Preoperative MDCT evaluation of congenital lung anomalies in children: comparison of axial, multiplanar, and 3D images.

OBJECTIVE: The objective of our study was to compare the preoperative diagnostic accuracy of axial, multiplanar, and 3D MDCT images for evaluating congenital lung anomalies in pediatric patients and to assess the potential added diagnostic value of multiplanar and 3D MDCT images in this setting. MATERIALS AND METHODS: We used our hospital information system to identify all consecutive pediatric patients younger than 18 years who had undergone preoperative MDCT angiography and had a pathologically proven congenital lung anomaly between June 2005 and February 2010. Each MDCT examination was reviewed independently by two experienced pediatric radiologists for the types, location, associated mass effect, and associated anomalous vessels of congenital lung anomalies on axial, multiplanar, and 3D MDCT images. The final diagnosis was determined by surgical and pathologic findings. Diagnostic accuracy, confidence level of diagnosis (scale of 1-3: 1 = highest confidence and 3 = lowest), perceived added diagnostic value of multiplanar or 3D MDCT images (scale of 1-5: 5 = highest added diagnostic value and 1 = lowest), and interobserver kappa agreement were evaluated. RESULTS: The final study cohort consisted of 46 pediatric patients (28 males and 18 females; mean age, 5.6 ± 6 [SD] months; range, 1 day-50 months). Histopathologic diagnoses included congenital pulmonary airway malformation (n = 19, 41%), sequestration (n = 15, 33%), congenital lobar emphysema (n = 7, 15%), and bronchogenic cyst (n = 5, 11%). Both independent reviewers correctly diagnosed types, location, associated mass effect, and associated anomalous arteries of all congenital lung anomalies with high accuracy (100%) and confidence level (mean confidence level < 1.2) on each type of image display (axial, multiplanar, and 3D). However, for the detection of anomalous veins, multiplanar and 3D images were associated with greater diagnostic accuracy and higher confidence level than axial images alone. Specifically, diagnostic accuracy for the detection of anomalous veins (n = 15; 33%) was 60% (9/15 cases) for axial MDCT images, 80% (12/15) for multiplanar MDCT images, and 100% (15/15) for 3D MDCT images (Friedman test, p = 0.011). Confidence levels for the detection of anomalous veins were significantly higher with 3D MDCT images (mean level = 1.0) and multiplanar MDCT images (mean level = 1.5) compared with axial MDCT images alone (mean level = 2.6) (Friedman test, p < 0.01). Both multiplanar and 3D MDCT images were found to provide added diagnostic value for accurately detecting anomalous veins associated with congenial lung anomalies (paired Student t tests, p < 0.012). CONCLUSION: Axial MDCT images allow accurate diagnosis of the types, location, associated mass effect, and anomalous arteries of congenital lung anomalies, but supplemental multiplanar and 3D MDCT images add diagnostic value for the evaluation of congenital lung lesions associated with anomalous veins.

Semi-Automated 3D Volumetric Renal Measurements in Polycystic Kidney Disease Using b0-Images-A Feasibility Study.

Autosomal dominant polycystic kidney disease (ADPKD) eventually leads to end stage renal disease (ESRD) with an increase in size and number of cysts over time. Progression to ESRD has previously been shown to correlate with total kidney volume (TKV). An accurate and relatively simple method to perform measurement of TKV has been difficult to develop. We propose a semi-automated approach of calculating TKV inclusive of all cysts in ADPKD patients based on b0 images relatively quickly without requiring any calculations or additional MRI time. Our purpose is to evaluate the reliability and reproducibility of our method by raters of various training levels within the environment of an advanced 3D viewer. Thirty patients were retrospectively identified who had DWI performed as part of 1.5T MRI renal examination. Right and left TKVs were calculated by five radiologists of various training levels. Interrater reliability (IRR) was estimated by computing the intraclass correlation (ICC) for all raters. ICC values calculated for TKV measurements between the five raters were 0.989 (95% CI = (0.981, 0.994), p < 0.01) for the right and 0.961 (95% CI = (0.936, 0.979), p < 0.01) for the left. Our method shows excellent intraclass correlation between raters, allowing for excellent interrater reliability.

Streptococcus milleri group pleuropulmonary infection in children: computed tomographic findings and clinical features.

OBJECTIVE: Streptococcus milleri group streptococci have recently been increasingly recognized as important pulmonary pathogens, but their imaging features have not been well documented in children. We have recently observed a number of cases of this infection among pediatric patients at our tertiary care, children's hospital. Our purpose was to investigate the computed tomographic (CT) findings and clinical features of S. milleri group pleuropulmonary infection in children. MATERIALS AND METHODS: We used our hospital information system to identify all consecutive pediatric patients (<18 years of age) who had both a microbiologically proven S. milleri group infection and a chest CT scan between December 1996 and May 2009. Each scan was systemically reviewed by 2 pediatric radiologists for pleural and lung parenchymal abnormalities. Pleural effusions were classified as either simple or complex and correlated with results of pleural fluid analysis. Computed tomographic findings were compared with chest radiographic findings in the subset of patients who underwent radiography within 24 hours of CT. Microbiological data, risk factors, immune status, patient management, and clinical outcome were systematically reviewed. RESULTS: The final study cohort consisted of 15 children (6 boys and 9 girls), ranging in age from 4.2 years to 17.7 years (mean, 10.8 years). All patients were immunocompetent without recognized risk factors for this infection. Thirteen pleural effusions were identified in 10 (67%) of the 15 patients, including 10 complex and 3 simple pleural effusions. All complex effusions at CT were consistent with empyemas by pleural fluid analysis. Lung parenchymal abnormalities were identified in 7 (47%) of the 15 patients, including lung abscess in 4 patients, consolidation in 2, and multiple bilateral pulmonary nodules and lung abscesses in 1. In the subset of 7 patients with comparison radiographs, radiographic and CT findings were concordant for the detection of lung abnormalities, except one case in which consolidation was diagnosed on chest radiography, whereas CT scan showed a lung abscess. Radiographs detected all 4 complex pleural effusions seen on CT scan, although it was not possible to characterize the effusions as simple or complex on the radiographs. Interventional procedures were required in all 15 patients, most commonly thoracentesis (n = 11) and chest tube drainage (n = 9). CONCLUSIONS: In children with S. milleri group pleuropulmonary infection, CT often demonstrates complex pleural effusions and lung abscesses, which usually require interventional procedures for effective treatment.

MDCT evaluation of pulmonary embolism in children and young adults following a lateral tunnel Fontan procedure: optimizing contrast-enhancement techniques.

BACKGROUND: Pulmonary embolism (PE) is a life-threatening thromboembolic complication in patients who have undergone a Fontan procedure for augmenting pulmonary blood flow in the setting of single-ventricle physiology. In patients following a Fontan procedure, lack of proper contrast agent mixing in the right atrium and sluggish, low-velocity blood flow within the Fontan circulation often results in suboptimal contrast enhancement within the pulmonary artery for evaluating PE. Unfortunately, there is a paucity of information describing the optimal contrast-enhancement technique with multidetector CT (MDCT) for evaluating PE in children and young adults following a Fontan procedure. OBJECTIVE: We illustrate the MDCT imaging findings of suboptimal contrast enhancement within the pulmonary artery, which can be mistaken for PE, in patients following a lateral Fontan procedure, and we discuss MDCT techniques to optimize contrast enhancement within the pulmonary artery in these patients for evaluating PE. MATERIALS AND METHODS: The MDCT imaging findings in pediatric and young adult patients following a lateral Fontan procedure and with clinically suspected PE are illustrated. We describe intravenous contrast agent injection techniques that can be used to optimize the contrast enhancement in the pulmonary artery in patients following a lateral Fontan procedure. RESULTS: The use of a suboptimal contrast-enhancement technique led to initial misdiagnosis and incomplete evaluation of PE in the three patients following a lateral Fontan procedure. Imaging in two patients showed that optimal evaluation of thrombosis in the Fontan pathway and PE in the pulmonary arteries can be successfully achieved with simultaneous upper- and lower-limb injections of contrast agent. CONCLUSION: This series demonstrates that suboptimal contrast enhancement can result in misdiagnosis or incomplete evaluation of PE in children and young adults following a lateral Fontan procedure. Careful attention to optimizing contrast enhancement during MDCT examination for evaluation of PE in these patients is essential to prevent misdiagnosis and incomplete evaluation.

DUETS (Dallas UtErus Transplant Study): The role of imaging in uterus transplantation.

OBJECTIVE: Uterus transplantation is rapidly becoming a viable clinical option for women with uterine-factor infertility and a desire for parenthood. Radiological imaging plays a central role in selecting the optimal living donors for uterus transplantation and serves to exclude any pathology and evaluate the uterine vasculature. The latter is the most important variable in the ultimate technical success of the uterus transplant. In this first report of imaging in the setting of uterus transplantation, we report our experience with living-donor selection, and the evolution of the imaging techniques that ultimately allowed a significant improvement in donor selection and transplant outcome. We also suggest a framework for preoperative imaging in uterus transplantation. METHODS: Between 2016 and 2018, 27 potential living donors were evaluated by imaging prior to uterine donation for uterus transplantation. Predonation imaging included a screening chest radiograph, dual-phase computed tomography (CT) angiograms of the abdomen and pelvis in the arterial and venous phases and pelvic sonography with Doppler. Seventeen potential donors additionally underwent multiphasic pelvic MR angiograms. The imaging performed was meant to display features of the vascular anatomy relevant for uterus transplantation. RESULTS: Out of the 27 potential live donors who were evaluated by imaging, 9 eventually donated their uterus for transplantation. The most frequent reason for exclusion was suboptimal quality of the vessels (33%), including small uterine arteries, the presence of atherosclerosis or small size/poor quality of the uterine or utero-ovarian veins, or both. The next most common reason was voluntary patient withdrawal or failure to complete the evaluation process (28%). Three potential donors (16.6%) were rejected for uterine factors, fibroids, and/or adenomyosis. Other reasons for donor rejection included ABO incompatibility and unfavorable psychological evaluation. CONCLUSION: Diagnostic imaging plays a crucial role in selecting appropriate potential donors, screening prospective recipients, planning the graft procedure, and following up on any graft or nongraft-related complications in both the donor and recipient after the transplantation procedure is performed. Contrast-enhanced CT and MR angiographies have complementary roles, especially when evaluating the donor for adequacy of the arterial and venous supply to the uterine graft and the experience gained from our series indicates that the inclusion of both modalities contributed directly to successful uterus transplant graft survival by selecting patients with favorable arterial and venous vasculature.

MDCT for computerized volumetry of pneumothoraces in pediatric patients.

RATIONALE AND OBJECTIVES: Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in multidetector computed tomography (MDCT) images for pediatric patients and to investigate the imaging parameters that may affect its accuracy. MATERIALS AND METHODS: Fifty-eight consecutive pediatric patients (mean age 12 ± 6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0-1.5 pitch, 0.6-5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 mL were visually identified in the left (n = 30) and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, MA) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs. RESULTS: The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 mL was 8.2%. For pneumothoraces ≥10 mL, ≥50 mL, and ≥200 mL, the mean differences were 7.7% (n = 57), 7.3% (n = 33), and 6.4% (n = 13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of -5.1% compared to manual volumetry. For all pneumothoraces ≥10 mL, the mean differences for slice thickness ≤1.25 mm, = 1.5 mm, and = 5.0 mm were 6.1% (n = 28), 3.5% (n = 10), and 12.2% (n = 19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n = 42, B70f) and 11.7% (n = 15, B31f), respectively. CONCLUSION: Our automated CAV scheme provides an accurate measurement of pneumothorax volume in MDCT images of pediatric patients. For accurate volumetric quantification of pneumothorax in children in MDCT images by use of the automated CAV scheme, we recommended reconstruction parameters based on a slice thickness ≤1.5 mm and the reconstruction kernel B70f.

Screening of asymptomatic children for tuberculosis is a lateral chest radiograph routinely indicated?

RATIONALE AND OBJECTIVES: The aim of this study was to determine whether a lateral chest radiograph provides additional diagnostic information to a posteroanterior (PA) radiograph in the screening of asymptomatic children with positive purified protein derivative (PPD) skin tests in a nonendemic area. MATERIALS AND METHODS: This was an Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective study of 605 consecutive pediatric patients (294 males, 311 females; mean age, 10.8 ± 5.2 years) with positive PPD skin test results, who underwent PA and lateral chest radiographs between July 2003 and May 2009 at a tertiary care pediatric hospital in a nonendemic area for tuberculosis (TB). Two pediatric radiologists independently reviewed each chest radiograph for evidence of abnormalities that may be indicative of acute or chronic TB infection. The reviewers first analyzed the PA radiograph alone and subsequently evaluated the PA and the lateral radiograph together to determine whether any observed abnormality was identified only on the lateral radiograph. When an abnormality was detected on both PA and lateral radiographs, the reviewers determined whether the abnormality on the lateral radiograph changed the reviewer's decision based on the PA radiograph alone. Assessment of nonconcordance between PA and lateral chest radiographs for each reviewer was evaluated by the McNemar test of matched binary pairs. Agreement between reviewers for detecting abnormalities on radiographs was evaluated by using the kappa (κ) statistic. RESULTS: The frequency of an abnormal chest radiograph related to TB was 1.8% (11/605). The PA radiograph showed abnormalities in all 11 (100%) children with radiographic abnormalities. Lateral radiographs showed abnormalities related to TB in 2 (18.2%) of 11 cases found to be abnormal on PA radiographs. Nine (81.8%) of 11 abnormalities on PA radiographs were not detected on the lateral chest radiographs. There was statistical evidence of nonconcordance between PA and lateral chest radiographs in detecting TB-related abnormalities for reviewer 1 (P < .001) and reviewer 2 (P = .004). In cases with abnormalities observed on both PA and lateral radiographs, there were no cases in which information obtained from the lateral chest radiograph resulted in a change in interpretation based on the PA radiograph alone. A high level of agreement was observed between the two independent reviewers in detecting TB-related abnormalities on PA radiographs (κ = 0.84, P < .001). CONCLUSIONS: A PA radiograph alone is sufficient for TB screening of asymptomatic pediatric patients with positive PPD skin test results in an area non-endemic for TB.