PubMed Health⌕ Search

Biomedical subjects

Andrea Laghi

Publications and source records attributed to Andrea Laghi.

At least 19 recordsLinked to original sources
PubMed2007

European Society of Gastrointestinal and Abdominal Radiology (ESGAR): consensus statement on CT colonography.

Rapid clinical dissemination of CT colonography (CTC) is occurring in parallel with continued research into technique optimisation and diagnostic performance. A need exists therefore for current guidance as to basic prerequisites for effective clinical implementation. A questionnaire detailing CTC technique, analysis, training and clinical implementation was developed by the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) CTC committee and circulated to all faculty members of previous ESGAR "hands-on" CTC training courses. Responses were collated and a consensus statement produced. Of 27 invited to participate, 24 responded. Reasonable consensus was reached on bowel preparation, colonic distension, patient positioning, use of IV contrast and optimal scan parameters. Both primary 2D and primary 3D analysis were advocated equally, with some evidence that more experienced readers prefer primary 2D. Training was universally recommended, although there was no consensus regarding minimum requirements. CTC was thought superior to barium enema, although recommended for screening only in the presence of validated local experience. There was consensus that polyps 4 mm or less could be ignored assuming agreement from local gastroenterological colleagues. There is increasing consensus amongst European experts as to the current best practice in CTC.

Advisory Committees↗
PubMed2006

Multidetector CT (64 Slices) of the liver: examination techniques.

Sixty-four-row MDCT, although developed primarily for cardiac imaging, has the potential to have a great impact on liver imaging as well. Liver-imaging protocols with sub-millimeter collimation improve longitudinal spatial resolution, making the acquired dataset a real isotropic volume perfectly designed for optimal three-dimensional rendering and accurate organ and lesion volumetry. The 64-row detector array offers a wide volumetric coverage (up to 40 mm), suitable not only for shortening scanning time and improving spatial resolution, but also for including a large volume per single rotation, particularly useful for accurate CT perfusion studies. In order to take full benefit from the enormous performance offered by new 64-row MDCT scanners, imaging protocols need to be redesigned. Due to the extremely short scanning window, contrast agent injection should be performed at high flow rate and followed by saline bolus chaser; the use of highly concentrated contrast media might be useful. Timing should be accurately calculated either by a test bolus or, better, by using an automatic bolus-detection technique. Radiation exposure is kept under control, using automatic device-modulating dose delivery according to the patient's anatomy. Finally, the evaluation of acquired volumetric datasets needs the extensive use of a dedicated workstation, with software with sophisticated rendering capabilities.

Artifacts↗
PubMed2006

Initial experience with magnetic resonance fluoroscopy in the evaluation of oesophageal motility disorders. Comparison with manometry and barium fluoroscopy.

The aim of this paper was to assess the diagnostic value of magnetic resonance (MR) fluoroscopy in the study of oesophageal motility disorders and to compare MR fluoroscopy results with those of manometry and barium contrast radiography. Twenty-five subjects referred for dysphagia and three patients in follow-up after pneumatic dilatation of the lower oesophageal sphincter to treat severe achalasia underwent esophageal manometry, barium contrast radiography and MR fluoroscopy. Examinations were performed on a 1.5 T scanner. Dynamic turbo- fast low angle shot (turbo-FLASH) sequences acquired during oral contrast agent administration were used to perform MR fluoroscopy. MR fluoroscopy correctly diagnosed achalasia in nine patients, uncoordination of esophageal body motility in ten and scleroderma oesophagus in one. Diagnostic performance was satisfactory, with a sensitivity of 87.5% and a specificity of 100% in the general depiction of motility alterations. Our work demonstrates that MR fluoroscopic examination in subject affected by oesophageal motility disorders is feasible and can properly depict motility and morphology alterations, achieving correct diagnosis in the majority of cases. Studies on larger populations are necessary to obtain statistically significant results.

Adult↗
PubMed2006

Polyp measurement and size categorisation by CT colonography: effect of observer experience in a multi-centre setting.

The extent measurement error on CT colonography influences polyp categorisation according to established management guidelines is studied using twenty-eight observers of varying experience to classify polyps seen at CT colonography as either 'medium' (maximal diameter 6-9 mm) or 'large' (maximal diameter 10 mm or larger). Comparison was then made with the reference diameter obtained in each patient via colonoscopy. The Bland-Altman method was used to assess agreement between observer measurements and colonoscopy, and differences in measurement and categorisation was assessed using Kruskal-Wallis and Chi-squared test statistics respectively. Observer measurements on average underestimated the diameter of polyps when compared to the reference value, by approximately 2-3 mm, irrespective of observer experience. Ninety-five percent limits of agreement were relatively wide for all observer groups, and had sufficient span to encompass different size categories for polyps. There were 167 polyp observations and 135 (81%) were correctly categorised. Of the 32 observations that were miscategorised, 5 (16%) were overestimations and 27 (84%) were underestimations (i.e. large polyps misclassified as medium). Caution should be exercised for polyps whose colonographic diameter is below but close to the 1-cm boundary threshold in order to avoid potential miscategorisation of advanced adenomas.

Chi-Square Distribution↗
PubMed2006

CT colonography interpretation times: effect of reader experience, fatigue, and scan findings in a multi-centre setting.

Our purpose was to assess the effect of reader experience, fatigue, and scan findings on interpretation time for CT colonography. Nine radiologists (experienced in CT colonography); nine radiologists and ten technicians (both groups trained using 50 validated examinations) read 40 cases (50% abnormal) under controlled conditions. Individual interpretation times for each case were recorded, and differences between groups determined. Multi-level linear regression was used to investigate effect of scan category (normal or abnormal) and observer fatigue on interpretation times. Experienced radiologists (mean time 10.9 min, SD 5.2) reported significantly faster than less experienced radiologists and technicians; odds ratios of reporting times 1.4 (CI 1.1, 1.8) and 1.6 (1.3, 2.0), respectively (P<or=0.001). Experienced and less-experienced radiologists took longer to report abnormal cases; ratio 1.2 (CI 1.1,1.4, P<0.001) and 1.2 (1.0, 1.3, P=0.03), respectively. All groups took 70% as long to report the final five cases as they did with an initial five; ratio 0.7 (CI 0.6 to 0.8), P<0.001. For technicians only, accuracy increased with longer reporting times (P=0.04). Experienced radiologists report faster than do less-experienced observers and proportionally spend less time interpreting normal cases. Technicians who report more slowly are more accurate. All groups reported faster as the study period progressed.

Clinical Competence↗
PubMed2006

Adult celiac disease: what is the role of MRI?

PURPOSE: To evaluate the ability of MRI to identify intra- and extraintestinal findings of celiac disease in an adult population. MATERIALS AND METHODS: Forty-one subjects (18 men and 23 women; mean age = 41.3 years; 31 with biopsy-proven celiac disease, and 10 healthy volunteers) underwent MRI of the small bowel. MR studies were performed on a 1.5-T magnet using T2-weighted half-Fourier single-shot turbo spin-echo (HASTE) and true fast imaging in steady-state precession (True-FISP) sequences. The MR features and sensitivity, and the specificity and accuracy of some of these features are described. RESULTS: In the 31 celiac patients, MRI showed bowel dilatation in 61.3% (N = 19), increased number of ileal folds in 48.4% (N = 15), reversed fold pattern abnormality in 38.7% (N = 12), increased wall thickness in 16.1% (N = 5), duodenal stenosis in 6.5% (N = 2), intussusception in 12.9% (N = 4), mesenteric lymphadenopathy in 41.9% (N = 13), mesenteric vascular changes in 22.6% (N = 7), ascites in 6.5% (N = 2), and no abnormalities in 12.9% (N = 4). The volunteers had unremarkable exams. The overall specificity and accuracy were 100%, and sensitivity was 79% and 75% for increased number of ileal folders and reversed fold pattern abnormality, respectively. CONCLUSION: MRI is able to demonstrate intra- and extraintestinal features that may lead to the diagnosis of celiac disease in adults.

Adult↗
PubMed2005

Virtual colonoscopy: clinical application.

Virtual colonoscopy (VC), also known as computed tomography Colonography (CTC), is a non-invasive test for the examination of the colon based on volumetric, thin-collimation CT acquisition of a cleansed and air-distended colon. The technique is easy, less labour-intensive than barium enema and conventional colonoscopy, and is inherently safer. Several studies demonstrate the ability of VC in the detection of colonic neoplastic lesions, not only large carcinomas, but also polyps. Currently, the most widely accepted clinical indication is incomplete or unsuccessful colonoscopy, which may be the result of redundant colon, patient intolerance to the procedure, spasm not resolving even with the use of spasmolytics, obstructing colo-rectal cancer. VC is also used to detect cancer in frail and immobile patients to avoid sedation during colonoscopy or the turning required during barium enema. The use of VC in patients under surveillance following colo-rectal cancer surgery is under investigation. Further studies are necessary in order to assess the cost-effectiveness of this approach. For colo-rectal cancer screening, a practical approach is to consider VC as a currently credible alternative screening method and as a reasonable alternative to the other colo-rectal cancer screening tests when a patient is unable or unwilling to undergo conventional colonoscopy.

Clinical Trials as Topic↗
PubMed2005

Clinical management of hepatic malignancies: ferucarbotran-enhanced magnetic resonance imaging versus contrast-enhanced spiral computed tomography.

This study compares ferucarbotran-enhanced magnetic resonance (MR) imaging with spiral computed tomography (CT) in the clinical management of patients with suspected hepatic malignancy. One hundred fifty-nine patients with suspected liver malignancy were included in a prospective, multicenter, phase IIIB clinical trial. Patients were examined with baseline plus contrast-enhanced spiral CT and with baseline plus ferucarbotran-enhanced MR imaging. For each patient, four maps of liver lesions were constructed by a trusted blind party on the basis of (a) baseline plus contrast-enhanced spiral CT, (b) baseline MR imaging, (c) baseline plus ferucarbotran-enhanced MR imaging, and (d) final diagnosis. Three blinded experts evaluated the treatment options for each map. The concordance of the treatment choice based on imaging with the treatment choice based on final diagnosis was verified. The final therapeutic decision was radical therapy for 85 patients, palliative therapy for 49 patients, and no treatment for 25 patients who had a final diagnosis of benign lesion. Proper treatment allocation was achieved in 121 (76%) of 159 patients when the evaluation was based on liver maps obtained from spiral CT, in 97 (61%) of 159 patients when the evaluation was based on liver maps obtained from baseline MR imaging, and in 136 (85%) of 159 patients when the evaluation was based on liver maps obtained from baseline plus ferucarbotran-enhanced MR imaging. MR imaging with ferucabotran was significantly superior to spiral CT for correct treatment allocation (P = 0.0167). Ferucarbotran-enhanced MR imaging is superior to spiral CT in clinical management of patients with suspected hepatic malignancy.

Adult↗
PubMed2005

Small bowel.

MR imaging, using modern equipment and a rigorous technical approach, can offer detailed morphologic information and functional data on the small bowel. The optimal study technique is debatable, although the oral administration of contrast material as a first-line approach is less expensive, faster, easier to perform, and better tolerated by patients. MR enteroclysis might be reserved for selected cases as a second-line study. The major clinical indication is the evaluation of patients who have suspected or known Crohn's disease. The absence of ionizing radiation, considering the young age of most of the patients and the frequency of the examinations, is an important advantage over other techniques (radiograph and CT enteroclysis).

Contrast Media↗
PubMed2005

Hepatocellular carcinoma: role of unenhanced and delayed phase multi-detector row helical CT in patients with cirrhosis.

PURPOSE: To determine, by using multi-detector row helical computed tomography (CT), the added value of obtaining unenhanced and delayed phase scans in addition to biphasic (hepatic arterial and portal venous phases) scans in the detection of hepatocellular carcinoma (HCC) in patients with cirrhosis. MATERIALS AND METHODS: Local ethical committee approval and patient consent were obtained. One hundred ninety-five patients (129 men, 66 women; mean age, 61 years; age range, 39-78 years) with 250 HCCs underwent multi-detector row helical CT of the liver. A quadruple-phase protocol that included unenhanced, hepatic arterial, portal venous, and delayed phases was performed. Analysis of images from hepatic arterial and portal venous phases combined, hepatic arterial and portal venous phases with the unenhanced phase, hepatic arterial and portal venous phases with the delayed phase, and all phases combined was performed separately by three independent radiologists. Relative sensitivity, positive predictive value, and area under the receiver operating characteristic curve (A(z)) were calculated for each reading session. RESULTS: Mean sensitivity and positive predictive values, respectively, for HCC detection were 88.8% (666 of 750 readings) and 97.8% (666 of 681 readings) for the combined hepatic arterial and portal venous phases, 89.2% (669 of 750 readings) and 97.8% (669 of 684 readings) for hepatic arterial and portal venous phases with the unenhanced phase, 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for hepatic arterial and portal venous phases with the delayed phase, and 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for all four phases combined. The reading sessions in which delayed phase images were available for interpretation showed significantly (P < .05) superior sensitivity and A(z) values. CONCLUSION: Unenhanced phase images are not effective for HCC detection. Because of the significant increase in HCC detection, a delayed phase can be a useful adjunct to biphasic CT in patients at risk for developing HCC.

Adult↗
PubMed2005

Contrast-enhanced sonography with SonoVue: enhancement patterns of benign focal liver lesions and correlation with dynamic gadobenate dimeglumine-enhanced MRI.

OBJECTIVE: Contrast-enhanced real-time low-mechanical-index sonography is a new diagnostic technique for the assessment of macro- and microcirculation. The purpose of our article is to describe contrast-enhancement patterns of different benign focal liver lesions using the second-generation contrast agent SonoVue and to compare these findings with those of gadobenate dimeglumine-enhanced MRI. CONCLUSION: SonoVue-enhanced real-time low-mechanical-index sonography provides specific contrast-enhancement patterns of different benign focal liver lesions, allowing accurate characterization. Findings on SonoVue-enhanced sonography correlate well with those obtained on gadobenate dimeglumine-enhanced MRI.

Adult↗
PubMed2004

Virtual colonoscopy.

Explore the source record for details and available documents.

Colonography, Computed Tomographic↗
PubMed2004

Computed tomographic colonography without cathartic preparation for the detection of colorectal polyps.

BACKGROUND AND AIMS: We prospectively compared the performance of low-dose multidetector computed tomographic colonography (CTC) without cathartic preparation with that of colonoscopy for the detection of colorectal polyps. METHODS: A total of 203 patients underwent low-dose CTC without cathartic preparation followed by colonoscopy. Before CTC, fecal tagging was achieved by adding diatrizoate meglumine and diatrizoate sodium to regular meals. No subtraction of tagged feces was performed. Colonoscopy was performed 3-7 days after CTC. Three readers interpreted the CTC examinations separately and independently using a primary 2-dimensional approach using multiplanar reconstructions and 3-dimensional images for further characterization. Colonoscopy with segmental unblinding was used as reference standard. The sensitivity of CTC was calculated both on a per-polyp and a per-patient basis. For the latter, specificity, positive predictive values, and negative predictive values were also calculated. RESULTS: CTC had an average sensitivity of 95.5% (95% confidence interval [CI], 92.1%-99%) for the identification of colorectal polyps > or =8 mm. With regard to per-patient analysis, CTC yielded an average sensitivity of 89.9% (95% CI, 86%-93.7%), an average specificity of 92.2% (95% CI, 89.5%-94.9%), an average positive predictive value of 88% (95% CI, 83.3%-91.5%), and an average negative predictive value of 93.5% (95% CI, 90.9%-96%). Interobserver agreement was high on a per-polyp basis (kappa statistic range, .61-.74) and high to excellent on a per-patient basis (kappa statistic range, .79-.91). CONCLUSIONS: Low-dose multidetector CTC without cathartic preparation compares favorably with colonoscopy for the detection of colorectal polyps.

Adult↗
PubMed2004

Decrease of signal intensity of myometrium and cervical stroma after ultrasmall superparamagnetic iron oxide (USPIO) particles administration: an MR finding with potential benefits in T staging of uterine neoplasms.

OBJECTIVES: Following the empiric observation of a significant decrease of signal intensity of both myometrium and cervical stroma on ultrasmall superparamagnetic iron oxide (USPIO)-enhanced images, the aim of our study was to evaluate whether USPIO-enhanced T2*-weighted gradient echo (GRE) images might provide any potential advantage on T-staging of uterine malignancies having surgery and histology as standard of reference MATERIALS AND METHODS: Seventeen female patients with known uterine malignancies underwent magnetic resonance (MR) imaging before and 24 hours after the intravenous administration of the USPIO agent. Imaging protocol included proton density-weighted turbo spin echo and T2*-weighted GRE sequences. Each patient underwent surgery within 14 days from the first MR examination, and histologic confirmation of tumor T-stage was obtained. Quantitative (calculation of signal-to-noise and contrast-to-noise ratios) and qualitative (visual assessment of T staging) analyses were performed on unenhanced and USPIO-enhanced images. RESULTS: Quantitative analysis showed a significantly lower (P < 0.05) signal-to-noise ratio of myometrium and cervical stroma on USPIO-enhanced compared with unenhanced images. In 15 of 17 patients (88.2%), the contrast-to-noise ratio between tumor and myometrium and between tumor and cervical stroma was higher on USPIO-enhanced compared with unenhanced images (P < 0.001). Qualitative analysis demonstrated that the GRE T2* USPIO-enhanced MR offers a better definition of the depth of tumor infiltration rather than the unenhanced GRE T2* images. CONCLUSION: The decrease of signal intensity of myometrium and cervical stroma on T2*-weighted GRE images after the intravenous administration of USPIO should be considered a constant and physiologic finding that improves tumor conspicuity in the majority of the cases, allowing more accurate T-staging of neoplastic lesions.

Adult↗