George S. Bisset

Repair of Congenital Heart Disease: A Primer–Part 1

Advances in the surgical management of congenital heart disease have led to enhanced patient survival and quality of life. Improvements in technology in computed tomography and magnetic resonance imaging have resulted in increasing use of cross-sectional imaging in these patients. Perioperative care in these patients requires that radiologists have an understanding of the surgical treatment and the resultant postoperative anatomy. Because many of these patients with treated congenital heart disease are being followed into the 4th and 5th decades of life, this is information that will fall within the domain of the radiologist who deals with adults. This review, which is presented in two parts, covers the major surgical procedures used for the treatment of congenital heart disease, and will be presented in two parts. In part 1, median sternotomy and its complications, palliative procedures, and complex repairs are discussed.

Prospective Comparison of MR Imaging and US for the Diagnosis of Pediatric Appendicitis

PURPOSE To prospectively compare nonenhanced magnetic resonance (MR) imaging and ultrasonography (US) for the diagnosis of pediatric appendicitis. MATERIALS AND METHODS This HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained from the patients parent or guardian. Eighty-one patients (34 male, 47 female; mean age, 12.3 years ± 3.5 [standard deviation]; range, 4-17 years) were enrolled in this prospective study. All patients underwent right lower quadrant US and nonenhanced, nonsedated abdominopelvic MR imaging examinations. Two pediatric radiologists blinded to US results independently reviewed the MR images. MR imaging and US findings were designated positive, negative, or equivocal for acute appendicitis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for MR imaging and US and compared by using two-sided McNemar test or the score statistics specified by Leisenring. Kappa statistics were generated to determine intertechnique agreement between MR imaging and US and interobserver agreement between the two primary MR imaging readers. RESULTS Thirty (37%) patients had pathologically proved acute appendicitis. When equivocal interpretations were designated positive, sensitivity was 93.3% for MR imaging (95% confidence interval [CI]: 77.9%, 99.2%) and 90.0% for US (95% CI: 73.5%, 97.9%), P > .99; specificity was 98% for MR imaging (95% CI: 89.6%, 100%) and 86.3% for US (95% CI:73.7%, 94.3%), P = .03; PPV was 96.5% for MR imaging (95% CI: 82.2%, 99.9%) and 79.4% for US (95% CI: 62.1%, 91.3%), P = .007; and NPV was 96.2% for MR imaging (95% CI: 86.8%, 99.5%) and 93.6% for US (95% CI: 82.4%, 98.7%), P = .45, with substantial intertechnique (κ = 0.77; 95% CI: 0.63, 0.90) and interobserver (κ = 0.76; 95% CI: 0.61, 0.91) agreement. When equivocal interpretations were designated negative, MR imaging sensitivity, specificity, PPV, and NPV were unchanged. For US, sensitivity was 86.7% (95% CI: 69.3%, 96.2%), P = .5; specificity was 100% (95% CI: 93.0%, 100%), P > .99; PPV was 100% (95% CI: 86.8%, 100%), P = .31; and NPV was 92.7% (95% CI: 82.4%, 98.0%), P = .16, with almost perfect intertechnique (κ = 0.92; 95% CI: 0.83, 1.00) and substantial interobserver (κ = 0.72; 95% CI: 0.58, 0.87) agreement. CONCLUSION Nonenhanced MR imaging demonstrates high diagnostic performance similar to that of US for suspected pediatric appendicitis.

Late Results of Reconstruction of the Right Ventricular Outflow Tract with Porcine Xenografts in Children

Thirty-three children, aged 2.5 to 17.5 years (mean, 8.3 years), having xenograft external conduits placed between the right ventricle and pulmonary artery were followed for 1 to 6 years postoperatively (mean, 3.5 years). There were no late deaths in the study group, and no infection of a valved conduit has been demonstrated. Twenty of these children were catheterized during the follow-up period. The gradients from the right ventricle to pulmonary artery ranged from 8 to 90 mm Hg (average, 31 mm Hg). A total of 8 patients were classified as having hemodynamically documented conduit failure, and an additional 2 patients are clinically expected to have conduit failure. This represents a total incidence of 30% xenograft conduit failure in a 6-year follow-up. Although the etiology of this dysfunction is probably multifactorial, factors such as valve size, conduit angulation, and immunological competence bear special consideration. We conclude that although valved external conduits continue to play an important role in the treatment of complex congenital heart disease, a valved conduit with greater longevity is needed for use in children.

PEDIATRIC HEPATIC IMAGING

Common indications for liver imaging in children include trauma, suspected mass, pre-liver transplantation, monitoring after liver transplantation, jaundice, or liver dysfunction. This article highlights areas where the pathology or imaging approach in children differs from that seen in adults. Topics covered include imaging of a suspected hepatic mass, neonatal jaundice, and segmented liver transplantation.

Pictorial essay: Imaging of liver tumors in the infant and child

Hepatosplenobi l ia ry masses comprise approximate ly 56 % of abdominal masses in the pediatric age-group. Hepatic tumors are classified into benign and malignant categories and then subclassified according to the cell of origin (mesenchymal versus epithelial). Solid benign tumors of epithelial origin include hemangioendothel ioma, most commonly detected under the age of 6 months, and cavernous hemangioma, which is generally a tumor of adulthood. Mesenchymal hamar tomas are rare, p redominant ly cystic tumors of deve lopmenta l origin. Liver te ra tomas make up the rarest group of benign tumors. The majori ty of mal ignant p r imary tumors are of epithelial origin and include hepa tob las toma and hepatocellular carcinoma. Sarcomas are usually undifferentiated, but may rarely differentiate into angiosarcoma, mixed mesenchymal sarcoma, or rhabdomyosarcoma. Metastat ic tumors to the liver are less c o m m o n in the pediatric pat ient than in the adult. C o m m o n sources of metastat ic disease to the liver in children include Wilms tumor, neuroblas toma, lymphoma, and leukemia [1, 2]. Because surgery represents the mainstay of therapy in many of these lesions, detailed preopera t ive anatomic mapping is essential. Imaging evaluation of these masses has included a wide array of modalities, including ultrasound, radionuclide techniques, computed tomography (CT), and magnet ic resonance imaging (MRI) . M R I has shown the greatest promise in recent years because it combines the nonradiat ion advantage of ul trasound with the exquisite anatomic detail of CT. In addition, there is no dependence upon contrast delivery for visualization of vascular structures a particularly impor tan t advantage in elucidating the potent ial

Marked acute tissue swelling following percutaneous sclerosis of low-flow vascular malformations: a predictor of both prolonged recovery and therapeutic effect

Purpose. To evaluate the significance of marked, acute swelling in patients after percutaneous sclerosis of low-flow vascular malformations, as a predictor of both prolonged recovery and likelihood of therapeutic effect.¶Materials and methods. In 22 patients who underwent percutaneous ethanol sclerosis of low-flow vascular malformations, we compared the incidence of prolonged recovery and lasting therapeutic effect between those patients with and without marked soft-tissue swelling following the procedure.¶Results. Five patients exhibited marked swelling after sclerosis. Four of these five had causes of prolonged recovery. These four recovered and all five eventually had marked therapeutic effect. Seventeen patients did not meet criteria for severe swelling. Only one of these patients had prolonged recovery. Eighteen of the 22 total patients had therapeutic effect. All 4 of the 22 total patients who had no therapeutic effect were in the group without marked swelling.¶Conclusions. Marked soft-tissue swelling, which occurs after percutaneous sclerosis of vascular malformations, is both a predictor of prolonged recovery and high likelihood of therapeutic effect.

Evaluation of Wedging of Lower Thoracic and Upper Lumbar Vertebral Bodies in the Pediatric Population

OBJECTIVE Anterior wedging of thoracolumbar vertebral bodies is often seen in children. The purpose of our study was to show whether mild anterior wedging of pediatric thoracolumbar junction vertebral bodies can be seen as a normal variant, rather than as the sequela of trauma. MATERIALS AND METHODS A retrospective review was performed of pediatric abdomen and pelvis CT performed between January 2004 and March 2006, excluding children at high risk for compression fractures. Twenty CT studies were randomly selected for each of five arbitrary age groups: < 3, 4-7, 8-11, 12-14, and 15-17 years (100 total CT studies). Using sagittal reformations, anterior and posterior heights of all T10-L3 vertebral bodies were measured to determine anterior-to-posterior vertebral body height ratio (A:P ratio). Inter- and intraobserver agreement was determined. The lower limit of normal (lower fifth percentile of the distribution) was estimated using quantile regression. RESULTS A:P ratio at the thoracolumbar junction was greater than 0.893 in 95% of children. There was no statistically significant correlation between age and the A:P ratio. There was strong intra- and interobserver agreement. CONCLUSION From T10 through L3, 95% of children have an A:P ratio greater than 0.893. This suggests that an A:P ratio less than 0.893 should raise the possibility of vertebral body injury. Because age was not statistically significant with respect to the A:P ratio, this value can be used across all pediatric age groups.

Little Leaguer's shoulder

A case of Little Leaguer’s shoulder in a skeletally immature patient is described with a review of the English literature. This entity manifests as widening of the proximal humeral physis and is well known to our orthopedic colleagues. To our knowledge, however, there is little in the current radiologic literature describing Little Leaguer’s shoulder. We describe such a case.

Development and validation of an ultrasound scoring system for children with suspected acute appendicitis

BackgroundTo facilitate consistent, reliable communication among providers, we developed a scoring system (Appy-Score) for reporting limited right lower quadrant ultrasound (US) exams performed for suspected pediatric appendicitis.ObjectiveThe purpose of this study was to evaluate implementation of this scoring system and its ability to risk-stratify children with suspected appendicitis.Materials and methodsIn this HIPAA compliant, Institutional Review Board-approved study, the Appy-Score was applied retrospectively to all limited abdominal US exams ordered for suspected pediatric appendicitis through our emergency department during a 5-month pre-implementation period (Jan 1, 2013, to May 31, 2013), and Appy-Score use was tracked prospectively post-implementation (July 1, 2013, to Sept. 30,2013). Appy-Score strata were: 1 = normal completely visualized appendix; 2 = normal partially visualized appendix; 3 = non-visualized appendix, 4 = equivocal, 5a = non-perforated appendicitis and 5b = perforated appendicitis. Appy-Score use, frequency of appendicitis by Appy-Score stratum, and diagnostic performance measures of US exams were computed using operative and clinical finding as reference standards. Secondary outcome measures included rates of CT imaging following US exams and negative appendectomy rates.ResultsWe identified 1,235 patients in the pre-implementation and 686 patients in the post-implementation groups. Appy-Score use increased from 24% (37/155) in July to 89% (226/254) in September (P < 0.001). Appendicitis frequency by Appy-Score stratum post-implementation was: 1 = 0.5%, 2 = 0%, 3 = 9.5%, 4 = 44%, 5a = 92.3%, and 5b = 100%. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 96.3% (287/298), 93.9% (880/937), 83.4% (287/344), and 98.8% (880/891) pre-implementation and 93.0% (200/215), 92.6% (436/471), 85.1% (200/235), and 96.7% (436/451) post-implementation – only NPV was statistically different (P = 0.012). CT imaging after US decreased by 31% between pre- and post-implementation, 8.6% (106/1235) vs. 6.0% (41/686); P = 0.048). Negative appendectomy rates did not change (4.4% vs. 4.1%, P = 0.8).ConclusionA scoring system and structured template for reporting US exam results for suspected pediatric appendicitis was successfully adopted by a pediatric radiology department at a large tertiary children’s hospital and stratifies risk for children based on their likelihood of appendicitis.

Fracture and Embolization of a Peripherally Inserted Central Venous Catheter

A case is presented of the fracture and embolization of a peripherally inserted central venous catheter. This novel complication is discussed in the context of patients in alternate care settings with emphasis on retrieval of the embolized catheter fragment, morbidity of catheter embolization, and precautions against inadvertent fracture in the home care setting.