Repeatability and reproducibility of 3D MR fingerprinting relaxometry measurements in normal breast tissue

Abstract

Background The 3D breast magnetic resonance fingerprinting (MRF) technique enables T1 and T2 mapping in breast tissues. Combined repeatability and reproducibility studies on breast T1 and T2 relaxometry are lacking. Purpose To assess test–retest and two‐visit repeatability and interscanner reproducibility of the 3D breast MRF technique in a single‐institution setting. Study Type Prospective. Subjects Eighteen women (median age 29 years, range, 22–33 years) underwent Visit 1 scans on scanner 1. Ten of these women underwent test–retest scan repositioning after a 10‐minute interval. Thirteen women had Visit 2 scans within 7–15 days in same menstrual cycle. The remaining five women had Visit 2 scans in the same menstrual phase in next menstrual cycle. Five women were also scanned on scanner 2 at both visits for interscanner reproducibility. Field Strength/Sequence Two 3T MR scanners with the 3D breast MRF technique. Assessment T1 and T2 MRF maps of both breasts. Statistical Tests Mean T1 and T2 values for normal fibroglandular tissues were quantified at all scans. For variability, between and within‐subjects coefficients of variation (bCV and wCV, respectively) were assessed. Repeatability was assessed with Bland–Altman analysis and coefficient of repeatability (CR). Reproducibility was assessed with interscanner coefficient of variation (CoV) and Wilcoxon signed‐rank test. Results The bCV at test–retest scans was 9–12% for T1, 7–17% for T2, wCV was <4% for T1, and <7% for T2. For two visits in same menstrual cycle, bCV was 10–15% for T1, 13–17% for T2, wCV was <7% for T1 and <5% for T2. For two visits in the same menstrual phase, bCV was 6–14% for T1, 15–18% for T2, wCV was <7% for T1, and <9% for T2. For test–retest scans, CR for T1 and T2 were 130 msec and 11 msec. For two visit scans, CR was <290 msec for T1 and 10–14 msec for T2. Interscanner CoV was 3.3–3.6% for T1 and 5.1–6.6% for T2, with no differences between interscanner measurements (P = 1.00 for T1, P = 0.344 for T2). Data Conclusion 3D breast MRF measurements are repeatable across scan timings and scanners and may be useful in clinical applications in breast imaging. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1133–1143.

Magnetic resonance fingerprinting Part 1: Potential uses, current challenges, and recommendations

“…More recently, 3D MRF with Bloch–Siegert B 1 + map correction and fat suppression was used to acquire full‐volume, T 1 and T 2 maps in the breast at a spatial resolution of 1.6 × 1.6 × 3 mm 3 in ~6 minutes . Panda et al conducted both repeatability and reproducibility studies in healthy subjects . In the work by Chen et al, MRF maps were useful in characterizing the breast lesions: T 1 and T 2 relaxation times measured in healthy subjects agreed with previous literature, and the T 2 relaxation time was significantly higher in invasive ductal carcinoma than in healthy tissue …”

“…In a phantom, when ground truth values are available, the bias of that method from the ground truth values should be presented, as shown in Fig. using data from Ma et al Ideally, the phantom is used not for a single validation, but repeatedly removed and then positioned in the scanner and imaged to generate repeatability data, as done in one day by Anderson et al, over multiple days on one system by Jiang et al, and reproducibility data, as done across three MRI systems by Cloos et al Repeatability and reproducibility data are also needed in vivo, and some studies were recently completed . Cloos et al presented results from a small study using three healthy controls, with two measurements across three systems.…”

“…Using the high‐resolution 3D MRF method, Ma et al performed repeatability studies using the ISMRM/NIST system phantom, and test–retest studies were completed in healthy volunteers . Panda et al conducted repeatability and reproducibility studies in the breast of healthy subjects, and they determined the coefficient of repeatability for T 1 to be 290 msec and for T 2 to be 14 msec . Thus, if an observed change was greater than the coefficient of repeatability (eg, ΔT 1 >290 msec or ΔT 2 >14 msec), it can be considered notable.…”

Magnetic resonance fingerprinting: from evolution to clinical applications

“…Separate in vivo MRF studies on hip cartilage, 55 brain, 62,63 cardiac tissue 64 and breast 65 showed good repeatability and reproducibility across scanners. In particular, repeatability coefficients of variation for T 1 and T 2 in the brain study were below 8% and 14%, respectively, 62 while it was better in breast tissue, ranging from 3 to 4% for T 1 and 5 to 7% for T 2 .…”

Magnetic resonance fingerprinting review part 2: Technique and directions

“…. Additionally, sequences have been modified for areas beyond neuro, including applications in the abdomen, breast, prostate, cardiac, knee and hip, among others. Examples from several of these works are presented in Fig.…”