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Biomedical subjects

C E Hutchinson

Publications and source records attributed to C E Hutchinson.

At least 19 recordsLinked to original sources
PubMed2006

MR measurement of articular cartilage thickness distribution in the hip.

OBJECTIVE: To develop a method to determine the distribution of articular cartilage in the hip and to evaluate the potential of the method in a study of normal weight-bearing effects in asymptomatic young volunteers. DESIGN: Six volunteers were scanned after periods of standing and lying supine, using 3D gradient-echo magnetic resonance imaging (MRI). The protocol was repeated for two successive weeks to determine reproducibility. The femoral and acetabular cartilage layers were segmented as a single unit and thickness distribution maps were calculated using a spherical bone model as a frame of reference. Thickness maps were combined over the population using the bone model and post-weight-bearing and post-resting maps were compared. RESULTS: Mean thickness values were compared using an analysis of variance and a significant increase in cartilage thickness of 0.05 mm (P=0.02) was observed. The reproducibility of the method, assessed using test-retest coefficient of variation was 2.5%. CONCLUSIONS: The technique is reproducible, sensitive to sub-millimetre changes in thickness and may be useful in monitoring changes due to disease progression in patients with arthritis of the hip.

Adult↗
PubMed2006

The relationship between acetabular retroversion and osteoarthritis of the hip.

Excessive acetabular cover secondary to a retroverted acetabulum causes pincer impingement, which may cause early osteoarthritis of the hip. Our aim was to determine if there was a relationship between acetabular version and osteoarthritis of the hip. Using image processing and analysis software we studied 117 CT images of the hip in patients aged less than 65 years who had undergone a CT virtual colonoscopy. The mean CT joint space of the 18 hips with acetabular retroversion was narrower compared with the 99 hips with normal acetabular alignment (p < 0.0001). A correlation of r = 0.46 (p < 0.01) was found between right hip acetabular version and the mean right hip joint space and of r = 0.31 (p = 0.02) between left hip acetabular version and the mean left hip joint space. Acetabular retroversion is associated with radiological evidence of osteoarthritis of the hip. An understanding of the mechanical basis of osteoarthritis of the hip allows early treatment of the underlying structural abnormality and prevents progression of the degenerative condition.

Acetabulum↗
PubMed2002

Assessing periarticular bone mineral density in patients with early psoriatic arthritis or rheumatoid arthritis.

BACKGROUND: Periarticular osteoporosis is an early finding in the hands of patients with rheumatoid arthritis (RA), due to release of bone resorbing cytokines from the inflamed synovium. There has been disagreement as to whether periarticular bone loss occurs in psoriatic arthritis (PsA). Bone mineral density (BMD) can now be measured accurately using dual energy x ray absorptiometry (DEXA). Recently, DEXA has been used to measure periarticular BMD at predefined regions of interest (ROIs) around the joints. OBJECTIVES: Firstly, to compare periarticular BMD around the finger joints of patients with early RA or PsA. Secondly, to determine whether periarticular bone loss is related to joint inflammation and radiological erosions in RA and PsA. METHODS: Seventeen patients with RA and 15 with PsA were recruited, all with disease duration of less than five years. All finger joints were examined by one person for swelling, or tenderness, or both. Hand radiographs were scored for the presence of erosions. Periarticular BMD was measured at 10 predetermined ROIs using a Hologic QDA-4500A fan-beam densitometer. RESULTS: Patients with PsA were less likely to be positive for rheumatoid factor (RF) (13% v 94%) and more likely to be men (60% v 23%) than patients with RA. There were no other clinical differences between patients with RA or PsA. Patients with RA had significantly lower BMD at each of the ROIs than those with PsA (p<0.05). However, these differences disappeared after adjusting for age and sex. Among patients with RA, those with a higher total number of swollen and/or tender hand joints had significantly lower periarticular BMD at the metocarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. No such association was found for patients with PsA. CONCLUSIONS: In early disease, periarticular bone loss occurred both in patients with RA and those with PsA. Among patients with RA, periarticular osteoporosis was related to measures of joint inflammation. There was no association between joint inflammation and periarticular bone loss in patients with PsA, which lends support to the hypothesis that the primary site of inflammation in PsA is extrasynovial.

Absorptiometry, Photon↗
PubMed2001

The assessment of irradiated bladder carcinoma using dynamic contrast-enhanced MR imaging.

AIM: To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) in distinguishing residual or recurrent tumour from radiation change in patients with bladder carcinoma. MATERIALS AND METHODS: Forty patients with biopsy proven bladder carcinoma were imaged before and at 4 and 12 months after radiotherapy (XRT) using conventional and dynamic contrast-enhanced magnetic resonance imaging at 0.5 Tesla. An enhancement of >1.54 times above baseline at 80 s post-contrast injection proved a reliable indicator of tumour before radiotherapy and was therefore applied to the assessment of patients after XRT. Conventional MR images and dynamic enhancement profiles (DEPs) from the site of previous tumour were scored by three radiologists for the presence of tumour at 4 and 12 months after XRT. Findings were compared with cystoscopic biopsy. RESULTS: Dynamic contrast-enhanced magnetic resonance imaging had negative predictive values of 100% and 93% for tumour recurrence at 4 and 12 months, respectively. The positive predictive values, sensitivity and specificity were 48, 100 and 48% at 4 months and 50, 80 and +76% at 12 months post XRT, respectively. CONCLUSION: Dynamic contrast-enhanced magnetic resonance imaging may prove reliable in excluding the presence of persistent or recurrent tumour up to 12 months after XRT.

Contrast Media↗
PubMed2001

Foot problems in patients with systemic sclerosis.

OBJECTIVES: To assess the nature of the foot problems experienced in patients with systemic sclerosis (SSc) and patient awareness of such problems. METHODS: Fifty unselected patients (42 females, eight males) with SSc were assessed by means of examination by a senior podiatrist, completion of a questionnaire detailing past and present foot problems, determination of random plasma glucose, plain X-rays of the feet, and measurement of the ankle/brachial index and of digital pulses by Doppler ultrasound. RESULTS: Eighty-six per cent of patients reported colour changes in their feet in response to temperature changes, 82% reported pain usually related to cold, 26% had suffered foot ulceration and 8% had a history of foot surgery. Podiatry assessment confirmed the presence of significant abnormalities, including ulcerations in 10%, pre-ulcerative lesions in 34%, toenail changes in 62%, callus formation in 80% and calcinosis in 18%. Forty per cent of the patients had problems with the fitting of shoes, and 19% had been provided with footwear from the hospital. Plain films of the feet demonstrated the presence of erosions in 6%, soft-tissue calcification in 17%, osteopenia in 26% and degenerative changes in 60% of cases. Ten per cent of the patients had an abnormal ankle brachial index (less than 1.0). Only 21% of the 47 patients in whom digital pulses were examined had normal pulses in all toes, and in 26% all toe pulses were absent. CONCLUSION: Although problems with the hands are well recognized in SSc, foot problems also occur in the majority of patients, and can be a cause of major disability. Care of the feet is therefore an important part of the management of SSC.

Adult↗
PubMed2000

Relationship of MRI and clinical staging to outcome in invasive bladder cancer treated by radiotherapy.

AIM: To compare MRI and clinical staging of invasive bladder cancer prospectively and identify additional prognostic features on MRI before radiotherapy. METHODS AND MATERIALS: 143 patients with a pathological diagnosis of transitional cell carcinoma underwent MRI (1.0 T) of the abdomen and pelvis before radical radiotherapy. Tumour size, site, degree of infiltration, presence of adenopathy and hydronephrosis were assessed and an appropriate radiological stage assigned. Following radiotherapy all patients received regular cystoscopic follow-up. Date of first relapse and date of death were recorded. RESULTS: The median follow-up was 2.8 years for survivors. Those patients upstaged from T2a clinically to T3b on MRI had a significantly worse outcome (P = 0.0078). In univariate analysis a number of MRI features were significantly associated with adverse outcome: tumour size, circumferential tumour extent, and presence of hydronephrosis (all P < 0.05). After adjustment for clinical T stage and histological grade, all these MRI features and the MRI T stage were found to confer additional prognostic information in predicting early disease relapse and death (P < 0.05). CONCLUSION: This study demonstrates that MRI before radiotherapy provides valuable additional prognostic information compared to clinical staging.

Aged↗
PubMed1999

The clinical significance of the high-intensity zone on lumbar spine magnetic resonance imaging.

STUDY DESIGN: Prospective observational study of anular tears, diagnosed by a high-intensity zone within the anulus on lumbar spine magnetic resonance imaging, and correlation with the clinical features. OBJECTIVES: To assess the prevalence of high-intensity zones in patients who are investigated for back and leg pain and to determine whether there are clinical features that can be used for diagnosis of the presence of a high-intensity zone. SUMMARY OF BACKGROUND DATA: Results in previous studies have shown that the presence of a high-intensity zone is associated with reproduction of a patient's pain on stress discography. Neural compression on magnetic resonance imaging has been shown to be associated with back pain, but to date, no study has correlated the presence of a high-intensity zone with the clinical features. METHODS: The lumbar spine magnetic resonance images in 156 patients in whom back and leg pain were investigated were analyzed for the presence and appearances of high-intensity zones. The clinical features of those patients with a high-intensity zone but with no evidence of neural compression on magnetic resonance imaging were analyzed by t test and X2 test. RESULTS: A high-intensity zone occurred in patients at a prevalence of 45.5% and usually occurred posteriorly (77%) and posterolaterally (22%) within the anulus. There were no features within the history, functional disability questionnaire, or physical examination that aided in a clinical diagnosis of those patients with a high-intensity zone. CONCLUSIONS: A high-intensity zone is a common finding in patients in whom low back and leg pain are investigated, but the presence of a high-intensity zone does not define a group of patients with particular clinical features.

Adolescent↗
PubMed1998

Pain drawings in the assessment of nerve root compression: a comparative study with lumbar spine magnetic resonance imaging.

STUDY DESIGN: Prospective comparative study of pain drawings with findings on lumbar spine magnetic resonance imaging. OBJECTIVES: To assess the ability of the pain drawing to predict the presence of nerve root compression. SUMMARY OF BACKGROUND DATA: Most research work has concentrated on the ability of the pain drawing to act as a screening method for psychological distress with less work directed at the influence the anatomic abnormality has on the pain drawing. METHODS: One hundred thirty-four consecutive outpatients attending for lumbar magnetic resonance imaging in the investigation of back and leg pain completed pain drawings and psychological testing immediately before the examination. The pain drawing was analyzed by previously reported criteria, and the magnetic resonance imaging was assessed independently for the presence of nerve compression by three radiologists. Multivariate stepwise discriminant analysis was used to identify patients with nerve compression on the basis of their pain drawing. RESULTS: Nerve compression was predicted by numbness in the anterolateral aspect of the foot. There was considerable overlap in the appearances of the pain drawings between patients with and without nerve compression, and the pain drawing correctly classified only 58% of patients with nerve compression. CONCLUSIONS: The pain drawing is not a good predictor of nerve compression on magnetic resonance imaging in a group of patients investigated for back and leg pain. It should be interpreted with caution and in light of the full clinical picture.

Adult↗
PubMed1998

Problem in diagnostic imaging: a patient with sciatica.

This article presents the imaging findings in a patient with sciatica. The reader is invited to identify the labeled anatomical structures and the lesions present. The discussion focuses on the anatomy of the lumbar spine and the relative merits of the various methods of imaging a patient with sciatica.

Adult↗
PubMed1998

The therapeutic impact of lumbar spine MRI on patients with low back and leg pain.

UNLABELLED: The influence of lumbar spine magnetic resonance imaging (MRI) on the management of patients with low back and leg pain, with a clinical diagnosis of neural compression, has been investigated by a controlled prospective observational study. The clinical features of the patients at the time of request for MRI have been compared with the subsequent management in order to define the clinical indications for lumbar spine MRI. METHODS: Clinical history, physical examination findings and tests of functional and psychological disability were all recorded at the time of request for MRI. Following MRI, patients were assessed without knowledge of the MRI findings and a diagnosis and management plan recorded. Immediate access to the MRI report and hard copy films was then provided and a revised diagnosis and management plan made. The clinical features and MRI findings were compared with the subsequent management. RESULTS: Seventy-two patients were examined, 65 (90.3%) had leg pain as a predominant feature and abnormalities in neurological examination were found in 31 (43%). Twenty-three of 48 (47.9%) of patients with a pre MRI management plan of surgery were changed to conservative management following the MRI. The diagnosis altered in 50 % of cases with the largest change in diagnosis occurring in 13 patients where MRI did not confirm the clinical impression of nerve root compression. Seventeen patients with no abnormality of neurological testing were subsequently treated by surgery which included all 12 patients treated by spinal fusion. CONCLUSIONS: The major impact of MRI was to move patients towards conservative treatment. A variety of features in the history and physical examination as well as MRI findings are predictors for surgical treatment. The variety of diagnoses and surgical options available make it difficult to define clear clinical guidelines for the use of MRI.

Adult↗
PubMed1998

Quantitative dynamic contrast enhanced MRI of recurrent pelvic masses in patients treated for cancer.

Recurrent tumour and post-treatment inflammatory masses may be difficult to differentiate on T2 weighted and post-contrast T1 weighted MR sequences. The purpose of this study was to assess the value of quantitative analysis of enhancement patterns in improving the separation of tumour recurrence from benign post-treatment masses in the pelvis. 32 patients with a total of 44 benign or malignant pelvic masses arising more than 6 months after treatment by surgery and/or radiotherapy were studied. After localizing the lesion on T1 and T2 weighted sequences, sequential T1 weighted spoiled gradient recalled echo (SPGR) images were obtained through the mass during bolus intravenous injection of 0.1 mmol kg-1 of Gd-chelate. Analysis of the maximum enhancement and proportion of maximum enhancement by 30, 60 and 90 s after onset of injection was performed prospectively by radiologists using standard manufacturer's software. Semi-automated analyses using software to provide irregular regions of interest and automated signal intensity measurements were also performed. Maximum enhancement was significantly greater in tumour recurrence than fibrosis following surgery, with better separation between the two groups using computer assisted analysis (p < 0.001) than manual analysis (p < 0.05). Separation between post-radiotherapy tumour recurrence and benign post-radiotherapy masses reached statistical significance for manual measurements of maximum enhancement (p < 0.05) but not for computer assisted analysis. There was no significant difference in enhancement rates between benign and malignant masses in post-radiotherapy patients. Measurement of the maximum enhancement of a mass alone does not reliably separate lesions in the post-radiotherapy patient but may be helpful when considered together with signal intensity and morphology on conventional MRI sequences.

Diagnosis, Differential↗
PubMed1997

The influence of chemical shift artifact on magnetic resonance imaging of the ligamentum flavum at 0.5 tesla.

STUDY DESIGN: Retrospective clinical magnetic resonance imaging study and prospective magnetic resonance imaging volunteer study of the appearance of the ligamentum flavum. OBJECTIVE: To demonstrate the effect of chemical shift artifact on the apparent thickness of the ligamentum flavum on axial magnetic resonance images. SUMMARY OF BACKGROUND DATA: The ligamentum flavum is a symmetric structure clearly seen on magnetic resonance images. Apparent unilateral thickening may be interpreted as indicating a pathologic process, and the influence of chemical shift artifact on the apparent thickness of the ligamentum flavum has not been emphasized. METHODS: Ligamenta flava thicknesses were measured from axial T1-weighted gradient echo magnetic resonance scans of 12 consecutive patients and various axial sequences in seven volunteers. RESULTS: The ligamentum flavum appeared consistently thicker on the lower side of the readout gradient field. This chemical shift effect could be manipulated by swapping phase and frequency or patient orientation in the magnet. CONCLUSIONS: Caution should be applied in attributing apparent asymmetry of the ligamenta flava to disease; the influence of chemical shift artifact should be considered.

Adolescent↗
PubMed1997

Problem in diagnostic imaging: have you got the nerve?

This article poses a diagnostic problem commonly encountered in neuroradiology and otolaryngology. The solution and ensuing discussion focus on the anatomy of the posterior cranial fossa (with emphasis on the cerebellopontine angle) and the relevant pathology. Current methods of imaging the posterior cranial fossa are explained and their relative merits discussed.

Cerebellopontine Angle↗
PubMed1997

The use of active shape models for making thickness measurements of articular cartilage from MR images.

Previously reported studied to quantify articular cartilage have used labor-intensive manual or semi-automatic data-driven techniques, demonstrating high accuracy and precision. However, none has been able to automate the segmentation process. This paper describes a fast, automatic, model-based approach to segmentation and thickness measurement of the femoral cartilage in 3D T1-weighted images using active shape models (ASMs). Systematic experiments were performed to assess the accuracy and precision of the technique with in vivo images of both normal and abnormal knees. Segmentation accuracy was determined by comparing the results of the segmentation with the boundaries delineated by a radiologist. The mean error in locating the boundary was 0.57 pixels. To assess the precision of the measurement technique, the mean thickness of the femoral cartilage was calculated for repeated scans of five healthy volunteers. A mean coefficient of variation (CV) of 2.8% was obtained for the thickness measurements.

Cartilage, Articular↗
PubMed1997

Contrast-modified gradient echo imaging using rotary echo preparatory pulses.

The use of on-resonance 121 binomial composite pulses in two- or three-dimensional magnetization-prepared gradient-recalled echo magnetic resonance imaging experiments generates rotary echoes, leading to an increase in contrast range that is, in part, determined by the ratio of T2 to T1. In comparison with other fast gradient-recalled echo imaging techniques designed for enhanced T2 contrast, this method is more robust with respect to radiofrequency field inhomogeneity and less sensitive with respect to motion artifacts. Three-dimensional parametric images may be calculated using least-squares fitting based on a simple model for steady-state longitudinal magnetization during the imaging sequences.

Brain↗
PubMed1997

A comparison of 2-D and 3-D FSE imaging in MR of the cervical spine.

The aim of the study was to assess whether a 3-D FSE sequence with real-time multiplanar reconstruction could replace our standard 2-D imaging of the cervical spine. MRI was performed on a GE Vectra 0.5 T system using a quadrature surface neck coil. Signal intensity of CSF, spinal cord, surrounding tissue and background were measured. Contrast to noise ratio and contrast between the different tissues was calculated for the different sequences. A subjective assessment of the various lesions was made. No statistical difference in tissue contrast was found between 2-D and 3-D images when the contrast between cord and CSF, or between cord and marrow was calculated. Contrast between cord and marrow was better on 3-D images. The contrast to noise ratio was better on 2-D images compared with the 3-D images for both cord/CSF and CSF/marrow but there was no difference between the 2-D and 3-D images for cord/marrow. In three patients the lesion was better demonstrated on the 3-D sequence than on the 2-D combination, but only in one of these was the abnormality not visible on the 2-D images; in six patients the 2-D images were considered superior. Although the 3-D sequence reduced overall imaging time we found that at 0.5 T contrast was inadequate, and that lesions were less clearly demonstrated than on the 2-D sequences. We conclude that a single 3-D sequence cannot satisfactorily replace the 2-D combination routinely used at 0.5 T.

Adolescent↗
PubMed1997

MRI of lumbar spondylosis: a comparison of sagittal T2 weighted and three sequence examinations.

The aim of this study was to determine whether a single T2 weighted sagittal sequence could replace the conventional three sequence examination of the lumbar spine. The T2 weighted sagittal image of 79 lumbar spine MRI examinations were retrospectively reported by three radiologists. Features relating to degenerative disease were recorded and an assessment made of whether further sequences were likely to add information. On a separate occasion the T1 weighted and T2 weighted sagittal and T2 weighted axial sequences were reported blind in relation to the initial assessment. Areas of disagreement were resolved by consensus opinion. The T2 weighted sequence was compared with the three sequences, taking the three sequence examination as the standard. Disc protrusions were diagnosed from the T2 weighted sagittal images with a sensitivity of 38% and a specificity of 97%. 22 discs reported as a disc bulge on the T2 weighted sequence were re-classified as a disc protrusion on axial images because of their focal nature. Central canal stenosis was diagnosed on the T2 weighted sagittal sequence with a sensitivity of 60% and a specificity of 95%. After assessing the T2 weighted sequence, it was thought unlikely that further sequences would add extra information in 60% of cases (48/79). However, further information was obtained in 21% of these cases (10/48) when all the sequences were assessed. The extra information gained by using all three sequences was considered to be of greater benefit than the time saved by using a single T2 sagittal sequence. Other diagnoses where the additional sequences proved helpful are discussed.

Female↗