Vascular channels in metacarpophalangeal joints: a comparative histologic and high-resolution imaging study

Abstract

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.

Assessment of Cortical Interruptions in the Finger Joints of Patients With Rheumatoid Arthritis Using HR-pQCT, Radiography, and MRI

“…In addition, the proportion of joints with at least two cortical interruptions (proportion of joints affected) was calculated. This cut‐off value was chosen because we expected at least one physiological interruption in the joints because of the presence of vascular channels …”

“…This cut-off value was chosen because we expected at least one physiological interruption in the joints because of the presence of vascular channels. (36) Bone density and microstructure parameters…”

High-Resolution Peripheral Quantitative Computed Tomography for Bone Evaluation in Inflammatory Rheumatic Disease

“…The high resolution of HR-pQCT not only reveals cortical interruptions meet the definition of erosions but also interruptions which have been hypothesized to be vascular channels. According to the SPECTRA erosion definition, the cortical interruption was suspected to be vascular channels if the interruption was characterized by a parallel cortical lining seen on two consecutive slices and two orthogonal planes (41).…”

“…Five could be evaluated with histology, and only one of these was a true vascular channel. While they are not vascular channels, these microchannels may provide a link between the synovium and the bone marrow (41). Another approach for investigating vascular channels was to inject the contrast agent Imeron into the ulnar and radial artery of six cadaveric hands prior to HR-pQCT scanning (44).…”

“…These findings do support the suggestion that bone has a large number of channels passing from the inside to the outside of the bone that is not necessarily linked to erosions, nor do all channels contain vessels. The shape of cortical interruptions cannot be used to accurately decide if cortical breaks contain vessels, as many cortical interruptions, that do not have a classic linear shape, contain vessels (41). Understanding the role of these various channels may be important to understand RA pathology.…”