Computed tomography of pulmonary veins: review of congenital and acquired pathologies.

Newer-generation CT scanners with ultrawide detectors or dual sources offer millisecond image acquisition times and significantly decreased radiation doses compared to historical cardiac CT and CT angiography. This technology is capable of nearly freezing cardiac and respiratory motion. As a result, CT is increasingly used for diagnosing and monitoring cardiac and vascular abnormalities in the pediatric population. CT is particularly useful in the setting of pulmonary vein evaluation because it offers evaluation of the entire pulmonary venous system and lung parenchyma. In this article we review a spectrum of congenital and acquired pulmonary venous abnormalities, including potential etiologies, CT imaging findings and important factors of preoperative planning. In addition, we discuss optimization of CT techniques for evaluating the pulmonary veins.

Computed tomography angiography in children with cardiovascular disease: low dose techniques and image quality.

Dose reduction techniques for computed tomography angiography (CTA) in children with cardiovascular diseases have the potential of reducing risks of radiation-induced cancer. To evaluate effectiveness of these techniques, both radiation dose and image quality must be compared. While clinically practical methods of estimating effective dose are available, there are no generally accepted metrics for the assessment of image quality in CTA. We introduce a measurable and reproducible image quality index, CTA QI. Using this index, along with calculated effective dose, we test the hypothesis that volume scan CTA delivers comparable image quality at substantially reduced radiation dose when compared to helical CTA. CTA QI is a measure of intraluminal contrast variation in three-dimensions, and it is calculated from standardized measurements of means and standard deviations of Hounsfield units in the thoracic descending aorta. From institutional database, 83 studies of CTA for thoracic cardiovascular diseases were retrospectively identified. CTA QI values were independently measured by two radiologists and compared using correlation. CTA QI and DLP-derived effective dose were compared for the following groups: non-cardiac gated wide-detector and helical CTA, ECG-synchronized retrospective wide-detector and helical CTA, ECG-synchronized wide detector retrospective and target technique CTA. Statistical significance was evaluated with the Student-t test. The correlations of CTA QI values between the radiologists were 0.83 and 0.92 for non-gated studies and ECG-synchronized studies respectively. Comparing non-gated volume scan CTA to helical CTA, there was a radiation dose reduction of 69% (P < 0.0001) without a significant change in CTA QI (1.4 ± 1.0 vs. 1.9 ± 1.4, P = 0.13). Comparing retrospective ECG-synchronized wide-detector CTA to helical CTA, there was a radiation dose reduction of 46% (P < 0.0001) with and improvement in CTA QI (1.0 ± 0.8 vs. 3.7 ± 3.4, P < 0.01). Comparing ECG-synchronized wide-detector target CTA to retrospective CTA, there was a radiation dose reduction of 68% (P < 0.0001, but at the cost of a significant reduction in CTA QI (2.0 ± 1.0 vs. 0.8 ± 0.4, P < 0.0044). CTA QI is a simple, reproducible metric of image quality suited for comparing CTA studies. Using this quality index, we establish that CTA performed with wide-detector scan techniques can yield substantially lower radiation dose without compromising diagnostic imaging quality. A wide-detector target technique can further reduce effective dose compared to wide-detector retrospective ECG-synchronization, but with a reduction in image quality.

Evaluation and management of central venous access complications.

Venous access is 1 of the most common interventional procedures in the USA. Using image guidance in the last 2 decades, obtaining venous access has become increasingly routine, and the complications commonly associated with the procedure have significantly decreased. However, interventional radiologists still encounter both early and late complications routinely associated with both central and peripherally inserted access devices. This article discusses the most common and some unusual complications seen with the placement of these devices. We also briefly discuss the management of these complications.

A neonate with left pulmonary artery thrombosis and left lung hypoplasia: a case report.

INTRODUCTION: Spontaneous intrauterine arterial thrombosis and congenital pulmonary hypoplasia are rare conditions and have not been reported to occur together. The literature rather includes two reports of babies with neonatal pulmonary artery occlusion and post-infarction cysts of the lungs. CASE PRESENTATION: We report a case of a live Caucasian male newborn with left lung hypoplasia that occurred in association with left pulmonary artery thrombosis. Despite a critical neonatal course, including extracorporeal membrane oxygenation, this infant is alive and well at 18 months of age without any neurodevelopmental sequelae or reactive airway disease. CONCLUSION: This association suggests the possibility of an intrauterine vascular event between the fifth and eighth weeks of gestation during early pulmonary artery and lung development.

Imaging findings in 512 children following all-terrain vehicle injuries.

BACKGROUND: Injuries related to all-terrain vehicle (ATV) use by children have increased in recent years, and the pattern of these injuries is not well known among radiologists. OBJECTIVE: Our purpose was to identify different radiologically diagnosed injuries in children suffering ATV-related trauma and determine associations among various injuries as well as between injuries and outcome. MATERIALS AND METHODS: The study included 512 consecutive children suffering from ATV injuries treated at a tertiary care pediatric hospital. All imaging studies were reviewed and correlated with injury frequency and outcome using multivariate analysis. RESULTS: Head injuries occurred in 244 children (48%) and in five of six deaths. Calvarial skull fractures occurred in 104 children and were associated with brain, subdural and epidural injuries. Brain and orbit injuries were associated with long-term disability. A total of 227 extremity fractures were present in 172 children (34%). The femur was the most commonly fractured bone. Nine children had partial foot amputations. Multiorgan injuries occurred in nearly half of the 97 children with torso injuries. Determinants for long-term disability or death were head injuries (odds ratio 3.4) and extremity fractures (odds ratio 3.3). CONCLUSION: Head and extremity injuries are the two most common injuries in children suffering ATV injuries and are associated with long-term disability. ATV use by children is dangerous and is a significant threat to child safety.

Tricuspid valve magnetic resonance imaging phase contrast velocity-encoded flow quantification for follow up of tetralogy of Fallot.

Our purpose was to identify E- and A-wave flow patterns across the tricuspid valve in tetralogy of Fallot (TOF) patients following repair using magnetic resonance imaging phase contrast velocity-encoded flow quantification and to correlate them with measurements of right ventricle enlargement. The study included 33 children following TOF repair who had MRI examinations that included cine imaging to quantify ventricle size and function and flow analysis across the atria-ventricular valves to evaluate ventricle in-flow patterns. The E:A ratio was calculated for each patient and the population separated into alpha (E:A ratio > or = 1.4) and beta (E:A ratio < 1.4) groups. Significant association was present between the beta group and right ventricle end diastolic volume index > or =140 ml/m(2) (P = 0.046), right ventricle end systolic volume index > or =70 ml/m(2) (P = 0.02), and end diastolic volume right ventricle to left ventricle > or = 2.0 (P = 0.003). A reduction in the E:A wave ratio across the tricuspid valve is associated with right ventricle diastolic dysfunction and correlated well in our study with right ventricle enlargement. This may be a useful criterion for determining the timing of valved pulmonary conduit surgery in children following TOF repair.

A dual contrast injection technique for multidetector computed tomography angiography of Fontan procedures.

Extracardiac and lateral tunnel Fontan palliations result in caval venous return to the branch pulmonary arteries without prior blood mixing in the right atrium. Single contrast injection techniques result in suboptimal pulmonary computed tomography angiography since blood streaming results in asymmetric pulmonary flow of injected contrast. We used a dual injection technique--dorsal foot vein and upper extremity vein to achieve optimal simultaneous opacification of the inferior and superior venae cavae and branch pulmonary arteries. The resulting dataset allowed for excellent 3D volume renderings and multiplanar reformat images useful for stenosis, aneurysm, and metal stent evaluation.

Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis.

BACKGROUND: Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. OBJECTIVE: Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. MATERIALS AND METHODS: Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 degrees , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). RESULTS: Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. CONCLUSION: It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis.

All-terrain vehicle injuries in children: injury patterns and prognostic implications.

BACKGROUND: All-terrain vehicle (ATV) accidents are common in children. Our purpose was to identify imaging patterns associated with ATV injuries in children. PATIENTS AND METHODS: The study group comprised 141 consecutive children admitted to a tertiary pediatric hospital following ATV accidents. Medical records were evaluated for demographics and patient outcome. All imaging studies were reviewed and abnormalities cataloged. RESULTS: Extremity fractures were the most common injuries in our study, occurring in 38% of patients. Lower extremity fractures were more common than upper extremity fractures. Partial foot amputation, an unusual injury, was present in three children. Torso injuries were present in 22% of the children. Pulmonary contusions, but not abdominal injuries, were significantly associated with long-term disability or death (p=0.01). Brain injuries occurred in 19% of the children and were significantly associated with death or long-term disability (p=<0.001). No association of brain injury and skull fracture was present. CONCLUSIONS: A wide variety of injuries were identified in children with ATV accidents. Partial foot amputation, an unusual injury, was identified in three children. Brain injuries and lung contusions detected by computed tomography were associated with long-term disability and death. Radiologists need to be aware of injuries associated with ATV accidents.