Assessment of infant gonadal dose irradiated from urine-contaminated diapers during diuretic renal scintigraphy.

OBJECTIVE: To estimate the gonadal doses irradiated from urine- contaminated diapers during diuretic renal scintigraphy. METHODS: Images of 31 patients (18 males and 13 females) with urine-contaminated diapers during 99m Tc-MAG3 renal scintigraphy were analyzed. The count rate of the diapers was converted into a time-activity curve based on the calibrated factor of the gamma camera system. The cumulative activity was determined from the area under the curve. By incorporating dose per unit cumulative activity pre-calculated from Monte Carlo simulation with 0-year phantom, the gonadal dose irradiated from diaper was calculated. To assess the degree of this additionally introduced dose from diapers, the calculated gonadal dose was compared to the internal gonadal dose from injected radiotracer activity. RESULTS: The cumulative activities irradiated from urine-contaminated diapers were 1.12 E04 ±â€…1.29E04 MBq.s in male infants, which was nearly half of the 1.94 E04 ±â€…1.80E04 MBq.s ( P  = 0.15) in female infants. However, the absorbed doses for testes in male infants were 7.37E-01 ±â€…8.50E-01 mGy, which was approximately 10 times the 6.38E-02 ±â€…5.94E-02 mGy for ovaries in female infants ( P  < 0.01). The diaper-introduced dose for testes and ovaries was 91.7% and 3.9% of the gonadal doses from the injected activity in patients with normal renal function, and 99.0% and 4.3% of those in patients with abnormal renal function. CONCLUSION: Urine-contaminated diapers introduced additional radiation doses to infant patients during 99m Tc-MAG3 renal scintigraphy. The gonadal doses were of significance in male infants who had nearly double the absorbed dose for the testes.

Accuracy of Chest Computed Tomography in Distinguishing Cystic Pleuropulmonary Blastoma From Benign Congenital Lung Malformations in Children.

Importance: The ability of computed tomography (CT) to distinguish between benign congenital lung malformations and malignant cystic pleuropulmonary blastomas (PPBs) is unclear. Objective: To assess whether chest CT can detect malignant tumors among postnatally detected lung lesions in children. Design, Setting, and Participants: This retrospective multicenter case-control study used a consortium database of 521 pathologically confirmed primary lung lesions from January 1, 2009, through December 31, 2015, to assess diagnostic accuracy. Preoperative CT scans of children with cystic PPB (cases) were selected and age-matched with CT scans from patients with postnatally detected congenital lung malformations (controls). Statistical analysis was performed from January 18 to September 6, 2020. Preoperative CT scans were interpreted independently by 9 experienced pediatric radiologists in a blinded fashion and analyzed from January 24, 2019, to September 6, 2020. Main Outcomes and Measures: Accuracy, sensitivity, and specificity of CT in correctly identifying children with malignant tumors. Results: Among 477 CT scans identified (282 boys [59%]; median age at CT, 3.6 months [IQR, 1.2-7.2 months]; median age at resection, 6.9 months [IQR, 4.2-12.8 months]), 40 cases were extensively reviewed; 9 cases (23%) had pathologically confirmed cystic PPB. The median age at CT was 7.3 months (IQR, 2.9-22.4 months), and median age at resection was 8.7 months (IQR, 5.0-24.4 months). The sensitivity of CT for detecting PPB was 58%, and the specificity was 83%. High suspicion for malignancy correlated with PPB pathology (odds ratio, 13.5; 95% CI, 2.7-67.3; P = .002). There was poor interrater reliability (κ = 0.36 [range, 0.06-0.64]; P < .001) and no significant difference in specific imaging characteristics between PPB and benign cystic lesions. The overall accuracy rate for distinguishing benign vs malignant lesions was 81%. Conclusions and Relevance: This study suggests that chest CT, the current criterion standard imaging modality to assess the lung parenchyma, may not accurately and reliably distinguish PPB from benign congenital lung malformations in children. In any cystic lung lesion without a prenatal diagnosis, operative management to confirm pathologic diagnosis is warranted.

Birth-related subdural hemorrhage: prevalence and imaging morphology.

BACKGROUND: Birth trauma accounts for 1-2% of the mortality in newborns with significant intracranial injuries presenting in the immediate postnatal period. However, a significant number of asymptomatic neonates harbor birth-related intracranial hemorrhage (ICH), with birth-related subdural hemorrhage (SDH) being a common occurrence on infant brain CT and MRI studies performed as a standard of care for a variety of reasons. Although clinically insignificant, birth-related SDH is frequently brought up in courts as an alternative explanation for SDH in suspected abusive head trauma. OBJECTIVE: The aim of this study was to determine prevalence, imaging morphology and distribution of birth-related SDHs on brain CT and MRI studies obtained as a standard of care in infants up to 1 month old. We further tried to ascertain the relationship of birth-related SDHs with mode of delivery and birth weight. MATERIALS AND METHODS: Infants up to the age of 1 month who had CT or MRI of the brain performed between Jan. 1, 2018, and March 29, 2020, were included in this retrospective observational study. In addition to the imaging data, we reviewed clinical history, birth history including birth weight and mode of delivery, and final diagnoses. RESULTS: Two hundred six infants younger than 30 days (range 0-29 days, mean 11.9 days, median 11 days and standard deviation [SD] 8.4 days) had a CT or MRI study during the study period. Among these, 58 infants were excluded as per the exclusion criteria. Among the included 148 infants, 88 (59.5%) had no imaging evidence of SDH. An additional 56 (37.8%) infants were assessed as having birth-related SDH based on review of clinical data. Within the birth-related SDH cohort (56 infants), only supratentorial SDH was identified in 5 (8.9%), only infratentorial SDH was identified in 14 (25%), while SDHs within both compartments were identified in 37 (66.1%) infants. The most common location for supratentorial birth-related SDH was along the occipital lobes (31/42, 73.8%), with other common locations being along the posterior interhemispheric fissure (30/42, 71.4%) and fronto-parietal convexity (9/42, 21.4%). The distribution of posterior fossa SDH was along the tentorium (38/51, 74.5%), along the cerebellum (38/51, 74.5%) and in both the locations (25/51, 49.0%). The rate of SDH was significantly higher in vaginal delivery group (46/84, 54.7%) as compared to caesarean section group (10/57, 17.5%) (P<0.05). We did not find any statistically significant difference between the birth weights of normal and birth-related SDH cohorts (P>0.05). CONCLUSION: Birth-related SDH is a common occurrence, with our study suggesting a prevalence of 37.8%. The most common distribution of birth-related SDH is within both the supra- and infratentorial compartments (66.1%) followed by infratentorial compartment (25%). The rate of birth-related SDH was significantly higher in vaginal delivery group as compared to caesarean section group.

Ambiguous Findings on Radiographs.

Findings with uncertain clinical significance are frequently encountered on radiographs. A structure or opacity visible on radiographs could be due to several causes ranging from artifact or external structure to malignancy or a life-threatening process. The approach that a radiologist chooses to address ambiguous findings can have a significant impact on a patient's health. In this article we discuss the causes and impact of ambiguous findings on radiographs. We also discuss the various strategies radiologists can adopt to maximize clinical value and, when needed, reach a definite diagnosis.

Clinical utilization of whole-body PET/MRI in childhood sarcoma.

Hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI) has emerged as a useful tool that combines the superior tissue contrast of MRI with the targeted functional imaging of PET. In the assessment of sarcomas in children, PET/MRI has the potential to serve as a single point of service, allowing superior anatomical imaging and evaluation of metabolic uptake during one imaging session. In this pictorial essay, we review our preliminary experience with PET/MRI in the evaluation of pediatric sarcoma. The limitations and contraindications of PET/MRI are also discussed.

Normal FDG uptake in the adenoids and palatine tonsils in children on PET/MRI.

BACKGROUND: Information about the normal [F-18]2-fluoro-2-deoxyglucose (FDG) uptake in the adenoids and palatine tonsils in children is not available. OBJECTIVE: The purpose of this study was to report the range of standardized uptake values (SUVs) in the normal adenoids and palatine tonsils in children, assess for the degree of asymmetry between the right and left tonsils and evaluate for the correlation of SUVs between the adenoids and tonsils. MATERIALS AND METHODS: Pediatric patients who had had an FDG positron emission tomography (PET)/magnetic resonance imaging (MRI) brain study in our institution from January 2018 to March 2019 were identified. Patients with a history of malignancy, adenoidectomy and/or tonsillectomy, incomplete imaging coverage of Waldeyer ring and the presence of artifact on PET/MRI were excluded. Two pediatric radiologists independently measured the mean and maximum SUVs of the right tonsil, left tonsil and the adenoids. Range, mean and standard deviation were calculated for all measurements. Ratios of SUV of the left to right tonsils and the adenoids to the tonsils were calculated. The paired t-test and Pearson's correlation test were used for statistical analysis with a P-value <0.05 considered to be significant. RESULTS: Sixty-one PET/MRI brain scans were performed in our institution during the study period. After reviewing for exclusion criteria, 41 patients were included in the study (mean age: 10.1 years, range: 2-17 years; 19 boys and 22 girls). The mean SUV was 5.30±1.57 in the right tonsil, 5.25±1.53 in the left tonsil and 4.56±1.90 in the adenoids. The maximum SUV was 8.47±2.22 in the right tonsil, 8.45±2.18 in the left tonsil and 7.59±2.94 in the adenoids. The difference between the SUVs of the right and left tonsil was not statistically significant (P=0.69 for mean SUV and P=0.90 for maximum SUV). There was a statistically significant moderately positive correlation between the FDG uptake in the adenoids and the right and left tonsil for both mean and maximum SUV (r=0.36-0.41; P=0.008-0.022). CONCLUSION: There is a wide variation of FDG uptake in the normal tonsils and adenoids in children. Uptake in the right and left tonsils is not significantly different. There is a moderately positive correlation between the FDG uptake in the adenoids and the tonsils.

E-cigarette, or vaping, product use-associated lung injury in adolescents: a review of imaging features.

BACKGROUND: There has been a recent increase in recognition of lung disease related to the use of electronic cigarettes (called "vaping"). These patients present with acute respiratory illness following exposure to vaporized cannabis or nicotine products and sometimes require hospitalization and intensive care. We describe the imaging findings of this disease entity in the pediatric population. OBJECTIVE: To describe the radiologic findings of lung injury associated with electronic cigarette use (vaping) in the adolescent pediatric population. MATERIALS AND METHODS: We identified all adolescents with acute respiratory illness and a history of electronic cigarette use who presented at our institution within a 3-month period (June 2019 through August 2019). We excluded adolescents with potential intercurrent pulmonary disease. We reviewed the charts for symptomatology and laboratory and pathology data. In addition, we reviewed the chest radiographs and chest CTs of these adolescents. RESULTS: The review group consisted of 12 teenage pediatric patients (10 boys and 2 girls; mean age 16.9 years, range 16.0-17.7 years) with acute respiratory illness found to have a temporal association with electronic cigarette use for cannabis products, nicotine, or both. Other etiologies for illness in these adolescents had been excluded by clinical and laboratory evaluation. All of the adolescents were admitted to the hospital for treatment. The clinical presentations included dyspnea, abdominal pain and constitutional symptoms. Pulmonary function testing that was performed in all patients during admission or follow-up demonstrated reduced diffusion capacity in 4/12 (33%), an obstructive ventilatory pattern in 4/12 (33%), a restrictive pattern in 1/12 (8%), and a mixed obstructive and restrictive pattern in 2/12 (17%) adolescents. Bronchoalveolar lavage studies, performed in 9 of the 12 adolescents, revealed inflammatory cells and lipid-laden macrophages. All of the patients underwent CT of the chest; the findings were notable for centrilobular ground-glass nodules (11/12; 92%) and confluent ground-glass opacities (12/12; 100%), with frequent subpleural sparing (9/12; 75%). Additionally, 6/12 (50%) adolescents demonstrated small pleural effusions; 6/12 (50%) had mild bronchial wall thickening; 9/12 (75%) had enlarged hilar or mediastinal lymph nodes; and 2/12 (17%) had a small pericardial effusion. CONCLUSION: As seen in our teenage population, e-cigarette, or vaping, product use-associated lung injury (EVALI) is characterized by centrilobular ground-glass nodules and ground-glass opacities with subpleural sparing. The imaging findings are most consistent with acute lung injury resulting from toxic inhalation. Because adolescent pediatric patients might not be forthcoming with their history of electronic cigarette use, it is important for the pediatric radiologist to be aware of the imaging patterns of this disease.

Fluoroscopic Diagnosis of Malrotation: Technique, Challenges, and Trouble Shooting.

A fluoroscopic upper gastrointestinal series is the most commonly used investigation for the diagnosis of malrotation and midgut volvulus. However, both false positive and false negative results can occur causing diagnostic confusion. Several physiologic states and pathologic conditions can mimic fluoroscopic appearance of malrotation. Proper fluoroscopic technique is essential to maximize diagnostic accuracy. In this pictorial essay, we discuss common diagnostic challenges in the diagnosis of malrotation and strategies radiologists can use to clarify the diagnosis in equivocal cases.

Complications of percutaneous gastrostomy and gastrojejunostomy tubes in children.

Percutaneous feeding tubes are generally considered a safe option for enteral feeding and are widely used in children who require long-term nutritional support. However, complications are not infrequent and can range from bothersome to life-threatening. Radiologists should be familiar with the imaging appearances of potential complications for optimal patient care. In this review, we discuss radiologic appearances of common complications and less frequent but serious complications related to percutaneous feeding tubes. Additionally, as fluoroscopic feeding tube evaluation is often requested as the initial imaging study, we also discuss the fluoroscopic appearances of some uncommon complications.

Avoiding misdiagnosis in postnatal presentation of congenital diaphragmatic hernia: A report of two cases and review of radiologic features.

Diagnosis of a congenital diaphragmatic hernia after the first day of life can be challenging. The clinical symptoms are often nonspecific, and initial radiographic findings in these patients may mimic many other acute chest conditions, including pneumonia, pleural effusion, and pneumothorax. In turn, diagnostic uncertainty may expose the patient to unnecessary and even potentially harmful interventions such as thoracostomy tube placement. As such, it is imperative that radiologists remain aware of this uncommon entity and recognize imaging findings which may provide clues to its diagnosis.

Spontaneous Intracranial Hypotension With Site of Leak Detected Only After 111In-DTPA Cisternogram.

A 54-year-old man with a 3-week history of orthostatic headache and acute on chronic subdural hematoma presented with imaging findings suggestive of spontaneous intracranial hypotension. Three myelograms were negative for leak, and nontargeted epidural blood patches did not result in symptom relief. A cerebrospinal fluid leak study using In-DTPA with SPECT/CT demonstrated a focal area of asymmetric activity at the left C2 nerve root. A left C2 root tie-off, targeted epidural blood patch, and Dura seal glue resulted in resolution of patient symptomatology highlighting the importance of fused SPECT/CT images in detection of an occult cerebral spinal fluid leak.

Why Thyroid Surgeons Are Frustrated with Radiologists: Lessons Learned from Pre- and Postoperative US.

Optimal treatment of thyroid cancer is highly dependent on accurate staging of the extent of disease at presentation. Preoperative ultrasonography (US) is the most sensitive method for detecting metastatic lymph nodes and is recommended as part of the standard preoperative workup. Missed findings on preoperative scans may lead to understaging and inadequate surgical management, which subsequently predispose these patients to residual disease postoperatively and a higher risk for recurrence, possibly requiring repeat surgery. Traditionally, thyroid US for pre- and postoperative staging has been performed by radiologists. However, there is a growing trend away from radiologist-performed US in favor of surgeon-performed US. Recent surgical and endocrinology literature has shown that, when compared with surgeon-performed US, radiologist-performed preoperative staging US is less accurate and is inadequate for presurgical planning, with higher local recurrence rates. This review highlights the importance of accurate preoperative US for patients with differentiated thyroid cancer, with specific attention to deficiencies that exist in general radiology department thyroid US reports. We present a standardized approach to neck US reporting that incorporates the newly updated 2015 recommendations from the American Thyroid Association and also addresses the pertinent questions for thyroid surgeons. By ensuring comprehensive preoperative assessment and improving thyroid US reporting, we seek to improve patient access to optimized care. ©RSNA, 2016.

Role of diffusion-weighted MRI in acute pyelonephritis: a prospective study.

BACKGROUND: Imaging is vital in diagnosis of complicated pyelonephritis and has been traditionally performed by computed tomography (CT). However, CT with contrast agents cannot be performed in patients with renal failure. Diffusion-weighted (DW) magnetic resonance imaging (MRI) has the potential to overcome this disadvantage. PURPOSE: To prospectively evaluate the accuracy of quantitative apparent diffusion coefficient (ADC) values to differentiate nephritis from renal abscesses in patients with pyelonephritis. MATERIAL AND METHODS: Forty-two patients with clinical and laboratory diagnosis of pyelonephritis underwent CT and DW MRI examinations. Diffusion images were obtained by using a non-breath-hold, single-shot echo-planar sequence with b values of 0, 600, and 1000 s/mm(2). Circular regions of interest were places on areas of nephritis, normal renal parenchyma, and renal abscesses as localized by CT and DW MRI images to obtain the ADC values of each of these regions. The ADC values of these three different tissue types were statistically compared using the one-way analysis of variance test for statistical significance. A P value <0.05 was considered to be statistically significant. RESULTS: For the diagnosis of pyelonephritis, DW MRI had a higher sensitivity of 95.3% as compared to that of non-contrast CT (66.7%) and contrast-enhanced CT (88.1%). Areas of nephritis had significantly lower ADC values (P < 0.001) than the normal renal cortical parenchyma. Also, renal abscesses had significantly lower ADC values (P < 0.001) than areas of nephritis. However, CT is more useful for the diagnosis of renal calculi and emphysematous pyelonephritis. CONCLUSION: ADC values derived from the diffusion sequence have significantly lower values in renal abscesses than in areas of nephritis.