Introduction
Musculoskeletal imaging focuses on the diagnostic imaging and treatment of diseases involving the joints, bones, muscles and spine. This includes imaging of arthritis, sports injuries, bone and soft tissue tumours, and muscular disorders. Our Department has been at the forefront of musculoskeletal imaging in Asia, and was the first to show a method for measuring glenoid bone loss in recurrent dislocation, which is now routinely used in radiology departments worldwide. We are one of the globally leading groups in osteoporotic vertebral fracture assessment. We are an active partner of MsOS (Hong Kong) and MrOS (Hong Kong) studies, which represents the first large-scale prospective cohort study ever conducted on bone health in Asian women. We confirmed that the spine osteoporotic fracture prevalence in elderly females is the same in Chinese, Korean, Japanese, Latin American, and slightly lower than white Caucasians. We confirmed that within the same mild/moderate vertebral grades, compared with the subjects without endplate/cortex fracture, subjects with endplate/cortex fracture are associated with a higher future risk of vertebral fracture. We have also showed that menopause accelerates disc degeneration in females. We established the prevalence and progression rate of spondylolisthesis in elderly Chinese men and women.
On-going Research
To establish a link between impaired bone marrow perfusion in osteoporosis and impaired cerebral perfusion
Establishing a link between impaired bone perfusion in osteoporosis and impaired cerebral perfusion (i.e. cerebrovascular disease) would be a significant step in (a) understanding the pathophysiology of both these common diseases and (b) the development of a single therapy to help both conditions.
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To prospectively evaluate the accuracy of ultrasound in characterizing superficial soft tissue tumors.
This prospective study was therefore designed to determine how frequently superficial soft tissue tumors could be characterized with a high level of confidence and the diagnostic accuracy of ultrasound in this particular setting. Secondary aims of the study were to further evaluate the overall accuracy of ultrasound in characterizing superficial soft tissue tumors as well as the accuracy of ultrasound in distinguishing benign from malignant superficial soft tissue tumors.
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Past Research
Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results
Y. X. J. Wáng, N. Che-Nordin, M. Deng, J. C. S. Leung, A. W. L. Kwok, L. C. He, J. F. Griffith, T. C. Y. Kwok, P. C. Leung
SUMMARY: Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/ and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity.
INTRODUCTION: The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented.
METHODS: Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant’s VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25–34% height loss) and severe (vd2s, 34–40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/ 3 or to grade-1 with ≥ 10% height loss.
RESULTS: Of subjects with Genant’s grades 0, − 1, − 2, and − 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20–34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates.
CONCLUSIONS: Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.
Prevalence of cervical spine degenerative changes in elderly population and its weak association with aging, neck pain, and osteoporosis
Xiao-Rong Wang, Timothy C. Y. Kwok, James F. Griffith, Blanche Wai Man Yu, Jason C. S. Leung, Yì Xiáng J. Wáng
BACKGROUND: To investigate the prevalence of MRI degenerative findings of cervical spine in elderly Chinese males and females.
METHODS: From a general population sample, cervical spine T2 weighted sagittal MR images were acquired in 272 males (mean age: 82.9±3.83) and 150 females (mean age: 81.5±4.27). Images were interpreted and degenerative changes were classified. Study subjects were divided into younger group (group A, ≤ 81 years) and older group (group B, >81 years). For neck pain, question was structured as ‘during the past 12 months, have you had any neck pain?’. Two hundred and fifty-two males and 134 females also had hip bone mineral density (BMD) measured.
RESULTS: 98.1% subjects exhibited at least one degenerative change at one or more vertebral levels. The C5/6 level had the highest overall frequency for degenerative changes. Most of the degenerative changes were more common in females. The older female group had higher prevalence or higher severity of degenerative findings than the younger group. Eleven point four percent of the males and 20.6% of the females reported neck pain, and male subjects with neck pain tended to have slightly higher prevalence of cervical degenerative changes. There was a weak trend that osteoporosis was associated with a higher prevalence of spinal cord high signal and a higher prevalence of spinal canal stenosis.
CONCLUSIONS: The age-dependence of cervical spine degenerative changes was more notable in females. Subjects with neck pain and subjects with osteoporosis were weakly associated with higher prevalence of cervical degenerative changes.
Vertebral Bone Mineral Density, Marrow Perfusion, and Fat Content in Healthy Men and Men with Osteoporosis: Dynamic Contrast-enhanced MR Imaging and MR Spectroscopy
James F. Griffith, David K. W. Yeung, Gregory E. Antonio, Francis K. H. Lee, Athena W. L. Hong, Samuel Y. S. Wong, Edith M. C. Lau, Ping Chung Leung
PURPOSE: To prospectively use hydrogen 1 (1H) magnetic resonance (MR) spectroscopy and dynamic contrast material–enhanced MR imaging to measure vertebral body marrow fat content and bone marrow perfusion in older men with varying bone mineral densities as documented with dual x-ray absorptiometry (DXA).
MATERIALS AND METHODS: This study had institutional review board approval, and all participants provided informed consent. DXA, 1H MR spectroscopy, and dynamic contrast-enhanced MR imaging of the lumbar spine were performed in 90 men (mean age, 73 years; range, 67–101 years). Vertebral marrow fat content and perfusion (maximum enhancement and enhancement slope) were compared for subject groups with differing bone densities (normal, osteopenic, and osteoporotic). The t test was used for comparisons between groups, and the Pearson test was used to determine correlation between marrow fat content and perfusion indexes.
RESULTS: Eight subjects were excluded, yielding a final cohort of 82 subjects (mean age, 73 years; range, 67–101 years) that included 42 subjects with normal bone density (mean T score, 0.8 ± 1.1 [standard deviation]), 23 subjects with osteopenia (mean T score, −1.6 ± 0.4), and 17 subjects with osteoporosis (mean T score, −3.2 ± 0.5). Vertebral marrow fat content was significantly increased in subjects with osteoporosis (mean fat content, 58.23% ± 7.8) (P = .002) or osteopenia (mean fat content, 55.68% ± 10.2) (P = .034) compared with that in subjects with normal bone density (50.45% ± 8.7). Vertebral marrow perfusion indexes were significantly decreased in osteoporotic subjects (mean enhancement slope, 0.78%/sec ± 0.3) compared with those in osteopenic subjects (mean enhancement slope, 1.15%/sec ± 0.6) (P = .007) and those in subjects with normal bone density (mean enhancement slope, 1.48%/sec ± 0.7) (P < .001).
CONCLUSIONS: Subjects with osteoporosis have decreased vertebral marrow perfusion and increased marrow fat compared with these parameters in subjects with osteopenia. Similarly, subjects with osteopenia have decreased vertebral marrow perfusion and increased marrow fat compared with these parameters in subjects with normal bone density.
Carpal Tunnel Syndrome: Diagnostic Usefulness of Sonography.
Shiu Man Wong, James F. Griffith, Andrew C. F. Hui, Sing Kai Lo, Michael Fu, Ka Sing Wong
PURPOSE: To prospectively evaluate accuracy of sonography for diagnosis of carpal tunnel syndrome (CTS) in patients clinically suspected of having the disease in one or both hands.
MATERIALS AND METHODS: A prospective cohort of 133 patients suspected of having CTS were referred to a teaching hospital between October 2001 and June 2002 for electrodiagnostic study. One hundred twenty patients (98 women, 22 men; mean age, 49 years; range, 19–83 years) underwent sonography within 1 week after electrodiagnostic study. Radiologist was blinded to electrodiagnostic study results. Seventy-five patients had bilateral symptoms; 23 patients, right-hand symptoms; and 22 patients, left-hand symptoms (total, 195 symptomatic hands). Cross-sectional area of median nerve was measured at three levels: immediately proximal to carpal tunnel inlet, at carpal tunnel inlet, and at carpal tunnel outlet. Flexor retinaculum was used as a landmark to margins of carpal tunnel. Optimal threshold levels (determined with classification and regression tree analysis) for areas proximal to and at tunnel inlet and at tunnel outlet were used to discriminate between patients with and patients without disease. Sensitivity, specificity, and false-positive and false-negative rates were derived on the basis of final diagnosis, which was determined with clinical history and electrodiagnostic study results as reference standard.
RESULTS: For right hands, sonography had sensitivity of 94% (66 of 70); specificity, 65% (17 of 26); false-positive rate, 12% (nine of 75); and false-negative rate, 19% (four of 21) (cutoff, 0.09 cm2 proximal to tunnel inlet and 0.12 cm2 at tunnel outlet). For left hands, sensitivity was 83% (53 of 64); specificity, 73% (24 of 33); false-positive rate, 15% (nine of 62); and false-negative rate, 31% (11 of 35) (cutoff, 0.10 cm2 proximal to tunnel inlet).
CONCLUSIONS: Sonography is comparable to electrodiagnostic study in diagnosis of CTS and should be considered as initial test of choice for patients suspected of having CTS.
DISCRIMINATORY SONOGRAPHIC CRITERIA FOR THE DIAGNOSIS OF CARPAL TUNNEL SYNDROME.
S. M. Wong, J. F. Griffith, A. C. F. Hui, A. Tang, K. S. Wong
OBJECTIVES: Sonographic examination of the median nerve has been suggested as a useful alternative to electrophysiologic study in the diagnosis of carpal tunnel syndrome. To determine its usefulness and the best diagnostic criterion, sonograms of patients with the disease were compared with sonograms of healthy subjects in a case–control study.
METHODS: Patients with carpal tunnel syndrome and asymptomatic controls who were matched for age and sex were enrolled and underwent sonography of the wrists. Eight separate sonographic criteria were analyzed in each wrist. Data from the patient group and the control group were compared to establish optimal diagnostic criteria for carpal tunnel syndrome, using receiver operating characteristic analytic techniques.
RESULTS: Thirty‐five patients with carpal tunnel syndrome and 35 asymptomatic controls were examined. Increased cross‐sectional area of the median nerve was found to be the most predictive measure of carpal tunnel syndrome, proximal to the tunnel inlet, at the tunnel inlet, and at the tunnel outlet, with significant differences between patients and controls. Using a receiver operating characteristic curve, a cut‐off value >0.098 cm2 at the tunnel inlet provided a diagnostic sensitivity of 89% and a specificity of 83%.
CONCLUSIONS: Sonographic measurement of the median nerve cross‐sectional area is both sensitive and specific for the diagnosis of carpal tunnel syndrome.
