Publishing and academic promotion

Clearly, academic endeavour has to be the single most important criterion for appointment to an academic position and for subsequent promotion. It is rare for excellence either in teaching or clinical practice to offset a poor publication record. However, the pressure to publish and gain related grant income can lead to problems in the normal academic pursuits of a department or institution. These and other related issues will be explored in this editorial.

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.

A randomized, controlled trial of routine early abdominal computed tomography in patients presenting with non-specific acute abdominal pain

AIM

To compare the effect of an initial early computed tomography (CT) examination versus standard practice (SP) on the length of hospital stay, diagnostic accuracy, and mortality of adults presenting with acute abdominal pain.

MATERIALS AND METHODS

Two hundred and five adults presenting with acute abdominal pain were randomized to undergo an early CT examination or current SP, which comprised supine abdominal and erect chest radiography. One hundred and ninety-eight patients (99 in each arm) were included in the analysis. The primary endpoint was the duration of inpatient stay; secondary endpoints were diagnostic certainty and mortality.

RESULTS

There was no significant difference in the length of hospital stay between the two arms (p=0.20). At randomization 36% (35 of 96) of CT patients and 49% (48 of 98) of SP patients were correctly diagnosed; 24h after randomization the correct diagnosis had been established in 84% of CT patients and 73% of SP patients. This refinement in diagnostic certainty was significantly better in the CT group (p<0.001). There was no difference in mortality between the two trial arms (p=0.31).

CONCLUSION

Early abdominal CT in patients with acute abdominal pain improves diagnostic certainty, but does not reduce the length of hospital stay and 6 month mortality.

CT of the chest can hinder the management of seminoma of the testis; it detects irrelevant abnormalities

To evaluate the role of chest CT in the initial staging of testicular seminomatous germ cell tumours. All patients referred to Addenbrooke's Hospital with testicular seminoma from 1 January 2000 to 31 December 2005 were included and case notes retrospectively reviewed. One hundred and eighty-two patients with testicular seminoma were identified, with a median age of 37 years (range 19–74). Most patients had stage I disease (86%). Twenty-four patients had abnormal abdominal CT findings. One hundred and fifty-eight had normal abdominal CT findings but, on initial staging, chest CT reported abnormalities in 13 patients, which, on further follow-up CT were deemed to be irrelevant to the diagnosis of seminoma. There was a further patient with a normal CT abdomen in whom chest CT detected obvious metastatic disease, which was seen on chest x-ray. Overall 18 cases required additional investigations and follow-up for abnormalities subsequently found to be benign. There was a false-positive rate of 10% for initial staging with chest CT. This is the largest reported series of staging CT chest in testicular seminoma. In all patients with normal abdominal CT, normal chest x-ray and abnormal chest CT, subsequent follow-up investigations demonstrated that the lung lesions were incidental findings.

A simple processing method allowing comparison of renal enhancing volumes derived from standard portal venous phase contrast-enhanced multidetector CT images to derive a CT estimate of differential renal function with equivalent results to nuclear medicine quantification

As iodinated contrast medium is cleared by glomerular filtration, it should be possible to apply the same principles utilized in radionuclide studies to derive differential renal function by comparison of enhancing renal volumes derived from contrast enhanced multidetector CT (CEMDCT). Having established a technique iteratively which appeared successful, a retrospective study was performed using 25 consecutive patients with a wide range of urological conditions who had undergone both CEMDCT, including the renal area in the portal venous phase, and nuclear medicine (NM) assessment of renal function with no urological intervention between the studies. Proprietary volume software was used to quantify the volume and attenuation of each kidney, the products of which (after subtraction of soft tissue attenuation derived from a region of interest over psoas) gave right and left enhancing renal volumes. The contribution by each kidney as a percentage of total renal enhancing tissue was derived. Comparison with NM studies resulted in excellent correlation of relative renal function by CEMDCT and NM assessments having a regression of near unity and a Pearson's correlation coefficient of 0.96. Bland Altman and Passing Bablock tests confirmed good agreement between the two methods with no bias. This is a simple, practicable processing technique using standard portal venous phase CEMDCT images to quantify differential function. This technique may allow a one-stop CT assessment of both anatomy and function.

16-Detector multislice CT in the detection of stress fractures: a comparison with skeletal scintigraphy

AIMS

To test the hypothesis that the improved resolution afforded by 16-detector computed tomography (CT) would translate to better stress fracture detection when compared with skeletal scintigraphy.

MATERIALS AND METHODS

Thirty-three cases of suspected stress fractures in 26 patients were investigated using skeletal scintigraphy and 16-detector CT performed on the same day. Planar images of the lower limbs were taken 3h post-injection of 400MBq (99m)Tc-methylene diphosphonate ((99m)Tc-MDP). (99m)Tc-MDP uptake was quantified at suspected fracture sites. CT was performed using a 16-detector multisection machine employing 0.75mm detectors and images reconstructed in 0.5mm increments. Examinations were reported independently and discordant results were compared at follow-up.

RESULTS

At initial reporting scintigraphy identified fractures in 13 of the 33 cases and CT identified four of the 33. In one case, on review of the CT images, a fracture was present in the distal fibula that was not initially identified. This resulted in eight scintigraphic-positive CT-negative discordant cases. The (99m)Tc-MDP uptake was significantly lower in the discordant fracture group compared with the concordant group (p<0.01).

CONCLUSIONS

Despite technological advances in CT, scintigraphy appeared to detect more stress fractures. As such, multidetector CT should not be used as a routine initial investigation in stress fracture detection. The potential use of (99m)Tc-MDP quantification at fracture sites is of interest and may be worth further investigation.

16 detector multislice CT versus skeletal scintigraphy in the diagnosis of wrist fractures: value of quantification of 99Tcm-MDP uptake

To compare the measured uptake of 99Tcm-methylene diphosphonate (99Tcm-MDP) in those scaphoid fractures seen on both 16 detector multislice CT and scintigraphy, with those seen only on scintigraphy. Over a 12 month period a total of 51 patients with suspected fracture underwent both conventional 99Tcm-MDP scintigraphy and 16 detector multislice CT on the same day. The 99Tcm-MDP uptake was then quantified in patients with identified fracture. This was measured by placing a region of interest (ROI) over the fracture site and the mean and maximum number of counts were compared with those in a similar size ROI placed over background bone activity. A total of 23 fractures were identified on scintigraphy of which 16 were also detected on CT (concordant). In seven cases the fracture was not seen on CT, even in retrospect (discordant). In the discordant cases, follow-up radiographs and MRI (where available) also failed to demonstrate a fracture. The mean fracture count to background bone activity ratio averaged 7.7 (range 3.2-18.5) for concordant fractures and 3.8 (range 1.7-5.3) for discordant fractures (t-test p=0.04). The maximum fracture count to background bone activity ratio averaged 12.7 (range 4.3-27.7) for concordant fractures and 6.3 (range 2.6-9.5) for discordant fractures (t-test p=0.03). It is speculated whether these discordant fractures with less 99Tcm-MDP uptake may represent a less severe injury such as bone bruise.

Noradrenergic receptor mRNA expression in adult rat superficial dorsal horn and dorsal root ganglion neurons

Noradrenaline (NAdr) has well documented analgesic actions at the level of the spinal cord. Released from bulbospinal projections onto superficial dorsal horn (SDH) neurons, NAdr modulates the excitability of these neurons through the activation of alpha1, alpha2 or beta adrenoceptors. This study utilised in situ hybridisation to determine the specific expression of adrenoceptors within adult rat lumbar SDH and dorsal root ganglion (DRG) neurons, and reports the presence of alpha1A, alpha1B, alpha2B, beta1 and beta2 adrenoceptor mRNA within SDH neurons, and the presence of alpha1A, alpha1B and alpha2C adrenoceptor mRNA within DRG neurons. The present study provides an insight into the modulation of sensory processing at the level of the spinal cord following adrenoceptor activation.

Screening with magnetic resonance imaging and mammography of a UK population at high familial risk of breast cancer: a prospective multicentre cohort study (MARIBS)

BACKGROUND

Women genetically predisposed to breast cancer often develop the disease at a young age when dense breast tissue reduces the sensitivity of X-ray mammography. Our aim was, therefore, to compare contrast enhanced magnetic resonance imaging (CE MRI) with mammography for screening.

METHODS

We did a prospective multicentre cohort study in 649 women aged 35-49 years with a strong family history of breast cancer or a high probability of a BRCA1, BRCA2, or TP53 mutation. We recruited participants from 22 centres in the UK, and offered the women annual screening with CE MRI and mammography for 2-7 years.

FINDINGS

We diagnosed 35 cancers in the 649 women screened with both mammography and CE MRI (1881 screens): 19 by CE MRI only, six by mammography only, and eight by both, with two interval cases. Sensitivity was significantly higher for CE MRI (77%, 95% CI 60-90) than for mammography (40%, 24-58; p=0.01), and was 94% (81-99) when both methods were used. Specificity was 93% (92-95) for mammography, 81% (80-83) for CE MRI (p<0.0001), and 77% (75-79) with both methods. The difference between CE MRI and mammography sensitivities was particularly pronounced in BRCA1 carriers (13 cancers; 92%vs 23%, p=0.004).

INTERPRETATION

Our findings indicate that CE MRI is more sensitive than mammography for cancer detection. Specificity for both procedures was acceptable. Despite a high proportion of grade 3 cancers, tumours were small and few women were node positive. Annual screening, combining CE MRI and mammography, would detect most tumours in this risk group.

Inflammatory Abdominal Aortic Aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysms (IAAA) are a variant of aortic aneurysm characterised by extensive peri-aneurysmal fibrosis, thickened walls and dense adhesions and represent between 3 and 10% of all abdominal aortic aneurysms (AAA). Surgery is technically challenging and is still associated with an increased morbidity and mortality. Controversy exists about aetiology and pathogenesis.

METHODS

We review the literature on the current theories, the available imaging modalities and the current thinking on management of IAAA. A Medline database search was performed. Articles were cross-referenced.

RESULTS AND CONCLUSIONS

Aneurysm development is multifactorial with important genetic and environmental factors. The literature supports the theory that IAAA arise from the same antigenic stimulus that is responsible for the non-IAAA, representing one extreme of an inflammatory spectrum. The results after open repair have improved and there is now little difference in the mortality between non-IAAA and IAAA repair. However, there is likely to be a role for endovascular stenting in IAAA management and this requires further study. It is clear that closer follow-up of patients after IAAA repair with either technique is necessary to monitor the inflammatory process. No evidence-based follow-up protocol exists but three to six-monthly monitoring of renal function and erythrocyte sedimentation rate (ESR) for 24 months post-repair would seem a reasonable regime.

False negative 16 detector multislice CT for scaphoid fracture

We discuss a case of a 19-year-old man with scaphoid trauma. We describe the imaging findings on three sets of radiographs, bone scintigraphy, CT and MRI. CT failed to identify a scaphoid fracture, which was present on 6 week radiographs, MRI and scintigraphy. The case illustrates that despite multidetector technology, CT still relies upon cortical and or trabecular displacement to demonstrate fractures.

Training improves medical student performance in image interpretation

The aim of this study was to objectively quantify the effects of radiological teaching on student performance in interpreting radiological images, and to establish whether training location affects performance. 114 clinical students were asked to anonymously interpret radiological cases before and after 26 weeks clinical training. Improvements were assessed by comparing performance on the median question in each assessment using the Kruskal-Wallis analysis. Variations according to different placements were assessed by the Mann-Whitney U-test. There was a highly significant (p<0.001) improvement in the performance of the group with training. The proportion of correct answers to the median question improved from 8% to 43%. Differences between training placements were non-significant. Our study suggests that radiology teaching significantly improves student performance. Future work should look to define the contribution of "clinical exposure" towards this improvement, as well as the various teaching methods employed.

16-detector multislice CT: dosimetry estimation by TLD measurement compared with Monte Carlo simulation

Computer simulations are widely used to estimate effective doses from CT examinations. The raw data often used in their estimations were obtained some years ago and made certain assumptions regarding CT unit design. At that time multidetector CT units were unavailable. Changes in design will limit the accuracy of computer simulated dosimetry on these machines. We therefore estimated CT dose on a 16-detector unit directly using thermoluminescent dosemeters (TLDs) and an anthropomorphic phantom. We found that the dose measured directly was 18% higher than the computer simulated dosimetry, in keeping with the previously recognised underestimation by computer simulation techniques compared with TLD measurements.

P2X2 and P2X3 receptor expression in human bladder urothelium and changes in interstitial cystitis

OBJECTIVE

To investigate whether the expression of P2X(3) receptors (implicated in the pathophysiology of pain) is altered in human bladder urothelium from patients with interstitial cystitis (IC, a major symptom of which is pain), and as P2X(2) receptors can be co-expressed with P2X(3) receptors, to assess their expression also.

PATIENTS AND METHODS

Bladder tissue samples were collected from patients undergoing cystectomy or radical prostatectomy. Patients with IC were diagnosed using the international criteria. RNA protein expression levels of both receptors were evaluated using reverse transcription-polymerase chain reaction (PCR), real-time quantitative PCR and Western blot analysis.

RESULTS

P2X(2) was expressed in the human urothelium, in a glycosylated form. There was less gene expression of P2X(3) in IC urothelium, whereas P2X(2) gene expression was unchanged. This contrasted with the protein expression, which was increased for both P2X(2) and P2X(3).

CONCLUSION

This is the first report of the expression of the P2X(2) receptor in human bladder urothelium. There was greater protein expression of both P2X(2) and P2X(3) in IC bladder urothelium which did not directly correlate with the gene expression. Changes in expression of P2X(2) and P2X(3) receptors may contribute to the pain that patients with IC have, and might provide novel drug targets.

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.

Evidence against the use of lumbar spine radiography for low back pain

AIM

To review abnormalities reported on plain radiographic examination of the lumbar spine in patients referred with low back pain by general practitioners. Additionally, we evaluated and stratified the prevalence of these abnormalities by age. Finally, the diagnostic impact of lumbar spine radiography for the diagnosis of degenerative change, fracture, infection and possible tumour, was modelled.

MATERIALS AND METHODS

A retrospective review of 2007 radiographic reports of patients referred with low back pain for lumbar spine radiography to a large radiology department was performed. The reports were classified into different diagnostic groups and subsequently stratified according to age. The potential diagnostic impact of lumbar spine radiography was modelled by using the prevalence of conditions studied as pre-test probabilities of disease.

RESULTS

The prevalence of reported lumbar spine degeneration increased with age to 71% in patients aged 65-74 years. The overall prevalence of fracture, possible infection, possible tumour was low in our study population: 4, 0.8 and 0.7%, respectively. Fracture and possible infection showed no association with age. Possible tumour was only reported in patients older than 55 years of age.

CONCLUSION

Although the prevalence of degenerative changes was high in older patients, the therapeutic consequences of diagnosing this abnormality are minor. The prevalence of possible serious conditions was very low in all age categories, which implies radiation exposure in many patients with no significant lesions.

Protocol for a national multi-centre study of magnetic resonance imaging screening in women at genetic risk of breast cancer

The protocol of the national multicentre study of Magnetic Resonance Imaging (MRI) as a method of screening for breast cancer in women at genetic risk is described. The sensitivity and specificity of contrast-enhanced MRI will be compared with two-view X-ray mammography in a comparative trial. Approximately 500 women below the age of 50 at high genetic risk of breast cancer will be recruited per year for 3 years, with annual MRI and X-ray examination continuing for up to 5 years. A symptomatic cohort will be measured in the initial phase of the study to ensure consistent reporting between centres. The MRI examination will comprise an initial high-sensitivity screening measurement, followed by a high-specificity measurement in equivocal cases. Retrospective analysis will identify the most specific indicators of malignancy. Sensitivity and specificity, together with diagnostic performance, diagnostic impact and therapeutic impact will be assessed with reference to pathology, follow-up and changes in diagnostic certainty and therapeutic decisions. The psychological impact of screening in this high-risk group will be ascertained.

Identification of MEK1 as a novel target for the treatment of neuropathic pain

(1) In the present study we have attempted to identify changes in gene expression which are associated with neuropathic pain using subtractive suppression hybridization analysis of the lumbar spinal cord of animals suffering streptozocin induced diabetic neuropathy. (2) Using this approach, we found a significant up-regulation of several key components of the extracellular signal-regulated kinase (ERK) cascade. These findings were confirmed by Western blot analysis, which demonstrated that the levels of active ERK1 and 2 correlated with the onset of streptozocin-induced hyperalgesia. (3) Intrathecal administration of the selective MAPK/ERK-kinase (MEK) inhibitor PD 198306 dose-dependently (1-30 micro g) blocked static allodynia in both the streptozocin and the chronic constriction injury (CCI) models of neuropathic pain. (4) The antihyperalgesic effects of PD 198306, in both the streptozocin and CCI models of neuropathic pain, correlated with a reduction in the elevated levels of active ERK1 and 2 in lumbar spinal cord. (5) Intraplantar administration of PD 198306 had no effect in either model of hyperalgesia, indicating that changes in the activation of ERKs and the effect of MEK inhibition are localized to the central nervous system. (6) In summary, we have demonstrated for the first time that the development of neuropathic pain is associated with an increase in the activity of the MAPK/ERK-kinase cascade within the spinal cord and that enzymes in this pathway represent potential targets for the treatment of this condition.

Lumbar lordosis: study of patients with and without low back pain

We used magnetic resonance imaging (MRI) to assess lumbar lordosis in 27 patients with low back pain and 19 patients and 10 volunteers with no known back pain. Our study aimed to investigate whether lordosis changes with age and is reduced in those with low back pain. Although our results confirm known observations that lumbar lordosis is more prominent in women (P < 0.01) and those with a higher body mass index (P < 0.04), we were unable to demonstrate any significant variation in lordosis with age. Nor could we demonstrate any difference in the degree of lordosis among women with or without back pain. Men with low back pain tended to have a less prominent lordosis, but this difference did not reach statistical significance. Therefore, a 'reduced lumbar lordosis' should be regarded as a very weak clinical sign.

Serotonin receptor mRNA expression in rat dorsal root ganglion neurons

In the present study, we have used in situ hybridization to examine the distribution of serotonin (5-HT) receptors in rat dorsal root ganglion (DRG) neurons. Within DRG neurons, mRNAs for 5-HT1B, 5-HT1D, 5-HT2A, 5-HT2B, 5-HT3B and 5-HT4 receptors were readily detected in small (<25 microm), medium (25-45 microm) and large (>45 microm) diameter neurons. In contrast mRNAs for 5-HT1A, 5-HT1E, 5-HT2C, 5-HT5A, 5-HT5B, 5-HT6 and 5-HT7 receptors were undetectable in these neurons. The present study provides an insight into the molecular profile of 5-HT receptor subtypes in neurons responsible for modulating sensory information.

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.

Single cell expression analysis--pharmacogenomic potential

A fundamental challenge in biology is to correlate physiology with gene expression in specific cell types. This can only be achieved by understanding gene expression at the level of the single cell because, in many systems, each cell has the capacity to express a unique set of genes. Therefore, each cell can be considered to be functionally distinct. A clearer understanding of gene expression differences at such a discrete level provides an opportunity to develop drugs with more targeted pharmacologies or with decreased side effects.

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS)

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS) is in progress. The study design, accrual to date, and related research projects are described. Revised accrual rates and expected recruitment are given. 15 cancers have been detected to date, from a total of 1236 screening measurements. This event rate and the tumour grades reported are compared with recent reports from other studies in women at high risk of breast cancer.

Appendicitis: spectrum of appearances on helical CT

Acute appendicitis has extremely varied clinical presentations. A delayed or missed diagnosis may result in severe adverse consequences. Helical CT is evolving as an important diagnostic aid, but the CT signs can be varied and can easily be overlooked by the unwary. This pictorial review illustrates the spectrum of radiological signs and appearances of appendicitis on helical CT.

Superficial collateral veins on abdominal CT: findings in cirrhosis and systemic venous obstruction

Inspection of the superficial veins of the abdominal wall has long been a routine part of the physical examination. To date, radiologists have given such veins rather scant attention, even though they are elegantly demonstrated by CT. We have performed a study of 21 patients with cirrhosis, 7 patients with caval obstruction and 28 normal control counterparts in order to determine whether superficial veins were more numerous in these two clinical conditions. The 7 patients with caval obstruction included 4 with superior and 3 with inferior vena cava obstructions. Electronic data from the CT examinations of these 28 cases and 28 controls were analysed on a viewing console. Superficial veins were significantly more numerous in patients with cirrhosis (mean maximum=5, p<0.01) and caval obstruction (mean maximum=9.1, p<0.01) than in the normal controls (mean maximum=2.1). The combination of too many superficial veins and a large superior mesenteric vein is a pointer towards cirrhosis. The presence of excessive superficial veins is yet another clue to the presence of underlying disease when analysing abdominal CT.

Body computed tomography in critically ill patients

The aim of the study was to assess the effectiveness of computed tomography in the management of critically ill patients. We performed a prospective study over a 4-month period. The requesting clinician was asked to document their clinical diagnosis and confidence thereof on a visual analogue scale. They were also asked about their management plan if computed tomography had not been available. After imaging, any change in the management plan was assessed. During the study period, 16 computed tomograms were performed on 14 patients. There were 21 possible clinical diagnoses: of these eight were confirmed, and 13 were refuted. Seven new diagnoses were established. Computed tomography did not help in the management of two patients and it led to more confusion in the management of one patient. The management of seven patients was altered after computed tomography and in six the management depended solely on computed tomography findings.

Supportive cushions produce no practical reduction in lumbar lordosis

It is common practice to place a pillow or bolster under the knees of patients undergoing lumbar spine CT or MRI. The use of such supportive cushions leads to gentle hip flexion that is thought to ease pain and "reduce lumbar lordosis". It is also thought to facilitate axial imaging through the discs. Observations in seven subjects who underwent lumbar spine MRI with and without such hip flexion showed no appreciable change in the degree of lordosis. As the use of such devices does not produce a practical reduction of lumbar lordosis, the decision to employ them should be made entirely with respect to patient comfort.

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.

Requests for body computed tomography: increasing workload, increasing indications and increasing age

Increasing numbers of increasingly elderly patients were being examined in our Body CT department. At the same time, some of our clinical colleagues perceived that their patients might be discriminated against on the basis of their age when allocating CT time. We therefore studied the population trends in our department over a 10-year period. The ages of patients attending the Body CT department were collected from the hospital's computer information system from 1995 to 2000 and from handwritten logbooks for the months of September 1988 and 1998. Comparison was made with population trends within the hospital and local demographic data. There has been an average increase of 11% per annum in the number of examinations performed in the Body CT unit. The average age of patients examined increased from 52.7 years in 1988 to 58.9 years in 1998. The largest increase occurred in the over 75-year population (18% rise per annum). Hospital and local demographic population profiles changed little during the same period. We are performing increasing numbers of body CT examinations on increasingly elderly patients. This is probably due to an increased willingness to investigate and treat elderly patients, rather than changes in the local population. There is no evidence of a general discriminatory policy on the basis of age.

Histopathological correlates of abnormal pericolic fat on CT in the assessment of colorectal carcinoma

The aim of this study was to assess the pathological significance of abnormal pericolic fat shown by CT in the context of colorectal carcinoma. CT and histopathological findings of 63 resected colorectal carcinomas were retrospectively reviewed. CT examinations were assessed by two observers for the presence or absence of abnormal pericolic fat (typically linear or nodular opacities) at tumour sites. Specimens were reviewed histopathologically for depth of tumour invasion, extramuscular tissue reaction, and number and largest size of tumour-involved and tumour-free lymph nodes. The sensitivity, specificity, positive predictive value and negative predictive value of pericolic fat in identifying extension of tumour infiltration beyond the muscle coat were 79% (42/53), 33% (2/6), 91% (42/46) and 15% (2/13), respectively. Despite these indicators of efficacy, the association between the presence of pericolic fat abnormality on CT and extramuscular extension of tumour (infiltration and/or nodal disease) or tissue reaction alone or in combination did not reach statistical significance (p>0.3 in all cases). Abnormal ("misty" or "mucky") pericolic fat in the assessment of colorectal cancer on CT is not a precise indicator of extramuscular extension of tumour, as it cannot clearly distinguish between tumour infiltration and tissue reaction beyond the muscle coat, or pericolic nodal involvement. However, it is a very helpful CT sign that may draw attention to the presence and site of a potential colonic abnormality.

Improving risk assessment: hip geometry, bone mineral distribution and bone strength in hip fracture cases and controls. The EPOS study. European Prospective Osteoporosis Study

Hip geometry and bone mineral density (BMD) have previously been shown to relate independently to hip fracture risk. Our objective was to determine by how much hip geometric data improved the identification of hip fracture. Lunar pencil beam scans of the proximal femur were obtained. Geometric and densitometric values from 800 female controls aged 60 years or more (from population samples which were participants in the European Prospective Osteoporosis Study, EPOS) were compared with data from 68 female hip fracture patients aged over 60 years who were scanned within 4 weeks of a contralateral hip fracture. We used Lunar DPX 'beta' versions of hip strength analysis (HSA) and hip axis length (HAL) applied to DPX(L) data. Compressive stress (Cstress), calculated by the HSA software to occur as a result of a typical fall on the greater trochanter, HAL, body mass index (BMI: weight/(height)2) and age were considered alongside femoral neck BMD (FN-BMD, g/cm2) as potential predictors of fracture. Logistic regression was used to generate predictors of fracture initially from FN-BMD. Next age, Cstress (as the most discriminating HSA-derived parameter), HAL and BMI were added to the model as potentially independent predictors. It was not necessary to include both HAL and Cstress in the logistic models, so the entire data set was examined without excluding the subjects missing HAL measurements. Cstress combined with age and BMI provided significantly better prediction of fracture than FN-BMD used alone as is current practice, judged by comparing areas under receiver operating characteristic (ROC) curves (p<0.001, deLong's test). At a specificity of 80%, sensitivity in identification was improved from 66% to 81%. Identifying women at high risk of hip fracture is thus likely to be substantially enhanced by combining bone density with age, simple anthropometry and data on the structural geometry of the hip. HSA might prove to be a valuable enhancement of DXA densitometry in clinical practice and its use could justify a more proactive approach to identifying women at high risk of hip fracture in the community.

Streptozocin-induced neuropathy is associated with altered expression of voltage-gated calcium channel subunit mRNAs in rat dorsal root ganglion neurones

Voltage-gated calcium channels (VGCCs) within sensory neurones are believed to perform an important role in neuropathic pain. In the present study we examine the changes in VGCC mRNA which occur following streptozocin- (STZ) induced diabetic neuropathy using in situ hybridization. STZ caused a significant increase in alpha(2)delta(1), alpha(2)delta(2), and alpha(2)delta(3) mRNA levels in all neuronal cell types. Similarly, mRNA levels of alpha(1F), alpha(1I), and alpha(1S) were increased in all cell types studied whilst alpha(1A) and alpha(1G) mRNAs were specifically upregulated in medium and large diameter neurones. In conclusion, we demonstrate that the induction of diabetic neuropathy is associated with dramatic changes in the expression of VGCCs.

Xe991 reveals differences in K(+) channels regulating chloride secretion in murine airway and colonic epithelium

The cognitive enhancer XE991 interacts with K(+) channels consisting of KCNQ2 and KCNQ3 heteromultimers to block the M-current. XE991 can also block KCNQ1 K(+) channels expressed in oocytes, but sensitivity is reduced when the channels are coexpressed with minK (KCNE1). The purpose of the study was to examine the interaction of XE991 with other types of K(+) channel, especially those in the basolateral membranes of murine epithelia. K(+) channel blockade was measured by the inhibition of chloride secretion resulting from depolarization. XE991 inhibited the chloride secretory current in colonic epithelia by an interaction with basolateral K(+) channels when forskolin was used as the stimulus. However, when 1-ethyl-2-benzimidazolinone (EBIO) was used to stimulate chloride secretion, XE991 was ineffective unless charybdotoxin was also present. Because EBIO also activates Ca(2+)-sensitive K(+) channels, whereas forskolin activates only cAMP-sensitive K(+) channels, it is concluded that the latter are the targets for XE991. XE991 had effects similar to those of 293B on epithelial chloride transport, for which the target is known to be KCNQ1/KCNE3 multimers. mRNA for both these components of the cAMP-sensitive K(+) channels were found in high abundance in the colon, whereas KCNE1 was barely detectable. Furthermore, both XE991 and 293B were active in colonic epithelia from KCNE1 knockout mice. By contrast, in nasal epithelium, the forskolin sensitive chloride secretory current was barely sensitive to XE991 but was sensitive to clofilium. Xenopus laevis oocytes in which both KCNQ1 and KCNE3 had been expressed were significantly more sensitive to XE991 than oocytes expressing only KCNQ1.

Expression of voltage-gated calcium channel subunits in rat dorsal root ganglion neurons

In the present study, we have used in situ hybridisation to examine the distribution of calcium channel subunits in rat dorsal root ganglion (DRG) neurons. Within DRG neurons, the calcium channel alpha subunit mRNAs alpha(1A), alpha(1B), alpha(1C), alpha(1D), alpha(1E), alpha(1I) and alpha(1S) were readily detected in small (<25 microm), medium (25-45 microm) and large (>45 microm) diameter neurons. alpha(1F) was present at very low levels in these neurons whilst alpha(1G) was virtually undetectable. The calcium channel auxiliary subunits alpha(2)delta(1) and alpha(2)delta(2) showed a complementary pattern of distribution to that of alpha(2)delta(3) in DRG neurons. alpha(2)delta(1) and alpha(2)delta(2) transcripts were expressed predominantly in small c-type sensory neurons and were present at lower levels in large Abeta-type sensory neurons. In contrast, alpha(2)delta(3) mRNA was present in high quantities in the large-diameter cells but was expressed at lower levels in small-diameter neurons of the DRG. The present study provides an insight into the molecular profile of calcium channel alpha(1) and alpha(2)delta subunits in the neurons responsible for transmitting sensory information.

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

PURPOSE

To evaluate the effect of magnetic resonance (MR) imaging of the wrist on clinicians' diagnoses, diagnostic certainty, and patient care.

MATERIALS AND METHODS

A controlled observational study was performed. Referring clinicians completed questionnaires about diagnosis and intended management before and after wrist MR imaging. One hundred eighteen consecutive patients referred for MR imaging of the wrist were recruited from the MR imaging units at a regional teaching hospital and a large district general hospital. The main measures were changes in the clinicians' leading and subsidiary diagnoses after MR imaging, their certainty in these diagnoses, and changes in intended patient care.

RESULTS

Questionnaires were incorrectly completed for five patients, questionnaires were not returned for three, appointments were canceled for 10, and two could not tolerate the MR examination. Complete follow-up data were available for 98 patients. The clinical diagnosis changed in 55 of 98 patients; in the remaining 43 patients, diagnostic certainty increased in 23. Clinicians reported that MR imaging had substantially improved their understanding of the disease in 67 of 98 patients. The care plan changed in 45 of 98 patients, with a shift away from surgical treatment. Twenty-eight patients were discharged without further investigation. MR imaging was similarly effective in the regional teaching center and the district general hospital.

CONCLUSION

MR imaging of the wrist influences clinicians' diagnoses and management plans.

Beta3, a novel auxiliary subunit for the voltage gated sodium channel is upregulated in sensory neurones following streptozocin induced diabetic neuropathy in rat

In the present study we have used in situ hybridization to examine the changes in mRNA expression of the voltage gated sodium channel subunits beta1 and beta3, which occur in response to streptozocin induced diabetic neuropathy. Under control conditions beta1 mRNA was detected throughout the spinal cord and in large dorsal root ganglion (DRG) Abeta fibres whilst beta3 mRNA was expressed exclusively in the layers I/II and X of the spinal cord and in small DRG c-fibres. Following streptozocin treatment, the expression of beta1 mRNA remained unchanged in both the spinal cord and DRG whilst beta3 message was significantly increased in both the spinal cord and in medium diameter Adelta type DRG neurones. In conclusion, the present study illustrates that the development of the neuropathic pain state is associated with distinct changes in the pattern of beta3 subunit expression and that these changes appear to be specific to the neuropathic pain state induced.