Search

Purpose: While a reliable differentiation between viral and bacterial pneumonia is not possible with chest X-ray, this study investigates whether ultra-low-dose chest-CT (ULDCT) could be used for this purpose., Methods: In the OPTIMACT trial 281 patients had a final diagnosis of pneumonia, and 96/281 (34%) had one or more positive microbiology results: 60 patients viral pathogens, 48 patients bacterial pathogens. These 96 ULDCT's were blindly and independently evaluated by two chest radiologists, who reported CT findings, pneumonia pattern, and most likely type of pathogen. Differences between groups were analysed for each radiologist separately, diagnostic accuracy was evaluated by calculating sensitivity., Results: The dominant CT finding significantly differed between the viral and bacterial pathogen groups (p = 0.04; p = 0.04). Consolidation was the most frequent dominant CT finding in both patients with viral and bacterial pathogens, but was observed significantly more often in those with a bacterial pathogen: 32/60 and 22/60 versus 38/48 and 31/48 (p = 0.005; p = 0.004). The lobar pneumonia pattern was more frequently observed in patients with a bacterial pathogen: 23/48 and 18/48, versus 10/60 and 8/60 for viral pathogens (p < 0.001; p = 0.004). For the bronchopneumonia and interstitial pneumonia patterns the proportions of viral and bacterial pathogens were not significantly different. Both radiologists suggested a viral pathogen correctly (sensitivity) in 6/60 (10%), for a bacterial pathogen this was 34/48 (71%)., Conclusion: Reliable differentiation between viral and bacterial pneumonia could not be made by pattern recognition on ULDCT, although a lobar pneumonia pattern was significantly more often observed in bacterial infection., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: To compare accuracy and interobserver agreement between radiologists with limited experience in the evaluation of abdominal MRI (non-experts), and radiologists with longer MR reading experience (experts), in reading MRI in patients with suspected appendicitis., Methods: MR imaging was performed in 223 adult patients with suspected appendicitis and read independently by two members of a team of eight MR-inexperienced radiologists, who were trained with 100 MR examinations previous to this study (non-expert reading). Expert reading was performed by two radiologists with a larger abdominal MR experience (>500 examinations) in consensus. A final diagnosis was assigned after three months based on all available information, except MRI findings. We estimated MRI sensitivity and specificity for appendicitis and for all urgent diagnoses separately. Interobserver agreement was evaluated using kappa statistics., Results: Urgent diagnoses were assigned to 147 of 223 patients; 117 had appendicitis. Sensitivity for appendicitis was 0.89 by MR-non-expert radiologists and 0.97 in MR-expert reading (p=0.01). Specificity was 0.83 for MR-non-experts versus 0.93 for MR-expert reading (p=0.002). MR-experts and MR-non-experts agreed on appendicitis in 89% of cases (kappa 0.78). Accuracy in detecting urgent diagnoses was significantly lower in MR-non-experts compared to MR-expert reading: sensitivity 0.84 versus 0.95 (p<0.001) and specificity 0.71 versus 0.82 (p=0.03), respectively. Agreement on urgent diagnoses was 83% (kappa 0.63)., Conclusion: MR-non-experts have sufficient sensitivity in reading MRI in patients with suspected appendicitis, with good agreement with MR-expert reading, but accuracy of MR-expert reading was higher., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Purpose: In patients with uterine cervical cancer, pretreatment recognition of uterine extension is crucial in treatment decision-making for fertility-sparing surgery and for target delineation in radiotherapy. Although MRI is generally considered the most reliable method, its value for detecting involvement of the uterine internal os is unclear., Methods: Medline, Embase and Cochrane databases were systematically searched (January 1997-December 2012) for MRI studies that measured the accuracy of involvement of the uterine internal os compared to histopathology as reference standard in patients with uterine cervical cancer. Data were assessed using the QUADAS tool. Accuracy concerned either involvement (yes/no) of the uterine internal os, or measuring invasion distance toward the uterine corpus., Results: Two retrospective and two prospective studies described 366 patients diagnosed with uterine cervical cancer FIGO stage IIB or below, in whom 64 (17%) had uterine internal os involvement. For three studies the summary estimates of specificity, sensitivity, negative predictive value (NPV), positive predictive value (PPV), and accuracy were 91%, 97%, 99%, 79% and 95%, respectively; one study had an area under the curve (AUC) of 0.8., Conclusion: MRI has a high level of accuracy; however, data are limited and for validation a large prospective study is needed that compares actual measurements on MRI with histopathological examination., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To summarize the incidence of contrast-induced nephropathy (CIN) and associations between CIN incidence and risk factors in patients undergoing intravenous contrast-enhanced computed tomography (CECT) with low- or iso-osmolar iodinated contrast medium., Methods: This review is performed in accordance with the preferred reporting items in systematic reviews and meta-analysis (PRISMA) guidelines. We searched the MEDLINE, EMBASE and Cochrane databases from 2002 till November 2012. Two reviewers included papers and extracted data. The pooled data were analysed by either fixed or random-effects approach depending on heterogeneity defined as the I(2) index., Results: 42 articles with 18,790 patients (mean age 61.5 years (range: 38-83 years)) were included. The mean baseline eGFR was 59.8 mL/min and ranged from 4 to 256 mL/min. Of all patients 45.0% had an estimated glomerular filtration rate (eGFR)<60 mL/min, 55.2% had hypertension; 20.2% had diabetes mellitus (DM) and 6.5% had congestive heart failure (CHF). The overall pooled CIN incidence, defined as a SCr increase of ≥ 25% or ≥ 0.5mg/dL, was 4.96% (95%CI: 3.79-6.47). Data analysis showed associations between CIN and the presence of renal insufficiency, DM, malignancy, age>65 years and use of non-steroidal anti-inflammatory drugs (NSAID's) with odds ratios of 1.73 (95%CI: 1.06-2.82), 1.87 (95%CI: 1.55-2.26), 1.79 (95%CI: 1.03-3.11), 1.95 (95%CI: 1.02-3.70) and 2.32 (95%CI: 1.04-5.19), respectively while hypertension, anaemia and CFH were not associated (p=0.13, p=0.38, p=0.40)., Conclusion: The mean incidence of CIN after intravenous iodinated CECT was low and associated with renal insufficiency, diabetes, presence of malignancy, old age and NSAID's use., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension, automatic carbon dioxide insufflation should be performed, preferably via a thin, flexible catheter. Hyoscine butylbromide is - when available - the preferred spasmolytic agent because of the positive effect on insufflation and pain/burden and its low costs. Scans in two positions are required for adequate distension and high polyp sensitivity and decubitus position may be used as an alternative for patients unable to lie in prone position. The great intrinsic contrast between air or tagging and polyps allows the use of low radiation dose. Low-dose protocol without intravenous contrast should be used when extracolonic findings are deemed unimportant. In patients suspected for colorectal cancer, normal abdominal CT scan protocols and intravenous contrast should be used in supine position for the evaluation of extracolonic findings. Dose reduction can be obtained by lowering the tube current and/or voltage. Tube current modulation reduces the radiation dose (except in obese patients), and should be used when available. Iterative reconstructions is a promising dose reducing tool and dual-energy CT is currently evaluated for its applications in CT-colonography. This review also provides our institution's insufflation procedure and scan parameters., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Objective: Compare colonic distension and perceived burden of CT-colonography between participants receiving hyoscine butylbromide (buscopan) and glucagon hydrochloride as bowel relaxant., Materials and Methods: Data were collected within a screening trial. Participants received 20mg buscopan intravenously or 1mg of glucagon intravenously (if buscopan contra-indicated). Colon distension per segment was assessed using a 4-point scale (prone and supine). Data on perceived burden of CT-colonography were collected using a questionnaire two weeks after the examination. Outcome measures between groups were compared using propensity score matching. We used a stratified Wilcoxon-Mann-Whitney test statistic for quantitative and Cochran-Mantel-Haenszel statistics for categorical variables., Results: 541 participants were included: 336 (62%) received buscopan and 205 received glucagon. All buscopan recipients had an adequately distended colon, compared to 96% in the glucagon group (RR 7.31, 95% CI: 1.61-33.28). More glucagon recipients scored the insufflation as rather or extremely burdensome (25% vs. 16%; overall mean score 2.7 vs. 2.4; p<0.001) and more found the entire CT-colonography rather or extremely burdensome (14% vs. 7%; 2.2 vs. 1.9; p=0.001). Most frequently reported side effects were a dry mouth in the buscopan group (15%) and nausea in the glucagon group (13%)., Conclusion: Compared to glucagon, premedication with buscopan results in significantly more adequately distended colons and a less burdensome procedure. When buscopan can be used, it is the preferred bowel relaxant., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To study the interobserver variability of MRI for visualization of the internal os and measuring the distance between tumor and the internal os in patients with early cervical carcinoma and to compare the distance between tumor and the internal os measured on MRI with invasion of the internal os determined by histopathology., Materials and Methods: All T2-weighed MRI examinations between January 2003 and December 2007 of patients who underwent hysterectomy, of ≤40 years, with clinical stage IB1 cervix carcinoma and tumor size ≤2cm were retrieved. 27 patients fulfilled these criteria. Two radiologists retrospectively reviewed the images for visualization of the internal os and the distance between tumor and the internal os; agreement and intraclass correlation coefficients (ICCs) were calculated to determine interobserver variability. The distance between tumor and the internal os measured on MRI was compared with invasion of the internal os determined by histopathology., Results: In 26 patients, visualization of the internal was rated as good or moderate by both radiologists (agreement 96%). In 15 patients, both radiologists observed a tumor and the ICC for the distance between tumor and the internal os was 0.752 (95%CI: 0.406-0.909). Assuming 5mm distance between tumor and the internal os on MRI as criterion for invasion of the internal os, 1 true-positive, 2 false-positives and none false-negatives were observed. Assuming 1cm as criterion increases the number of false-positives, respectively 3 and 5 by radiologist 1 and radiologist 2., Conclusion: MRI has high interobserver values for visualization of the internal os and no false-negatives for involvement of the internal os., (Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.)

Purpose: Incidental extracolonic findings affect patient treatment and cost. Therefore, to consider magnetic resonance colonography (MRC) as a tool for colorectal cancer and polyps screening, more knowledge is needed on extracolonic findings. In this study, we sought to determine the prevalence and the spectrum of extracolonic findings in patients with an increased risk colorectal cancer that underwent bright lumen MRC., Materials and Methods: MRC examinations were performed in 210 patients. A gadolinium solution was administered rectally for distension of the colon. Extracolonic findings were scored by two radiologists and classified by using C-RADS Reporting System. All findings (with advice regarding work-up) were reported to the patient's physician and followed up for 4.5 years on average., Results: Extracolonic findings were found in 125 (59.5%) patients. Ten (4.8%) had "potentially important" findings (C-RADS category E4). Twenty-five patients (11.9%) had "likely unimportant" findings (E3), 90 (42.8%) had "clinically unimportant" findings (E2) and 85 (40.5%) had a normal exam (E1). In 14 (6.7%) patients additional work-up was performed for their incidentally discovered lesions. In three of them surgery was performed. After work-up, only in two (1.0%) patients a malignancy was found., Conclusion: The number of new relevant extracolonic findings is small and the required additional work-up is limited. This should be considered for implementation of 'bright lumen' MRC as a screening tool., (Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To prospectively evaluate a new imaging sequence (4D THRIVE) for whole liver perfusion in high temporal and spatial resolution. Feasibility of parametric mapping and its potential for characterizing focal liver lesions (FLLs) are investigated., Materials and Methods: Fifteen patients suspected for colorectal liver metastases (LMs) were included. Parametric maps were evaluated qualitatively (ring-enhancement and lesion heterogeneity) and compared to three-phased contrast-enhanced MRI. Quantitative analysis was based on average perfusion values of entire FLLs. Reference standard comprised surgery with histopathology or follow-up imaging. Fisher's exact test was used for qualitative and Kruskal-Wallis test for quantitative analysis., Results: In total 29 LMs, 17 hemangiomas and 4 focal nodular hyperplasias were evaluated. FLLs could be differentiated by qualitative assessment of parametric maps respectively three-phased contrast-enhanced MRI (Fisher's p<0.001 for comparisons between LMs and hemangiomas and LMs and FNHs for both ring-enhancement and lesion heterogeneity) rather than by quantitative analysis of parametric maps (Chi-square for Kep=0.33 (p=0.847) and Chi-square for Kel=1.35 (p=0.509))., Conclusion: This preliminary study shows potential of 4D THRIVE for whole liver imaging enabling calculation of parametric maps. Qualitative rather than quantitative analysis was accurate for differentiating malignant and benign FLLs., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To compare lesion conspicuity and image quality between single-shot spin echo echo planar imaging (SS SE-EPI) before, immediately and 5min after intravenous (IV) injection of superparamagnetic iron oxide (SPIO) for detecting and characterizing focal liver lesions (FLLs)., Materials and Methods: Twenty-five patients suspected for colorectal liver metastases were prospectively included. Lesion detection and characterization were compared between all SS SE-EPI and T2-weighted turbo spin echo (T2w TSE) sets (two-sided Fisher's exact test). Image quality and lesion conspicuity were compared for SS SE-EPI sets using rank order statistic (RIDIT). Reference standard comprised of surgery, biopsy and/or follow-up., Results: Reference standard demonstrated 18 benign and 43 malignant FLLs. Best lesion detection (p<0.05) was achieved with non-contrast-enhanced SS SE-EPI. Lesion characterization was best using all T2w TSE sequences. Best image quality and lesion conspicuity (p<0.05) was achieved with non-contrast-enhanced SS SE-EPI., Conclusion: Non-contrast-enhanced SS SE-EPI was best for lesion detection. SS SE-EPI sequences were not useful for lesion characterization (differentiation between benign and malignant lesions). Unenhanced SS SE-EPI did not allow differentiation especially as many benign FLLs were hyperintense on the highest b-value images. Combining unenhanced and SPIO-enhanced SS SE-EPI performed better but still was not clinically useful due to variable degree of uptake and vascular pooling of SPIO for (especially) benign FLLs. T2w TSE with SPIO-enhancement was needed for characterization.

Purpose: To assess the added value of true diffusion (D), perfusion factor (f) and apparent diffusion coefficient at low b-values (ADC(low)) for differentiation between liver metastases and hemangiomas based on respiratory-triggered high-resolution Black-Blood Single-Shot SpinEcho Echo Planar Imaging (BB SS SE-EPI)., Materials and Methods: Twenty-five patients suspected for malignant colorectal liver lesions were included in this study. A total of 106 lesions were examined. Different b-value images were compared for lesion conspicuity, image quality and artifacts using rank order statistic (RIDIT) and Student's t-test. D, f, and ADC(low) values were calculated. Pearson correlation coefficient is used for comparison of interobserver variability., Results: Best lesion conspicuity (p<0.05) was achieved with BB SS SE-EPI (b=0 and 10s/mm(2)); best image quality (p<0.05) with b=10s/mm(2). Image artifacts were lowest (p<0.05) with b=0s/mm(2). Over the whole sample, D in metastases (D(met)) was significantly (p<0.05) lower than D in hemangiomas (D(hem)); f and ADC(low) of metastases (f(met), respectively, ADC(lowmet)) were significantly (p<0.05) higher than f and ADC(low) of hemangiomas (f(hem), respectively, ADC(lowhem)). All Pearson correlations were statistically significant at a 0.01 level., Conclusions: This preliminary study shows the potential of BB SS SE-EPI as a useful technique to aid in differentiating between liver metastasis and hemangioma. The calculation of D, f and ADC(low) provides useful additional information for differentiating metastases from hemangiomas.

Objective: MR enteroclysis has become an important tool to visualize the complete small bowel wall and extramural structures. In many centers, this technique is rapidly becoming the first-line technique for small bowel visualization. MR enteroclysis yields a diagnosis of thickened jejunal loops in some patients. In this paper, we describe an MR enteroclysis protocol and review the literature on jejunum abnormalities with several sample cases., Conclusion: Jejunum abnormalities are not uncommon. These abnormalities can be self-limiting, but some patients suffer from infectious and other pathologic conditions of the small bowel necessitating intervention.