Assessment of referral patterns for CT KUB in a tertiary setting.

The purpose of this study was to assess the referral patterns and the use of unenhanced renal tract CT (CT KUB) for investigating patients presenting with clinically suspected renal colic. We retrospectively reviewed 500 consecutive CT KUB studies requested for suspected renal colic carried out at a single institution between December 2006 and July 2007. Follow-up radiology reports and discharge summaries on the hospital clinical Intranet were also reviewed. Studies were analysed for characteristics including patient demographics, referring clinical team, time of referral, final diagnosis and requirement for further imaging. The majority of requests were from Emergency (ED) or Urology Departments (49%, 245 out of 500, and 37%, 186 out of 500, respectively). The positive rate for urolithiasis was 67% (337 out of 500), the negative rate was 25% (123 out of 500), and 8% (40 out of 500) of patients had alternative significant findings. Female patients were more likely to have a negative study than male patients (35 versus 20%, P < 0.0001) and more likely to have alternative significant pathology (12 versus 6%, P < 0.0001). Patients referred by specialities other than Urology and ED were more likely to be female and have a negative or alternative finding (P < 0.0001). CT KUB is a widely used first method of investigation for patients with suspected renal colic with a high positive predictive value allowing rapid diagnosis and intervention. However, given the high rate of negative or alternative findings on CT KUB in young women, especially those referred by specialities other than ED or Urology, ultrasound should be considered as an alternative imaging method to minimise unnecessary radiation exposure.

A pilot study of children's exposure to CCA-treated wood from playground equipment.

Arsenic from chromated copper arsenate (CCA)-treated wood, widely used in playgrounds and other outdoor equipment, can persist as surface residues on wood. This raises concerns about possible health risks associated with children playing on CCA-treated playgrounds. In a Pilot Study, 11 children (13-71 months) in homes with and without CCA-treated playgrounds were evaluated with post-exposure hand rinses and urine for total arsenic. Samples of wood, soil, and mulch, as well as synthetic wipes, were sampled for total arsenic. In non-CCA-treated playgrounds vs. CCA-treated playgrounds, respectively, wood arsenic was <2.0 mg/kg vs. mean arsenic 2370 mg/kg (range 1440-3270 mg/kg); soil arsenic was <3.0 mg/kg vs. mean arsenic of 19 mg/kg (range 4.0-42 mg/kg); mulch arsenic at one non-CCA-treated playground was 0.4 mg/kg vs. two CCA-treated playgrounds of 0.6 and 69 mg/kg. The arsenic removed using a synthetic wipe at non-CCA-treated playgrounds was <0.5 microg, while mean arsenic from CCA-treated wood was 117 microg (range 1.0-313). The arsenic mass from hand rinses for children who played at non-CCA-treated playgrounds was <0.2 microg, while mean arsenic mass was 0.6 microg (range <0.2-1.9) at CCA-treated playgrounds. Mean urinary total arsenic levels were 13.6 pg/ml (range 7.2-23.1 pg/ml) for all children evaluated, but there was no association between access to CCA-playgrounds and urinary arsenic levels. Arsenic speciation was not performed. This preliminary Pilot Study of CCA-treated wood playgrounds observed dislodgeable arsenic on 11 children's hands after brief periods of play exposure. Future efforts should increase the number of children and the play exposure periods, and incorporate speciation in order to discriminate between various sources of arsenic.

Percutaneous abscess drainage in the UK: A national survey and single centre study.

AIM: To establish the current practice for management of radiologically placed percutaneous drains for abdominal sepsis in the UK and prospectively study the management of radiologically placed drains at our institution. METHOD: A questionnaire on the management of radiologically placed drains was sent to all radiology departments on a Royal College of Radiologists database. We prospectively followed all drains placed by our radiology department for drainage of abdominal collections, over a 7-month period. RESULTS: A total of 210 questionnaires were sent for the national survey, of these 117 were returned (55.7%). The majority of departments (70.5%) reported that after drain insertion the clinical team took over daily management. Just over 5% of departments either formally managed the drain or obtained final outcome data. From October 2003 to April 2004 we followed 63 consecutive drains placed in 45 patients, for abdominal sepsis. Thirty-nine drains (61.9%) were curative and 17 (26.9%) drains failed. Three drains (4.8%) were placed for palliation, and four drains (6.4%) were placed in order to temporise prior to surgery. Forty-three (68.3%) drains had a successful primary outcome: success after secondary percutaneous abscess drainage (PAD) improved to 46 (73.0%) drains. Two (3%) major complications occurred. CONCLUSIONS: The current approach in the UK to management of radiologically placed drains differs significantly from that practised in the USA. The most common type of support offered by radiology departments in the UK is of informal advice and follow-up, with the clinical team managing the patient's drain. Observations in our hospital highlighted problems relating to drain management that may impact on the success of PAD. We suggest that more formal radiological support after PAD would improve communication and potentially improve outcomes.

Audit of a policy of magnetic resonance imaging with diffusion-weighted imaging as first-line neuroimaging for in-patients with clinically suspected acute stroke.

AIM: To audit the feasibility and use of diffusion-weighted (DW) magnetic resonance imaging (MRI) as initial neuroimaging for in-patients with clinically suspected acute stroke. MATERIALS AND METHODS: In April 2000, MRI with DW and T2-weighted sequence was locally instituted as initial neuroimaging for patients with clinically suspected acute stroke. This retrospective study reviewed imaging performed for in-patients with suspected acute stroke over a 9-month period. Data were collected on image type, result and need for repeat imaging. RESULTS: During the study period, 124 patients had neuroimaging for suspected cerebrovascular accident, and 119 were MRI safe. Eighty-eight (73.9%) patients underwent DW MRI as first-line investigation. Five patients were not MRI safe and 31 had computed tomography (CT) as first-line imaging due to lack of available MRI capacity. Repeat neuroimaging was performed in 16 (12.9%) patients. Study times were comparable for both types of neuroimaging: a mean of 13 min for MRI and 11 min for CT. CONCLUSION: The audit standard was achieved in 88 (73.9%) patients. The use of DW MRI as a first-line investigation for patients with a clinical diagnosis of acute stroke is achievable in a district general hospital setting.

Oral bioavailability of lead and arsenic from a NIST standard reference soil material.

The oral bioavailability of soil contaminants is measured using in vitro or in vivo techniques. Current efforts in our laboratory are focused on the comparisons of in vitro methods for bioavailability estimation with the presently employed in vivo techniques, such as animal models. We present a comparison of two techniques for oral bioavailability estimation: in vitro dissolution and in vivo rat feeding using a standard reference soil. Lead (Pb) and arsenic (As) were chosen because of the range of concentration in this soil as well as the large historical database of bioavailability values for these metals. Metal solubility was measured using a sequential soil extraction in synthetic analogues of human saliva, gastric and intestinal fluids. The soluble metal was defined as the bioaccessible fraction. Oral bioavailability of Pb and As was measured in Sprague Dawley rats by determining metal levels in the major organs and urine, feces, and blood at 1-, 2-, and 3-day time points. Extractions to determine bioaccessibility yielded a gastric component of 76.1% and 69.4% for Pb and As, respectively, and intestinal components were 10.7% and 65.9%. The oral bioavailability of the standard reference soil was 0.7% and 37.8% for Pb and As, respectively. Bioaccessibility was greater than bioavailability for both metals in both gastrointestinal compartments. Although Pb had the highest soil concentration of the selected metals, it was the least bioavailable, while As was highly available in both the in vitro and in vivo method. These types of data allow for an in vitro-in vivo comparison of a soil whose metal concentrations have been certified and validated.