Minimal-preparation abdomino-pelvic CT in frail and elderly patients: prognostic value of colonic and extracolonic findings.

AIM: To examine the overall survival of patients who had had been referred for minimal preparation abdomino-pelvic computed tomography (MPCT), and to assess the prognostic value of the colonic and extracolonic findings detected. METHODS AND MATERIALS: The survival of a cohort of 1029 elderly and frail patients, with clinical symptoms and signs suspicious for colorectal cancer (CRC), who had undergone MPCT between 1995 and 1998 was investigated. Univariate and multivariate survival analyses were undertaken according to the presence of CRC and extracolonic abnormalities (ECA). RESULTS: The median age of the 1029 patients was 79.4 years. The overall median survival following MPCT was 5.4 years; and 6.6 years if no abnormality was detected. On multivariate analysis, age, sex, CRC status, and number of ECAs were significant factors in overall survival. Median survival for those with confirmed CRC [n=91 (prevalence, 8.8%)] was 1.1 years, compared with 5.9 years without CRC (p<0.0001); and 2.4 years for those with one or more ECA [n=245 (prevalence, 23.8%)], compared with 6.1 years without ECA (p<0.0001). Survival was progressively shorter for increasing numbers of ECAs; and shorter for previously unknown non-CRC malignancies (n=24) compared with CRC (p<0.0001). CONCLUSIONS: MPCT appears to have prognostic potential in this patient population, with significant reductions in survival if a CRC or ECA is detected. The detection of ECA would appear to have at least as important an impact on the usefulness of the examination as the detection of CRC.

The CT appearances of sclerosing mesenteritis and associated diseases.

Sclerosing mesenteritis is characterized by non-specific inflammation of the mesenteric fat associated with variable amount of fibrosis. The aetiology is unclear; the pathogenesis is obscure, and even its nomenclature remains variable. It is a rare condition with imaging features that can be mistaken either for a mesenteric neoplasm or for a wide variety of non-neoplastic inflammatory conditions. Knowledge of the imaging features of this condition may prevent unwarranted aggressive therapy. This review discusses the pathogenesis, clinical manifestations of this condition, as well as illustrating the characteristic computed tomography (CT) features of sclerosing mesenteritis. A rational approach to the differential diagnosis is discussed.

Minimal preparation CT for the diagnosis of suspected colorectal cancer in the frail and elderly patient.

Colorectal cancer is a common malignancy with an increased incidence in the elderly population. Traditional methods of evaluating this disease have included double contrast barium enema and colonoscopy. Unfortunately, in the frail and elderly patient, these investigations can be difficult to perform and are often not tolerated. Minimal preparation computed tomography (MPCT) of the colon has been suggested as an alternative in this patient population. In this technique, no bowel preparation is used apart from the administration of oral contrast medium. The patient is imaged only in the supine position, without per rectal insufflation of gas or barium. This article reviews the experience to date of MPCT in detecting colonic tumours, and compares its efficacy to the traditional methods. A meta-analysis of the studies allowed estimation of the pooled sensitivity of MPCT to be 83% (95% confidence interval: 76-89%), and pooled specificity to be 90% (95% CI: 85-94%). An added advantage of MPCT is the ability to identify extra-colonic pathology, and this aspect is also reviewed. In addition, the common radiological features and pitfalls in identifying colonic tumours by MPCT are discussed.

Multislice CT of the abdomen.

Major advances have been made in CT technology since its introduction 30 years ago. Examination time has been markedly reduced and it is possible to cover considerably larger scan ranges. Multidetector technology now allows near isotopic imaging with the ability to perform high quality multiplanar reconstructions. It is also now possible to image in well defined vascular phases. In this article we share our experience in the use of multislice CT and detail protocols used in imaging of the abdomen.

Extracolonic findings in patients undergoing abdomino-pelvic CT for suspected colorectal carcinoma in the frail and disabled patient.

AIM: The aims of this study were to evaluate the extracolonic findings identified in patients undergoing minimal preparation abdomino-pelvic CT in place of barium enema or colonoscopy for the detection of possible colorectal carcinoma. MATERIALS AND METHODS: The CT technique involved helical acquisition (10 mm collimation, 1.5 pitch) following 2 days of preparation with oral contrast medium only. Extracolonic findings were evaluated in the light of subsequent follow-up and accuracy. The evaluation included assessment of the potential contribution of the extracolonic finding(s) to staging the cancer in the subset of patients who had colorectal carcinoma, and to account for the patients' presenting symptoms and signs in the remaining patients. RESULTS: A total of 344 extracolonic findings were detected in 261 CT examinations, from amongst a total of 1077 cases (24%). Extracolonic findings were potentially important in staging in 32 of the 98 (33%) cases subsequently found to have colorectal cancer. There were 284 extracolonic findings amongst the 221 cases who proved not have colorectal cancer. One hundred and twenty-four (44%) of these 284 findings were actively followed up by clinicians, and 33 (12%) ultimately had a surgical intervention. Fifty-six percent (160/284) of the findings were determined to be correct (by further investigation, autopsy, and/or clinical follow-up); the remainder were incorrect or indeterminate (n = 56) or had no follow-up (n = 68). The commonest extracolonic findings were focal liver lesions (found in 42/1077, 4%) and abdominal aortic aneurysms (31/1077, 3%). Twenty-four (24/1077, 2%) previously unknown extracolonic malignancies were detected. Ten percent (106/1077) of the patients had extracolonic findings that could potentially have accounted for their presenting symptoms. CONCLUSIONS: CT has the added benefit, compared with colonoscopy and barium enema, of not just evaluating the colon but also of detecting extracolonic abnormalities. Such findings may be useful in staging the cancer, may explain the patient's presenting symptoms, and may detect other potentially serious disorders.

Unusual causes of colonic wall thickening on computed tomography.

Computed tomography (CT) appearances in "colitis" are often non-specific, and include mural thickening and mesenteric fat stranding. In the western world, the majority of cases will have, or be subsequently diagnosed with, inflammatory bowel disease, pseudomembranous colitis or ischaemic colitis. However, other rare conditions may also produce these rather non-specific signs. We present a number of cases demonstrating colonic wall thickening on CT due to rarer diagnoses, which are correlated with the histopathological features. Some of these CT appearances have not been described previously in the literature.

The impact of helical computed tomography on the diagnosis of unsuspected inflammatory bowel disease in the large bowel.

Inflammatory bowel diseases (IBD) are diagnoses that can be easily overlooked clinically. The aim of this study was to investigate if CT is able to make a contribution to the identification of previously unsuspected cases of IBD. We retrospectively identified cases in which the possibility of an IBD was raised in CT reports (over a 4-year period), by utilising a keyword search of the radiology database. Cases with a previously known or suspected IBD were rigorously excluded by review of case notes, and endoscopic, radiological, histological and microbiological findings. The CT images of the identified cases were reviewed by a blinded observer to document the extent of bowel wall thickening, the location of lesion(s), and presence of peri-colic fat abnormality, ascites and/or collections. The observer also attempted to corroborate the presence, and to identify the type, of IBD based on the CT appearances alone. Thirty-five cases (out of approximately 19,000 body CTs performed) of clinically unsuspected IBD were identified, of which 27 underwent further investigation. An IBD was confirmed in 48% (13 of 27): Crohn's disease (n=6), ulcerative colitis (n=2), pseudomembranous colitis (n=3) and other (n=2), of which 70% (9 of 13) were correctly typed by the reviewer. Inflammatory bowel disease was not substantiated in the remainder (14 of 27), although 7 of these had other bowel pathologies: diverticular disease (n=4); and carcinoma (n=3). Prospectively determining the presence, and furthermore type, of IBD on CT is challenging largely because of the considerable overlap in the appearances of the individual IBDs and indeed of normality. Nevertheless, CT is able to identify clinically unsuspected cases and radiologists should be alert to this treatable and not infrequently elusive diagnosis.

Evaluation of CT in identifying colorectal carcinoma in the frail and disabled patient.

Frail and physically or mentally disabled patients frequently have difficulty in tolerating formal colonic investigations. The aims of this study were to evaluate the accuracy of minimal-preparation CT in identifying colorectal carcinoma in this population and to determine the clinical indications and radiological signs with the highest yield for tumour. The CT technique involved helical acquisition (10-mm collimation, 1.5 pitch) following 2 days of preparation with oral contrast medium only. The outcome of 4 years of experience was retrospectively reviewed. The gold standards were pathological and cancer registration records, together with colonoscopy and barium enema when undertaken, with a minimum of 15 months follow-up. One thousand seventy-seven CT studies in 1031 patients (median age 80 years) were evaluated. CT correctly identified 83 of the 98 colorectal carcinomas in this group but missed 15 cases; sensitivity and specificity (with 95% confidence interval) 85% (78-92%) and 91% (90-93%), respectively. Multivariate analysis identified: (a) a palpable abdominal mass and anaemia to be the strongest clinical indications, particularly in combination (p<0.0025); and (b) lesion width and blurring of the serosal margin of lesions to be associated with tumours (p<0.0001). Computed tomography has a valuable role in the investigation of frail and otherwise disabled patients with symptoms suspicious for a colonic neoplasm. Although interpretation can be difficult, the technique is able to exclude malignancy with good accuracy.

Caecal carcinomas in the elderly: useful signs in minimal preparation CT.

OBJECTIVE: Frail, elderly and immobile patients frequently have difficulty in tolerating formal colonic investigations. Caecal tumours may account for up to 35% of colonic tumours. Barium enema and colonoscopy have limitations in assessing this region. The aims of this study were to evaluate the accuracy of a minimal preparation CT technique (merely with prolonged oral contrast medium) in identifying caecal carcinomas and to determine helpful radiological signs. MATERIALS AND METHODS: The CT technique involved helical acquisition following 2 days of preparation with oral contrast medium. The outcome of 4 years' experience (1995-1998) was reviewed. The gold-standards were pathological and cancer registration records, together with colonoscopy and barium enema where available, with a minimum of 15 months' follow-up. RESULTS: CT correctly identified 27 of 30 caecal carcinomas, and missed three, in a total of 1077 CT studies in 1031 patients (median age 80 years). There were also 21 false-positive cases in which CT incorrectly raised the possibility of a caecal tumour. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were 90%, 98%, 99% and 56%, respectively. Serosal margin blurring, tumour length, presence of abnormal peri-colic fat and terminal ileal wall thickening were identified as useful radiological signs. CONCLUSIONS: Minimal preparation CT is able to identify caecal carcinomas with fair accuracy. Such evaluation may become important given the increasing population age and evidence of a 'proximal shift' in the site of colonic tumours in the elderly.

A prospective randomised study comparing enteroclysis with small bowel follow-through examinations in 244 patients.

The purpose of this study was to determine whether small bowel enema or barium follow-through is the most appropriate examination for the routine investigation of patients without documented small bowel disease referred from outpatient sources in our hospital. Two hundred and forty-four patients were prospectively randomised to either small bowel enema (SBE) or barium follow-through (FT). Radiation doses and room times were recorded for the first 95 patients and abnormal results were documented for all. One hundred and twelve FTs and 75 SBEs were performed. The incidence of abnormal results was low overall and comparable in the two groups. There were significantly more abnormalities in the FT group which required further investigations for confirmation. Of those assigned to SBE, 19% were converted to FT due to patient refusal and technical failure. Radiation doses were similar in the two groups, but the time spent occupying the fluoroscopy room was significantly shorter for FT. In our department FT is as effective as SBE in detecting small bowel abnormalities de novo. The radiation dose is similar, but more FTs can be performed per list. Follow-through is also less invasive than SBE and therefore we use this technique as the first line of investigation in this group of patients.

CT and bowel disease.

CT has now come of age in the detection and demonstration of bowel pathology and is likely to supplant traditional imaging techniques further in the future. Its role here has been greatly aided by the advent of fast spiral CT sequences and, with the development of even faster multidetector CT systems, this can only increase.

How reliable is modern breast imaging in differentiating benign from malignant breast lesions in the symptomatic population?

AIM: To assess the ability of mammography and ultrasound individually and in combination to predict whether a breast abnormality is benign or malignant in patients with symptomatic breast disease. MATERIALS AND METHODS: Patients included were those in whom histological confirmation of the abnormality following surgical excision was available. Mammographic and ultrasound appearances were prospectively classified using a four-point scale (1 = no significant lesion, 2 = benign lesion, 3 = possibly malignant, 4 = probably malignant). RESULTS: Histological confirmation following surgical excision was available in 559 patients, of which 303 were benign and 256 were malignant. The imaging classification was correlated with histology in these 559 lesions. In predicting final histology, the sensitivity and specificity of mammography alone were 78.9 and 82.7%, respectively, of ultrasound alone were 88.9 and 77.9%, respectively, and of mammography and ultrasound in combination were 94.2 and 67.9%, respectively. Only one patient had both a mammogram and ultrasound reported as normal (category 1 for both tests) in whom subsequent histology revealed a carcinoma (0.4% of all carcinomas). CONCLUSION: We found that the extensive use of ultrasound increases the cancer detection rate in this selected population by 14%.

Changing to core biopsy in an NHS breast screening unit.

We recently changed from using fine needle aspiration cytology to using core biopsy exclusively in the assessment of screen detected abnormalities. Two hundred and two biopsies (1% of women screened) were performed. Surgical histological confirmation was obtained in 111 patients (101 malignant and 10 benign). The remaining patients were either returned to standard 3-yearly screening or early repeat screening after 1 year. Analysis of the results was performed in accordance with the standards specified in the National Health Service Breast Screening Programme (NHSBSP) Publication Number 22. Absolute sensitivity was 89.3%, complete sensitivity was 93.2%, specificity (including patients undergoing both surgical excision and follow-up) was 88.7%. The predictive value of a positive (malignant) core biopsy result was 100%. The false negative rate was 3.9%. Twelve (5.9%) biopsies were classified inadequate for diagnosis. Core biopsy is a safe and accurate way of assessing screen detected abnormalities and can be used as a substitute for fine needle aspiration cytology with results that exceed the National Health Service Breast Screening Programme target standards, even in the learning phase.

The significance of low grade right iliac fossa uptake on 99Tcm-HMPAO labelled white cell scans.

Technetium-99m HMPAO labelled white cell scanning is now an accepted method for assessing the activity of inflammatory bowel disease. However, false positive results have been demonstrated. This study was conducted to assess the significance of low grade uptake on 99Tcm-HMPAO labelled white cell scans in the right iliac fossa (RIF) in the context of possible inflammatory bowel disease (IBD). 32 patients over a period of 1 year had low grade RIF uptake as the predominant abnormality. 20 of these had no prior diagnosis of inflammatory bowel disease. Only one case in this group was subsequently diagnosed as having Crohn's disease. Nodular lymphoid hyperplasia (NLHP) and non-steroidal anti-inflammatory drugs (NSAIDs) were also associated with low grade RIF uptake. Possible explanations for these findings are discussed.

CT of the colon in frail elderly patients.

CT is presented as an alternative to barium enema examination for the investigation of the colon in frail elderly patients. Carcinomas can be detected reliably and the investigation is better accepted by patients and staff alike. Furthermore, extracolonic lesions are shown. Obviously small polyps are missed, but such lesions are less relevant in older patients. The CT technique is described, and some of the initial difficulties encountered during the adoption of this policy are discussed.