BackgroundTo study the reliability and validity of high-resolution peripheral quantitative CT (HR-pQCT) with microCT (μCT) as gold standard in the visual detection of cortical breaks in metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints.MethodsTen cadaveric fingers (10 MCP and 9 PIP joints) were imaged by HR-pQCT and μCT and visually analyzed by two independent readers. Intra- and interreader reliability were evaluated for the presence (yes/no, kappa statistics) and the total number (intraclass correlation coefficient, ICC) of cortical breaks. Sensitivity, specificity, positive and negative predictive value (PPV respectively NPV) of HR-pQCT in detecting cortical breaks were calculated.ResultsWith HR-pQCT, mean 149 cortical breaks were identified and with μCT mean 129 (p < 0.05). Intrareader reliability for the presence of a cortical break per quadrant was 0.52 (95 % CI 0.48–0.56) and 0.71 (95 % CI 0.67–0.75) for HR-pQCT and μCT, respectively, and for the total number of cortical breaks 0.61 (95 % CI 0.49–0.70) and 0.75 (95 % CI 0.68–0.82). Interreader reliability for the presence of a cortical break per quadrant was 0.37 (95 % CI 0.33–0.41) and 0.45 (95 % CI 0.41–0.49) for HR-pQCT and μCT, respectively, and for the number of cortical breaks 0.55 (95 % CI 0.43–0.65) and 0.54 (95 % CI 0.35–0.67). Sensitivity, specificity, PPV and NPV of HR-pQCT were 81.6, 64.0, 81.6, and 64 % respectively.ConclusionCortical breaks were commonly visualized in MCP and PIP joints with HR-pQCT and μCT. Reliability of both HR-pQCT and μCT was fair to moderate. HR-pQCT was highly sensitive to detect cortical breaks with μCT as gold standard.Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-016-1148-y) contains supplementary material, which is available to authorized users.

We evaluated whether cortical interruptions classified as vascular channel (VC) on high-resolution peripheral quantitative computed tomography (HR-pQCT) could be confirmed by histology. We subsequently evaluated the image characteristics of histologically identified VCs on matched single and multiplane HR-pQCT images. Four 3-mm thick portions in three anatomic metacarpophalangeal joint specimens were selected for histologic sectioning. First, VCs identified with HR-pQCT were examined for confirmation on histology. Second and independently, VCs identified by histology were matched to single and multiplane HR-pQCT images to assess for presence of cortical interruptions. Only one out of five cortical interruptions suggestive for VC on HR-pQCT could be confirmed on histology. In contrast, 52 VCs were identified by histology of which 39 (75%) could be classified as cortical interruption or periosteal excavation on matched single HR-pQCT slices. On multiplane HR-pQCT images, 11 (21%) showed a cortical interruption in at least two consecutive slices in two planes, 36 (69%) in at least one slice in two planes and five (10%) showed no cortical interruption. Substantially more VCs were present in histology sections than initially suggested by HR-pQCT. The small size and heterogeneous presentation, limit the identification as VC on HR-pQCT.