inversion time were optimized to be 60 mm and 500 ms, respectively. Compared to conventional gradient recalled echo imaging without inversion, the proposed technique significantly increased the contrast-to-noise ratios between the LA and the right atrium by 20-fold (P < 0.01), increased the contrast-to-noise ratios between the PVs and right atrium by 10-fold (P < 0.03), and increased the contrast-to-noise ratios between the PVs, LA and pulmonary artery by 4-fold (P < 0.01 for both). The signal-to-noise ratios of the PVs and the LA were similar with and without the inversion slab (P > 0.3). The proposed technique greatly enhances the conspicuity of the PVs and LA without significant loss of signal-to-noise ratio.
Hu P, Chuang M, Ngo L, Stoeck C, Peters D, Kissinger K, Goddu B, Goepfert L, Manning W, Nezafat R. Coronary MR imaging: effect of timing and dose of isosorbide dinitrate administration. Radiology. 2010;254(2):401–9.
PURPOSE: To quantify the effect of sublingual isosorbide dinitrate (ISDN) administration on coronary magnetic resonance (MR) imaging. MATERIALS AND METHODS: Written informed consent was obtained from all participants, and the HIPAA-compliant protocol was approved by the Institutional Review Board. Coronary MR imaging was performed at 1.5 T before and after administration of ISDN (2.5 or 5 mg) in 25 healthy adult volunteers (mean age, 23 years +/- 4; nine men, 16 women) with three-dimensional targeted (n = 20, randomized into four groups) or whole-heart (n = 5) acquisitions with gradient-recalled echo (GRE) or balanced steady-state free precession (SSFP) sequences. Image quality was assessed by two cardiologists on a four-point scale. Signal-to-noise ratio (SNR), vessel diameter, and vessel sharpness were characterized. A linear mixed-effects model was used for data analysis. A P value of less than .05 was considered to indicate a significant difference. RESULTS: The maximum SNR enhancement with 5 mg of ISDN (GRE: 22.0% +/- 10.7%; SSFP: 20.1% +/- 6.0%) was similar (P > .05) to that with 2.5 mg (GRE: 21.9% +/- 5.4%; SSFP: 19.1% +/- 3.0%). However, the time to maximum SNR enhancement for the 5-mg dose (15.5 minutes +/- 6.0) was earlier (P < .01) than that for 2.5 mg (23.5 minutes +/- 6.7). The increase in vessel diameter with 5 mg of ISDN was greater than that with 2.5 mg (P < .05 for both GRE and SSFP sequences). The coronary images were sharper after ISDN administration (P < .03). Subjective image quality score significantly improved after ISDN administration for GRE images (P < .05 for both doses) but was similar for SSFP images (P = .24 for 2.5 mg; P = .27 for 5 mg). Whole-heart coronary SNR was improved about 10% after ISDN administration (P < .05). CONCLUSION: Sublingual ISDN improves coronary MR imaging SNR. Practitioners need to consider the dose and temporal effects of ISDN when performing coronary MR imaging.
Depa M, Sabuncu M, Holmvang G, Nezafat R, Schmidt E, Golland P. Robust Atlas-Based Segmentation of Highly Variable Anatomy: Left Atrium Segmentation. Stat Atlases Comput Models Heart. 2010;6364:85–94.
Automatic segmentation of the heart's left atrium offers great benefits for planning and outcome evaluation of atrial ablation procedures. However, the high anatomical variability of the left atrium presents significant challenges for atlas-guided segmentation. In this paper, we demonstrate an automatic method for left atrium segmentation using weighted voting label fusion and a variant of the demons registration algorithm adapted to handle images with different intensity distributions. We achieve accurate automatic segmentation that is robust to the high anatomical variations in the shape of the left atrium in a clinical dataset of MRA images.