Skeletal Radiology

Painful right elbow mass

Perspective from a pediatric orthopedic deformity surgeon

Alkaptonuria—an atypical case: multi-modality imaging review Abstract Alkaptonuria is a rare inborn metabolic disorder due to a mutation in the homogentisic acid oxidase enzyme (HGO) gene on chromosome 3q. As HGO is deficient in alkaptonuria patients, there is an accumulation of homogentisic acid in the blood and urine. Homogentisic acid gets deposited in the soft tissues, tendons, cartilages, large joints and intervertebral discs. Ochronosis usually affects the dorsolumbar spine and typically spares the cervical spine and sacroiliac joints. However, in this case of isolated ochronosis, we report co-existent extensive cervical spine degenerative changes and cervical vertebral fusion, which has not been described in the literature so far.

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Bone metastases with multiple fluid-fluid levels from gastric cancer: a case report and review of literature Abstract We report the case of a 54-year-old man with 6 months of progressive sacral pain. Computed tomography showed a large osteolytic mass in the sacrum with multiple osteolytic foci in the ilium and lumbar spine. Magnetic resonance imaging revealed multiple fluid-fluid levels in the sacral lesion as well as in the lumbar foci. The multiple bone lesions were initially diagnosed as a primary sacral malignancy with multiple bone metastases. A biopsy of the sacral lesion under the guidance of computed tomography was performed and a metastatic adenocarcinoma from the stomach or lung was found pathologically. Finally, a gastric tubular adenocarcinoma was detected by endoscopic biopsy and the diagnosis of the patient was gastric cancer with uncommon multiple bone metastases.

Painful right elbow mass

Surface-type chondromyxoid fibroma in an elderly patient: a case report and literature review Abstract Chondromyxoid fibroma (CMF) is a rare benign bone neoplasm that typically occurs in young adults. Juxtacortical or surface-type CMF are rarer still and we present the case of a surface-type CMF in a 78-year-old woman, with only one other case described in a patient of a similar age previously. This patient was an otherwise healthy woman who presented for evaluation of a palpable lump in the anterior proximal tibia. Initial radiographs obtained demonstrated a focal soft tissue fullness immediately anterior to the anterior cortex of the proximal tibia, which contained faint chondroid-like matrix internally. There was associated scalloping of the anterior tibial cortex. MRI confirmed the presence of a juxtacortical, enhancing lesion. Subsequent excisional biopsy was performed and histopathology demonstrated features, which was consistent with surface-type CMF. At a 6-month follow-up the patient remained free of recurrence. In a patient of this age, paraosteal chondrosarcoma should be excluded. Surface-type CMF, although rare, has been described in older patients and while it is unlikely to feature in a list of differential considerations on initial imaging, awareness of the entity is important.

Subacromial impingement anatomy and its association with rotator cuff pathology in women: radiograph and MRI correlation, a retrospective evaluation Abstract Objective To evaluate the relationships between acromial anatomy and developmental alterations with rotator cuff tears in female patients and compare these parameters on radiographs and corresponding MRIs along with inter-reader performance. Materials and methods Patient demographics, symptoms, and acromial characteristics on radiograph (acromial index, lateral acromion angle, subacromial space on AP and Y- views, acromial anterior and lateral downsloping) and MRI (shape, slope, spur, osteoarthrosis, os acromiale) were recorded. Radiographic and MRI findings were compared and correlated with rotator cuff pathology on MRI. Inter-reader analysis was performed. Results A total of 140 MRIs from 137 female patients were included. No significant correlation (p > 0.05) existed between acromial parameters and rotator cuff tears, except for a smaller subacromial space on the Y view and spurs correlated with subscapularis tendon tear (p = 0.02, p = 0.04). The presence of lateral downsloping on MRI correlated with a smaller lateral acromion angle (p = 0.0002) and the presence of lateral downsloping on radiography (p = 0.0015). Inter-reader agreements were good to excellent (ICC: 0.65–0.89). Conclusion Subacromial impingement anatomy characteristics have no significant associations with supraspinatus or infraspinatus tears in symptomatic women. Among different measures, supine MRI can be reliably used to identify lateral downsloping of the acromion.

Susceptibility-weighted MR imaging to improve the specificity of erosion detection: a prospective feasibility study in hand arthritis Abstract Objective To evaluate the diagnostic potential of susceptibility-weighted imaging (SWI) for the detection of erosions of the hand, compared to T1-weighted (T1w) magnetic resonance imaging (MRI). Computed tomography (CT) was used as a reference standard. Materials and methods We prospectively investigated 37 patients with suspected arthritic activity of the hand. All patients underwent T1w, SWI, and CT on the same day. Patients were randomized to MRI or CT first. CT, T1w, SWI, and T1w/SWI were scored for erosions according to OMERACT RAMRIS guidelines. Specificity, sensitivity, and diagnostic accuracy were separately calculated for T1w, SWI, and T1w/SWI on a per-patient and per-bone basis using CT as reference. The one-tailed McNemar test was performed to test the number of erosion-positive patients in T1w, SWI, and T1w/SWI for non-inferiority. Measured erosion sizes were compared using Pearson's test. Results CT was positive for erosions in 16 patients and 55 bones. SWI and T1w/SWI had superior diagnostic accuracy (91.2 and 93.8%) compared to T1w (87.8%) driven by a higher specificity (93.8 and 96.5%) compared to T1w (88.8%). On the patient level, SWI and T1w/SWI showed non-inferiority (p = 0.11 and p = 0.38) but not T1w alone (p < 0.0001). The lesion size on CT correlated better with SWI (Pearson's r = 0.92) compared to T1w (r = 0.69). Conclusions Adding SWI to a standard MRI protocol has the potential to improve erosion detection in hands by increasing specificity. SWI depicts bony erosions more accurately compared to standard MRI techniques.

MRI and ultrasound of the hands and wrists in rheumatoid arthritis. I. Imaging findings Abstract The management of patients with rheumatoid arthritis (RA) has rapidly evolved with the development of newer disease-modifying drugs and the recognition that long-term damage can be mitigated by an earlier and more-informed use of these medications. Historically, radiographs were the mainstay of imaging in RA patients, but radiographic joint narrowing and erosions are late and insensitive findings in the disease. MRI (with intravenous contrast agent) and ultrasound (with power Doppler interrogation) of the hands and wrists are able to demonstrate erosions earlier and with greater sensitivity than radiographs. More importantly, these imaging studies also depict synovitis and active soft-tissue inflammation, which represents a precursor to structural damage. Additionally, MRI can show inflammation within the bones (osteitis), which is proving to be the most important prognosticator of an aggressive disease course. Part I of this review discusses the imaging techniques, pitfalls, definitions, and comparative studies of MRI and ultrasound for identifying and quantifying erosions, synovitis, and osteitis. Part II will demonstrate how these imaging findings influence the clinical management of RA patients throughout their disease course, from presentation through clinical remission.