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Biomedical subjects

A G Chalmers

Publications and source records attributed to A G Chalmers.

At least 19 recordsLinked to original sources
PubMed2005

MRI assessment of the bony pelvis may help predict resectability of rectal cancer.

OBJECTIVE: The outcome after surgical treatment of rectal cancer may be influenced by the technical difficulty of the operation, which is thought to be affected by pelvic size. The aim of this study was to examine the association between bony pelvic dimensions and CRM involvement. PATIENTS AND METHODS: All patients with primary rectal cancer between December 1999 and January 2002 were studied. Staging was performed by pelvic MRI. Nine pelvic dimensions were measured from the MR images on a workstation. Pathology reports were obtained for all patients and the mesorectal specimen was examined. Technical difficulty was assessed by circumferential resection margin (CRM) involvement. RESULTS: Of 126 patients with primary rectal cancer, 88 had staging MRI and rectal excision; there were significant differences between the sexes in all 9 pelvic dimensions (P < 0.05). In females, the interspinous diameter was significantly shorter in patients with CRM involvement compared with patients with a negative CRM. In female patients predicted to have a negative CRM, the anteroposterior diameter of the inlet, the anteroposterior diameter of the midplane and the transverse diameter of the midplane (interspinous distance) were significantly shorter in patients who actually had a positive CRM compared with those in whom the CRM was negative. In male patients, there was no correlation between pelvic dimensions and CRM status. CONCLUSIONS: In certain patients with rectal cancer, CRM positivity may be predicted from pre-operative MRI pelvic measurements. This may influence the choice of adjuvant therapy.

Aged↗
PubMed2005

An unusual case of ureteric obstruction.

We report a case of a 33-year-old female presenting with right sided abdominal pain, a right iliac fossa mass and right hydronephrosis. The mass was subsequently shown to represent an isolated desmoid tumour compromising the adjacent ureter. The patient had no predisposing factors for this pathology. This is an uncommon occurrence and we discuss the imaging features and differential diagnosis.

Adult↗
PubMed2001

Evaluation of the role of pre-operative magnetic resonance imaging in the management of rectal cancer.

OBJECTIVES: This study assesses the ability of body coil magnetic resonance imaging (MRI) to pre-operatively stage mural penetration, nodal status and circumferential resection margin (CRM) involvement of rectal cancer. PATIENTS AND METHODS: Between 1995 and 1997, MRI using a body coil was performed in consecutive patients with primary rectal carcinomas. Group A: 67 patients underwent surgery without long course neo-adjuvant therapy. Predicted tumour stage was compared to the histology of the specimen. Group B: 21 patients with MRI evidence of advanced disease, underwent long course neo-adjuvant therapy followed by repeat MRI prior to surgery. The second scan assessed response to treatment and likelihood of CRM involvement at subsequent surgery. RESULTS: Group A: Accuracy of pre-operative staging was: 'T' stage - 54%, 'N' stage - 77%, involvement of CRM by tumour - 97%. Group B: After long course neo-adjuvant therapy the second MRI scan was 95% accurate in predicting CRM involvement by tumour. CONCLUSION: In this study pre-operative rectal cancer staging with MRI and a body coil lacks accuracy in predicting mural penetration and nodal involvement. Body coil MRI can accurately predict the potential for CRM involvement. This technique may help determine which patients require long course neo-adjuvant therapy.

Journal Article↗
PubMed1999

Renal metastases from a squamous cell carcinoma of the larynx.

Laryngeal squamous cell carcinoma (SCC) tends to exhibit local spread with a low incidence of distal metastases. The majority of distal metastases are to the lungs and renal involvement is extremely rare. We present a case of laryngeal SCC with metastatic spread to the left kidney presenting as a large, mainly cystic mass. The radiological differentiation of renal metastases from primary renal tumours is discussed.

Adult↗
PubMed1997

T2-weighted and dynamic enhanced MRI in acute pancreatitis: comparison with contrast enhanced CT.

The purpose of this study was to compare T2-weighted and dynamic contrast enhanced MRI with contrast enhanced CT in patients with severe acute pancreatitis. Thirty-two patients were examined using axial T2-weighted spin-echo imaging (TR 1801, TE 15/90) and a multi-slice rapid gradient-echo sequence (TR 135, TE 4, FA 80 degrees) (FLASH) in axial and coronal planes. Fifteen 5 mm axial slices at 10 mm intervals were acquired during a single breath-hold of 19 s before, and at 10 and 40 s after a bolus injection of Gd-DTPA. Additional FLASH images in the coronal plane were obtained 2 min after injection of contrast medium. MR was compared with contemporary enhanced CT by two blinded observers who scored pancreatic viability and the content of intra and extra-pancreatic fluid collections. The presence of gas, calcification and haemorrhage was noted. Abnormalities in adjacent organs, evidence of vascular occlusion and indicators of aetiology were also recorded. MR and CT were concordant in distinguishing viable pancreatic tissue from areas of necrosis. MR appeared to be more effective than CT in characterizing the content of fluid collections and in demonstrating gall stones, although CT remains superior in detecting flecks of gas and calcification. MR carries some advantages over CT and can be regarded as an alternative primary technique in patients with severe pancreatitis.

Acute Disease↗
PubMed1997

Breast metastasis from non-small cell lung cancer.

Breast is an unusual site for metastatic disease, particularly for non-small cell lung cancer. We report an unusual case of metastatic breast lesions from a primary anaplastic lung tumor and discuss the common and uncommon sites of metastasis from lung carcinomas.

Breast Neoplasms↗
PubMed1997

The role of imaging in acute pancreatitis.

The roles of ultrasound, computed tomography and magnetic resonance in the evaluation and management of acute pancreatitis are discussed with emphasis on the advantages and disadvantages of each. The importance of imaging in the diagnosis of pancreatic necrosis, acute fluid collections, pancreatic abscess, pseudocysts and vascular complications is reviewed. The use of interventional techniques as opposed to surgical intervention is discussed.

Abscess↗
PubMed1997

Spiral computed tomography and operative staging of gastric carcinoma: a comparison with histopathological staging.

BACKGROUND: Much controversy exists as to the value of computed tomography (CT) in the preoperative staging of gastric cancer, because of its limited ability to identify correctly lymph node (LN) metastases, invasion of adjacent organs, or hepatic and peritoneal metastases. Spiral CT scanners have a number of potential advantages over conventional scanners, including the absence of respiratory misregistration, image reconstruction smaller than scan collimation permitting overlapping slices and optimisation of intravenous contrast enhancement. AIM: To compare the performance of spiral CT and operative assessment against formal (TNM) pathological staging. PATIENTS AND METHODS: A study of 105 consecutive patients who underwent both spiral CT and operative staging was performed. All CT scans were reviewed by a radiologist who commented on tumour location and size, evidence of adjacent organ invasion, lymph node metastases to both N1 and N2 nodes, and evidence of hepatic and peritoneal metastases. All patients underwent careful operative assessment at the time of surgery, along the lines suggested by Rohde and colleagues. RESULTS: Spiral CT remained poor at identifying LN metastases to both N1 and N2 lymph nodes, with sensitivity ranging from 24 to 43%; specificity, however, was 100%. Operative staging was superior, with sensitivities between 84 and 94%, but specificity was much lower (63-74%). Spiral CT correctly detected 13 of 17 cases of invasion of either the colon or the mesocolon (sensitivity 76%) compared with 16 of 17 cases at operative staging (sensitivity 94%). Spiral CT correctly identified three of six cases with invasion of the pancreas (sensitivity 50%) compared with six of six cases on operative staging (sensitivity 100%). Spiral CT correctly identified 12 of 17 cases of peritoneal metastases (sensitivity 71%) and four of seven cases of hepatic metastases (sensitivity 57%). CONCLUSION: Whilst spiral CT remains poor at identifying lymph node metastases, it correctly identified most cases with invasion of either the colon or the mesocolon and half the cases of pancreatic invasion. It was of value in detecting peritoneal metastases and some cases with hepatic metastases. At present, at Leeds General Infirmary spiral CT is performed routinely on all patients with gastric cancer and a selective staging laparoscopy policy is adopted in those patients in whom the status of the peritoneal cavity and liver is in doubt.

Adult↗
PubMed1997

Imaging appearances of ileouterine fistula complicating recurrent adenocarcinoma of the rectum.

Enterouterine fistulae are rare and nowadays are most commonly due to pelvic tumours. We review the literature and present the case of a woman who presented with an ileouterine fistula following surgery and radiotherapy for recurrent rectal adenocarcinoma. The presence of tumour within the fistula track may also have been a significant aetiological factor. Magnetic resonance imaging (MRI) is an excellent method to demonstrate the site and size of the track and has not, to date, been used to identify such a fistula.

Adenocarcinoma↗
PubMed1995

Pseudothrombosis of the infra-renal inferior vena cava during helical CT.

Pseudothrombosis of the infra-renal vena cava is a frequent finding during post-contrast helical computed tomography (CT) studies of the abdomen. Three hundred consecutive patients undergoing contrast-enhanced helical studies were evaluated prospectively to document the incidence of pseudothrombosis. Typical CT findings are illustrated and a significant difference in incidence between the male and female population noted.

Female↗
PubMed1995

The radiological treatment of hepatic artery aneurysms.

Improvements in the quality and availability of cross-sectional imaging should result in more frequent detection of hepatic artery aneurysms before rupture. Interventional radiological treatment for extra-hepatic lesions has not previously been discussed in the literature. We present two cases of extra-hepatic hepatic artery aneurysms treated using different endovascular techniques and discuss the relative merits of these approaches.

Adult↗
PubMed1995

Case report: the demonstration of aortocaval fistulae by helical computed tomography.

We report the helical computed tomography findings in two patients with spontaneous aortocaval fistula (ACF) complicating abdominal aortic aneurysm. The use of overlapping slices produced high quality multiplanar reformats which provided anatomical information about the likely site of the ACF and also the relationship of the renal arteries to the neck of the aneurysm.

Aged↗
PubMed1994

Longitudinal stress fractures of the tibia: MRI features in two cases.

Longitudinal stress fractures of the tibia are a recognized but unusual finding in long distance runners. Two cases are presented in which the diagnosis on plain films and scintigraphy (in one case) was not evident. Both patients were referred for MRI. Coronal short tau inversion recovery (STIR) sequences demonstrated extensive hyperintense longitudinal intramedullary signal changes in the tibia. T1-weighted spin-echo scans showed corresponding but less extensive regions of reduced signal intensity. In one case, enhancement of this area was seen following i.v. dimeglumine-gadopentetate (Gd-DTPA). Adjacent soft-tissue abnormality and periosteal reaction was seen in one case but in neither patient was a fracture line identified. Thin section CT with sagittal reformats demonstrated an irregular intracortical longitudinal lucent fracture line which was distinct from the nutrient foramen, establishing the diagnosis.

Adult↗
PubMed1994

The role of immediate cytological evaluation in CT-guided biopsy.

A prospective study of 130 fine-needle aspiration biopsies (FNAB) was performed on 110 consecutive patients to assess the contribution of immediate cytological evaluation (ICE). All biopsies were performed under CT guidance using either 20 gauge or 22 gauge aspiration needles. Two distinct patient groups were derived from two hospitals. In one hospital a consultant cytologist was usually present, whereas in the other immediate cytological evaluation was not generally available. Overall, a consultant cytologist was present for 52% of the biopsies. The accuracy of the procedure, the number of needle passes made, the complication rates with and without ICE were assessed for each hospital population group. The overall accuracy, with and without ICE, was 72%. Although slightly fewer specimens were deemed inadequate when ICE was available, this difference did not reach statistical significance.

Biopsy, Needle↗