Quantitative apparent diffusion coefficient (ADC) values as an imaging biomarker for fibrosis in pediatric Crohn's disease: preliminary experience.

PURPOSE: To compare histopathology with ADC values in strictured bowel segments in pediatric patients with known Crohn's disease and surgical bowel resection. METHODS: Magnetic resonance enterography (MRE) images of 14 subjects with Crohn's disease who had surgical bowel resection for strictures were retrospectively reviewed. Five of 14 subjects had DWI (b=0, 500, 1000) sequences included in the MRE study. ADC measurements were made by placing ROI's in the strictured bowel wall and compared to full-thickness histologic analysis of resected specimens. ADC values were also compared to control ADC measurements (in normal and inflamed-nonstenotic bowel segments) as well as the mean ADC values of Crohn's patients published in the literature. RESULTS: All five subjects had transmural fibrosis. The mean ADC value with b = 500 was 0.92 ± 0.10 × 10(-3) mm(2)/s and with b = 1000 was 0.8 ± 0.05 × 10(-3) mm(2)/s. There was a significant difference in ADC values between strictures and inflamed-nonstenotic segments (p=0.0143) and between normal and diseased bowel segments (p=0.009-0.0143). CONCLUSIONS: Quantitative ADC measures of transmural fibrosis are lower compared to the reported values of inflammation in Crohn's disease. To our knowledge, this is the first pediatric pilot study to investigate the correlation of quantitative DWI with histology of surgical specimens in pediatric patients with Crohn's disease. Our results are comparable to a recently published study in adult Crohn's patients showing a significant correlation between a decrease in ADC values and fibrosis.

Resident interpretation of emergency CT scans in the evaluation of acute appendicitis.

PURPOSE: Radiology resident interpretation of computed tomographic (CT) scans at academic institutions often guides management of cases of suspected acute appendicitis in the emergency department. The purpose of this study was to compare resident and faculty interpretation of CT scans obtained for acute appendicitis. MATERIALS AND METHODS: From December 16, 1999, to July 13, 2000, CT was performed in 103 consecutive patients between the hours of 9:00 PM and 8:00 AM who were suspected of having acute appendicitis. The authors compared the residents' preliminary written interpretations with both the final reports written by the faculty and the surgical findings. The faculty interpreting the CT scans were aware of resident interpretations but were not aware that a study was being conducted. RESULTS: The final faculty interpretation and the preliminary resident interpretation were identical in 96 of the 103 patients (93%; 95% confidence interval: 87.8%, 97.2%). In only one patient was a scan originally interpreted as negative interpreted as positive by the faculty member. Clinically, the patient did not have acute appendicitis, and surgery was not perforrmed. CONCLUSION: In the diagnosis of acute appendicitis, image interpretations made by adequately trained radiology residents can be expected to closely match those of the radiology faculty, and the practice of after-hours interpretation of such studies by radiology residents is safe.

Magnetic resonance imaging of myocardial infarction during prothrombin complex concentrate therapy of hemophilia A.

In patients with hemophilia, prothrombin complex concentrates (PCCs) have been successfully used to bypass inhibitors to factor VIII during bleeding episodes. The use of PCCS, including FEIBA (factor eight inhibitor bypassing activity), has been associated with thromboembolic complications. Myocardial infarction (MI) is a rare but serious complication, reported in 13 previous cases, six in the pediatric age group. In all four patients who died during the acute MI, autopsy revealed extensive myocardial hemorrhage. The hearts of three other patients examined at least 5 months after the acute MI showed no evidence of prior hemorrhage. Magnetic resonance (MR) imaging has been shown to be able to evaluate the sequelae of myocardial infarction in adults with coronary artery disease and in children with Kawasaki syndrome. We report the first case of the use of MR imaging in the evaluation of myocardial damage during the acute stage of a FEIBA-associated MI in a 10-year-old boy.

Congenital fusion of the fourth and fifth metacarpals associated with primary gonadal failure.

Congenital fusion of the fourth and fifth metacarpals is described in a male infant and his maternal grandfather. Primary gonadal failure, which is present in the infant, has not been noted in previously, reported cases. The pedigree in this family is compatible with X-linked recessive or autosomal dominant inheritance with incomplete penetrance.

Computed radiography in neonatal and pediatric intensive care units: a comparison of 2.5 K x 2 K soft-copy images vs digital hard-copy film.

OBJECTIVE: The goal of the study was to determine whether soft-copy images on high-resolution monitors (2.5 K x 2 K) are suitable for primary interpretation of images from pediatric and neonatal intensive care units. The hypotheses were that hard and soft images yield similar diagnostic information, and that both residents and faculty radiologists can use monitors effectively. Previous reports have produced conflicting results; the need for larger sample sizes has been emphasized. MATERIALS AND METHODS: One thousand one hundred and four images produced by computed radiography using the Kodak Ectascan Imagelink system were prospectively analyzed by two pediatric radiologists, one reading hard copy and the other soft copy of the same images. Bias was controlled by equal distribution of modalities between observers and by daily alternation of modality. Hard- and soft-copy observations of presence or absence of nine specific tubes and nine specific diagnostic findings were compared. Interobserver differences between pediatric radiologists and radiology residents were studied on additional images. The kappa statistic was used to evaluate the level of agreement for all observations. RESULTS: There was excellent agreement between hard and soft copy interpretation for each tube and diagnostic finding (kappa values 0.93-1.0) and excellent interobserver agreement between two pediatric radiologists (kappa values 0.84-1.0). The level of agreement between radiology residents and pediatric radiologist was excellent for the most objective findings. All results were statistically significant (p < 0.001). CONCLUSION: High resolution soft-copy images are suitable for primary interpretation in patients in pediatric and neonatal intensive care units.

MR imaging of deferoxamine-induced bone dysplasia in an 8-year-old female with thalassemia major.

Bone changes in thalassemic patients receiving deferoxamine therapy for iron chelation include metaphyseal and growth plate irregularities. We present a case of an 8-year-old female with thalassemia major, who had magnetic resonance imaging after plain radiographs had shown metaphyseal changes in the distal femur. The signal characteristics of these abnormalities were consistent with hyaline cartilage; the surrounding marrow showed no evidence of iron overload.

Maternal cocaine abuse: the spectrum of radiologic abnormalities in the neonatal CNS.

The purpose of this study was to determine the pattern and frequency of CNS abnormalities in the offspring of cocaine-abusing mothers. The study group consisted of a retrospective review of all neonates born or admitted to our neonatal intensive care unit over a 1-year period who met criteria for maternal cocaine abuse (43 patients). A control group (62 patients) was obtained from patients seen during the same interval and the cases were matched for gestational age and race. The radiologic studies were analyzed by two independent reviewers, and CNS abnormalities were assessed by means of sonography, CT, or MR. By matching the study and control groups for gestational age, we eliminated the higher frequency of prematurity. This allowed us to determine if maternal cocaine use was associated with any intracranial abnormalities other than those seen with prematurity. The frequency of intracranial hemorrhage, ventricular enlargement, and periventricular leukomalacia was not significantly different between the study and control groups. The frequency of cortical infarction was 17% in the study group and 2% in the control group. The frequency of major congenital malformation was 12% in the study group and 0% in the control group. All five of the congenital malformations seen were midline CNS abnormalities, particularly neural tube defects. It is postulated that the higher statistically significant frequency of stroke and congenital malformations in the babies of maternal cocaine abusers is related to vasospasm caused by cocaine when used in the third and first trimesters, respectively.

Deferoxamine-induced bone dysplasia in patients with thalassemia major.

Metaphyseal irregularity and abnormal vertebral bodies resembling a bone dysplasia were seen in two of five children with thalassemia major who were begun on a regimen of hypertransfusion and chelation with deferoxamine before the age of 3 years. Similar changes were not seen in 22 other children in whom chelation was started after the age of 3. Whether the dysplastic bone growth was related to drug dose or age of onset of chelation could not be determined, as deferoxamine dosages differed in the two groups. Findings on radiographs included flattening of the thoracic and lumbar vertebral bodies, circumferential metaphyseal osseous defects, sharp zones of provisional calcification, and widened growth plates. Healing was noted in one of the patients after the dose of deferoxamine was decreased. Zinc levels in both affected patients did not differ from those in the 25 other chelated patients.

Radiographic features of craniometadiaphyseal dysplasia, wormian bone type.

We describe the radiographic findings in two siblings with a previously unrecognized craniotubular bone dysplasia. We call this condition craniometadiaphyseal dysplasia, wormian bone type. Because the parents of the siblings are consanguineous, this is probably a genetically determined condition with an autosomal recessive type of transmission. The findings in the siblings are compared with those of a woman with the same condition, previously reported as an example of craniometaphyseal dysplasia. The combination of findings in these patients seems diagnostic: characteristic skull changes including multiple wormian bones; wide long tubular bones without normal metaphyseal flaring; wide short tubular bones without normal diaphyseal constriction and sometimes actual diaphyseal expansion; and wide ribs and clavicles.

Enteric fistula formation secondary to necrotizing enterocolitis.

We report two cases of enterocolonic fistula formation following necrotizing enterocolitis, and a review of the six previously published cases. Ischemic mechanism is the most likely cause. The fistulas were diagnosed by upper gastrointestinal series and contrast enema.

Spondylometaphyseal dysplasia, corner fracture type: a heritable condition associated with coxa vara.

The authors present the radiographic features of a previously incompletely delineated bone dysplasia, which they call spondylometaphyseal dysplasia, corner fracture type. This is a dominant heritable condition associated with short stature and developmental coxa vara. The progressive hip deformity usually causes significant disability requiring surgical correction. Developmental coxa vara, simulated corner fractures of long tubular bones, and vertebral body abnormalities result in a diagnostic constellation. Knowledge of these distinctive radiologic features allows accurate diagnosis, which in turn should lead to appropriate genetic counseling and possibly to earlier, more efficacious surgical treatment of the coxa vara.

Imaging of prenatally detected intra-abdominal extralobar pulmonary sequestration.

Intra-abdominal extralobar pulmonary sequestration is a rare congenital anomaly which may present as an abdominal mass. We describe a case of intra-abdominal extralobar pulmonary sequestration detected prenatally as a left suprarenal mass. The ultrasound, computed tomography and magnetic resonance imaging findings are illustrated and correlated with the pathologic findings.

Neonatal necrotizing enterocolitis: air in Morison pouch.

Six newborn infants with necrotizing enterocolitis (NEC) were noted to have air confined to Morison pouch as an early sign of pneumoperitoneum. Air in Morison pouch appears as a triangular lucency in the right upper quadrant. Extraluminal air in this location is easily mistaken for air within a loop of bowel if its characteristic appearance is not specifically sought. Review of the literature revealed no reported cases of NEC in which air in Morison pouch was mentioned. The authors' observation of six patients suggests that air in Morison pouch may be more common than previously recognized. Air in Morison pouch has the same significance as more obvious signs of pneumoperitoneum, and its detection is an indication for surgery.

Calcified neonatal renal vein thrombosis demonstration by CT and US.

Two cases of calcified renal vein thrombosis (RVT) were diagnosed, incidentally, within the first weeks of life. The CT images present the virtually diagnostic branching pattern of calcification that has been previously noted on pathology specimen radiographs. The CT and US images show peripheral renal vein, central renal vein and inferior vena cava calcification conforming to the two theoretical origins of intravascular calcification. The patients had normal laboratory results and no symptoms related to renal vein or inferior vena cava thrombi.

Safety of metallic surgical clips in patients undergoing high-field-strength magnetic resonance imaging.

Use of metallic clips with ferromagnetic properties in patients undergoing a large variety of surgical procedures, and in particular, in coronary artery and other vascular reconstructions, has become increasingly popular. The safety of these commonly used surgical clips when subjected to high-intensity diagnostic magnetic resonance imaging fields is still debated. Commonly used hemostatic metallic clips manufactured by the Weck and US Surgical Corporations were tested in an in vitro system to assess their safety with regard to migration and displacement. The two tested hemostatic metallic clips proved safe and did not migrate or become dislodged when they underwent magnetic resonance imaging scans. This is in direct contrast to multiple cerebral aneurysm clips, also tested, which have highly ferromagnetic properties and were previously shown to migrate with disastrous results in patients undergoing diagnostic magnetic resonance imaging scans. This study supports the continued widespread use of small metallic hemostatic clips in the myriad of procedures in which they are presently used and illustrates the need for methods of evaluating such devices before they are clinically implanted.

Adrenal hemorrhage and renal vein thrombosis in the newborn: MR imaging.

Three newborn infants with flank masses underwent magnetic resonance (MR) imaging after ultrasound (US) indicated adrenal hemorrhage and/or renal vein and inferior vena cava thrombosis. MR imaging was valuable in defining the hemorrhagic nature of echogenic and hypoechoic suprarenal masses and in delineating thrombi within the renal veins and inferior vena cava. Two infants with renal parenchymal damage had abnormal radionuclide scans and abnormal corticomedullary distinction on MR images. The major role of MR imaging may be in the early course of these conditions, when added diagnostic specificity is likely to affect patient management. In most instances, size of hemorrhage and intravenous clots, as well as renal size, may be accurately followed with US, while radionuclide scanning remains necessary for evaluation of renal functional impairment.

Childhood retroperitoneal fibrosis.

Retroperitoneal fibrosis is rarely considered in the differential diagnosis of ureteral obstruction in children even when clinical presentation and radiologic findings are typical. In a 12-year-old boy admitted with a 2-week history of flank pain computed tomography showed an enhancing mass obstructing the left ureter. Pathologic examination of the mass and adjacent segment of ureter revealed retroperitoneal fibrosis.