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Development of in vivo multi-slice spiral T1rho mapping in cartilage at 3T and its application to osteoarthritis
| Content Provider | Semantic Scholar |
|---|---|
| Author | Li, Xiaojuan Han, Eric T. Crane, Jason C. Link, Thomas M. Ma, Bing-Qi Blumenkrantz, Gabrielle Keshari, Kayvan R. Newitt, David C. Majumdar, Sharmila |
| Copyright Year | 2005 |
| Abstract | prep is proportional to exp(-TSL/ T1 ). Data with varying TSLs were acquired, and a Levenberg-Marquardt mono-exponential fitting algorithm developed in C was used to reconstruct a pixel-by-pixel T1 map. Cylindrical homogeneous agarose gel phantoms were used for sequence development and reproducibility studies. Nine volunteers (4 female and 5 male, ages 22-61, median=30) without OA symptoms and five patients (1 female and 4 male, ages 18-62, median=52) with OA symptoms and/or radiologic findings of cartilage degeneration were examined on a 3T GE Excite Signa MR scanner using a quadrature knee coil. Among them, four volunteers were scanned twice to study reproducibility. The acquisition parameters were: 14 interleaves/slice, 4,096 points/interleaf, FOV=15 or 16cm, effective in- plane resolution = 0.6 * 0.6 mm, slice thickness = 3mm, skip = 1mm, number of slice = 14-16, TR/TE = 2s/5.8ms, TSL=20/40/60/80 ms, spin lock frequency = 500 Hz, total acquisition time approximately 13 minutes. T1 -weighted images with the shortest TSL were registered to high-resolution T1-weighted SPGR images acquired in the same exam. The transformation matrix was applied to the reconstructed T1 map. Cartilage was segmented semi-automatically based on high-resolution SPGR images using a software package based on IDL (Interactive Data Language) developed in-house. 3D cartilage contours were generated and overlaid to the registered T1 map. Mean, standard deviation, and median T1 values were calculated. A non-parametric rank test was used to compare T1 values between controls and patients. RESULTS Fig. 2 shows T1 values through the 18 slices of an agar phantom (concentration approximately 4%, g/ml) collected in a single multi-slice acquisition with a median of 54 ms. The T1 values were consistent with those obtained with the single slice method and the variation from first slice to last was within 3.7%. The reproducibility (average coefficient of variation for median T1 ) was 1.46% for phantoms and 4.80% for volunteers. Table 1 shows the mean and standard deviation of median T1 within femoral (trochlea) and patellar cartilage respectively for healthy volunteers and patients with OA. A significant difference was found in T1 of femoral cartilage between controls and patients. Fig. 3 shows the T1 -weighted images of a healthy volunteer. Fig. 4 shows T1 maps for a healthy volunteer (a) and a patient with OA (b). |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://cds.ismrm.org/ismrm-2005/Files/00479.pdf |
| Alternate Webpage(s) | https://cds.ismrm.org/ismrm-2005/Files/00479.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
