Dilatation of the spinal epidural venous plexus in patients with prominent epidural fat.

OBJECTIVE: The purpose of this study was to evaluate the correlation between the dilatation of the spinal epidural venous plexus (SEVP) and the amount of epidural fat (EF). METHODS: Between January 2007 and January 2012, 116 patients with prominent EF and 116 control subjects without prominent EF were included in this study. On the lumbar MR images, we graded the amount of EF and counted the number of vertebrae to determine the longitudinal extent of the EF. We evaluated and classified the dilatation of the SEVP and the degree of central canal stenosis. RESULTS: SEVP dilatation significantly differed between the group with prominent EF and the control group (p-value < 0.0001). Dilatation of the anterior epidural veins was seen in all subjects with dilatation of the SEVP. In the group with prominent EF, 80 (69%) patients showed dilatation of the posterior epidural veins. The longitudinal extent of the prominent EF was significantly associated with the grade of SEVP dilatation. The EF grade and the sum of the EF grades of all levels of the lumbar spine with prominent EF showed a positive correlation with the grade of central canal stenosis (r = 0.421 and r = 0.347, respectively; p-value < 0.0001). CONCLUSION: The dilatation of epidural veins was statistically significant in patients with prominent EF. The detection of SEVP dilatation on MR images may be helpful for spine surgery involving the epidural space. ADVANCES IN KNOWLEDGE: Owing to the risk of bleeding, the detection of SEVP dilatation on MRI may be helpful when considering decompression surgery with a posterior approach for spinal stenosis caused by prominent EF.

Usefulness of the fast spin-echo three-point Dixon (mDixon) image of the knee joint on 3.0-T MRI: comparison with conventional fast spin-echo T2 weighted image.

OBJECTIVE: To compare the quality of two different imaging methods, three-point Dixon (mDixon) and fast spin-echo (FSE) T2 weighted image (T2WI) [and fat suppression (FS) T2WI], and to assess the utility of mDixon for the imaging of knee joint pathology. METHODS: This retrospective study included 66 patients who underwent both mDixon and FSE T2WI (and FS T2WI) of the knee joint. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the two sequences at the articular cartilage and ligament were measured. Two radiologists independently evaluated the anatomic identification score and diagnostic performances of the two sequences. RESULTS: The mean SNRs and CNRs of the patellar cartilage, femoral cartilage and anterior cruciate ligament (ACL) were significantly higher on T2WI and FS T2WI than on mDixon imaging, with the exception of the mean SNR of ACL on in-phase images. Most of the anatomic identification scores did not show significant differences, except for inferiorities of the in-phase mDixon in the evaluation of the cruciate ligament. There were no significant differences in sensitivity, specificity and accuracy between mDixon and T2WI regarding diagnostic performance. CONCLUSION: mDixon images have equivalent anatomic identification ability with the exception of cruciate ligament delineation on in-phase images and have a diagnostic performance comparable with that of FSE T2WI for meniscal, cartilage and ligament injuries of the knee joint. There would be a net saving in time, if mDixon was the only sequence used. ADVANCES IN KNOWLEDGE: The mDixon images have equivalent anatomic identification abilities, with the exception of cruciate ligament delineation on in-phase images and have a diagnostic performance comparable with that of FSE T2WI for meniscal, cartilage and ligament injuries of the knee joint.

The effects of daily irradiation with polychromatic visible polarized light on human lymphocyte populations.

OBJECTIVE: The goal of this randomized, placebo controlled, double-blind study was to investigate the effects of transcutaneous irradiation with polychromatic visible polarized light (540-780 nm; 68% polarization; power density 3.0 E-10 W/cm(2)) on a subset population of human lymphocytes using flow cytometry. BACKGROUND DATA: The biomodulation and therapeutic effects of visible light of different wavelengths are well known, but the immunological effects of polychromatic visible polarized light have not been investigated sufficiently. METHODS: Before and after 28 consecutive days of irradiation, blood samples were collected from the subjects and the population count of the lymphocyte subset was measured. RESULTS: The absolute count of total lymphocytes, CD3(+) lymphocytes, and CD3(+)CD4(+) lymphocytes increased by 7% (p = 0.023), 9% (p = 0.058), and 13% (p = 0.021), respectively. Yet the absolute count of WBCs, CD3(+)CD8(+), CD19(+), and CD16(+)56(+) lymphocytes did not change significantly. CONCLUSION: The application of polychromatic visible polarized light with the aforementioned features increases the CD3(+)CD4(+) lymphocyte population. It is suggested that this regimen may be useful for the promotion of natural defenses in cell-mediated immunity.