Barium enema or computed tomography for the frail elderly patient?

Lumbar Transforaminal Epidural Steroid Injections: Incidental Extraspinal Findings on Planning Imaging

OBJECTIVE

Planning imaging performed during CT-guided procedures may occasionally contain important incidental findings. The purpose of this study was to identify and characterize by clinical relevance the extraspinal findings detected on planning imaging for CT-guided lumbar transforaminal epidural steroid injections (TFESIs).

MATERIALS AND METHODS

Four radiologists retrospectively evaluated the planning scout views and CT studies for 488 consecutive CT-guided lumbar TFESIs performed in 400 patients over a 1-year period. Incidental extraspinal findings were identified and used to characterize patients by the need for follow-up using the CT Colonography Reporting and Data System (C-RADS), a classification scheme originally developed to characterize incidental findings on CT colonography. Patients with C-RADS E4 findings have potentially important findings that should be communicated to the referring physician; patients with C-RADS E3 findings have findings that are likely unimportant, but workup may be indicated. All previously unknown C-RADS E3 and E4 findings discovered in the course of this research were reported to referring physicians for appropriate patient follow-up.

RESULTS

Ten of 400 (2.5%) patients were classified as C-RADS E4; the most common C-RADS E4 finding was vascular aneurysm or stenosis (4/400, 1.0%). Thirteen of 400 (3.3%) patients were classified as C-RADS E3; the most common C-RADS E3 finding was hepatomegaly (4/400, 1.0%). Of 22 patients with C-RADS E3 and E4 findings unknown to clinicians, the finding for only one (4.5%) was communicated to clinicians at the time of the procedure.

CONCLUSION

Clinically important incidental extraspinal findings were identified in 5.8% of patients on the planning imaging performed for CT-guided lumbar TFESIs. Communication of clinically important findings was poor (4.5%).

The feasibility of colorectal cancer detection using dual-energy computed tomography with iodine mapping

AIM

To assess the feasibility of colorectal cancer detection using dual-energy computed tomography with iodine mapping and without bowel preparation or bowel distension.

MATERIALS AND METHODS

Consecutive patients scheduled for preoperative staging computed tomography (CT) because of diagnosed or high suspicion for colorectal cancer were prospectively included in the study. A single contrast-enhanced abdominal CT acquisition using dual-source mode (100 kV/140 kV) was performed without bowel preparation. Weighted average 120 kV images and iodine maps were created with post-processing. Two observers performed a blinded read for colorectal lesions after being trained on three colorectal cancer patients. One observer performed an unblinded read for lesion detectability and placed a region of interest (ROI) within each lesion.

RESULTS

In total 21 patients were included and 18 had a colorectal cancer at the time of the CT acquisition. Median cancer size was 43 mm [interquartile range (IQR) 27-60 mm] and all 18 colorectal cancers were visible on the 120 kV images and iodine map during the unblinded read. During the blinded read, observers found 90% (27/30) of the cancers with 120 kV images only and 96.7% (29/30) after viewing the iodine map in addition (p = 0.5). Median enhancement of colorectal cancers was 29.9 HU (IQR 23.1-34.6). The largest benign lesions (70 and 25 mm) were visible on the 120 kV images and iodine map, whereas four smaller benign lesions (7-15 mm) were not.

CONCLUSION

Colorectal cancers are visible on the contrast-enhanced dual-energy CT without bowel preparation or insufflation. Because of the patient-friendly nature of this approach, further studies should explore its use for colorectal cancer detection in frail and elderly patients.

Investigating the frail elderly patient with lower bowel symptoms: what do we do now and can we improve?

AIMS

To assess the utility of flexible sigmoidoscopy (FS) and minimal preparation CT (MPCT) in investigating lower gastrointestinal (LGI) symptoms in elderly patients who are too frail to undergo colonoscopy or spiral CT.

METHODS

All FS examinations performed in patients aged over 70 between 1 January and 31 December 2008 were analysed. Predictors of usefulness were determined using multivariable analysis. In patients who also underwent MPCT, we analyzed the correlation between FS and MPCT.

RESULTS

426 FS were performed. Bowel preparation was inadequate in 24% of procedures. Indications in which FS was useful were: radiological abnormality (odds ratio [OR] 9.32), history of polyps (OR 4.54) and rectal bleeding (OR 1.73). Indications for which FS was least useful were: change in bowel habit (OR 0.22), diarrhoea (OR 0.46) and constipation (OR 0.38).

CONCLUSIONS

LGI investigation in frail elderly patients can be rationalised according to indication. Performing FS and MPCT together is not always necessary.

Accuracy of minimal-preparation computerized tomography in the investigation of suspected colorectal cancer in frail patients: the experience of Western General Hospital, Edinburgh

Traditional methods of investigating suspected colorectal carcinoma (CRC) such as barium enema, colonoscopy and computerized tomography (CT) pneumocolon are often poorly tolerated by frail or elderly patients. Comparatively, minimal-preparation CT (MPCT) is a non-invasive investigation that does not require bowel preparation. The aim of this study was to review MPCTs carried out at the Western General Hospital, Edinburgh, and compare findings with current published data. Retrospective analysis of 85 patients (age range 55-99 years) who underwent MPCTs at the Western General Hospital between May 2005 and June 2008 was undertaken. Results were followed up using clinical notes, pathological and surgical databases. Subsequent outcomes were analysed (average follow-up 22 months). The prevalence of CRC within the study cohort was 0.14. Sensitivity of MPCT was 1 (95% confidence interval [CI], 0.69-1) with a specificity of 0.93 (95% CI, 0.84-0.97). Thirty percent of patients were found to have extracolonic findings requiring further investigation or intervention. Of the patients, 4.7% had an extracolonic malignancy diagnosed on MPCT. MPCT is a sensitive and specific method of investigating CRC in the elderly, infirm or immobile. Our results were found to be comparable with that of current published data, validating the service provided at the Western General Hospital.

Patient acceptability of CT colonography compared with double contrast barium enema: results from a multicentre randomised controlled trial of symptomatic patients

OBJECTIVES

To determine patient acceptability of barium enema (BE) or CT colonography (CTC).

METHODS

After ethical approval, 921 consenting patients with symptoms suggestive of colorectal cancer who had been randomly assigned and completed either BE (N = 606) or CTC (N = 315) received a questionnaire to assess experience of the clinical episode including bowel preparation, procedure and complications. Satisfaction, worry and physical discomfort were assessed using an adapted version of a validated acceptability scale. Non-parametric methods assessed differences between the randomised tests and the effect of patient characteristics.

RESULTS

Patients undergoing BE were significantly less satisfied (median 61, interquartile range [IQR] 54-67 vs. median 64, IQR 56-69; p = 0.003) and experienced more physical discomfort (median 40, IQR 29-52 vs. median 35.5, IQR 25-47; p < 0.001) than those undergoing CTC. Post-test, BE patients were significantly more likely to experience 'abdominal pain/cramps' (68% vs. 57%; p = 0.007), 'soreness' (57% vs. 37%; p < 0.001), 'nausea/vomiting' (16% vs. 8%; p = 0.009), 'soiling' (31% vs. 23%; p = 0.034) and 'wind' (92% vs. 84%; p = 0.001) and in the case of 'wind' to also rate it as severe (27% vs. 15%; p < 0.001).

CONCLUSION

CTC is associated with significant improvements in patient experience. These data support the case for CTC to replace BE.

Accuracy of routine nontargeted CT without colonography technique for the detection of large colorectal polyps and cancer

BACKGROUND

To assess the accuracy of routine contrast-enhanced computed tomography for the detection of large colorectal polyps and cancer.

METHODS

The study group consisted of 100 patients who underwent abdominal computed tomography and optical colonoscopy evaluation before any treatment or intervention. Invasive colorectal carcinoma and large polyps (>or=10mm) were found at colonoscopy in 29 and 16 patients, respectively. Computed tomography studies with oral and IV contrast were retrospectively reviewed as 5-mm thick sections in standard soft tissue windows by 3 readers. The readers scored each segment for polyp or cancer utilizing a 5-point scale for receiver operating characteristic analysis.

RESULTS

By-patient sensitivity/specificity for cancer detection for each reader was 69.0%/88.7%, 65.5%/84.5%, and 82.8%/77.5%, respectively. Pooled sensitivity, specificity, and accuracy for cancer was 72.4%, 83.6%, and 80.3%, respectively. The empiric area under the receiver operating characteristic curves for the readers ranged from 0.775 to 0.857. By-patient sensitivity for large polyps was poor with a pooled sensitivity of 14.5%.

CONCLUSIONS

Standard computed tomography not tailored to colorectal investigation was moderately effective for detecting invasive cancers, but insensitive for large polyps. Unsuspected cancer should be a part of the standard search pattern for routine computed tomography interpretation, but more advanced colonography techniques are necessary for detecting large polyps.

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.

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.

Incidental lesions found on CT colonography: their nature and frequency

CT colonography has been used to detect colonic polyps and cancers, but its effect in practice will also be influenced by the frequency with which extracolonic lesions of various types are detected. We performed a systematic review of the types of incidental lesions found on CT colonography. This is necessary to model the benefits and harms of detecting extracolonic lesions. Primary clinical studies of extracolonic findings on CT colonography were identified from electronic databases, scanning reference lists and hand searches of relevant journals and conference proceedings. A data collection proforma was used to collect information on extracolonic findings. 17 discreet studies were identified, involving 3488 patients. In total 40% of patients were recorded to have abnormalities and many had more than one abnormality. Nearly 14% of patients had further investigations and 0.8% were given immediate treatment. Extracolonic cancers were detected in 2.7% (0.9% had N0M0 cancers) and 0.9% had an aortic aneurysm. The number of extracolonic findings was high in all studies. While only a small population were judged "important", the prevalence of serious lesions outside the colon was nevertheless higher than in many other screening programs.

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.

Minimal preparation computed tomography instead of barium enema/colonoscopy for suspected colon cancer in frail elderly patients: an outcome analysis study

AIM

To evaluate the efficacy of minimal preparation computed tomography (MPCT) in diagnosing clinically significant colonic tumours in frail, elderly patients.

MATERIALS AND METHODS

A prospective study was performed in a group of consecutively referred, frail, elderly patients with symptoms or signs of anaemia, pain, rectal bleeding or weight loss. The MPCT protocol consisted of 1.5 l Gastrografin 1% diluted with sterile water administered during the 48 h before the procedure with no bowel preparation or administration of intravenous contrast medium. Eight millimetre contiguous scans through the abdomen and pelvis were performed. The scans were double-reported by two gastrointestinal radiologists as showing definite (>90% certain), probable (50-90% certain), possible (<50% certain) neoplasm or normal. Where observers disagreed the more pessimistic of the two reports was accepted. The gold standard was clinical outcome at 1 year with positive end-points defined as (1) histological confirmation of CRC, (2) clinical presentation consistent with CRC without histological confirmation if the patient was too unwell for biopsy/surgery, and (3) death directly attributable to colorectal carcinoma (CRC) with/without post-mortem confirmation. Negative end-points were defined as patients with no clinical, radiological or post-mortem findings of CRC. Patients were followed for 1 year or until one of the above end-points were met.

RESULTS

Seventy-two patients were included (mean age 81; range 62-93). One-year follow-up was completed in 94.4% (n=68). Mortality from all causes was 33% (n=24). Five histologically proven tumours were diagnosed with CT and there were two probable false-negatives. Results were analysed twice: assuming all CT lesions test positive and considering "possible" lesions test negative [brackets] (95% confidence intervals): sensitivity 0.88 (0.47-1.0) [0.75 (0.35-0.97)], specificity 0.47 (0.34-0.6) [0.87 (0.75-0.94)], positive predictive value 0.18 [0.43], negative predictive value 0.97 [0.96], positive likelihood ratio result 1.6 [5.63], negative likelihood ratio result 0.27 [0.29], kappa 0.31 [0.43]. Tumour prevalence was 12%. A graph of conditional probabilities was generated and analysed. A variety of unsuspected pathology was also found in this series of patients.

CONCLUSIONS

MPCT should be double-reported, at least initially. "Possible" lesions should be ignored. Analysis of the graph of conditional probability applied to a group of frail, elderly patients with a high mortality from all causes (33% in our study) suggests: (1) if MPCT suggests definite or probable carcinoma, regardless of the pre-test probability, the post-test probability is high enough to warrant further action, (2) frail, elderly patients with a low pre-test probability for CRC and a negative MPCT should not have further investigation, (3) frail, elderly patients with a higher pre-test probability of CRC (such as those presenting with rectal bleeding) and a negative MPCT should have either double contrast barium enema (DCBE) or colonoscopy as further investigations or be followed clinically for 3-6 months. MPCT was acceptable to patients and clinicians and may reveal significant extra-colonic pathology.

CT colonography: methods, pathology and pitfalls

Computed tomography colonography (CTC) is a relatively new technique that is currently challenging more established methods of large bowel imaging. Several workers have suggested CTC surpasses the barium enema and approaches conventional endoscopy for detection of colorectal neoplasia. Accurate diagnosis relies on technically good studies, the main aim of which is adequate bowel cleansing and distension. Furthermore, the learning curve is steep and normal colonic anatomy has to be re-learned in a CT context. This review aims to describe the technique, revise the imaging features of both normal and pathological colon, and to highlight potential diagnostic pitfalls and their avoidance.

Updates in surgical oncology for elderly patients

Elderly patients affected by solid tumours are frequently encountered on the surgical ward. Prejudice regarding operative risks and long term outcomes may alter their surgical management. Large series of elderly cancer subjects have been analysed and conclusive data are now available, to better tailor their management. Specific epidemiological data are presented in this review, screening programs critically considered, treatment procedures discussed, and the effectiveness of follow-up protocols is analysed together with cost effectiveness issues. Quality of life issues should not be neglected, and a continuous educational endeavour targeted at specialists and general practitioners is desirable.

The use of minimal preparation computed tomography for the primary investigation of colon cancer in frail or elderly patients

AIM

To assess the place of computed tomography (CT) of the colon in frail or elderly patients with symptoms suggestive of colon cancer.

METHOD

A total of 195 patients (median age 76 years) underwent CT of the abdomen and pelvis following the administration of positive oral contrast medium but no bowel preparation. All had symptoms suggestive of colon cancer. CT findings were classified as normal/diverticular disease (DD), possible colon cancer, definite colon cancer or extracolonic pathology. Accuracy of CT was assessed against patient outcome. Association between symptoms and colon cancer was assessed by chi-squared test.

RESULTS

There were 47 deaths and median follow up for those alive was 16 months. Overall sensitivity of CT was 100% and specificity 87% for detection of colon cancer. One hundred and ten normal/DD CT examinations had no significant bowel lesion on follow up. Of 12 cases defined as 'definite cancers' on CT, there were nine colon cancers, two extracolonic cancers, and one normal. Of 23 'possible cancers' on CT, there were two colon cancers, three DD masses and 18 normal/DD. Fifty examinations had extracolonic findings including 33 (17%) cases of significant abdominal disease. CT findings led to a halt in investigations in 115 cases (59%), colonoscopy in 18 (9%) cases and surgery in 16 (8%) cases. None of the symptoms present showed a significant association with colon cancer (all P > 0.05).

CONCLUSION

Minimal preparation CT is a non-invasive and sensitive method for investigating colon cancer in frail or elderly patients. It has a 100% negative predictive value and also detects a large number of extracolonic lesions.

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.

Optimization of scanning parameters for CT colonography

To determine the optimal collimation, pitch and reconstruction interval for CT colonography, 10 spherical polyps between 1 mm and 10 mm diameter and made of tissue equivalent material with a CT number of 40 Hounsfield units (HU) were placed in the colon of an anthropomorphic phantom. The phantom was scanned at slice thicknesses of 3 mm, 5 mm and 7 mm and pitches of 1.0, 1.3, 1.5, 1.7 and 2.0 on an IGE Hispeed advantage system. Images were reconstructed for each scanning parameter at the minimum intervals allowed along the z-axis. The optimum scanning protocol was assessed by measuring maximum contrast between the polyp and air, sensitivity for detection of each polyp along the z-axis, and relative radiation dose. In addition, images were reviewed separately by two radiologists who graded polyp conspicuity as: 0, not seen; 1, faintly seen; 2, well seen. It was found that varying the scanning parameters caused a marked alteration in the maximum contrast between each polyp and air. For example, for the 5 mm polyp, the range of contrasts from best to worst case was 910-490 HU. It was noted that with contrasts of less than 500 HU, polyps were only faintly seen. A slice thickness of 3 mm with a pitch of 2 offers optimal polyp conspicuity with a relatively low radiation dose, we conclude that scanning parameters can be optimized for threshold contrast, radiation dose and subjective conspicuity. We propose an optimal parameter of 3 mm slice thickness and pitch 2.

Colon carcinoma: MR imaging with CO2 enema--pilot study

Prior to surgery, seven patients with known colonic tumors underwent breath-hold single-shot fast spin-echo magnetic resonance imaging during a CO2 enema. The images were evaluated for depiction of tumor, adjacent structures, and the remaining colon, and findings were compared with findings at surgery. In all seven patients, the tumor was demonstrated, and in four (57%), breach of the muscularis propria was correctly predicted.

Immediate CT pneumocolon for failed colonoscopy; comparison with routine pneumocolon

AIM

To assess the role and reliability of 2D CT pneumocolon in the diagnosis of colonic malignancy, and compare feasibility of referral sources.

MATERIALS AND METHODS

A prospective study of 50 patients with suspected large bowel malignancy. Patients underwent bowel cleansing, rectal air insufflation and contrast enhanced CT with 5 mm collimation, 3 mm reconstruction and a pitch of 1.4. Subsequent correlation was with pathology (16), colonoscopy (13), barium enema (5), ERCP (1) and clinical follow-up alone (8).

RESULTS

Diagnostic images were obtained in 43/50 patients (86% feasibility). Follow-up was obtained in 35/43 patients (one patient died of an unrelated cause, and seven patients were deemed unfit for further investigation). Seventeen colonic carcinomas were diagnosed (three false-positives: one ischaemic colitis, one diverticular stricture and one faecal mass), one diverticular stricture, one fistula, one pancreatic carcinoma and one ovarian malignancy. The remaining 14 were negative. Overall sensitivity was 100% (for lesions >1.5 cm) with a specificity of 94% for structural abnormalities, but only 82% for the correct identification of malignancy.

CONCLUSION

Computed tomography (CT) pneumocolon is a reliable alternative to barium enema where colonoscopy is incomplete, with the advantage of extraluminal screening, and examination of the proximal bowel. In the frail elderly or young unfit patient, it is a valuable additional diagnostic tool.

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.

Should air contrast computed tomography become the first investigation of the colon of frail or elderly patients?

OBJECTIVE

Air contrast computed tomography (ACCT) is an alternative test to barium enema or colonoscopy. We review our experience of this test as the first investigation of frail, elderly patients with lower gastrointestinal symptoms, and record the subsequent clinical course of these patients to evaluate the efficacy of the technique.

PATIENTS AND METHODS

We performed 109 ACCT studies on frail patients aged 70 years or over with lower gastrointestinal symptoms. The findings were correlated with subsequent investigations and surgical findings. Patients with normal scans were followed up in out-patients or by their GP. Average follow up was 17 months.

RESULTS

A good quality complete examination of the colon was achieved in 97% of patients. Of 109 examinations 34 (31%) were reported as normal, 65 (60%) as diverticular disease, nine (8%) as demonstrating a colonic malignancy and one (1%) showed a benign polyp. One sigmoid tumour was missed initially but diagnosed on a repeat ACCT study.

CONCLUSION

ACCT is a reliable, well-tolerated technique in elderly frail patients.

Spiral CT of the abdomen: increased diagnostic potential

Over the last 10 years, spiral CT has become the optimal method of performing all CT within the abdomen and pelvis. Not only has the technique improved the quality of individual examinations, it has also opened up many new diagnostic possibilities which are currently being evaluated and compared with the concurrent advances in ultrasound and MRI. These new diagnostic possibilities are discussed in this review article. So too are the economic advantages of the shorter data-acquisition times which also make the examination much better tolerated by the patient.

Ultrasound, CT and colonoscopy of colonic cancer

Barium enema and colonoscopy are commonly used for the investigation of suspected colonic cancer. These techniques are relatively invasive and both the investigation and the preceding bowel preparation are demanding, particularly in the elderly. A prospective, blinded trial was conducted to compare ultrasound (US) and CT with colonoscopy. CT and colonoscopy were performed on 50 patients with symptoms suggesting colonic cancer. Both radiological investigations were performed prior to the bowel preparation for colonoscopy. US was performed without any preparation and oral contrast medium was the only preparation used for CT. Colonoscopy detected six cancers, all of which were diagnosed by both US and CT. In addition, US and CT diagnosed a further cancer not seen on colonoscopy due to an incomplete study. US had a sensitivity and specificity of 100% and CT a sensitivity of 100% and a specificity of 84%. US and CT were poor at diagnosing polyps. If the detection of polyps greater than 2 cm is included then US sensitivity falls to 67% and CT sensitivity falls to 89% and specificity rises to 88%. In conclusion, both US and CT are possible alternatives to colonoscopy in the investigation of symptomatic patients with suspected colonic cancer. The use of these techniques could markedly reduce the need for colonoscopy in this patient population with attendant cost savings. Non-invasive imaging has particular advantages in the elderly who cope poorly with both the bowel preparation and the procedure.

Is minimal preparation computed tomography comparable with barium enema in elderly patients with colonic symptoms?

The barium enema (BE) examination in the elderly is often an unsatisfactory investigation. Recent papers have proposed computed tomography (CT) as an alternative method of investigation. They have used a variety of preparation techniques prior to the CT study such as bowel preparation, rectal air insufflation, tap water enemas and intravenous contrast medium. We wished to devise a minimal preparation, minimal supervision technique that could realistically replace the standard BE. One hundred and eighteen elderly patients admitted with symptoms referable to the large bowel had an unenhanced CT following oral contrast medium commenced the previous evening, followed at an interval by a BE performed to a standard technique. Both techniques congruently gave negative reports in 66 (68.8%) individuals. Ten tumours were confidently diagnosed on CT. One annular tumour of the sigmoid colon and one case of colitis were diagnosed on BE only and the severity of a diverticular stricture was underestimated on CT. CT raised the possibility of lesions in 3 (3.1%) patients where the BE was negative. Ten (8.5%) patients had significant abnormalities identified outside the colon using CT. Seven (5.9%) barium enemas were abandoned or severely limited. Minimal preparation, minimal supervision CT is a practical alternative to BE in the frail elderly patient. Radiologists and referring clinicians should be aware that occasionally lesions will not be identified on CT but CT has the advantage that other significant pathology unrelated to the colon may be detected.

Retention balloon catheters and barium enemas: attitudes, current practice and relative safety in the UK

Balloon catheters have been associated with increased morbidity and mortality leading some to believe they should be banned, yet others find them both useful and safe if used properly. Questionnaires were sent to all Consultant Radiologists in the UK to document current practice. Particular attention focused on whether eight safety aspects are considered during their use. In this entirely retrospective study complications with both balloon and standard tip catheters were recorded during the 3-year-period 1992 to 1994 to assess their relative safety. Twenty-two percent of UK Radiologists routinely used a rectal balloon. This was not associated with any increase in mortality, but extraperitoneal rectal perforation was increased by a factor of 2.5. The routine use of retention balloon catheters may not be justified.

Radiology in the detection and prevention of colorectal cancer

Imaging techniques available for detection of colorectal cancer include barium enema, endoscopy, computed tomography (CT), ultrasound, magnetic resonance (MR) and immunoscintigraphy. Technical advances continue rapidly and prompt frequent re-evaluation of the optimal approach to management of these patients. Barium enema and colonoscopy are the main techniques for evaluation of symptomatic patients, although CT may well assume the predominant role within a few years. Variation in quality of barium enemas and colonoscopy poses a challenge for continuing medical education (CME) activities. Screening of asymptomatic individuals has to be considered separately for high, moderate and low risk population. Recommendations have to be made at present in the absence of evidence of effectiveness. Staging of disease pre-operatively is of limited value. Follow-up after surgery should be primarily clinical although endoscopy, CT, MR, ultrasound and immunoscintigraphy all have specific roles in the evaluation of patients suspected of harbouring recurrent disease.

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.

Contemporary radiological examination of the lower gastrointestinal tract

The morphological spectrum of colonic disease is wide. Various treatment modalities may influence the macroscopic aspect of colonic lesions and render a pathological differential diagnosis occasionally difficult or impossible. Before starting therapy in patients suspected of having colonic disease, a physician should undertake a thorough radiological and endoscopic evaluation of the extent and severity of disease activity in the large bowel (Ruderman and Farmer, 1987). DCBE and colonoscopy are complementary imaging modalities, each test has its own intrinsic advantages and merits (Lichtenstein and Rothstein, 1991). DCBE remains the cornerstone in the detection of fistulas, strictures, perforations and estimating depth of ulcerations. Colonoscopy and biopsy remain the most sensitive imaging modalities to identify mucosal involvement (Dijkstra, 1992). The main clinically relevant discrepancies between colonoscopy and DCBE consist of inflammatory lesions without distortion of the mucosal relief and inflammation in the form of small, superficial erosions and ulcers (Dijkstra, 1992).

Computed tomography of the colon in elderly people

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