Pediatric Considerations in Computed Tomographic Angiography.

Cardiovascular disease in children comprises a diverse collection of diseases involving multiple organ systems. Abnormality in children is predominately congenital but also may be acquired. Although noninvasive vascular imaging modalities such as magnetic resonance angiography and ultrasound lack ionizing radiation, with improving technology and an increased focus on radiation dose reduction, computed tomographic angiography (CTA) continues to have a role in evaluating cardiovascular disease in pediatric patients. This review focuses on specific considerations of CTA that the radiologist or ordering provider should consider when imaging the pediatric cardiovascular system.

Ultrasound of the pediatric chest.

Historically, the evaluation of the pediatric chest has been accomplished via CT and conventional radiography. Our objective is to discuss and illustrate the role of US as a non-ionizing radiation alternative in the evaluation of the pediatric chest. US is a valuable tool in the evaluation of the pediatric chest. It can be used as a first-line modality in the evaluation of superficial lumps and bumps of the chest wall, diaphragmatic motion, the thymus and pleural effusions, and it can play a valuable secondary role in evaluation of mediastinal masses and pulmonary parenchymal disease.

Esophageal obstruction and intracardiac "mass" in association with omphalocele closure.

Patients with large omphaloceles are subject to anatomical displacement and morphological distorsion after surgical repair. We report 2 such complications in an infant after repair of a giant omphalocele that contained both liver and bowel. Esophageal obstruction resulted from sharp, anterior angulation of the distal esophagus that hindered placement of a feeding tube in the neonatal period. At 1 year of age, routine cardiac evaluation led to the discovery of a "mass" within the heart caused by invagination of a tongue of liver tissue into the right atrium. Knowledge of these less well-recognized anatomical variations is important to avoid unnecessary interventions.

Evaluation of pulmonary embolism in a pediatric population with high clinical suspicion.

BACKGROUND: Pulmonary embolism (PE) is an underdiagnosed entity in the pediatric population in part because of the low level of suspicion and awareness in the clinical world. OBJECTIVE: To examine its relative prevalence, associated risk factors and imaging features in our pediatric population. MATERIALS AND METHODS: A total of 92 patients age 21 years and younger with a high clinical suspicion of PE and who had available radiographic studies were identified from January 2003 to September 2006. Patients with a positive CT scan or a high probability ventilation/perfusion scan formed the case group; patients with a high clinical suspicion of PE and no radiographic evidence of PE or deep venous thrombosis (DVT), randomly matched in age and sex, became the matched control group. We reviewed the charts of both groups and analyzed the imaging studies. RESULTS: In our hospital, the prevalence of PE in patients with a strong suspicion of PE was 14%. The overall prevalence of thromboembolic disease (PE and/or DVT) was 25%. Recent surgery or orthopedic procedure, blood dyscrasias and contraceptive use were more common in patients with PE. No child died of PE in our study. The youngest child with PE in our study was 13 years. Girls were twice as likely to develop PE as boys. CONCLUSION: PE is a relatively common diagnosis in our tertiary care pediatric population when the clinical suspicion is high. We suggest increased awareness and index of suspicion in order to initiate prompt diagnostic imaging and treatment.

Congenital high airway obstruction syndrome: MR/US findings, effect on management, and outcome.

BACKGROUND: Congenital high airway obstruction syndrome (CHAOS) is a rare disorder defined as any fetal abnormality that obstructs the larynx or trachea. Prompt airway intervention at delivery after accurate prenatal diagnosis may allow survival of this otherwise fatal condition. OBJECTIVE: To identify prenatal MRI findings in CHAOS, to compare these findings with those of fetal US, to determine if imaging alters diagnosis and management decisions, and to correlate prenatal with postnatal imaging findings. MATERIALS AND METHODS: Records and MRI scans of ten fetuses with CHAOS were reviewed, and the findings correlated with outside and same-day fetal US and postnatal imaging findings. Fetal lung volumes were measured on MRI scans. RESULTS: Large lung volumes were found in 90% of the fetuses. Increased lung signal intensity, inverted diaphragm, and a dilated, fluid-filled lower airway were identified in all. The obstruction level was identified in 90%. MRI changed screening US diagnosis in 70%, but was concordant with the tertiary care US imaging in 90%. Seven fetuses were terminated or died in utero, and three fetuses survived after ex utero intrapartum tracheostomy placement. Autopsy or bronchoscopy performed in 60% confirmed CHAOS. Postnatal chest radiographs and CT showed hyperinflation, while US and fluoroscopy showed diminished diaphragmatic motion. CONCLUSION: MRI demonstrates large lung volumes, increased lung signal intensity, inverted diaphragm, and dilated fluid-filled lower airway, and usually identifies the obstruction level. The degree of correlation between MRI and tertiary prenatal US is high, but CHAOS is frequently misdiagnosed on screening US. Correct diagnosis may enable planned airway management. Voluminous lungs and diaphragmatic abnormalities persist on postnatal imaging.

Assessment of age-related changes in abdominal organ structure and function with computed tomography and positron emission tomography.

With the size of the aged population in the United States expected to grow considerably during the next several decades, the number of imaging studies performed on such aged individuals will similarly increase. Thus, it is important to understand normal age-related changes in the structural and functional imaging appearance of the abdominal organs. We therefore present preliminary data and a review of the literature relevant to structural and functional changes in the abdominal organs of children and older adults. In a retrospective study of both adult and pediatric populations, we used computed tomography (CT), positron emission tomography (PET), and PET/CT imaging to investigate age-associated changes in size, attenuation, and metabolic function of the abdominal organs. Organs of interest include the liver, spleen, pancreas, kidneys, adrenal glands, stomach, small bowel, colon, and rectum. Although volumes of adult liver, spleen, pancreas, and kidneys do not change significantly with age, adult left and right adrenal gland volumes do significantly increase with age (r = 0.2823, P = 0.0334, and r = 0.3676, P = 0.0049, respectively). Also, the attenuation of adult liver (r = -0.2122, P = 0.0412), spleen (r = -0.4508, P < 0.0001), pancreas (r = -0.5124, P = 0.0007), and left and right adrenal gland (r = -0.5835, P < 0.0001 and r = -0.6135, P < 0.0001, respectively) decrease significantly with increasing age. Every organ studied in the pediatric population demonstrates a positive association between organ volume and age. Significant age-related changes in organ function are noted in the adult liver and small bowel, with the liver demonstrating a positive association between metabolic activity and age (r = 0.4434, P = 0.0029) and the small bowel showing an inverse association between mean small bowel standardize uptake value and age (r = -0.2435, P = 0.0174). Also, the maximum overall small bowel and colon metabolic activity in children increases with age (r = 0.6478, P = 0.0008). None of the other organs studied (ie, spleen, pancreas, adrenal glands, stomach, colon, rectum) demonstrate significant changes in metabolism with advancing age. The metabolic volumetric product (calculated as the product of organ volume and mean organ SUV) of the liver and spleen does not change significantly with age. In conclusion, various abdominal organs demonstrate differential changes in volume, attenuation, and/or metabolism with increasing age in pediatric and adult populations.

Assessment of age-related morphological and functional changes of selected structures of the head and neck by computed tomography, magnetic resonance imaging, and positron emission tomography.

The head and neck is a complex anatomical region that can be evaluated using many imaging modalities. It is important to discern normal structures from ones that are affected by disease and to study how these structures change in their morphological and functional properties with aging. Therefore, using magnetic resonance imaging (MRI), we retrospectively evaluated volumes of the parotid glands, submandibular glands, thyroid gland, tongue, soft palate, and lingual tonsils in 64 subjects ages 13 to 81 years. Volume, attenuation (HU), and metabolic activity (maximum SUV) of the parotid, submandibular, and thyroid glands were assessed retrospectively using positron emission tomography/computed tomography (PET/CT) imaging in 35 subjects ages 10 to 76 years. Metabolic activity (maximum SUV) of the parotid, submandibular, and sublingual glands; tongue; adenoids; and tonsils (lingual and palatine) were evaluated retrospectively using PET imaging in 15 subjects ages 6 to 20 years. Metabolic volumetric products of the parotid, submandibular, and thyroid gland were calculated and analyzed with increasing age in subjects who underwent PET/CT imaging. Structures that exhibited statistically significant changes (P < 0.05) with increasing age included the submandibular glands, thyroid gland, soft palate, and adenoids. The CT volume of the submandibular glands increased with age, and the attenuation decreased with age with statistical significance. The thyroid gland volume, as measured using MRI, showed a statistically significant decrease with aging. The volume of the soft palate and lingual tonsils, as measured by MRI, exhibited a statistically significant decrease in volume with aging. The maximum SUV of the adenoids demonstrated a statistically significant decrease with aging. In conclusion, CT, MRI, and PET may be used to quantitatively and qualitatively assess structures of the head and neck and are useful in the assessment of structural and functional changes of these structures with aging.

Detection of age-related changes in thoracic structure and function by computed tomography, magnetic resonance imaging, and positron emission tomography.

It is useful to understand the normal changes in structure and function in the thorax that occur with age. Thus, we present the following quantitative preliminary data obtained from retrospective quantitative analysis of computed tomography (CT) and positron emission tomography (PET) examinations in subjects 0 to 90 years of age: Mean lung standard uptake values were found to significantly increase with increasing age and with increasing body mass index (BMI). Mean lung attenuation was seen to statistically significantly decrease with increasing age in subjects who had a CT scan, had a nonsignificant tendency to decrease with increasing age in subjects with a PET/CT scan, had a nonsignificant tendency to increase with increasing BMI, and was seen to significantly increase with increasing mean lung standard uptake values. Mean lung volumes were not noted to significantly change with increasing age in adult subjects whether or not they were normalized to the craniocaudal thoracic lengths, although mean lung volumes significantly increased with increasing age in pediatric subjects. Mean lung volumes had a nonsignificant tendency to decrease with increasing BMI, although normalized mean lung volumes significantly decreased with increasing BMI. Lung metabolic volumetric products were not noted to significantly change with increasing BMI or with increasing age. In this work, we also review the literature regarding normal structural and functional changes in the thorax with age.

Imaging the pediatric prostate.

The prostate gland is not often the target of imaging in children but may be imaged during investigation of symptoms related to the lower genitourinary tract such as hematuria, urinary retention, dysuria, and incontinence or during an evaluation for suspected congenital anomalies. Ultrasound and voiding cystourethrography are useful for initial evaluation of congenital and neoplastic disorders of the prostate. MR imaging and CT are useful in delineating more detailed anatomy before surgical planning and in determining the organ of origin in a patient who has a large pelvic mass.

Accuracy of magnetic resonance imaging in predicting absence of fixation of head and neck cancer to the prevertebral space.

BACKGROUND: The purpose of this study was to determine the preoperative accuracy of preservation of the retropharyngeal fat plane on magnetic resonance (MR) images in predicting the absence of fixation or extension of head and neck carcinomas to the prevertebral space. METHODS: The MR images of 75 patients with T3 or T4 primary pharyngeal or laryngeal cancers seen over a 5-year period and treated at our Head and Neck Cancer Center were retrospectively reviewed. The MR images were independently and blindly evaluated by two head and neck radiologists for preservation of the retropharyngeal fat plane between the tumor and prevertebral musculature. In cases in which the fat was preserved, the prevertebral muscle complex was assessed for the presence of T2 hyperintensity and enhancement. All patients underwent panendoscopy, surgery, or both. RESULTS: Forty of 75 patients had preservation of the retropharyngeal fat plane between the tumor and the prevertebral compartment on T1-weighted images. In all 40 cases, the prevertebral muscles had a normal appearance on T2-weighted and enhanced MR images. Intraoperative assessment revealed absence of fixation of tumor to the prevertebral fascia in 39 of 40 cases, and these tumors were resectable. CONCLUSION: In patients with advanced head and neck carcinomas, preservation of the fat between the tumor and the prevertebral musculature on unenhanced T1-weighted images reliably predicts absence of prevertebral space fixation.

Epiglottic carcinoma as a cause of laryngeal penetration and aspiration.

OBJECTIVE. The purpose of our investigation was to review a series of patients with epiglottic carcinoma to elucidate the clinical and videofluoroscopic findings in these individuals. CONCLUSION. Patients with epiglottic carcinoma often present with symptoms of aspiration or pharyngeal dysphagia of relatively brief duration in the absence of a preexisting neurologic disease. In this clinical setting, barium studies are useful not only for detecting the epiglottic carcinoma but also for delineating the presence and mechanism of laryngeal penetration or tracheobronchial aspiration.