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Biomedical subjects

G D Shackelford

Publications and source records attributed to G D Shackelford.

At least 19 recordsLinked to original sources

Soft-copy versus hard-copy cranial sonography: intraobserver agreement and workstation efficiency.

OBJECTIVE: The objective of the study was to determine the intraobserver agreement, confidence level, and efficiency in interpretation of soft-copy (workstation) versus hard-copy (laser-printed film) sonograms of the cranium. MATERIALS AND METHODS: Cranial sonograms of 100 premature infants were randomly reviewed twice on both soft-copy and hard-copy images by three observers and were graded for hemorrhage using a five-level scale. The kappa statistic was calculated to measure intraobserver agreement. Differences in agreement were tested for statistical significance with a test for marginal homogeneity. Observers rated their confidence in interpretation using a six-point ordinal scale. Total viewing time was recorded, and videotaped sessions were analyzed for image handling time (opening each case, closing each case, and selecting the next case) and interpretation time. RESULTS: For soft copy versus hard copy, the mean kappa value was .73; for hard-copy 1 versus hard-copy 2, .71; and for soft-copy 1 versus soft-copy 2, .65. None of these differences was statistically significant (p > .05). The mean confidence score was the same for soft copy (5.3) and hard copy (5.3). On average, the observers needed 24 min longer to review 100 studies on soft copy than on hard copy. Opening and closing times for soft copy were significantly faster than for hard copy (p = .0001); however, case selection for soft copy, which was not needed for hard copy, took 4.69-9.09 sec per case. Extrapolated to 100 cases, case selection accounted for 8-15 min of viewing time. CONCLUSION: Radiologist agreement and confidence in the interpretation of cranial sonograms for hemorrhage was the same for soft copy and hard copy. However, viewing times were longer for soft copy. Elimination of inefficiency in case selection could improve image-handling time.

Cerebral Hemorrhage

Unrecognized retention of intraorbital graphite pencil fragments: the role of computerized tomography.

Children with unrecognized intraorbital pencil fragments may come to attention because of surrounding abscess and granuloma formation, after a long delay, and may be suspected to have an intraorbital neoplasm. Two such patients are reported, with emphasis on CT findings. Recognition of the CT manifestations of intraorbital pencil fragments may allow a more conservative surgical intervention than that for presumed intraorbital neoplasm.

Child

Ureteropelvic junction obstruction in infants mimicking ureterovesical junction obstruction on sonography.

We present two infants with ureteropelvic junction obstruction with very large renal pelves, which extended to the level of the urinary bladder. In both cases, the distal aspect of the renal pelvis simulated a dilated distal ureter, leading to the incorrect sonographic diagnosis of ureterovesical junction obstruction. Awareness of this potential pitfall on sonography is important when imaging infants with prenatal diagnosis of hydronephrosis.

Diagnosis, Differential

Inflammatory myofibroblastic tumor of the spleen: report of a case in an adolescent.

Inflammatory myofibroblastic tumor (IMT) is an uncommon quasineoplastic process occurring in young patients. Splenic involvement is uncommon and occurs predominantly in older, adult patients. We present the youngest patient reported to date with splenic inflammatory myofibroblastic tumor and discuss the clinical, pathological and imaging features of this lesion.

Adolescent

Binary nature and radiographic identifiability of craniosynostosis.

RATIONALE AND OBJECTIVES: Two independent gold standards and diagnoses from three-dimensional computed tomography (CT) images were used to examine the possibility that craniosynostosis is a binary abnormality that potentially may be diagnosed without error. METHODS: Surgical reports, histology of excised sutures, and three-dimensional CT images were compared for 25 children undergoing surgical management of craniosynostosis. Surgical reports identified sutures as normal or abnormal. Histology reported suture closure on a 5-point scale. Four radiologists used three-dimensional CT images to diagnose sutures on a 6-point rated response scale. RESULTS: Sutures with histology 0, 1, or 2 were normal on surgical reports, and those with histology 3 or 4 were abnormal. Most readers achieved nearly perfect sensitivity and specificity. Reader confidence was unrelated to degree of pathology. CONCLUSION: Craniosynostosis appears to be binary in our sample. Surgical reports, pathology results, and three-dimensional CT images read by experienced viewers achieved nearly perfect agreement.

Cranial Sutures

Craniosynostosis: diagnostic imaging with three-dimensional CT presentation.

PURPOSE: To measure diagnostic performance and preference of two three-dimensional CT reconstruction modalities (voxel-gradient and surface-projection) displayed two ways (conventional and unwrapped) in craniosynostosis confirmed by surgical inspection and histologic analysis of resected sutures. METHODS: High-resolution 2-mm contiguous CT sections were obtained and three-dimensional reconstruction images generated for 25 infants and children with skull deformities before surgical treatment of craniosynostosis. Two pediatric radiologists and two neuroradiologists first ranked images by their own preferences for diagnostic use. Then they diagnosed craniosynostosis from images presented in random order and blinded. The standard of reference was inspection during surgery and histologic evaluation of excised sutures. Finally, reviewers repeated their subjective preference tests. RESULTS: The least experienced radiologist had 100% sensitivity for all imaging modalities and specificities ranging from 43% to 83%. The two most experienced radiologists performed nearly identically, with sensitivities of 96% and specificities of 100%. After performing diagnostic tasks using all image types, all radiologists preferred conventional surface projections. CONCLUSION: Experienced readers can achieve nearly perfect diagnostic performance using the latest three-dimensional CT reconstruction images, making it a contribution to the diagnostic process. Although performance is nearly identical for all modalities, readers strongly prefer conventionally presented surface-projection images.

Algorithms

Unusual manifestations of Langerhans cell histiocytosis of the head and neck. Case report with pseudoaneurysm of external carotid artery, tracheal, mandibular, and sphenoid involvement.

Langerhans cell histiocytosis of the head and neck is an uncommon histiocytic proliferative disorder that often clinically resembles an inflammatory process. A pseudoaneurysm of the external carotid artery was found by contrast-enhanced CT and confirmed by Doppler ultrasonography and angiography in a 9 year old girl with a lytic lesion of the mandible, a prior severe tracheal inflammatory process, and sclerotic lesions of the sphenoid wings. Biopsies of the mandibular lesion, pseudoaneurysm, and trachea demonstrated Langerhans cell histiocytosis. In cases of LCH with head and neck involvement, contrast-enhanced CT allows adequately detailed initial evaluation of the protean manifestations of this disorder.

Aneurysm

Early occurrence of end-stage renal disease in a patient with infantile nephropathic cystinosis.

We report the case of a patient with infantile nephropathic cystinosis who required renal transplantation at age 30 months. Exhaustive evaluation did not identify a cause of progressive renal failure other than cystinosis. The patient's genetic lesion was allelic with those of other patients with cystinosis; fusion of this patient's fibroblasts with fibroblasts from another patient with infantile nephropathic cystinosis did not demonstrate complementation of the biochemical defect.

Clone Cells

Imaging the urinary tract.

Since the advent of US, nearly every malformation of the urinary tract has been diagnosed in utero. Physiologic dilatation of the renal pelvis occurs and can be misdiagnosed as hydronephrosis, so the normal gestational development of the urinary tract, and its visualization by ultrasound, should be understood. Gestational diagnosis is important for family counseling, collaboration of the perinatal team, and for determining both the future evaluation needs and the possibility of intervention. Those infants at high risk, as well as others who have specific signs and symptoms of possible urinary tract disease, deserve prompt and careful postnatal imaging studies. Ultrasonograms may be combined with other imaging modalities in specific circumstances to provide accurate diagnoses and some functional information.

Congenital Abnormalities

Postpneumonectomy syndrome after left lung resection.

A female infant with a right-sided aortic arch and ligamentum arteriosum underwent a left pneumonectomy for perinatal interstitial emphysema. Radiographic, bronchoscopic, and surgical evidence of compression of the right bronchial tree by the aorta, ligamentum arteriosum, right pulmonary artery, and thoracic spine subsequently developed. This report documents a rare example of postpneumonectomy syndrome following left lung resection.

Bronchi

Magnesium tocolysis and neonatal bone abnormalities: a controlled study.

This study was conducted to investigate the relationship between maternal administration of intravenous (IV) magnesium sulfate and radiographic abnormality of neonatal long bones. Eleven neonates in the exposed group were born to mothers who had received IV magnesium tocolysis for more than 7 days. Two gestational age-matched unexposed neonates were selected for each member of the exposed group. Initial chest radiographs of exposed and unexposed neonates were reviewed in random sequence by a pediatric radiologist who was blinded to exposure status. On evaluation of the proximal humeri, six neonates had radiographic abnormalities consisting of transverse radiolucent and/or sclerotic bands; all six were in the exposed group. The difference in radiographic findings between the exposed and unexposed groups was statistically significant (P less than .001). These results support the existence of a causal relationship between prolonged IV magnesium tocolysis and abnormal fetal bone mineralization. Further study is needed to elucidate the mechanism and clinical significance of these bone changes.

Abnormalities, Drug-Induced

Craniosynostosis: diagnostic value of three-dimensional CT reconstruction.

Three-dimensional computed tomography (CT) has an important role in determining the presence and extent of congenital and acquired craniofacial deformities. The authors compared the sensitivity and specificity of three-dimensional CT in the detection and characterization of craniosynostosis with that of planar CT and skull radiography. Eighty-two patients with isolated and syndromal synostoses were imaged with CT and three-dimensional CT, and 42 with skull radiography. Three-dimensional CT scan processing was performed by shaded-surface reconstruction, volumetric, and depth-coded methods. Two trained observers read each scan series in a blinded fashion. Diagnostic utility of the images was determined with receiver operating characteristic analysis. The observers ranked three-dimensional shaded images higher than the other types, with three-dimensional volumetric images second and three-dimensional surface images ranked third. Results of this study demonstrate that three-dimensional shaded-surface reconstruction from CT scans is superior to conventional plain radiographs and CT scans in diagnosing craniosynostosis.

Adolescent

Craniosynostosis: image quality, confidence, and correctness in diagnosis.

The authors used the diagnosis of craniosynostosis to compare subjective evaluation of image quality with objective diagnostic utility. They studied in detail the responses of one observer, who read plain radiographs, computed tomographic (CT) scans, and three-dimensional reconstructions of CT scans (obtained with three different methods) for 82 patients with this diagnosis. The observer rated image quality and certainty in diagnosis made from each image. Subjective and objective performances were found to be strongly linked. High-quality images served as the basis for more accurate diagnoses than low-quality images. The increase in diagnostic performance results primarily from increased specificity, a fact that suggests that specificity and the concomitant diagnosis of normalcy are the focus of attention when image quality is evaluated.

Adolescent

Granulomatous hepatitis associated with cat scratch disease.

In three patients with cat scratch disease the liver was affected. All three had high fever (39 degrees C) for more than 3 weeks. Two of them had no peripheral adenopathy. Computed tomography of the abdomen revealed focal hepatic defects in two patients and periportal and periaortic adenopathy in the third. At laparotomy, there were nodules on the liver surfaces of all patients and histological examination revealed necrotising granulomata. The Warthin-Starry silver stain showed organisms consistent in appearance with the cat scratch bacillus in the liver and a periaortic lymph node of one patient, in the liver of the second patient, and in the axillary lymph node of the third. In all three patients the clinical findings and radiological abnormalities improved without specific therapy. A review of the surgical pathology files of Washington University revealed only two other cases of granulomatous hepatitis in children over a 6-year period. These findings indicate that cat scratch disease should now be included in the differential diagnosis of granulomatous hepatitis, at least in children. The absence of peripheral adenopathy in two of the three patients with granulomatous hepatitis suggests that the clinical spectrum of cat scratch disease may be broader than previously appreciated.

Cat-Scratch Disease

Acute renal infarction: diagnosis by Doppler ultrasound.

A young infant undergoing balloon angioplasty for pulmonic stenosis developed global right renal infarction as a complication of cardiac catheterization via the femoral vein. A second patient developed segmental infarction of a recently transplanted kidney due to occlusion of a polar artery. Although routine renal sonography of these patients was normal, duplex Doppler sonography documented the absence of renal arterial and venous flow.

Adolescent