Direct coronal CT scanning of the neonatal chest

BACKGROUND

The purpose of this study was to attempt to improve upon conventional coronal computed tomographic (CT) images of neonatal chest which to date have been made by reformatting thinly spaced axial images.

MATERIALS AND METHODS

Nine neonates were studied by direct coronal CT scans with the patients' long axis 90 degrees to the scanning table. They were studied to further define their thoracic abnormalities detected on plain film. Spiral CT and cine scan (Imatron) were utilized.

RESULTS

Congenital lung lesions such as congenital cystic adenomatoid malformation could not be diagnosed but their anatomical location could be accurately depicted, enabling easier surgical planning. The arterial supply to bronchopulmonary sequestrations was also identifiable. Tracheobronchial abnormalities such as tracheobronchus and bronchial atresia were also identifiable. Causing of air trapping, both intrinsic such as an atretic bronchus and extrinsic such as vascular compression were readily demonstrated.

CONCLUSION

With neither special devices nor paraphernalia, the described method of direct coronal CT scans were both feasible and provided significant information. This technique allows for improved assessment of the tracheobronchial tree and more accurate detection, localization, and characteristics of lesions adjacent to the diaphragm.

Worsening enterocolitis in neonates: diagnosis by CT examination of urine after enteral administration of iohexol

Perforation, a severe complication of necrotizing enterocolitis (NEC), has a high mortality rate. Recently, we presented a new technique for evaluation of NEC: measuring the CT attenuation coefficient of urine after oral administration of iohexol. We present three cases of neonates with NEC who demonstrated serial increases in urine CT attenuation coefficients, all of whom subsequently deteriorated clinically and radiographically. Surgery in all three cases confirmed severe necrosis and/or perforation. These three cases suggest that the CT attenuation coefficient of urine after oral administration of iohexol may be a more sensitive indicator of NEC severity, progression, and perforation than clinical evaluation and radiography. More investigation is necessary, but eventually, this noninvasive technique may be able to decrease morbidity and mortality by predicting the need for surgical intervention or more aggressive medical management of NEC before perforation occurs.

Necrotizing enterocolitis: diagnosis with CT examination of urine after enteral administration of iodinated water-soluble contrast material

PURPOSE

To develop a new method for diagnosing necrotizing enterocolitis with use of computed tomography (CT).

MATERIALS AND METHODS

Urine specimens from 22 neonates were obtained 8-12 hours after iohexol was administered enterally. Twelve neonates had suspected (n = 5) or definite (n = 7) necrotizing enterocolitis, and 10 neonates without necrotizing enterocolitis underwent routine upper gastrointestinal study. Urine from another 13 neonates without necrotizing enterocolitis who did not receive iohexol was collected. The attenuation coefficient of each urine specimen was determined with CT.

RESULTS

The mean CT attenuation coefficient of urine from neonates who did not receive iohexol was 5.6 HU +/- 3.9, and that from neonates without necrotizing enterocolitis who underwent upper gastrointestinal study was 6.7 HU +/- 3.2. The mean CT attenuation coefficient of urine from patients with suspected necrotizing enterocolitis was 26.0 HU +/- 3.4, and that in patients with definite necrotizing enterocolitis was 71.0 HU +/- 18.8. The mean CT attenuation coefficients in neonates with necrotizing enterocolitis were significantly different from that in patients without necrotizing enterocolitis who underwent upper gastrointestinal study.

CONCLUSION

Urine from neonates with necrotizing enterocolitis show significantly higher CT attenuation coefficients than those from patients without necrotizing enterocolitis. CT examination of urine may allow early detection of necrotizing enterocolitis.

Ringed esophagus (feline esophagus) in childhood

Feline esophagus is a term describing a specific radiological and endoscopic appearance of the esophagus that is attributed to chronic esophagitis. To date only one report has described this appearance in childhood. We present a histologically documented case of this entity including follow-up studies after therapy for esophagitis.

Renal cell carcinoma after therapy for neuroblastoma

OBJECTIVE

An unfortunate consequence of increased success in childhood cancer survival rates is the increase in the number of secondary malignant neoplasms after therapy for the initial lesion. Renal cell carcinoma can occur as a secondary malignant neoplasm after therapy for neuroblastoma and may become more common as more patients with treated neuroblastomas survive into adulthood. We studied one case and reviewed four cases of secondary renal cell carcinoma to determine if the relationship between these two neoplasms is significant.

CONCLUSION

An awareness of the association between these two neoplasms is important in the diagnostic follow-up of neuroblastoma so that secondary renal cell carcinoma is not confused with recurrence of primary disease.

Left paraduodenal hernia leading to ileal obstruction

Left paraduodenal hernias are a rare cause of abdominal pain or obstruction. However, because there is high associated mortality (20 %), prompt and accurate diagnosis is essential. Because internal hernias are not detectable on physical examination, imaging is relied upon for pre-operative diagnosis. Although both computed tomography and barium studies demonstrate left paraduodenal hernias as a cluster of bowel located posterior to the stomach and to the left of the distal duodenum with absence of the normal interdigitation between loops, the findings may be subtle. Knowledge of these findings can avoid an unnecessary delay in diagnosis. We present the case of a 15-year-old girl with a left paraduodenal hernia, where initial CT and barium studies demonstrated nonobstructed jejunum within the hernia sac. Two weeks later a repeat study showed obstructed distal ileum, rather than proximal jejunum, within the sac.