Biomedical subjects

J P Crabbe

Publications and source records attributed to J P Crabbe.

13 recordsLinked to original sources

PubMed2001

Magnetic resonance imaging of the wrist in early rheumatoid arthritis: a pictorial essay.

This pictorial essay describes the changes seen in the wrist in early rheumatoid arthritis (RA) on MRI. Magnetic resonance imaging can demonstrate bone erosions, bone marrow signal changes, synovitis and tenosynovitis in early rheumatoid arthritis. Magnetic resonance imaging of the wrist can identify erosions in RA earlier than plain radiographs and can detect more erosions. Common sites include the capitate, lunate and scaphoid. Bone marrow signal changes occur frequently and are most common in the capitate, lunate and triquetrum. Synovial thickening and enhancement are clearly demonstrated with MRI and are most commonly seen in the radiocarpal joint (RCJ). Tenosynovitis can be seen in the wrist in more than half of patients presenting with RA. This most commonly involves the extensor carpi ulnaris tendon and is seen as sheath fluid, thickening and enhancement.

Arthritis, Rheumatoid↗

PubMed1996

Occult femoral neck fractures in the elderly: optimisation of investigation.

AIMS: A relatively common clinical problem is the elderly patient who presents with strong clinical suspicion of femoral neck fracture, but normal initial radiographs. Our aim was to analyse the methods by which such a patient was investigated in a large hospital in New Zealand. We wished to determine the cost-effectiveness of current practice, in the light of recent trends overseas. METHODS: We retrospectively reviewed the records of 410 patients over 50 years of age presenting acutely to Auckland Hospital over a 12 month period, in whom trauma hip radiographs had been requested. We recorded initial radiographical diagnosis, admission or discharge following acute assessment, further radiological investigations, and the time taken to make the final diagnosis. RESULTS: Twenty-five patients with suspected occult femoral neck fracture underwent further radiological investigation, consisting of plain radiographs, scintigram, and CT, singly or in combination. The final diagnosis was achieved by repeat radiographs in 10 patients, and by scintigraphy in 15 patients. The time to arrive at the final diagnosis was on average 9.6 days when the diagnosis was made by radiographs, and 5.3 days when the diagnosis was made by scintigraphy. The overall average time taken to achieve the diagnosis was 7.0 days. CONCLUSIONS: Our analysis shows that the bed cost is the major expense incurred by the delayed diagnosis of a suspected occult femoral neck fracture. Various studies have shown the accuracy of magnetic resonance imaging in the assessment of these fractures. This practice is not yet routinely established throughout New Zealand. However, an urgent MRI study, performed at the time of initial assessment could markedly reduce the cost of managing this patient group.

Cost-Benefit Analysis↗

PubMed1996

Association of bone mineral density and sex hormone levels with osteoarthritis of the hand and knee in premenopausal women.

Mechanical stress on the cartilage and metabolic and/or hormonal influences have been suggested as possible etiologic factors for osteoarthritis. This paper reports findings from data collected in 1992 that were used to examine associations between osteoarthritis and risk factors in 573 Caucasian women aged 24-45 years from the Michigan Bone Health Study. Radiographs of the dominant hand and both knees were evaluated using the Kellgren and Lawrence grading scale. The prevalence of osteoarthritis (grade 2 or higher) in this population was 2.8% for hands and 3.6% for knees. Using polytomous multiple logistic regression, the authors found older age, increasing bone mineral density, and decreasing testosterone levels to be significantly associated with increasing hand scores. Older age and hand injury were significantly associated with grades of 2 or higher. Increasing osteoarthritis knee scores were associated with older age, increasing bone density, increasing body mass index, and current use of hormone replacement therapy. A knee grade of 2 or higher was associated with increasing estradiol levels, knee injury, and higher blood pressure. This study indicates that age, bone density, and injury are risk factors common to the development of hand and knee osteoarthritis in this non-elderly female population.

Adult↗

PubMed1995

Gradient-echo MR imaging of the temporomandibular joint: diagnostic pitfall caused by the superficial temporal artery.

OBJECTIVE: In routine MR imaging of the temporomandibular joints, a low-signal structure posterosuperior to the mandibular condyle is occasionally seen on the two-dimensional gradient-echo sequence. The structure is ovoid and may have a higher-signal core, simulating a loose body within the joint. We undertook a clinical and cadaveric study to determine the cause of this finding. MATERIALS AND METHODS: In a clinical study, we reviewed the MR images of 100 temporomandibular joints. We scored each joint for the presence and appearance of a low-signal structure posterosuperior to the mandibular condyle: type 1 was ovoid with a low-signal rim and a higher-signal core, type 2 was ovoid with uniformly low signal, type 3 was a low-signal structure inseparable from the posterior wall of the glenoid fossa, and type 4 was normal. Using this scoring system, we determined the appearance and frequency of the finding on two-dimensional gradient-echo, T1-, T2-, and proton density-weighted images. To determine the cause of the finding, we correlated the imaging and anatomic findings in a cadaveric specimen. RESULTS: Of the 100 MR images of joints reviewed, 22 showed a type 1 structure, 24 a type 2 structure, 11 a type 3 structure, and 43 were normal. The finding was seen only on the two-dimensional gradient-echo sequences, never on the spin-echo sequences. Correlation between the imaging and anatomic findings in the cadaveric specimen showed that the finding was caused by the superficial temporal artery. The variability in its appearance is thought to result from the complex manifestations of flowing blood within this artery. CONCLUSION: The finding posterosuperior to the mandibular condyle seen on two-dimensional gradient-echo MR images is a flow phenomenon within the superficial temporal artery. Recognition of the nature of this finding will avoid mistaking it for disease, such as an intraarticular loose body.

Adult↗

PubMed1994

Improving report turnaround time: an integrated method using data from a radiology information system.

OBJECTIVE: In the face of a changing health care system and increased competition, radiology departments need to become more efficient. One measurement of efficiency is promptness in producing a final report. Many large radiology centers have radiology information systems (RIS) that track work flow, collecting tremendous amounts of data. Most, however, lack an appropriate analytic mechanism. We have developed an integrated system that allows continual monitoring of radiology work flow and thus of opportunities to apply interventions. This system can form an important component of the quality management process in the radiology department. MATERIALS AND METHODS: In developing the system, we identified seven key steps in the work-flow process. When left to chance, these steps occur out of sequence and large delays occur. A scheme was devised to improve the sequencing of the work flow by using the data collected from the RIS, sorted by radiology division and patient type. Biweekly, the appropriate data file is transferred to each division for analysis, via the department's computer network. A one-step process follows, using desktop Macintosh computers and a custom program written in Microsoft Excel. Extracted data are quickly converted into a tailored division summary, and a report is automatically generated. RESULTS: The result summary format is uniform throughout the department, allowing ease of review at divisional and departmental meetings. Problems can be immediately localized to a specific step in the work-flow process. Automation of much of the system allows continual, near-real-time review of work flow. Using this approach, we have seen a sustained reduction of average report turnaround time. CONCLUSION: This system allows continual monitoring of work flow. It is largely automated and lends itself well to inclusion in the quality management program of any radiology department.

Medical Records Systems, Computerized↗

PubMed1993

Bone scintigraphy in blastomycotic osteomyelitis.

A case of disseminated North American blastomycosis is described in which the full extent of the multifocal osteomyelitis was depicted by Tc-99m MDP scintigraphy. Skeletal involvement by this disease is not uncommon, yet the utility of bone scintigraphy has not been reported. The efficacy with which the whole body may be examined makes this technique especially appropriate for a hematogenously disseminated and often multifocal form of osteomyelitis where radiographically occult and asymptomatic lesions may be present.

Blastomycosis↗

PubMed1993

Reactive soft-tissue mass associated with osteoid osteoma: correlation of MR imaging features with pathologic findings.

The authors retrospectively reviewed three cases of histologically documented osteoid osteoma in which magnetic resonance (MR) imaging was performed prior to surgical excision. In all three cases, MR imaging demonstrated abnormal signal intensity characteristics, and use of gadopentetate dimeglumine resulted in enhancement. These findings correlated with a reactive soft-tissue mass with myxomatous change, as well as with cell-depleted, juxtanidal bone marrow that contained proteinaceous material. These MR imaging findings can easily be confused with those of a malignant tumor or osteomyelitis.

Adolescent↗

PubMed1992

Usefulness of an acoustic edge artifact in assessment of the Ilizarov corticotomy interval.

Thirty-three ultrasound examinations of the corticotomy interval of patients undergoing Ilizarov procedures were retrospectively evaluated for the presence or absence of an acoustic edge artifact. This artifact, consisting of a fine anechoic band, has been previously described in phantom models and is presumed to be due to phase cancellation effects. We demonstrated this artifact in 8 of 33 examinations. The artifact proved helpful in identifying the location of the corticotomy margin, even when this margin was obscured by the presence of developing periosteal new bone. Attention to technical factors is, however, important. We believe that this artifact may have a useful role in the routine monitoring of the Ilizarov patient.

Adolescent↗

PubMed1992