S. Gregory Jennings

Computed Tomography Demonstration of Lipomatous Metaplasia of the Left Ventricle Following Myocardial Infarction

Replacement of myocardium by fat, particularly of the right ventricle, is often diagnosed as arrhythmogenic right ventricular dysplasia. At autopsy, however, 68% of scars associated with chronic ischemic heart disease have shown fatty metaplasia in the scar. Four patients with a past history of previous myocardial infarctions and computed tomography demonstration of fatty change in left ventricular regions of hypokinesis and infarction are presented. It is proposed that these findings represent ischemic fatty metaplasia, an alternative etiology of fatty tissue replacing myocardium.

The prevalence of uncommon fractures on skeletal surveys performed to evaluate for suspected abuse in 930 children: Should practice guidelines change?

OBJECTIVE The objective of our study was to evaluate the prevalence and site of fractures detected on skeletal surveys performed for suspected child abuse at a tertiary childrens hospital and to determine whether any survey images may be eliminated without affecting clinical care or the ability to make a diagnosis. MATERIALS AND METHODS We identified all skeletal surveys performed for suspected abuse from 2003 to 2009 of children younger than 2 years. Repeated studies were excluded, as were studies not performed to evaluate for suspected abuse. From the reports, we documented the sites of all the fractures. RESULTS. Nine hundred thirty children (515 boys and 415 girls) with a median age of 6 months met the entry criteria for the study. Fractures were detected in 317 children (34%), of whom 166 (18%) had multiple fractures. The most common sites for fractures were the long bones (21%), ribs (10%), skull (7%), and clavicle (2%). Ten children (1%) had fractures in the spine (n = 3), pelvis (n = 1), hands (n = 6), and feet (n = 2). All 10 children had other signs of physical abuse. CONCLUSION In skeletal surveys performed for suspected child abuse, fractures limited to sites other than the long bones, ribs, skull, and clavicles are rare. The additional radiation exposure and cost of obtaining radiographs of the spine, pelvis, hands, and feet may outweigh their potential benefit. Given the rarity of fractures of the spine, pelvis, hands, and feet, consideration may be given to eliminating those views from routine skeletal surveys performed to evaluate for suspected child abuse.

Testicular Microlithiasis in Children and Associated Testicular Cancer

PURPOSE To evaluate the prevalence of testicular microlithiasis (TM) in children who have undergone scrotal ultrasonography (US) and their association with testicular tumors. MATERIALS AND METHODS This HIPAA-compliant study with waiver of informed consent was approved by the institutional review board. From 2003 to 2012, all patients with scrotal US and report mentioning calcifications or microlithiasis and all patients with testicular tumors from pathology database were identified. US studies were evaluated for the type of TM (classic ≥5 microliths or limited <5 microliths in a single view) and change in follow-up studies if available. Medical charts were reviewed for US indication, underlying medical conditions, and pathologic abnormalities, when available. Fisher exact test was used to analyze the association of testicular tumors and TM. RESULTS A total of 3370 boys had scrotal US, 83 (2%) of whom had TM or microcalcifications in the report. TM was usually bilateral (n = 62, 75%) and classic (n = 59, 71%) type.TM was significantly less common in those younger than 2 years of age than in older age groups (0.1% vs 3.1%, P < .0001). The most common indication for US was scrotal pain (40 of 83 patients, 48%), and the most common associated medical condition was cryptorchidism (nine of 83 patients, 11%). Testicular tumor was significantly more likely in boys with TM (12% vs 0.3%, P < .01). Five (83%) of six patients with premalignant or benign tumors had a premalignant condition (cryptochydism in two and Peutz-Jeghers syndrome in three). Four patients with TM had malignant testicular tumors, all diagnosed after the age of 16 years. CONCLUSION TM has a prevalence of 2% in boys who undergo scrotal US. It is most commonly bilateral, classic type, and stable at follow-up studies. There is a significant association of TM and testicular tumors. Malignant tumors were seen only in adolescent boys.

Diagnosis of Chronic Pancreatitis by Using Apparent Diffusion Coefficient Measurements at 3.0-T MR Following Secretin Stimulation

PURPOSE To prospectively measure pancreatic apparent diffusion coefficient (ADC) before and after secretin administration in subjects with and without chronic pancreatitis (CP) who underwent magnetic resonance (MR) cholangiopancreatography with diffusion-weighted (DW) imaging at 3.0 T. MATERIALS AND METHODS Institutional review board approval of this HIPAA-compliant study was obtained. Healthy volunteers, and patients with suspected and/or known CP who were scheduled for MR cholangiopancreatography, were recruited and gave written informed consent. All subjects underwent 3.0-T MR cholangiopancreatography, including serial DW imaging sequences (b = 0, 200, and 400 sec/mm(2)) acquired for 15 minutes after secretin administration. The referring gastroenterologist then classified subjects as healthy or with mild or severe CP, given endoscopic retrograde cholangiopancreatographic and/or clinical findings. CP severity was analyzed for sex and age. Mean presecretin and maximum postsecretin ADCs were compared between groups. Pairwise mean ADCs for healthy versus mild CP patient groups, healthy versus severe CP patient groups, and mild versus severe CP patient groups were compared. Presecretin ADC threshold levels for CP discrimination were calculated (P < .05). RESULTS Thirty-two subjects were imaged; four CP patients were excluded owing to severe artifact, and the remaining 28 (15 healthy patients, five with mild CP, and eight with severe CP) comprised the study population. All CP patients had endoscopic retrograde cholangiopancreatographic confirmation of CP. Mild or severe CP patients were older than healthy patients; sex distribution did not vary among groups. Mean presecretin and maximum postsecretin ADCs were higher in healthy patients than in either mild or severe CP groups (P < .01), but did not vary between mild and severe CP groups (P = .25-0.28). An ADC of less than 220 x 10(-5) mm(2)/sec was optimal for delineating between healthy and CP patients. CONCLUSION Pancreatic ADC obtained with DW imaging at 3.0 T prior to secretin administration may help diagnose CP; postsecretin ADC response does not distinguish CP severity.

Comparison of Secretin-Stimulated Magnetic Resonance Pancreatography and Manometry Results in Patients with Suspected Sphincter of Oddi Dysfunction

RATIONALE AND OBJECTIVES To measure main pancreatic duct diameter (PDD) with magnetic resonance pancreatography (MRP) before and after secretin injection in patients with suspected sphincter of Oddi dysfunction (SOD) and to determine if the diameter change is predictive of sphincter of Oddi manometry (SOM) results. MATERIALS AND METHODS We identified all patients during the study period referred for SOM for clinically suspected SOD; patients with an intact sphincter and without contraindication to MRP examination were considered for study entry. Consenting patients underwent MRP, including dynamic imaging of the pancreatic duct after intravenous administration of porcine secretin followed by SOM during endoscopic retrograde cholangiopancreatography. MRP was defined as abnormal when PDD remained increased by > or = 1.0 mm from baseline 15 minutes after secretin injection. SOM was abnormal when basal sphincter pressure (SP) was > or = 40 mm Hg. Mean PDD before and after secretin administration was compared within normal and abnormal SP groups with two-tailed unpaired t-test; the mean difference between baseline and peak PDD and duration of > or = 0.5 mm increase in PDD was compared between groups with two-tailed t-test. P < .05 was considered significant. RESULTS Of 70 patients referred for SOM, 30 met all entry criteria, gave consent to participate, and underwent both MRP and SOM. Ten of 30 patients (33%) had normal SP; 20 (67%) were abnormal. PDD increased significantly after secretin injection (normal SP, 1.62 +/- 0.73 to 2.78 +/- 0.77 mm, P < .01; abnormal SP, 1.45 +/- 0.26 to 2.32 +/- 0.75 mm, P < .01). There was no difference between normal and abnormal SP groups in amount of PDD increase (1.15 +/- 0.75 vs. 0.88 +/- 0.72 mm; P = .33) or duration of > or = 0.5 mm increase in PDD (5.28 +/- 8.76 vs. 13.60 +/- 13.00 minutes; P = 0.07). CONCLUSIONS In patients with suspected sphincter of Oddi dysfunction, magnetic resonance pancreatography demonstrated PDD increase following secretin injection but did not predict the results of manometry.

Optimization of hybrid iterative reconstruction level in pediatric body CT.

OBJECTIVE The objective of our study was to attempt to optimize the level of hybrid iterative reconstruction (HIR) in pediatric body CT. MATERIALS AND METHODS One hundred consecutive chest or abdominal CT examinations were selected. For each examination, six series were obtained: one filtered back projection (FBP) and five HIR series (iDose(4)) levels 2-6. Two pediatric radiologists, blinded to noise measurements, independently chose the optimal HIR level and then rated series quality. We measured CT number (mean in Hounsfield units) and noise (SD in Hounsfield units) changes by placing regions of interest in the liver, muscles, subcutaneous fat, and aorta. A mixed-model analysis-of-variance test was used to analyze correlation of noise reduction with the optimal HIR level compared with baseline FBP noise. RESULTS One hundred CT examinations were performed of 88 patients (52 females and 36 males) with a mean age of 8.5 years (range, 19 days-18 years); 12 patients had both chest and abdominal CT studies. Radiologists agreed to within one level of HIR in 92 of 100 studies. The mean quality rating was significantly higher for HIR than FBP (3.6 vs 3.3, respectively; p < 0.01). HIR caused minimal (0-0.2%) change in CT numbers. Noise reduction varied among structures and patients. Liver noise reduction positively correlated with baseline noise when the optimal HIR level was used (p < 0.01). HIR levels were significantly correlated with body weight and effective diameter of the upper abdomen (p < 0.01). CONCLUSION HIR, such as iDose(4), improves the quality of body CT scans of pediatric patients by decreasing noise; HIR level 3 or 4 is optimal for most studies. The optimal HIR level was less effective in reducing liver noise in children with lower baseline noise.

Conscious sedation for patients undergoing enteroclysis: Comparing the safety and patient-reported effectiveness of two protocols

OBJECTIVE To compare the safety and patient-reported effectiveness of two regimens for conscious sedation during enteroclysis. MATERIALS AND METHODS We surveyed two groups of outpatients and retrospectively reviewed procedure records for conscious sedation and complications. Patients were divided into Group One (received sedative/amnesic diazepam), and Group Two, (received amnesic/sedative, midazolam and analgesic fentanyl). RESULTS All enteroclyses were successfully completed; there were no hospital admissions due to complications. In Group One (n=106), mean dose of diazepam was 12.7 mg. 25% had oxygen desaturation (n=25), and post-procedure vomiting without aspiration (n=1). 56% of outpatients completed phone surveys, and 68% recalled procedural discomfort. In Group Two (n=45), mean doses were 3.9 mg midazolam and 108 mcg fentanyl. 31% had desaturation (n=13), and post-procedure vomiting without aspiration (n=1). 87% had only a vague recall of the procedure or of any discomfort. CONCLUSION A combination of amnesic and fentanyl prevented the recall of discomfort of nasoenteric intubation and infusion in most patients who had enteroclysis compared to diazepam. Most of the patients would undergo the procedure again, if needed.

Diagnostic errors from digital stitching of scoliosis images – the importance of evaluating the source images prior to making a final diagnosis

BackgroundDigital methods are used for scoliosis imaging. Separate images of the thoracic and lumbar/sacral spine are acquired. These are then stitched into a single image. This process has some potential disadvantages.ObjectiveTo assess anatomical errors in digitally stitched scoliosis films.Materials and methodsEighty-six scoliosis studies were evaluated for stitching errors. The incidence of a stitching error resulting in an abnormality on the stitched image that could not be verified on the source images was calculated. Subgroups were analyzed based on the presence/absence of spinal hardware and standing/supine technique.ResultsFourteen exams (16%) had stitching errors that could result in a false diagnosis if not correlated with the source images. The majority were errors of vertebral alignment. There was no significant difference in error rate with the presence or absence of hardware (P = 0.73) or patient positioning (P = 0.34).Conclusion16% of digital scoliosis exams had stitching errors that could result in a false diagnosis. The error rate was not influenced by spinal hardware or patient positioning. These results stress the importance of correlating any abnormality on the stitched image with the exam’s source images; if not, a false diagnosis of abnormality will be made.

Is the new ACR-SPR practice guideline for addition of oblique views of the ribs to the skeletal survey for child abuse justified?

OBJECTIVE The purpose of our study was to determine whether adding oblique bilateral rib radiography to the skeletal survey for child abuse significantly increases detection of the number of rib fractures. MATERIALS AND METHODS We identified all patients under 2 years old who underwent a skeletal survey for suspected child abuse from January 2003 through July 2011 and who had at least one rib fracture. These patients were age-matched with control subjects without fractures. Two randomized radiographic series of the ribs were performed, one containing two views (anteroposterior and lateral) and another with four views (added right and left oblique). Three fellowship-trained radiologists (two in pediatrics and one in trauma) blinded to original reports independently evaluated the series using a Likert scale of 1 (no fracture) to 5 (definite fracture). We analyzed the following: sensitivity and specificity of the two-view series for detection of any rib fracture and for location (using the four-view series as the reference standard), interobserver variability, and confidence level. RESULTS We identified 212 patients (106 with one or more fractures and 106 without). The sensitivity and specificity of the two-view series were 81% and 91%, respectively. Sensitivity and specificity for detection of posterior rib fractures were 74% and 92%, respectively. There was good agreement between observers for detection of rib fractures in both series (average kappa values of 0.70 and 0.78 for two-views and four-views, respectively). Confidence significantly increased for four-views. CONCLUSION Adding bilateral oblique rib radiographs to the skeletal survey results in increased rib fracture detection and increased confidence of readers.

Effect of Tube Voltage on CT Noise Levels in Different Phantom Sizes

OBJECTIVE The purpose of this study was to determine the effect of lowering tube voltage on dose and noise in cylindric water phantoms to optimize quality and decrease the radiation dose for body CT. MATERIALS AND METHODS We performed CT on cylindric water phantoms with diameters of 10, 20, 25, and 30 cm, simulating the abdomen of an infant, child, adolescent, and adult. We used tube voltages of 120, 100, and 80 kVp. The CT dose index (32-cm reference) ranged from 1 to 10 mGy in 10- and 20-cm phantoms and from 2 to 20 mGy in the 25- and 30-cm phantoms. The noise was measured at the center and periphery of the scans. Central and peripheral doses were measured in 16- and 32-cm CT dose index phantoms, and the ratio of central to peripheral doses was calculated. RESULTS At the same noise levels, there was no significant increase in dose in 10-cm cylindric water phantoms when tube voltage was decreased to either 80 or 100 kVp. In 20-, 25-, and 30-cm phantoms, there was a 1-6% increase in dose when tube voltage was decreased to 100 kVp. Central-to-peripheral noise ratios increased 7-37% with increased phantom size. The measured peripheral dose increased as much as 5%. CONCLUSION Our findings support the practice of lowering tube voltage to 80 kVp for imaging of infants and to 100 kVp for imaging of older children. The increase in peripheral dose with decreased tube voltage is minimal and is unlikely to cause substantial change in the effective dose.