CT colonography: optimisation, diagnostic performance and patient acceptability of reduced-laxative regimens using barium-based faecal tagging

To establish the optimum barium-based reduced-laxative tagging regimen prior to CT colonography (CTC). Ninety-five subjects underwent reduced-laxative (13 g senna/18 g magnesium citrate) CTC prior to same-day colonoscopy and were randomised to one of four tagging regimens using 20 ml 40%w/v barium sulphate: regimen A: four doses, B: three doses, C: three doses plus 220 ml 2.1% barium sulphate, or D: three doses plus 15 ml diatriazoate megluamine. Patient experience was assessed immediately after CTC and 1 week later. Two radiologists graded residual stool (1: none/scattered to 4: >50% circumference) and tagging efficacy for stool (1: untagged to 5: 100% tagged) and fluid (1: untagged, 2: layered, 3: tagged), noting the HU of tagged fluid. Preparation was good (76–94% segments graded 1), although best for regimen D (P = 0.02). Across all regimens, stool tagging quality was high (mean 3.7–4.5) and not significantly different among regimens. The HU of layered tagged fluid was higher for regimens C/D than A/B (P = 0.002). Detection of cancer (n = 2), polyps ≥6 mm (n = 21), and ≤5 mm (n = 72) was 100, 81 and 32% respectively, with only four false positives ≥6 mm. Reduced preparation was tolerated better than full endoscopic preparation by 61%. Reduced-laxative CTC with three doses of 20 ml 40% barium sulphate is as effective as more complex regimens, retaining adequate diagnostic accuracy

Feasibility study of computed tomography colonography using limited bowel preparation at normal and low-dose levels study

The purpose was to evaluate low-dose CT colonography without cathartic cleansing in terms of image quality, polyp visualization and patient acceptance. Sixty-one patients scheduled for colonoscopy started a low-fiber diet, lactulose and amidotrizoic-acid for fecal tagging 2 days prior to the CT scan (standard dose, 5.8–8.2 mSv). The original raw data of 51 patients were modified and reconstructed at simulated 2.3 and 0.7 mSv levels. Two observers evaluated the standard dose scan regarding image quality and polyps. A third evaluated the presence of polyps at all three mSv levels in a blinded prospective way. All observers were blinded to the reference standard: colonoscopy. At three times patients were given questionnaires relating to their experiences and preference. Image quality was sufficient in all patients, but significantly lower in the cecum, sigmoid and rectum. The two observers correctly identified respectively 10/15 (67%) and 9/15 (60%) polyps ≥10 mm, with 5 and 8 false-positive lesions (standard dose scan). Dose reduction down to 0.7 mSv was not associated with significant changes in diagnostic value (polyps ≥10 mm). Eighty percent of patients preferred CT colonography and 13% preferred colonoscopy (P<0.001). CT colonography without cleansing is preferred to colonoscopy and shows sufficient image quality and moderate sensitivity, without impaired diagnostic value at dose-levels as low as 0.7 mSv

Frequency and Nature of Incidental Extra-Enteric Lesions Found on Magnetic Resonance Enterography (MR-E) in Patients with Inflammatory Bowel Diseases (IBD)

The aim of this study was to determine the occurrence of extra-enteric findings in a large cohort of patients undergoing magnetic resonance enterography (MR-E) and to classify the clinical significance of these findings.We retrospectively analyzed 1154 MR-E performed in 1006 patients referred to our radiological department between 1999-2005. The reasons for referral were suspected or proven inflammatory bowel diseases (IBD) (n = 710), further diagnostic work-up for small bowel disease because of non-specific abdominal symptoms (SBD; n = 182) or suspected small bowel malignancies (SBM; n = 114). All extra-enteric findings were reviewed by a radiologist and a gastroenterologist and were classified as having high, moderate, or low significance for further diagnostic or therapeutic procedures.The average age of all patients was 40+/-16 (Mean+/-SD) years (y) (IBD 35+/-13 y; SBD 49+/-16 y; SBM 57+/-15 y). A total of 1113 extra-enteric findings were detected in 600 of 1006 patients (59.6%). Of these findings 180 (16.2%) were judged as having a high, 212 (19.0%) a moderate and 721 (64.8%) a low significance. On a per group basis in patients with IBD 12.0% of the findings were of major clinical significance compared to 13.7% and 33.3% in patients with SBD and SBM, respectively. The most common major findings were abscesses (69.9%) in the IBD group and extraintestinal tumors, metastases or masses in the SBD and SBM groups (41.9% and 74.2%, respectively).MR-E reveals a substantial number of extra-enteric findings, supporting the role of a cross-sectional imaging method for the evaluation of the small bowel

Does CT colonography have a role for population-based colorectal cancer screening?

Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool tests, with endoscopy used as an adjunct in some countries. Computed tomographic colonography (CTC) is a potential screening test, with an estimated sensitivity of 88 % for advanced neoplasia ≥10 mm. Recent randomised studies have shown that CTC and colonoscopy have similar yields of advanced neoplasia per screened invitee, indicating that CTC is potentially viable as a primary screening test. However, the evidence is not fully elaborated. It is unclear whether CTC screening is cost-effective and the impact of extracolonic findings, both medical and economic, remains unknown. Furthermore, the effect of CTC screening on CRC-related mortality is unknown, as it is also unknown for colonoscopy. It is plausible that both techniques could lead to decreased mortality, as for sigmoidoscopy and gFOBT. Although radiation exposure is a drawback, this disadvantage may be over-emphasised. In conclusion, the detection characteristics and acceptability of CTC suggest it is a viable screening investigation. Implementation will depend on detection of extracolonic disease and health-economic impact

P3HT-Based Solar Cells: Structural Properties and Photovoltaic Performance

Each year we are bombarded with B.Sc. and Ph.D. applications from students that want to improve the world. They have learned that their future depends on changing the type of fuel we use and that solar energy is our future. The hope and energy of these young people will transform future energy technologies, but it will not happen quickly. Organic photovoltaic devices are easy to sketch, but the materials, processing steps, and ways of measuring the properties of the materials are very complicated. It is not trivial to make a systematic measurement that will change the way other research groups think or practice. In approaching this chapter, we thought about what a new researcher would need to know about organic photovoltaic devices and materials in order to have a good start in the subject. Then, we simplified that to focus on what a new researcher would need to know about poly-3-hexylthiophene:phenyl-C61-butyric acid methyl ester blends (P3HT: PCBM) to make research progress with these materials. This chapter is by no means authoritative or a compendium of all things on P3HT:PCBM. We have selected to explain how the sample fabrication techniques lead to control of morphology and structural features and how these morphological features have specific optical and electronic consequences for organic photovoltaic device applications

Acute paraplegia after myelography : decompensation of a herniatad thoracic disc

A 71-year-old patient presented with low back pain and slowly progressive weakness of both legs. Within a few hours after lumbar myelography, paraplegia below level L2 evolved. MR-imaging revealed a discogenic stenosis at level Th10/11. Immediate decompression by costo-transversectomy led to reversal of the neurological deficits

Comparison of CT angiography with MR angiography in the preoperative assessment of living kidney donors

BACKGROUND: The aim of the study was to prospectively compare the diagnostic performance of CT angiography (CTA) with MR angiography (MRA) in the preoperative assessment of living renal donors. METHODS: Forty-eight potential living renal donors (mean 51 years, 29-67 years) underwent multislice CTA and gadolinium-enhanced MRA. Six potential donors were excluded. Forty-two donors underwent minimal invasive retroperitoneoscopic nephrectomy (left 36, right 6) and their datasets available for analysis independently performed by two blinded radiologists. The surgical status served as gold standard. RESULTS: In 42 donors (84 kidneys), CTA identified 63 kidneys with 1 artery (MRI 61), 19 with 2 arteries (MRI 20), one with three arteries (MRI 2), and one with four arteries (MRI 1). Considering only the side with the surgical status available for verification, both CT and MRI correctly characterized 35 of 36 donors with a single renal artery and five of six with one supernumerary artery. Two false positives were two arteries suggested as supernumerary both in CT and MRI not confirmed during surgery. CTA and MRA both correctly identified three accessory renal veins in two donors. CONCLUSION: CTA and MRA had the same accuracy for characterization of renal vasculature in the preoperative assessment of living renal donors

Clinical and radiologic features of pulmonary edema

Pulmonary edema may be classified as increased hydrostatic pressure edema, permeability edema with diffuse alveolar damage (DAD), permeability edema without DAD, or mixed edema. Pulmonary edema has variable manifestations. Postobstructive pulmonary edema typically manifests radiologically as septal lines, peribronchial cuffing, and, in more severe cases, central alveolar edema. Pulmonary edema with chronic pulmonary embolism manifests as sharply demarcated areas of increased ground-glass attenuation. Pulmonary edema with veno-occlusive disease manifests as large pulmonary arteries, diffuse interstitial edema with numerous Kerley lines, peribronchial cuffing, and a dilated right ventricle. Stage 1 near drowning pulmonary edema manifests as Kerley lines, peribronchial cuffing, and patchy, perihilar alveolar areas of airspace consolidation; stage 2 and 3 lesions are radiologically nonspecific. Pulmonary edema following administration of cytokines demonstrates bilateral, symmetric interstitial edema with thickened septal lines. High-altitude pulmonary edema usually manifests as central interstitial edema associated with peribronchial cuffing, ill-defined vessels, and patchy airspace consolidation. Neurogenic pulmonary edema manifests as bilateral, rather homogeneous airspace consolidations that predominate at the apices in about 50% of cases. Reperfusion pulmonary edema usually demonstrates heterogeneous airspace consolidations that predominate in the areas distal to the recanalized vessels. Postreduction pulmonary edema manifests as mild airspace consolidation involving the ipsilateral lung, whereas pulmonary edema due to air embolism initially demonstrates interstitial edema followed by bilateral, peripheral alveolar areas of increased opacity that predominate at the lung bases. Familiarity with the spectrum of radiologic findings in pulmonary edema from various causes will often help narrow the differential diagnosis