Patient centring and scan length: how inaccurate practice impacts on radiation dose in CT colonography (CTC).

OBJECTIVE: The aim of this study was to acknowledge errors in patients positioning in CT colonography (CTC) and their effect in radiation exposure. MATERIALS AND METHODS: CTC studies of a total of 199 patients coming from two different referral hospitals were retrospectively reviewed. Two parameters have been considered for the analysis: patient position in relation to gantry isocentre and scan length related to the area of interest. CTDI vol and DLP were extracted for each patient. In order to evaluate the estimated effective total dose and the dose to various organs, we used the CT-EXPO® software version 2.2. This software provides estimates of effective dose and doses to the other various organs. RESULTS: Average value of the patients' position is found to be below the isocentre for 48 ± 25 mm and 29 ± 27 mm in the prone and supine position. It was observed that the increase in CTDI and DLP values for patients in Group 1, due to the inaccurate positioning, was estimated at about 30% and 20% for prone and supine position, respectively, while in Group 2, a decrease in CTDI and DLP values was estimated at about 16% and 18% for prone and supine position, respectively, due to an average position above isocentre. A dose increase ranging from 4 up to 13% was calculated with increasing the over-scanned region below anal orifice. CONCLUSION: Radiographers and radiologists need to be aware of dose variation and noise effects on vertical positioning and over-scanning. More accurate training need to be achieved even so when examination protocol varies from general practice.

Comparison of US Strain Elastography and Entero-MRI to Typify the Mesenteric and Bowel Wall Changes during Crohn's Disease: A Pilot Study.

PURPOSE: To evaluate and compare the mesenteric and bowel wall changes during Crohn's disease (CD) on ultrasonography (US) Strain Elastography (SE) and Enterography Magnetic Resonance Imaging (E-MRI). METHODS: From July 2014 to September 2016, 35 patients with ileocolonoscopy diagnosis of CD were prospectively examined with E-MRI and in the same time with US and SE. RESULTS: A total of 41 affected bowel segments and 35 unaffected bowel segments in 35 patients were evaluated. US-SE color-scale coding showed a blue color pattern in the fibrotic mesentery and bowel wall in 15 patients and a green color pattern in the edematous ones in 20 patients. The signal of the bowel wall and mesenteric fat was iso/hypointense on T2-weighted sequence in the fibrotic pattern (23/35 and 12/35 patients) and hyperintense in the edematous pattern (12/35 and 23/35 patients). Mean ADC values were, respectively, 2,58 ± 0,33 × 10-3 for the fibrotic mesentery and 2,14 ± 0,28 × 10-3 for edematous one. There was a statistical correlation between US-SE color-scale and T2 signal intensity and between the US-SE color-scale and ADC maps. CONCLUSIONS: US-SE, ADC, and signal intensity on T2-weighted sequences on MR prove to be useful tools for the evaluation of CD pattern.

The Videofluorographic Swallowing Study in Rheumatologic Diseases: A Comprehensive Review.

Autoimmune connective tissue diseases are a heterogeneous group of pathologies that affect about 10% of world population with chronic evolution in 20%-80%. Inflammation in autoimmune diseases may lead to serious damage to other organs including the gastrointestinal tract. Gastrointestinal tract involvement in these patients may also due to both a direct action of antibodies against organs and pharmacological therapies. Dysphagia is one of the most important symptom, and it is caused by failure of the swallowing function and may lead to aspiration pneumonia, malnutrition, dehydration, weight loss, and airway obstruction. The videofluorographic swallowing study is a key diagnostic tool in the detection of swallowing disorders, allowing to make an early diagnosis and to reduce the risk of gastrointestinal and pulmonary complications. This technique helps to identify both functional and structural anomalies of the anatomic chain involved in swallowing function. The aim of this review is to systematically analyze the basis of the pathological involvement of the swallowing function for each rheumatological disease and to show the main features of the videofluorographic study that may be encountered in these patients.

Degree of colonic distension: intrapatient comparison between CT colonography and CT with water enema.

PURPOSE: Compare colonic distension using CT colonography (CTC) and CT with water enema (CTWE) in the same patients. METHODS AND MATERIALS: Twenty-seven patients who underwent both CTC and CTWE, considering separately supine (CTC-S) and prone (CTC-P) acquisition of CTC were included. The colon was divided into six segments, performing both a qualitative and quantitative analysis. RESULTS: Adequate distension of sigmoid colon was more frequently achieved with CTC-P and CTWE compared to CTC-S (P<.05). CTC-P and CTWE showed better distension of the left colon compared to CTC-S (P<.01 and P=.03 regarding sigmoid colon, respectively; P=.01 and P=.03 regarding descending colon, respectively). CONCLUSIONS: Computed tomography (CT) studies of the colon should be customized to fulfill the clinical query.