ABSTRACT
PURPOSE: The bone medullar adiposity is a marker of bone quality to the point that there is a need to investigate the factors which influence or not the density and distribution of this fat in the spine, especially at the lumbar level. The purpose was to test the feasibility of a Dixon three-point technique and investigate the vertebral marrow fat distribution. MATERIAL AND METHODS: A sagittal sequence Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-squares Estimation (IDEAL) IQ was performed on the lumbar spine of 46 subjects who were not suffering from any bone disease (21 women and 25 men, aged 18-77 years). Medulla adiposity was determined directly from the measurement of the fat fraction in each vertebral body (T12 to S1) obtained on the fat cartography automatically generated by the IDEAL sequence. RESULTS: Average vertebral fat fraction was 36.48% (SD 12.82), with a tendency to increase with age and to higher values among men. We observed a craniocaudal gradient of the fat fraction (ß = 1.37; p < 0,001; SD 0.11) increasing with age in the lumbar spine from T12 to L5. Through multivariate analysis, this gradient was adjusted for sex, weight and height of the subjects. CONCLUSION: This feasibility study shows the existence of a physiological craniocaudal gradient of vertebral medullar adiposity from T12 to L5. This gradient increases with age but it is independent of sex or BMI. The IDEAL sequence allows quick and reproducible measurement of the spine vertebral medullar adiposity.
ABSTRACT
OBJECTIVE: Compared with standard systematic transrectal ultrasound (TRUS)-guided biopsies (SBx), targeted biopsies (TBx) using magnetic resonance imaging (MRI)/TRUS fusion could increase the detection of clinically significant prostate cancer (PCa-s) and reduce non-significant PCa (PCa-ns). This study aimed to compare the performance of the two approaches. MATERIALS AND METHODS: A prospective, single-center study was conducted on all consecutive patients with PCa suspicion who underwent prebiopsy multiparametric MRI (mpMRI) using the Prostate Imaging Reporting and Data System (PI-RADS). All patients underwent mpMRI/TRUS fusion TBx (two to four cores/target) using UroStation™ (Koelis, Grenoble, France) and SBx (10-12 cores) during the same session. PCa-s was defined as a maximal positive core length ≥4 mm or Gleason score ≥7. RESULTS: The study included 191 patients (at least one suspicious lesion: PI-RADS ≥3). PCa was detected in 55.5% (106/191) of the cases. The overall PCa detection rate and the PCa-s detection rate were not significantly higher in TBx alone versus SBx (44.5% vs 46.1%, p = .7, and 38.2% vs 33.5%, p = .2, respectively). Combined TBx and SBx diagnosed significantly more PCa-s than SBx alone (45% vs 33.5%, p = .02). PCa-s was detected only by TBx in 12% of cases (23/191) and only by SBx in 7.3% (14/191). Gleason score was upgraded by TBx in 16.8% (32/191) and by SBx in 13.6% (26/191) of patients (p = .4). CONCLUSIONS: The combination of TBx and SBx achieved the best results for the detection and prognosis of PCa-s. The use of SBx alone would have missed the detection of PCa-s in 12% of patients.
