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Background: Iterative reconstruction is offered by all vendors to achieve similar or better CT image quality at lower doses than images reconstructed with filtered back-projection.Objective: The purpose of this study was to investigate the dose-reduction potential for pediatric abdominal CT imaging when using either a commercially available hybrid or a commercially available model-based iterative reconstruction algorithm from a single manufacturer.Materials and Methods: A phantom containing four low-contrast inserts and a uniform background with total attenuation equivalent to the abdomen of an average 8-year-old child was imaged on a CT scanner (IQon; Philips Healthcare, Cleveland, OH). We reconstructed images using both hybrid iterative reconstruction (iDose4) and model-based iterative reconstruction (Iterative Model Reconstruction). The four low-contrast inserts had circular cross-section with diameters of 3 mm, 5 mm, 7 mm and 10 mm and contrasts of 14 Hounsfield units (HU), 7 HU, 5 HU and 3 HU, respectively. Helical scans with identical kilovoltage (kV), pitch, rotation time, and collimation were repeated on the phantom at volume CT dose index (CTDIvol) of 2.0 milligrays (mGy), 3.0 mGy, 4.5 mGy and 6.0 mGy. We measured the contrast-to-noise ratio (CNR) in each rod across scans. Additionally, we collected sub-images containing each rod and sub-images containing the background and used them in two-alternative forced choice observer experiments with four observers (two radiologists and two physicists). We calculated the dose-reduction potential of both iterative reconstruction algorithms relative to a scan performed at 6 mGy and reconstructed with filtered back-projection.Results: We calculated dose-reduction potential by either matching average equal observer performance in the two-alternative forced choice experiments or matching CNR. When matching CNR, the dose-reduction potential was 34% to 45% for hybrid iterative reconstruction and 89% to 95% for model-based iterative reconstruction. When matching average observer performance, the dose-reduction potential was 9% to 30% for hybrid iterative reconstruction and 57% to 74% for model-based iterative reconstruction. The range in dose-reduction potential depended on the rod size and contrast level.Conclusion: Observer performance in this phantom study indicates that the dose-reduction potential indicated by an observer study is less than that of CNR; extrapolating the results to clinical studies suggests that the dose-reduction potential would also be less. [ABSTRACT FROM AUTHOR]

Background: Many patients at our pediatric hospital have had a contrast-enhanced CT of the abdomen and pelvis performed by an outside imaging facility before admission. We have noticed that many of these exams are multiphase, which may contribute to unnecessary radiation dose.Objective: To determine the frequency of multiphase acquisitions and radiation dose indices in contrast-enhanced CTs of the abdomen and pelvis performed by outside imaging facilities in patients who were subsequently transferred to our pediatric hospital for care, and compare these metrics to contrast-enhanced CTs of the abdomen and pelvis performed internally.Materials and Methods: A retrospective analysis was performed of contrast-enhanced CTs of the abdomen and pelvis from outside imaging facilities uploaded to our picture archiving and communication system (PACS) between January 1, 2012, and December 31, 2015. CT images and dose pages were reviewed to determine the number of phases and dose indices (CT dose index-volume [CTDIvol], dose-length product, size-specific dose estimate). Exams for abdominal or pelvic mass, trauma or urinary leak indications were excluded. Data were compared to internally acquired contrast-enhanced CTs of the abdomen and pelvis by querying the American College of Radiology (ACR) Dose Index Registry. This review was institutional review board and HIPAA compliant.Results: There were 754 contrast-enhanced CTs of the abdomen and pelvis from 104 outside imaging facilities. Fifty-three percent (399/754) had 2 phases, and 2% (14/754) had 3 or more phases. Of the 939 contrast-enhanced CTs of the abdomen and pelvis performed internally, 12% (115) were multiphase exams. Of 88% (664) contrast-enhanced CTs of the abdomen and pelvis from outside imaging facilities with dose data, CTDIvol was 2.7 times higher than our institution contrast-enhanced CTs of the abdomen and pelvis (939) for all age categories as defined by the ACR Dose Index Registry (mean: 9.4 vs. 3.5 mGy, P<0.0001). The majority (74%) of multiphase exams were performed by 9 of 104 outside imaging facilities.Conclusion: Multiphase acquisitions in routine contrast-enhanced CT of the abdomen and pelvis exams at outside imaging facilities are more frequent than those at a dedicated pediatric institution and contribute to unnecessary radiation dose. A contrast-enhanced CT of the abdomen and pelvis exam from an outside imaging facility with two passes may have as much as four times to six times the dose as the same exam performed with a single pass at a pediatric imaging center. We advocate for imaging facilities with high multiphase rates to eliminate multiple phases from routine contrast-enhanced CT of the abdomen and pelvis exams in children. [ABSTRACT FROM AUTHOR]

Background: Default pediatric protocols on many digital radiography systems are configured based on patient age. However, age does not adequately characterize patient size, which is the principal determinant of proper imaging technique. Use of default pediatric protocols by inexperienced technologists can result in patient overexposure, inadequate image quality, or repeated examinations.Objective: To ensure diagnostic image quality at a well-managed patient radiation exposure by transitioning to thickness-based protocols for pediatric portable abdomen radiography.Materials and Methods: We aggregated patient thickness data, milliamperes (mAs), kilovoltage peak (kVp), exposure index (EI), source-to-detector distance, and grid use for all portable abdomen radiographs performed in our pediatric hospital in a database with a combination of automated and manual data collection techniques. We then analyzed the database and used it as the basis to construct thickness-based protocols with consistent image quality across varying patient thicknesses, as determined by the EI.Results: Retrospective analysis of pediatric portable exams performed at our adult-focused hospitals demonstrated substantial variability in EI relative to our pediatric hospital. Data collection at our pediatric hospital over 4 months accumulated roughly 800 portable abdomen exams, which we used to develop a thickness-based technique chart.Conclusion: Through automated retrieval of data in our systems' digital radiography exposure logs and recording of patient abdomen thickness, we successfully developed thickness-based techniques for portable abdomen radiography. [ABSTRACT FROM AUTHOR]

Background: Nasoduodenal tube (NDT) placement is typically performed at the bedside and two-view abdominal radiographs are usually used to confirm tube position. Anecdotally, in most instances the lateral view is unnecessary and utilizes more than twice the radiation than an anteroposterior (AP) view alone.Objective: We hypothesize that NDT location can be determined using only the AP view, with the NDT position determined on two views utilized as the gold standard.Materials and Methods: A search was performed for all two- or three-view abdominal radiographs from September 2012 to September 2013 with the phrase "ND tube" in the reason field of the requisition. These studies were independently reviewed by two radiologists and scored for anatomical tube position in three different scenarios: AP view alone, the lateral view alone, and both views together, with the latter serving as the gold standard. The anatomical scores were subsequently grouped to reflect clinically significant scenarios. Comparative analysis was performed with the original and clinically grouped scores.Results: A total of 102 patients and 306 separate two-view exams were evaluated. Of the 102 patients, 55 had at least two separate exams. Across raters, concordances of AP and lateral scores relative to the gold standard assessment were 88% and 73% for anatomical scores, and 91.5% and 86.4% for clinically grouped data. Trend differences for fewer errors were found with the AP compared to the lateral view. There were statistically significant group differences with a greater number of false-negative errors in the lateral data set. No clear differences were found when comparing AP and lateral ratings for false-positive errors. Upon review of the common errors, we determined a few imaging findings on AP radiographs that can help assess the need for an additional lateral view.Conclusion: A single AP view is sufficient to determine the NDT position in most cases. Two views should be reserved for cases where the NDT position cannot be definitively assessed. Transitioning toward the single AP view to evaluate the NDT position could have immediate consequences for dose reduction. [ABSTRACT FROM AUTHOR]

Background: Pediatric patients requiring transfer to a dedicated children's hospital from an outside institution may undergo CT imaging as part of their evaluation. Whether this imaging is performed prior to or after transfer has been shown to impact the radiation dose imparted to the patient. Other quality variables could also be affected by the pediatric experience and expertise of the scanning institution.Objective: To identify differences in quality between abdominal CT scans and reports performed at a dedicated children's hospital, and those performed at referring institutions.Materials and Methods: Fifty consecutive pediatric abdominal CT scans performed at outside institutions were matched (for age, gender and indication) with 50 CT scans performed at a dedicated freestanding children's hospital. We analyzed the scans for technical parameters, report findings, correlation with final clinical diagnosis, and clinical utility. Technical evaluation included use of intravenous and oral contrast agents, anatomical coverage, number of scan phases and size-specific dose estimate (SSDE) for each scan. Outside institution scans were re-reported when the child was admitted to the children's hospital; they were also re-interpreted for this study by children's hospital radiologists who were provided with only the referral information given in the outside institution's report. Anonymized original outside institutional reports and children's hospital admission re-reports were analyzed by two emergency medicine physicians for ease of understanding, degree to which the clinical question was answered, and level of confidence in the report.Results: Mean SSDE was lower (8.68) for children's hospital scans, as compared to outside institution scans (13.29, P = 0.03). Concordance with final clinical diagnosis was significantly lower for original outside institution reports (38/48, 79%) than for both the admission and study children's hospital reports (48/50, 96%; P = 0.005). Children's hospital admission reports were rated higher than outside institution reports for completeness, ease of understanding, answering of clinical question, and level of confidence of the report (P < 0.001).Conclusion: Pediatric abdominal CT scans performed and interpreted at a dedicated children's hospital are associated with higher technical quality, lower radiation dose and a more clinically useful report than those performed at referring institutions. [ABSTRACT FROM AUTHOR]

Background: Colonic volvulus is rare in children and associated with colonic dysmotility. Diagnosis of colonic volvulus on radiographs in these patients can be challenging. The purpose of the study was to identify the accuracy of abdominal radiographs and findings suggestive of colonic volvulus.Materials and Methods: A retrospective (2003- 2014) study of all children with colonic volvulus proven surgically or endoscopically reviewed their medical charts for underlying disease and clinical presentation as well as their original radiograph reports. Two pediatric radiologists (reader 1 and reader 2) independently reviewed the radiographs. The kappa test was used to evaluate interobserver variability.Results: There were 19 cases of colonic volvulus in 18 patients (11 males) a mean age 14 years. Cecal volvulus was the most common finding at 14/19 cases (74%). Sixteen of 18 (89%) patients had neurological impairment and 10 of 18 (56%) had intestinal dysmotility. The most common presentation was abdominal distension (14/19 [74%]) and pain (11/19 [58%]). Colonic volvulus was diagnosed in only 7/16 (44%) of the abdominal radiographs. The specific finding of a coffee-bean sign was retrospectively observed only by reader 2 in two cases. Absence of rectal gas and focal colonic loop dilation were the most common findings by the readers (average 73.5% and 87%, respectively) with Kappa values of 0.3 and 0.38, respectively.Conclusion: Diagnosis of colonic volvulus in children can be challenging. Radiologists should be alerted to the possibility of colonic volvulus when there is focal colonic loop distention or absent rectal gas. [ABSTRACT FROM AUTHOR]

Background: Although practice patterns vary, scout radiographs are often routinely performed with pediatric fluoroscopic studies. However few studies have evaluated their utility in routine pediatric fluoroscopy.Objective: To evaluate the value of scout abdomen radiographs in routine barium or water-soluble enema, upper gastrointestinal (GI) series, and voiding cystourethrogram pediatric fluoroscopic procedures.Materials and Methods: We retrospectively evaluated 723 barium or water-soluble enema, upper GI series, and voiding cystourethrogram fluoroscopic procedures performed at our institution. We assessed patient history and demographics, clinical indication for the examination, prior imaging findings and impressions, scout radiograph findings, additional findings provided by the scout radiograph that were previously unknown, and whether the scout radiograph contributed any findings that significantly changed management.Results: We retrospectively evaluated 723 fluoroscopic studies (368 males and 355 females) in pediatric patients. Of these, 700 (96.8%) had a preliminary scout radiograph. Twenty-three (3.2%) had a same-day radiograph substituted as a scout radiograph. Preliminary scout abdomen radiographs/same-day radiographs showed no new significant findings in 719 (99.4%) studies. New but clinically insignificant findings were seen in 4 (0.6%) studies and included umbilical hernia, inguinal hernia and hip dysplasia. No findings were found on the scout radiographs that would either alter the examination performed or change management with regard to the exam.Conclusion: Pre-procedural scout abdomen radiographs are unnecessary in routine barium and water-soluble enema, upper GI series, and voiding cystourethrogram pediatric fluoroscopic procedures and can be substituted with a spot fluoroscopic last-image hold. [ABSTRACT FROM AUTHOR]

Background: Size-specific dose estimate is gaining increased acceptance as the preferred index of CT dose in children. However it was developed based on non-clinical data.Objective: To compare the accuracy of size-specific dose estimate (SSDE) based on geometric and body weight measures in pediatric chest and abdomen CT scans, versus the more accurate [Formula: see text] (mean SSDE based on water-equivalent diameter).Materials and Methods: We retrospectively identified 50 consecutive children (age <18 years) who underwent chest CT examination and 50 children who underwent abdomen CT. We measured anteroposterior diameter (DAP) and lateral diameter (DLAT) at the central slice (of scan length) of each patient and calculated DAP+LAT (anteroposterior diameter plus lateral diameter) and DED (effective diameter) for each patient. We calculated the following in each child: (1) SSDEs based on DAP, DLAT, DAP+LAT, DED, and body weight, and (2) SSDE based on software calculation of mean water-equivalent diameter ([Formula: see text] adopted standard within our study). We used intraclass correlation coefficient (ICC) and Bland-Altman analysis to compare agreement between the SSDEs and [Formula: see text].Results: Gender and age distribution were similar between chest and abdomen CT groups; mean body weight was 37 kg for both groups, with ranges of 6-130 kg (chest) and 8-107 kg (abdomen). SSDEs had very strong agreement (ICC>0.9) with [Formula: see text]. SSDEs based on DLAT had 95% limits of agreement of up to 43% with [Formula: see text]. SSDEs based on other parameters (body weight, DAP, DAP+LAT, DED) had 95% limits of agreement of up to 25%.Conclusion: Differences between SSDEs calculated using various indications of patient size (geometric indices and patient weight) and the more accurate [Formula: see text] calculated using proprietary software were generally small, with the possible exception for lateral diameter, and provide acceptable dose estimates for body CT in children. [ABSTRACT FROM AUTHOR]

Background: Contrast enema, voiding cystourethrography and upper gastrointestinal studies are the most common fluoroscopic procedures in children. Scout abdomen radiographs have been routinely obtained prior to fluoroscopy and add to the radiation exposure from these procedures. Elimination of unnecessary routine scout radiographs in select studies might significantly reduce radiation exposure to children and improve the overall benefit-to-risk ratio of these fluoroscopic procedures.Objective: To determine the radiation exposure contribution of the preliminary/scout abdomen radiographs with respect to the radiation exposure of the total procedure.Materials and Methods: We retrospectively collected demographic information and radiation exposure values of dose area product (in Gy-cm(2)) and entrance air kerma (in mGy) - initially for the scout abdomen radiographs done prior to fluoroscopy and subsequently the total procedural radiation values (the combined values of the scout radiograph and fluoroscopic radiation exposure) - in children who underwent contrast enemas, voiding cystourethrograms and upper gastrointestinal studies in a 4-month period. The radiation parameters, including fluoroscopy time, dose area product and entrance air kerma, were available in the log book maintained in the fluoroscopy suite. Fluoroscopy procedures were performed on a single fluoroscopy machine using four frames per second pulse rate and other radiation-minimizing techniques. Usage of the grid to obtain scout radiographs was also recorded. The proportion of radiation exposure from the scout radiograph relative to that of the total procedure was calculated by dividing the individual parameters of the scout to the total procedural values and multiplied by 100 to express these values as a percentage. We calculated mean, median and range and performed statistical analysis of the data.Results: A total of 151 procedures performed on 71 males and 80 females qualified for the study. The age range of the patients was 2 days to 18 years, with a mean of nearly 3.5 years (40 months) and median of 15 months. There were 63 upper gastrointestinal studies, 65 voiding cystourethrography studies and 23 contrast enema studies. The fluoroscopy time for all procedures combined ranged from 0.1 min (6 s) to 2 min, with mean and median values of 0.4 min and 0.3 min, respectively. The fractional radiation exposure contribution for the dose area product of scout abdomen radiograph to the total procedure ranged from 4% to 98%, with mean and median values of 51% and 49%, respectively. The fractional contribution of the scout radiograph to the total procedure for the entrance air kerma values ranged from 6% to 97%, with mean and median values of 29% and 26%, respectively. There was a significant negative correlation (P<0.001) between fluoroscopy radiation time and the proportion of radiation parameters of scout radiograph to total procedural values.Conclusion: Scout radiographs can contribute a significant proportion (median values of approximately 50% for the dose area product and 26% for the entrance air kerma) of radiation exposure in common fluoroscopy procedures in children. [ABSTRACT FROM AUTHOR]

Background: A radiologic diagnosis of hypochondroplasia is hampered by the absence of age-dependent radiologic criteria, particularly in the neonatal period.Objective: To establish radiologic criteria and scoring system for identifying neonates with fibroblast growth factor receptor 3 (FGFR3)-associated hypochondroplasia.Materials and Methods: This retrospective study included 7 hypochondroplastic neonates and 30 controls. All subjects underwent radiologic examination within 28 days after birth. We evaluated parameters reflecting the presence of (1) short ilia, (2) squared ilia, (3) short greater sciatic notch, (4) horizontal acetabula, (5) short femora, (6) broad femora, (7) metaphyseal flaring, (8) lumbosacral interpedicular distance narrowing and (9) ovoid radiolucency of the proximal femora.Results: Only parameters 1, 3, 4, 5 and 6 were statistically different between the two groups. Parameters 3, 5 and 6 did not overlap between the groups, while parameters 1 and 4 did. Based on these results, we propose a scoring system for hypochondroplasia. Two major criteria (parameters 3 and 6) were assigned scores of 2, whereas 4 minor criteria (parameters 1, 4, 5 and 9) were assigned scores of 1. All neonates with hypochondroplasia in our material scored ≥6.Conclusion: Our set of diagnostic radiologic criteria might be useful for early identification of hypochondroplastic neonates. [ABSTRACT FROM AUTHOR]

Background: Organ dose is essential for accurate estimates of patient dose from CT.Objective: To determine organ doses from a broad range of pediatric patients undergoing diagnostic chest-abdomen-pelvis CT and investigate how these relate to patient size.Materials and Methods: We used a previously validated Monte Carlo simulation model of a Philips Brilliance 64 multi-detector CT scanner (Philips Healthcare, Best, The Netherlands) to calculate organ doses for 40 pediatric patients (M:F = 21:19; range 0.6-17 years). Organ volumes and positions were determined from the images using standard segmentation techniques. Non-linear regression was performed to determine the relationship between volume CT dose index (CTDIvol)-normalized organ doses and abdominopelvic diameter. We then compared results with values obtained from independent studies.Results: We found that CTDIvol-normalized organ dose correlated strongly with exponentially decreasing abdominopelvic diameter (R(2) > 0.8 for most organs). A similar relationship was determined for effective dose when normalized by dose-length product (R(2) = 0.95). Our results agreed with previous studies within 12% using similar scan parameters (e.g., bowtie filter size, beam collimation); however results varied up to 25% when compared to studies using different bowtie filters.Conclusion: Our study determined that organ doses can be estimated from measurements of patient size, namely body diameter, and CTDIvol prior to CT examination. This information provides an improved method for patient dose estimation. [ABSTRACT FROM AUTHOR]

Background: The clinical significance of a pulmonary nodule that is detected incidentally on CT studies in children is unknown. In addition, there is limited information regarding the management of incidentally detected pulmonary nodules discovered on abdominal CT studies in children.Objective: The purpose of this study was to investigate the clinical significance of incidental pulmonary nodules detected on abdominal CT studies in children.Materials and Methods: This was a retrospective study performed following institutional review board approval. Abdominal CT reports in patients younger than 18 years of age from July 2004 to June 2011 were reviewed for the terms "nodule," "nodular" or "mass" in reference to the lung bases. The study population included those pediatric patients in whom pulmonary nodules were initially detected on abdominal CT studies. The largest pulmonary nodules detected on CT studies were evaluated for their features (size, shape, margin, attenuation, location, and presence of calcification and cavitation). Follow-up CT studies and clinical records were reviewed for demographic information, history of underlying malignancies and the clinical outcome of the incidental pulmonary nodules. Comparison of malignant versus benign pulmonary nodules was performed with respect to the size of the nodule, imaging features on CT, and patient history of malignancy using the Student's t-test and Fisher exact test. Youden J-index in receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off size for suggesting a high risk of malignancy of incidentally detected pulmonary nodules.Results: Pulmonary nodules meeting inclusion criteria were detected in 62 (1.2%) of 5,234 patients. The mean age of patients with nodules was 11.2 years (range: 5 months-18 years). Thirty-one patients (50%) had follow-up CT studies and two of these patients (6%) were subsequently found to have malignant pulmonary nodules. Both of these patients had a history of malignancy. Of the remaining 31 patients without follow-up CT studies, none had a history of malignancy. Clinical follow-up data was available in 26 of these 31 patients (84%) and none had any evidence of malignant pulmonary nodule development. There was a significant association between history of malignancy and incidentally detected pulmonary nodules on abdominal CT studies subsequently found to be malignant (P = 0.036). The size was significantly larger for the malignant pulmonary nodules compared to the benign pulmonary nodules with a size ≥7 mm in diameter being the optimal cut-off for suggesting a high risk of malignancy (11.5 ± 6.4 mm vs. 4.7 ± 3.0 mm, P = 0.003).Conclusion: The incidence of pulmonary nodules found on pediatric abdominal CT studies is 1.2%. The incidence of malignancy in such pulmonary nodules is low (3%) and only seen in the setting of pulmonary nodules ≥7 mm in diameter in children with a history of malignancy. Therefore, further investigation is warranted for pulmonary nodules that are ≥7 mm in children with a history of malignancy while further imaging work-up may not be necessary in the remaining patients in this pediatric patient population. [ABSTRACT FROM AUTHOR]

Background: Abdominal CT angiography has been increasingly used for evaluation of various conditions related to abdominal vasculature in the pediatric population. However, no direct comparison has evaluated the quality of abdominal CT angiography in children using hand versus mechanical administration of intravenous (IV) contrast agent.Objective: To compare hand versus mechanical administration of IV contrast agent in the quality of abdominal CT angiography in the pediatric population.Materials and Methods: We retrospectively reviewed the electronic medical record to identify pediatric patients (≤18 years) who had abdominal CT angiography between August 2012 and August 2013. The information obtained includes: (1) type of administration of IV contrast agent (hand [group 1] versus mechanical [group 2]), (2) size (gauge) of IV catheter, (3) amount of contrast agent administered and (4) rate of contrast agent administration (ml/s). Two reviewers independently performed qualitative and quantitative evaluation of abdominal CT angiography image quality. Qualitative evaluation of abdominal CT angiography image quality was performed by visual assessment of the degree of contrast enhancement in the region of interest (ROI) based on a 4-point scale. Quantitative evaluation of each CT angiography examination was performed by measuring the Hounsfield unit (HU) using an ROI within the abdominal aorta at two levels (celiac axis and the inferior mesenteric artery) for each child. Analysis of variance (ANOVA) using the F-test was applied to compare contrast enhancement within the abdominal aorta at two levels (celiac axis and inferior mesenteric artery) between hand administration and mechanical administration of IV contrast methods with adjustment for age.Results: We identified 46 pediatric patients (24 male, 22 female; mean age 7.3 ± 5.5 years; range 5 weeks to 18 years) with abdominal CT angiography performed during the study period. Of these patients, 16 (35%; 1.7 ± 2.2 years; range 5 weeks to 5 years) had hand administration of IV contrast agent and 30 (65%; 10.2 ± 4.2 years; range 4-18 years) had mechanical administration of IV contrast agent. All 46 abdominal CT angiography studies were of diagnostic quality based on qualitative evaluation (all ≥3). All abdominal CT angiography studies from both groups showed diagnostic quality of contrast enhancement (>150 HU) at both the celiac axis and the inferior mesenteric artery (IMA) levels. The contrast enhancement of the abdominal aorta was not significantly different between the IV contrast administration methods at either the celiac axis level (360 ± 158 vs. 353 ± 116, P = 0.24) or the IMA level (340 ± 140 vs. 351 ± 90, P = 0.27), adjusting for age.Conclusion: Diagnostic-quality abdominal CT angiography can be achieved using hand administration of IV contrast agent in infants and young children (≤5 years). [ABSTRACT FROM AUTHOR]

Background: Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. Objective: To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. Materials and methods: We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. Results: There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group ( P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Conclusion: Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. [ABSTRACT FROM AUTHOR]

Background: Much has been written regarding the incidence, types, importance and management of abdominal CT incidental findings in adults, but there is a paucity of literature on incidental findings in children. Objective: We sought to determine the prevalence and characteristics of extra-appendiceal and incidental findings in pediatric abdominal CT performed for suspected appendicitis. Materials and methods: A retrospective review was performed of abdominal CT for suspected appendicitis in a pediatric emergency department from July 2010 to June 2012. Extra-appendiceal findings were recorded. Any subsequent imaging was noted. Extra-appendiceal findings were divided into incidental findings of doubtful clinical significance, alternative diagnostic findings potentially providing a diagnosis other than appendicitis explaining the symptoms, and incidental findings that were abnormalities requiring clinical correlation and sometimes requiring further evaluation but not likely related to the patient symptoms. Results: One hundred sixty-five children had abdominal CT for suspected appendicitis. Seventy-seven extra-appendiceal findings were found in 57 (34.5%) patients. Most findings (64 of 77) were discovered in children who did not have appendicitis. Forty-one of these findings (53%) could potentially help explain the patient's symptoms, while 30 of the findings (39%) were abnormalities that were unlikely to be related to the symptoms but required clinical correlation and sometimes further work-up. Six of the findings (8%) had doubtful or no clinical significance. Conclusion: Extra-appendiceal findings are common in children who undergo abdominal CT in the setting of suspected appendicitis. A significant percentage of these patients have findings that help explain their symptoms. Knowledge of the types and prevalence of these findings may help radiologists in the planning and interpretation of CT examinations in this patient population. [ABSTRACT FROM AUTHOR]

Background: Pediatric radiography presents unique challenges in balancing image quality and patient dose. Removing the anti-scatter grid reduces patient dose but also reduces image contrast. The benefit of using an anti-scatter grid decreases with decreasing patient size. Objective: To determine patient thickness thresholds for anti-scatter grid use by comparing scatter-to-primary ratio for progressively thinner patients without a grid to the scatter-to-primary ratio for a standard adult patient with a grid. Materials and methods: We used Solid Water™ phantoms ranging in thickness from 7 cm to 16 cm to simulate pediatric abdomens. The scatter-to-primary ratio without a grid was measured for each thickness at 60 kVp, 70 kVp and 80 kVp for X-ray fields of view (FOV) of 378 cm, 690 cm and 1,175 cm using indirect digital radiography (iDR) and computed radiography (CR). We determined thresholds for anti-scatter grid use by comparing the intersection of a fit of scatter-to-primary ratio versus patient thickness with a standard adult scatter-to-primary ratio measured for a 23-cm phantom thickness at 80 kVp with an anti-scatter grid. Dose area product (DAP) was also calculated. Results: The scatter-to-primary ratio depended strongly on FOV and weakly on kVp; however DAP increased with decreasing kVp. Threshold thicknesses for grid use varied from 5 cm for a 14 × 17-cm FOV using iDR to 12 cm for an 8 × 10-cm FOV using computed radiography. Conclusions: Removing the anti-scatter grid for small patients reduces patient dose without a substantial increase in scatter-to-primary ratio when the FOV is restricted appropriately. Radiologic technologists should base anti-scatter grid use on patient thickness and FOV rather than age. [ABSTRACT FROM AUTHOR]

Background: No study reported in the literature comprehensively compares findings on neonatal abdominal radiographs with sonography. Objective: To compare the findings on abdominal radiographs and sonograms in infants in intensive care, to better understand how the various intestinal gas patterns on radiographs relate to the spectrum of appearances on sonography and, second, to evaluate the ability of sonography to differentiate necrotizing enterocolitis from other intestinal pathology. Materials and methods: We prospectively evaluated sonograms and radiographs, blinded to the other modality and to clinical information. Patients' charts were reviewed by a third blinded reader and used as a reference standard for diagnosis. We made associations between sonographic findings, radiographic intestinal gas patterns and clinical diagnoses. Results: We included 75 infants with gestational ages between 23 weeks and 41 weeks. Sonographic abnormalities were present in infants with all radiographic intestinal gas patterns, including normal patterns. We only saw absent intestinal perfusion and fluid collections on sonography (suggesting intestinal necrosis and sealed perforation) in infants with intestinal dilatation with elongation on radiographs. Separation of intestinal loops on radiographs was most commonly caused by reasons other than intestinal wall thickening. Increased intestinal echogenicity or free fluid with echoes on sonography correlated with a diagnosis of necrotizing enterocolitis, whereas anechoic free fluid correlated with absence of necrotizing enterocolitis. Conclusion: Sonography is complementary to radiographs in infants with suspected intestinal pathology, with a spectrum of appearances seen on each modality. Some sonographic findings either strongly suggest necrotizing enterocolitis or supply evidence against this diagnosis. [ABSTRACT FROM AUTHOR]

Background: Abdominal radiography is the reference standard in imaging neonates with necrotizing enterocolitis (NEC); however, ultrasound of the abdomen including bowel may be of value in this setting. Objective: To correlate sonographic and radiographic findings with patient outcomes in NEC. Materials and methods: We reviewed sonographic and radiographic exams, as well as clinical, pathological and laboratory records. Ultrasound images were reviewed for free intraperitoneal gas, peritoneal fluid, pneumatosis intestinalis, portal gas, bowel vascularity, bowel wall thickness and echogenicity, peristalsis and the presence of dilated bowel with anechoic contents. Contemporaneously acquired radiographs were reviewed for intraperitoneal gas, pneumatosis intestinalis, portal gas, the sentinel loop sign and gas pattern. Patients were categorized into two groups based on clinical outcome. Results: Forty-four neonates receiving 55 sonograms were included. Focal fluid collections, echogenic free fluid, increased bowel wall echogenicity and increased bowel wall thickness were statistically significant in predicting an unfavorable outcome. Other features approached significance in predicting poor outcomes: free peritoneal gas, pneumatosis intestinalis, aperistalsis, bowel wall thinning and absent bowel perfusion. Anechoic free peritoneal fluid predicted a good outcome. The sentinel loop sign on radiographs predicted an unfavorable outcome. Conclusions: Abdominal sonography and radiography in patients with NEC can help prognosticate the outcome. [ABSTRACT FROM AUTHOR]

Background: Free intraperitoneal fluid can be an important sign in an abdominal inflammatory process or abdominal trauma. It is often present in children with abdominal pain, but it is a nonspecific finding. A minimal amount of free intraperitoneal fluid is considered normal. Objective: The purpose of this study was to evaluate the incidence, location and volume of free fluid in the abdomen and pelvis in a population of asymptomatic children. Materials and methods: In this prospective study, we performed clinically indicated abdominal and pelvic sonography, using high-resolution transducers, in 200 asymptomatic children: 104 (52%) girls, 96 (48%) boys; ages 6 days-15 years (mean 3 years 8 months). US studies were performed and prospectively evaluated by two experienced pediatric radiologists. Patients with any condition that could result in the accumulation of free intraperitoneal fluid as well as postpubertal girls were excluded from the study. Results: Free intraperitoneal fluid was seen in 12 children (6%), only in the pelvis. Fluid volume never exceeded 1 ml. Conclusion: Our study suggests that 1 ml or less of free intraperitoneal fluid detected in the pelvis is probably insignificant. [ABSTRACT FROM AUTHOR]

Background: Four scoring methods exist to assess severity of fecal loading on plain abdominal radiographs in constipated patients (Barr-, Starreveld-, Blethyn- and Leech). So far, the Starreveld score was used only in adult patients. Objective: To determine accuracy and intra- and inter-observer agreement of the Starreveld scoring method in the diagnosis of functional constipation among pediatric patients. In addition, we compared the Starreveld with the Barr scoring method. Materials and methods: Thirty-four constipated and 34 non-constipated children were included. Abdominal radiographs, obtained before treatment, were rated (Starreveld- and Barr) by 4 observers. A second observation after 4 weeks was done by 3 observers. Cut-off level for the Starreveld score, accuracy as measured by the area under the receiver operator characteristics curve, and inter- and intra-observer agreement were calculated. Results: Cut-off value for the Starreveld score was 10. AUC for Starreveld score was 0.54 and for Barr score 0.38, indicating poor discriminating power. Inter-observer agreement was 0.49-0.52 4 (Starreveld) and 0.44 (Barr), which is considered moderate. Intra-observer agreement was 0.52-0.71 (Starreveld) and 0.62- 0.76 (Barr). Conclusion: The Starreveld scoring method to assess fecal loading on a plain abdominal radiograph is of limited value in the diagnosis of childhood constipation. [ABSTRACT FROM AUTHOR]

Background: Congenital pouch colon (CPC) is a rare form of high ano-rectal malformation (ARM) in which part of or the entire colon is replaced by a pouch with a fistula to the genito-urinary tract. According to the Saxena-Mathur classification CPC is divided into five types. Although plain abdominal radiographs are taken in infants with suspicion of CPC to detect large dilatation of the pouch, the determination of the type of CPC is made during surgical exploration. Since large variations in the length of normal colon are present in the various types, management strategy options can be determined only at the time of surgery. Objective: The aim of this study was to review abdominal radiographs of children with congenital pouch colon (CPC) and evaluate their value in determining the type of CPC prior to surgical exploration to assist pre-operative planning. Materials and methods: Over a 12-year period (1995-2007), CPC was documented in 80 children (52 boys and 28 girls, age range 1 day-9 years, median 2.4 days) and retrospective analysis of plain abdominal radiographs of 77 children at the time of presentation was performed. Radiographic findings were correlated with surgical findings. Results: Of 77 children, 5 were excluded from the study since the pouch colon was perforated. The direction of the pouch apex was correlated with surgical findings to determine the CPC type ( P < 0.0001, Fisher exact test). Type 1 (17/18) and type 2 CPC (18/18) were characterized by a single large pouch with the apex positioned in the left hypochondrium. In type 3 CPC (2/2) the pouch apex was directed towards the right hypochondrium. In type 4 CPC the apex of the pouch was directed towards the right hypochondrium (28/33); however in 5 children it was towards the left hypochondrium. In type 5 CPC ( n = 1) the radiograph was inconclusive. Conclusion: Plain abdominal radiographs have a predictive value in determining the type of CPC and obviating the need for an invertogram. [ABSTRACT FROM AUTHOR]

Background: Enteroclysis (EC) has been widely and successfully used for evaluation of the small bowel in adults for about 30 years. However, despite recently improved intubation and examination techniques, in many paediatric radiology centres it is still not the preferred conventional barium study for the evaluation of small bowel pathology in children.Objective: To share our 10 years of experience and review the feasibility of EC in 83 older children and teenagers, in terms of both technique and pathological findings.Materials and Methods: Between 1996 and 2006, EC was performed by the standard technique described by Herlinger to 83 children between 7 and 18 years of age. The indication for the study was jointly decided by the paediatric radiologist and the clinician. None of the examinations was converted to follow-through studies because of patient refusal or technical failure. Morphological changes, mucosal abnormalities, luminal abnormalities, perienteric structures, the location of the disease, indirect findings regarding the bowel wall and functional information were evaluated.Results: All the children tolerated the procedure without difficulty. Out of 83 patients, 63 had abnormal findings. The spectrum of diagnoses were Crohn disease (n = 23), nonspecific enteritis (n = 10), malabsorption (n = 8), intestinal tuberculosis (n = 6), intestinal lymphoma (n = 5), Peutz-Jegher syndrome (n = 3), adhesions (n = 2), Behçet disease (n = 2), back-wash ileitis due to ulcerative colitis (n = 2), common-variable immune deficiency (n = 1) and lymphangiectasis (n = 1).Conclusion: EC can easily be performed in children over 7 years of age and when performed using a correct technique it shows high diagnostic performance without any complications in the evaluation of small bowel diseases in older children and teenagers. [ABSTRACT FROM AUTHOR]

Background: Concern has been raised about the potential risks related to radiation exposure from CT scans, particularly among children. However, to date, there are few data available describing the magnitude of pediatric CT utilization.Objective: The aim of the study was to explore patterns of CT use in pediatric patients, with respect to time, use of multiple scans, body regions imaged, and medical diagnoses.Materials and Methods: Records of 22,223 scans performed on 18,075 people aged < or =18 years over the period 1999-2003, including diagnoses recorded within 21 days after the examination, were obtained from a large Israeli Health Maintenance Organization (1,600,000 members).Results: The highest annual CT examination rate (per 1,000) was recorded in 2001 (10.1) compared to 7.0 and 6.3 in 1999 and 2003, respectively. The lowest rate (three scans per 1,000) was found for 3-year-old children, with increasing rates with age. The head was the most frequently scanned region, both in young children (78%) and adolescents (39%). Symptoms of ill-defined conditions and injuries were documented in 22% and 10% of all scans, respectively.Conclusions: Although the results suggest that children comprise only 3% of all patients undergoing CT, this important modality must be carefully used because of their increased radiosensitivity, higher effective radiation doses, and longer life expectancy. [ABSTRACT FROM AUTHOR]

Background: The data concerning the value of a plain abdominal radiograph in childhood constipation are inconsistent. Recently, positive results have been reported of a new radiographic scoring system, "the Leech method", for assessing faecal loading.Objective: To assess intra- and interobserver variability and determine diagnostic accuracy of the Leech method in identifying children with functional constipation (FC).Materials and Methods: A total of 89 children (median age 9.8 years) with functional gastrointestinal disorders were included in the study. Based on clinical parameters, 52 fulfilled the criteria for FC, six fulfilled the criteria for functional abdominal pain (FAP), and 31 for functional non-retentive faecal incontinence (FNRFI); the latter two groups provided the controls. To assess intra- and interobserver variability of the Leech method three scorers scored the same abdominal radiograph twice. A Leech score of 9 or more was considered as suggestive of constipation. ROC analysis was used to determine the diagnostic accuracy of the Leech method in separating patients with FC from control patients.Results: Significant intraobserver variability was found between two scorers (P=0.005 and P<0.0001), whereas there was no systematic difference between the two scores of the other scorer (P=0.89). The scores between scorers differed systematically and displayed large variability. The area under the ROC curve was 0.68 (95% CI 0.58-0.80), indicating poor diagnostic accuracy.Conclusions: The Leech scoring method for assessing faecal loading on a plain abdominal radiograph is of limited value in the diagnosis of FC in children. [ABSTRACT FROM AUTHOR]

Background: Enlarged mesenteric lymph nodes (MLN) are frequently seen in children with abdominal pain and, in the absence of other disorders, have been attributed to primary mesenteric lymphadenitis.Objective: To evaluate the prevalence of enlarged MLN (short axis>or=5 mm) as detected by abdominal CT in children with a low likelihood for mesenteric lymphadenopathy.Materials and Methods: During a 14-month period, we identified all non-contrast abdominal CT examinations performed at a tertiary care pediatric hospital for evaluation of suspected or known renal stones. Two radiologists reviewed the examinations and recognized all enlarged MLN, measured the short-axis diameter, and noted the quadrant location.Results: Sixty-one children were identified who met entry criteria; mean age was 10.7 years (range 1.1-17.3 years). Enlarged MLN were found in 33 (54%) of the 61 children; the largest enlarged MLN was most frequently in the right lower quadrant (RLQ) (29 of 33, 88%). Seventeen of the 61 children (28%) had three or more enlarged MLN; all were in the RLQ. The largest short-axis diameter measured was 10 mm.Summary: MLN with a short-axis diameter of >5-10 mm are commonly found on abdominal CT examination of children with a low likelihood for mesenteric lymphadenopathy and should be considered a non-specific finding. A short-axis diameter of 8 mm might better define the upper limit of normal mesenteric lymph node size in children. [ABSTRACT FROM AUTHOR]

Multi-detector-row computed tomography (MDCT) enables rapid, noninvasive, high-resolution, and three-dimensional imaging of pediatric vascular diseases. In this paper, we explore the adaptation of the MDCT angiographic principles to pediatric patients for vascular diseases of the abdomen, pelvis, and extremities. Special emphasis is placed on the practical aspects of how to perform these studies. Optimizations of scan parameters, contrast medium usage, radiation dose, and three-dimensional image processing are discussed in detail. We provide practical guidance on how to choose between MR angiography and CT angiography. Finally, we review important pediatric vascular diseases, categorized into traumatic injuries, inherited vascular diseases, congenital vascular diseases, vasculitides, and surgical planning and assessment. In each category, we discuss how CT angiography can be tailored to maximize its clinical benefits. [ABSTRACT FROM AUTHOR]

The objectives of the study were (1) to determine the interobserver variation in interpretation of abdominal radiographs in children with clinically suspected intussusception, and (2) to determine the diagnostic value of abdominal radiographs in these patients. One hundred and eighty-two plain abdominal radiographic examinations (AXR) performed in children with clinically suspected intussusception were reviewed blind to the clinical history and findings of air enema. The presence or absence of nine AXR signs relevant to intussusception was documented. Each AXR was categorized as equivocal, positive or negative for intussusception, with the aim of achieving no false negatives. Interobserver variation in the identification of AXR signs and radiologic diagnoses was calculated using the kappa statistic for 60 cases assessed independently by three observers. Using the findings of air enema as gold standard, the prevalence of AXR signs in all patients with (60) and without (122) intussusception was determined and their diagnostic values calculated. The best observer agreement was for the presence of sparse small bowel gas (supine, k = 0.68) and the worst for the presence of cecal gas (erect, k = 0.18). All three observers agreed intussusception to be present or absent in only 7 of 60 cases and the majority agreement was equivocal in more than half. Overall agreement between observers for the diagnosis of intussusception was k = 0.30. The best positive predictors of intussusception were the soft tissue mass and sparse large bowel gas, with likelihood ratios of 3.9 and 2.5. Cecal feces predicted against intussusception, likelihood ratio 0.11. AXR was equivocal in 53%, positive in 21% and negative in 26%. Where a firm radiographic diagnosis was made, the diagnostic accuracy of AXR was 84%.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

A controlled prospective study, in an animal model chosen to simulate portable neonatal radiography, was performed to compare the response of the Philips Computed Radiography (CR) system and conventional 200 speed film-screen (FS) to variation in imaging kVp. Acceptable images were obtained on the CR system over a very wide kVp range. In contrast the FS system produced acceptable images over a narrow kVp range. This ability suggests that the CR system should eliminate the need for repeat examinations in cases where a suboptimal kVp setting would have resulted in an unacceptable FS image. CR technology should therefore be ideally suited to portable radiography especially in situations where selection of correct exposure factors is difficult as in the neonatal nursery. [ABSTRACT FROM AUTHOR]

In order to reassess the diagnostic reliability of the abdominal plain film examination in suspected intussusception, the findings in 100 consecutive cases of this disorder were analysed. Then, these were compared with the same number of cases in which the diagnosis had been rejected by means of barium enema. It was found that a positive plain film diagnosis of intussusception was possible in 89 patients. In 11 cases inconclusive plain film findings called for supplementary barium enemas to establish the diagnosis. In the reference group intussusception was excluded on the basis of plain film findings alone in 74% of cases. In the remaining 26% of patients a barium enema proved necessary to reject the diagnosis of suspected intussusception. [ABSTRACT FROM AUTHOR]

The article discusses the common pitfalls in pediatric abdominal imaging, which include plain abdominal radiographs (AXR) and ultrasonography (US). It is stated that AXR needs clinical correlation through an upper gastrointestinal (UGI) series if the child is stable and if not, surgery would be performed. It notes that in neonates with necrotizing enterocolitis, AXR remains the most important imaging modality. It also mentions that in intussusception, US is the primary diagnostic modality.

We report a 9-year-old boy who had swallowed a small dressmaker’s pin during an art & craft class. Confirmation of ingestion of the pin and its passage through the gut was achieved with abdominal radiography. When the pin had not passed after 8 days, and with increasing concern about the likelihood of perforation, US was used to locate its exact position to allow surgical removal. This case report illustrates the unique use of US to reveal the intraappendiceal location of an ingested foreign body, facilitating its surgical removal. [ABSTRACT FROM AUTHOR]

We describe the CT findings in an initially asymptomatic boy aged 2 years 9 months with a gastrocolic fistula following percutaneous endoscopic gastrostomy (PEG) placement. The findings consisted of an unusual configuration of the gastrostomy tubing on an abdominal radiograph and upper gastrointestinal study indicating the possibility of transcolic PEG placement, which was confirmed with limited section CT. This well-known and major complication following a common procedure may be recognized on plain abdominal radiography, but it has not to our knowledge been documented previously on CT in a child. [ABSTRACT FROM AUTHOR]

We report the imaging findings in a case of neonatal spontaneous gastric perforation presenting as massive hydroperitoneum rather than pneumoperitoneum. Plain abdominal radiography showed a diffuse ground-glass opacity with paucity of bowel gas. Subsequent ultrasonography demonstrated numerous echogenic peritoneal fluid collections containing echogenic debris shown at surgery to be due to milk and bile. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to compare the quality of 1 : 1 and 1.5 : 1 pitch helical contrast-enhanced thoracic and abdominal CT images in children who cannot cooperate for breath holding.Materials and Methods: This is a retrospective study of 33 contrast-enhanced CT examinations in 11 children of 0-4 years of age. All children had an initial CT study using 1 : 1 pitch helical scanning followed over the next 6-36 months by one to four CT examinations with 1.5 : 1 pitch. Radiation dose with the two techniques was measured with a pencil ionization chamber.Results: The two techniques provided comparable overall image quality. There was 33 % less radiation dose with 1.5 : 1 pitch helical scanning.Conclusion: The 1.5 : 1 pitch helical CT provides comparable quality images and a smaller radiation dose than 1 : 1 pitch in examining children aged 0-4 years. [ABSTRACT FROM AUTHOR]

The article presents abstracts on medical topics which include the effects of oral contrast for abdominal computed tomography in children on gastric fluid volume, the predictive indicators for bowel injury in pediatric patients, and the failure rate of nonoperative management in children with splenic or liver injury.

A 6-month-old-boy who presented with an abdominal mass disclosed a well-formed fetus in the retroperitoneum. This mass was retrospectively noted at the age of 1 month. Comparison of two radiographic examinations done 5 month apart clearly demonstrated the enlargement of an included fetus in the bearer's abdomen. Our report of this rare condition focuses on the growth of the fetus-in-fetu detected by roentgenograms. [ABSTRACT FROM AUTHOR]

The article presents abdominal radiographic images of a 12-year-old boy suffering from abdominal pain.

The article focuses on the supine abdominal radiograph and enema of a 13-year-old boy with one-day medical history of coffee-ground emesis.