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Biomedical subjects

P W Bearcroft

Publications and source records attributed to P W Bearcroft.

At least 19 recordsLinked to original sources
PubMed2001

Magnetic resonance imaging of the wrist: diagnostic performance statistics.

AIM: To review the published diagnostic performance statistics for magnetic resonance imaging (MRI) of the wrist for tears of the triangular fibrocartilage complex, the intrinsic carpal ligaments, and for osteonecrosis of the carpal bones. MATERIALS AND METHODS: We used Medline and Embase to search the English language literature. Studies evaluating the diagnostic performance of MRI of the wrist in living patients with surgical confirmation of MR findings were identified. RESULTS: We identified 11 studies reporting the diagnostic performance of MRI for tears of the triangular fibrocartilage complex for a total of 410 patients, six studies for the scapho-lunate ligament (159 patients), six studies for the luno-triquetral ligament (142 patients) and four studies (56 patients) for osteonecrosis of the carpal bones. CONCLUSIONS: Magnetic resonance imaging is an accurate means of diagnosing tears of the triangular fibrocartilage and carpal osteonecrosis. Although MRI is highly specific for tears of the intrinsic carpal ligaments, its sensitivity is low. The diagnostic performance of MRI in the wrist is improved by using high-resolution T2* weighted 3D gradient echo sequences. Using current imaging techniques without intra-articular contrast medium, magnetic resonance imaging cannot reliably exclude tears of the intrinsic carpal ligaments. Hobby, J. L. (2001). Clinical Radiology, 56, 50-57.

Carpal Bones↗
PubMed2001

MR imaging of the wrist: effect on clinical diagnosis and patient care.

PURPOSE: To evaluate the effect of magnetic resonance (MR) imaging of the wrist on clinicians' diagnoses, diagnostic certainty, and patient care. MATERIALS AND METHODS: A controlled observational study was performed. Referring clinicians completed questionnaires about diagnosis and intended management before and after wrist MR imaging. One hundred eighteen consecutive patients referred for MR imaging of the wrist were recruited from the MR imaging units at a regional teaching hospital and a large district general hospital. The main measures were changes in the clinicians' leading and subsidiary diagnoses after MR imaging, their certainty in these diagnoses, and changes in intended patient care. RESULTS: Questionnaires were incorrectly completed for five patients, questionnaires were not returned for three, appointments were canceled for 10, and two could not tolerate the MR examination. Complete follow-up data were available for 98 patients. The clinical diagnosis changed in 55 of 98 patients; in the remaining 43 patients, diagnostic certainty increased in 23. Clinicians reported that MR imaging had substantially improved their understanding of the disease in 67 of 98 patients. The care plan changed in 45 of 98 patients, with a shift away from surgical treatment. Twenty-eight patients were discharged without further investigation. MR imaging was similarly effective in the regional teaching center and the district general hospital. CONCLUSION: MR imaging of the wrist influences clinicians' diagnoses and management plans.

Humans↗
PubMed2000

An assessment of the effectiveness of magnetic resonance imaging of the shoulder: literature review.

OBJECTIVE: To analyse and compare all papers published to date (August 2000) that quantify the effectiveness, defined as the impact of clinician's diagnosis or management plans, or patient outcome, of MRI of the shoulder. DESIGN: A computerised search of Index Medicus with a broad search strategy relating to shoulder MRI was performed. Manual assessment of all papers listed was undertaken with classification of each paper depending on whether it addressed questions of (1) technical performance, (2) diagnostic performance or (3) outcome. RESULTS: Four of 265 qualifying papers addressed aspects of effectiveness and these were reviewed. The impact on the clinician's diagnosis varied widely between papers: the primary diagnosis was altered in 23% to 68% of cases, and the management plans were subsequently changed in 15% to 61% of cases. Only one paper addressed the impact on patient health. CONCLUSIONS: The effectiveness of MRI of the shoulder depends on the clinical skills of the referring clinician and prevalence of disease in the study population. This will have implications when the effectiveness of an imaging technique between different institutions is compared, and this in turn will influence any comparisons of cost-effectiveness.

Cost-Benefit Analysis↗
PubMed2000

The use of ultrasound-guided cutting-needle biopsy in paediatric neck masses.

OBJECTIVE: Neck masses are common in children. Although there is a low incidence of therapeutically significant pathology, biopsy is occasionally required for evaluation. Open biopsy or fine needle aspiration may be used to obtain tissue. Open biopsy provides material suitable for histological analysis but requires general anaesthesia. Cytological material obtained by fine needle aspiration is often inconclusive. A core of histological material may also be obtained by percutaneous cutting-needle biopsy, a recognised procedure at other anatomical sites, usually performed under local anaesthesia. MATERIALS AND METHODS: There are few accounts using cutting needles in adult neck masses and no previous paediatric series. We present our experience of ultrasound-guided core biopsies of neck masses in 15 children ranging in age from three months to 16 years. RESULTS: Thirteen biopsies were easily performed without sedation as an outpatient procedure under topical and injected local anaesthetic. In all fifteen cases the procedure was well tolerated and a tissue successfully obtained. CONCLUSION: Ultrasound guided cutting needle biopsies of head and neck masses of children can be performed under local anaesthesia in the majority of cases.

Adolescent↗
PubMed2000

Assessment of quantitative computed tomographic cerebral perfusion imaging with H2(15)O positron emission tomography.

Assessment of quantitative cerebral blood flow on a conventional fast CT machine without the use of specialized equipment may be valuable in the investigation of acute stroke and head injury. We aimed to compare a single slice CT perfusion sequence with H2(15)O positron emission tomography using the sagittal sinus as an input function, a method that avoids unnecessary orbital irradiation. Eight patients were studied, two patients with gliomas, and six with arteriovenous malformations. The dynamic CT perfusion sequence was performed by acquiring the same 10 mm slice 10 times over 30 sec during a 50 ml bolus of intravenous contrast medium given at a rate of 7.5 ml sec-1 using a power injector. The CT perfusion studies were completed without complication. Co-registration was sub-optimal in one patient. Overall the correlation between the two methodologies was encouraging with an average r2 value of 0.524 for individual analyses. When two patients with high flow arteriovenous malformations were excluded the average r2 value increased to 0.640. The results of this CT perfusion methodology are encouraging. Having shown its feasibility, further studies in conditions with lower rates of cerebral blood flow are warranted.

Adult↗
PubMed2000

Incidence of vertebral fractures in the first three months after orthotopic liver transplantation.

BACKGROUND AND OBJECTIVES: High rates of bone loss and increased fracture incidence have been reported in patients undergoing liver transplantation, mainly within the first post-operative year. The pathogenesis of post-transplantation bone disease has not been clearly established, but the high doses of glucocorticoids used for immunosuppression may contribute. The use of lower doses in recent years has been associated, in some studies, with lower rates of bone loss and decreased fracture incidence. The aim of this prospective study was to establish the incidence of vertebral fractures in the first 3 months in patients undergoing liver transplantation for chronic liver disease and to identify risk factors for fracture in these patients. DESIGN AND METHODS: Thirty-seven adults with end-stage liver disease were studied prospectively prior to and 3 months after liver transplantation. Vertebral fractures were assessed semi-quantitatively from lateral spine X-rays and bone mineral density measured using dual energy X-ray absorptiometry. RESULTS: Prior to transplantation, prevalent vertebral fractures were present in 13 patients (35%). New fractures developed after transplantation in 10 patients (27% of total) and were significantly more common in those with a prevalent vertebral fracture pre-operatively (P<0.02). Osteoporosis, defined as a bone mineral density T score below -2.5, was present in 39% of patients prior to transplantation, but bone mineral density was not helpful in predicting incident fracture, whether measured before or after transplantation. Over the 3-month study period, significant bone loss occurred in the femoral neck (P<0.05) but not the lumbar spine. CONCLUSIONS: Our results demonstrate a high incidence of vertebral fracture in the first 3 months after liver transplantation and indicate that prevalent vertebral fracture is an important risk factor for the subsequent development of fracture in these patients. Prevention of post-transplantation bone disease should focus both on optimizing bone mass prior to transplantation and preventing bone loss in the early post-operative period.

Absorptiometry, Photon↗
PubMed2000

Communication of doubt and certainty in radiological reports.

We have investigated the reliability of communication of uncertainty in radiological reports. The 18 most commonly used verbal expressions of probability were identified from a series of radiological reports. 11 clinicians (three radiologists, three rheumatologists and five orthopaedic surgeons) recorded the probability that they ascribed to each of the 18 expressions using visual analogue scales. Each subject was re-tested on four occasions at least 1 week apart. The results were analysed to assess reproducibility within and between individuals. We found considerable variation in the probabilities assigned to many commonly used expressions between subjects, and between repeated testing of the same subject. Some expressions were rated much more consistently than others. "Absent", "excludes", "unlikely", "probable", "certain" and "definite" were the most consistently rated expressions. We have identified a potential source of misunderstanding in radiological reports owing to differences in interpretation of expressions used by radiologists and referring clinicians.

Diagnostic Services↗
PubMed2000

Management of neck lumps--a triage model.

We report our experience in the out-patient triage of 100 patients presenting with a lump in the neck. The out-patient visit consisted of a general history and examination, assessment of the upper air and food passages and, where indicated, ultrasound and core needle biopsy of the lump. Other investigations were performed as appropriate. One hundred neck lump patients were seen in a 9 month period. Ninety-six of these lumps were diagnosed on an out-patient basis, only four requiring admission for formal excision biopsy. Among the diagnoses were eleven lymphomas, nine parotid neoplasms, nine lymph node metastases, five thyroglossal cysts, and four branchial cysts. Almost half the patients seen had either a reactive lymphadenopathy, or no abnormality. The establishment of a tissue diagnosis on an out-patient basis allowed appropriate referrals to be made and management plans to be formulated. The theoretical risk of seeding of malignant cells in the needle tract is acknowledged and discussed.

Adolescent↗
PubMed1999

Follow-up of musculoskeletal tumours. 2. Metastatic disease.

Both the prognosis and the morbidity of a patient with a primary malignant musculoskeletal tumour have improved over the past 25 years due to the advent of adjuvant chemotherapy and limb-sparing surgery. This has important implications for the role of imaging at the time of initial diagnosis and during follow-up. This pictorial essay reviews the imaging and pitfalls in the interpretation of musculoskeletal sarcoma metastases using a variety of radiological techniques. The optimal imaging strategy will be stressed.

Bone Neoplasms↗
PubMed1999

Diagnostic and therapeutic impact of MRI and arthrography in the investigation of full-thickness rotator cuff tears.

Investigation of shoulder pain is important before surgical treatment. The presence or absence of a full-thickness rotator cuff tear (FTRCT) may determine the type of surgical treatment. Both MRI and conventional arthrography can be used, but little is known about their relative diagnostic and therapeutic impact. We performed a prospective trial assessing: (a) the influence of MRI and arthrography results on the clinician's diagnostic thinking (diagnostic impact); (b) the influence of the results on the clinician's therapeutic thinking (therapeutic impact); and (c) the diagnostic performance of the two techniques in patients with surgical confirmation. A total of 104 consecutive patients with shoulder problems referred to a specialist orthopaedic shoulder clinic underwent pre-operative investigation with MRI and arthrography. The surgeon's diagnosis, diagnostic confidence and planned treatment were measured before the investigation, and then again after the results of each investigation. Before the presentation of the investigation, results, the patients were randomised into two groups. In one group MRI was presented first; in the other group, arthrography. The MRI results led to fewer changes in diagnostic category (14 of 46, 30%) than arthrography (20 of 54, 37%), but the difference was not significant (P > 0.5). Magnetic resonance imaging led to slightly more changes in planned management (17 of 47, 36%) than arthrography (14 of 55, 25%), but again the difference was not statistically significant (P > 0.3). The results of the second investigation always had less diagnostic and therapeutic impact than the first. The accuracy of MRI for FTRCT in 38 patients with surgical confirmation was 79%, sensitivity 81% and specificity 78%; the accuracy of arthrography was 82%, sensitivity 50% and specificity 96%. The clinical diagnosis and management plan can be adequately defined by a single radiological investigation. Magnetic resonance imaging and arthrography had fairly similar diagnostic and therapeutic impact and comparable accuracy, although MRI was more sensitive and less specific. Magnetic resonance imaging may be the preferred investigation because of its better demonstration of soft tissue anatomy.

Adult↗
PubMed1999

MR cholangiopancreatography: prospective comparison of a breath-hold 2D projection technique with diagnostic ERCP.

The aim of this study was to compare prospectively a breath-hold projection magnetic resonance cholangiopancreatography (MRCP) technique with diagnostic endoscopic retrograde cholangiopancreatography (ERCP). Seventy-six patients with suspected strictures or choledocholithiasis were referred for MRCP and subsequent ERCP examination, which were performed within 4 h of each other. The MRCP technique was performed using fat-suppressed rapid acquisition with relaxation enhancement (RARE) projection images obtained in standardised planes with additional targeted projections as required by the supervising radiologist. Two radiologists (in consensus) assessed the MRCP results prospectively and independently for the presence of bile duct calculi, strictures, non-specific biliary dilatation and pancreatic duct dilatation, and recorded a single primary diagnosis. The ERCP was assessed prospectively and independently by a single endoscopist and used as a gold standard for comparison with MRCP. Diagnostic agreement was assessed by the Kappa statistic. The MRCP technique failed in two patients and ERCP in five. In the remaining 69 referrals ERCP demonstrated normal findings in 23 cases, strictures in 19 cases, choledocholithiasis in 9 cases, non-specific biliary dilatation in 14 cases and chronic pancreatitis in 4 cases. The MRCP technique correctly demonstrated 22 of 23 normal cases, 19 strictures with one false positive (sensitivity 100 %, specificity 98 %), all 9 cases of choledocholithiasis with two false positives (sensitivity 100 %, specificity 97 %), 12 of 14 cases of non-specific biliary dilatation and only 1 of 4 cases of chronic pancreatitis. There was overall good agreement for diagnosis based on a kappa value of 0.88. Breath-hold projection MRCP can provide non-invasively comparable diagnostic information to diagnostic ERCP for suspected choledocholithiasis and biliary strictures and may allow more selective use of therapeutic ERCP.

Adult↗
PubMed1999

Magnetic resonance imaging or arthrography for shoulder problems: a randomised study.

OBJECTIVE: Diagnostic technologies are often assessed merely by their accuracy, rather than by their impact on diagnosis and patient management. To this end the authors have undertaken a study to assess the diagnostic and therapeutic impact of magnetic resonance imaging (MRI) and arthrography of the shoulder for patients referred from a rheumatology clinic. METHODS AND PATIENTS: Patients referred from a rheumatology clinic with symptoms warranting imaging of the shoulder were randomised to either MRI or arthrography. Data on the clinician's diagnostic confidence and management were recorded before and after imaging using questionnaires. Patients were followed-up at least 10 months after imaging to see how management plans evolved, and what proportion of patients required further imaging. RESULTS: Fifty three shoulders underwent imaging over a year and entered into the study; 29 randomised to MRI and 24 to arthrography. Both MRI and arthrography had a similar beneficial diagnostic impact in terms of clinical diagnoses (refuted and retained) and new diagnoses established. MRI and arthrography had a similar therapeutic impact, although MRI was associated with a significant shift towards surgical intervention. CONCLUSION: MRI and arthrography a have similar diagnostic and therapeutic impact.

Adult↗
PubMed1998

The use of spiral computed tomography in musculoskeletal radiology of the lower limb: the calcaneus as an example.

The advent of spiral (helical) computed tomography (CT) has markedly increased the speed of modern CT systems and has found a use in a variety of musculoskeletal applications. However, the limitations of the technique must be understood if examinations are to be tailored and optimised. This review puts the limitations and advantages into context by outlining how spiral CT can be applied to musculoskeletal imaging of the lower limb. Imaging of intra-articular fractures of the calcaneus serves as a timely example of how the imaging parameters can be optimised and where the technique can offer potential advantages over conventional CT.

Ankle Joint↗
PubMed1997

Magnetic resonance imaging of the coraco-acromial ligament.

The coraco-acromial ligament is important first for the stability of the shoulder joint and second because it can impinge on the rotator cuff. In this study we demonstrate how the coraco-acromial ligament can be shown by magnetic resonance imaging (MRI) in the axial plane as well as in the more conventional coronal and sagittal planes.

Humans↗
PubMed1997

Non-invasive cholangio-pancreatography by breath-hold magnetic resonance imaging: preliminary results.

AIMS: A preliminary comparison of a prototype breath-hold magnetic resonance cholangio-pancreatography (MRCP) technique for non-invasive imaging of the pancreatic and biliary ducts with endoscopic retrograde cholangio-pancreatography (ERCP). METHOD: Twenty ERCP and MRCP examinations were performed in 19 patients referred for routine ERCP with suspected biliary or pancreatic abnormalities. The MRCP technique employed a modified heavily T2-weighted thick slice RARE sequence that allowed up to three images to be obtained in a 16 second breath-hold. The examinations were reported independently and the findings compared. RESULTS: MRCP accurately discriminated between patients without obstruction (n = 12) and those with (n = 8) and correctly diagnosed the cause of obstruction (three choledocholithiasis, five malignant stricture). In the 12 patients without obstruction the examinations were concordant in eight. In the remaining four patients MRCP provided more information than the corresponding ERCP study, diagnosing a pseudocyst in one patient and visualizing the entire pancreatic duct in three patients in whom this was not possible at ERCP. CONCLUSIONS: These preliminary results suggest that a breath-hold MRCP technique may allow the selection of those patients with obstructive lesions that require therapeutic ERCP intervention, and may have the potential to reduce the need for diagnostic ERCP examinations.

Adult↗
PubMed1997

Magnetic resonance imaging of the shoulder: assessment of effectiveness.

OBJECTIVES: To quantify how magnetic resonance imaging (MRI) influences clinicians' diagnosis, diagnostic confidence and management plans in patients with shoulder problems. To investigate whether such changes are associated with an improvement in health. METHODS: A prospective observational study on all patients referred to a regional centre for MRI of the shoulder over a 6-month period. Data on diagnosis, diagnostic confidence and proposed management before MRI were compared with diagnoses and actual management after MRI. In addition, short form 36 item (SF-36) health survey data were collected at referral and again 6 months later. RESULTS: In 86 of 99 MRI referrals there was sufficient clinical data for the patient to enter the study. MRI led to previously unsuspected diagnoses in 20 of 59 patients where the clinicians had provided full diagnostic information before and after the examination. When MRI confirmed the clinical diagnosis, significant improvements in clinicians' diagnostic confidence were found (P < 0.001). MRI led to a change in management (P < 0.05) in 44 (62%) of the 71 patients where full management plans were available. Health survey results were available in 62 patients; although there were some improvements in SF-36 scores, these did not reach statistical significance. CONCLUSION: Magnetic resonance imaging of the shoulder significantly influences clinicians' diagnoses and management plans. However, patients do not record a statistically significant improvement in health-related quality of life over 6 months.

Adolescent↗