Postpartum Bone Marrow Edema at the Sacroiliac Joints May Mimic Sacroiliitis of Axial Spondyloarthritis on MRI.

OBJECTIVE: The objective of our study was to compare MRI findings in the sacroiliac joints of postpartum women (as a model of mechanical changes) and women with known axial spondyloarthritis (as an inflammatory model). SUBJECTS AND METHODS: For this prospective multicenter age-matched, case-control study, sacroiliac joint MRI examinations of 30 healthy women (mean age, 34.0 years) in the early postpartum period (mechanical group) and 30 age-matched women (mean age, 33.8 years) with known axial spondyloarthritis (retrospective inflammatory group) were compared. Blinded to clinical information, readers assessed MR images using the following scoring systems: Spondyloarthritis Research Consortium of Canada (SPARCC) MRI index, Berlin method, Assessment of Spondyloarthritis International Society (ASAS) criteria, and SPARCC MRI structural score. Descriptive statistics as percentages of the different findings (i.e., bone marrow edema [BME], erosion, fatty bone marrow replacement, backfill, ankylosis) and scores between groups and between delivery modes were compared. RESULTS: In the postpartum group, 63.3% (19/30) of women showed BME around the sacroiliac joints compared with 86.7% (26/30) of women in the spondyloarthritis group (based on ASAS criteria). Erosions were uncommon in the postpartum group (10.0% [3/30] postpartum vs 56.7% [17/30] spondyloarthritis). Fatty bone marrow replacement, backfill, and ankylosis were not seen in the postpartum group. In subjects with positive MRI findings for sacroiliitis based on ASAS criteria, the SPARCC MRI index (mean ± SD, 13.6 ± 14.5 vs 13.0 ± 10.7; p = 0.818) and Berlin method (4.5 ± 3.0 and 5.5 ± 3.5, p = 0.378) were not different between the postpartum and spondyloarthritis groups. Scores were not different between birth modalities. CONCLUSION: Pregnancy-induced BME at the sacroiliac joints, as a result of prolonged mechanical stress, was present in 63.3% of women who underwent MRI during the early postpartum period and may mimic sacroiliitis of axial spondyloarthritis.

High-resolution chromosomal microarrays in prenatal diagnosis significantly increase diagnostic power.

OBJECTIVE: The objective of this study was to determine for the first time the reliability and the diagnostic power of high-resolution microarray testing in routine prenatal diagnostics. METHODS: We applied high-resolution chromosomal microarray testing in 464 cytogenetically normal prenatal samples with any indication for invasive testing. RESULTS: High-resolution testing revealed a diagnostic yield of 6.9% and 1.6% in cases of fetal ultrasound anomalies and cases of advanced maternal age (AMA), respectively, which is similar to previous studies using low-resolution microarrays. In three (0.6%) additional cases with an indication of AMA, an aberration in susceptibility risk loci was detected. Moreover, one case (0.2%) showed an X-linked aberration in a female fetus, a finding relevant for future family planning. We found the rate of cases, in which the parents had to be tested for interpretation of unreported copy number variants (3.7%), and the rate of remaining variants of unknown significance (0.4%) acceptably low. Of note, these findings did not cause termination of pregnancy after expert genetic counseling. The 0.4% rate of confined placental mosaicism was similar to that observed by conventional karyotyping and notably involved a case of placental microdeletion. CONCLUSION: High-resolution prenatal microarray testing is a reliable technique that increases diagnostic yield by at least 17.3% when compared with conventional karyotyping, without an increase in the frequency of variants of uncertain significance.

MR imaging of pubic symphysis after uncomplicated vaginal delivery and planned caesarean delivery in the first postpartum week.

PURPOSE: To compare changes in the pubic symphysis between women with vaginal delivery and women with caesarean sections within the first postpartum week. MATERIALS AND METHODS: After institutional review board approval 30 healthy women were prospectively examined with MRI (transverse STIR-sequence) three days after delivery. 17 women with vaginal delivery (mean age 33.2 ±â€¯4 years) and 13 with caesarean delivery (35.2 ±â€¯5.6 years) were compared by two musculoskeletal radiologists. Bone marrow edema (location and extent), fluid in the joint gap, joint space width and stress fractures were assessed. RESULTS: Prevalence of bone marrow edema was high and not different between groups (13/17 (76.5%) vaginal deliveries) and 10/13 (76.9% caesarean deliveries) for reader 1 (p = 0.992) and 14/17 (82.4%) and 10/13 (76.9%) for reader 2 (p = 0.762). Size of bone marrow edema was not statistically significantly different for both readers (results reader 1: right side 2.5 ±â€¯3.3 mm vs. 6.3 ±â€¯7.3 mm, p = 0.300; left side 3.4 ±â€¯4.1 mm vs. 4.1 ±â€¯4.6 mm, p = 0.837). Fluid in the joint was seen in 4/17 (23.5%) vs. 2/13 (15.4%) (p = 0.580) for reader 1 (similar for reader 2). Joint space width did not differ between groups (2.6 ±â€¯0.7 mm vs. 3.1 ±â€¯1.2 mm, p = 0.198). Pubic symphysis diastasis (joint space width > 10 mm) was not observed. Interreader agreement for these parameters was substantial to almost perfect (0.671-0.984, kappa values/intraclass correlation). Reader 1 found no stress fractures, while reader 2 suspected 1 stress fracture on a right pubic bone in a woman after caesarean delivery. CONCLUSIONS: Pubic bone marrow edema is present in 3 of 4 women in the first postpartum week unrelated to the delivery mode.