Elias Kazam

Maternal infection, fetal inflammatory response, and brain damage in very low birth weight infants

Echolucent images (EL) of cerebral white matter, seen on cranial ultrasonographic scans of very low birth weight newborns, predict motor and cognitive limitations. We tested the hypothesis that markers of maternal and feto-placental infection were associated with risks of both early (diagnosed at a median age of 7 d) and late (median age = 21 d) EL in a multi-center cohort of 1078 infants <1500 ×g. Maternal infection was indicated by fever, leukocytosis, and receipt of antibiotic; feto-placental inflammation was indicated by the presence of fetal vasculitis (i.e. of the placental chorionic plate or the umbilical cord). The effect of membrane inflammation was also assessed. All analyses were performed separately in infants born within 1 h of membrane rupture (n= 537), or after a longer interval (n= 541), to determine whether infection markers have different effects in infants who are unlikely to have experienced ascending amniotic sac infection as a consequence of membrane rupture. Placental membrane inflammation by itself was not associated with risk of EL at any time. The risks of both early and late EL were substantially increased in infants with fetal vasculitis, but the association with early EL was found only in infants born ≥1 after membrane rupture and who had membrane inflammation (adjusted OR not calculable), whereas the association of fetal vasculitis with late EL was seen only in infants born <1 h after membrane rupture (OR = 10.8;p= 0.05). Maternal receipt of antibiotic in the 24 h just before delivery was associated with late EL only if delivery occurred <1 h after membrane rupture (OR = 6.9;p= 0.01). Indicators of maternal infection and of a fetal inflammatory response are strongly and independently associated with EL, particularly late EL.

Computed tomography of the spine and spinal cord.

Configurations of 50 normal lumbar canals at each vertebral level were assessed and the dimensions of the canal at these levels measured. The appearances of the contents of the canal and their absorption values were carefully analyzed in the lumbar, cervical, and thoracic regions. Of 75 scans of patients with specific spinal symptoms, 38 showed abnormalities representing 19 pathological entities. The appearances of these lesions on scans are compared with normal scans, and the usefulness of CT scans in assessing lesions of the bone and within the canal is discussed.

White matter disorders of prematurity: Association with intraventricular hemorrhage and ventriculomegaly

OBJECTIVES Because intraventricular hemorrhage (IVH) often precedes the development of sonographically defined white matter damage (WMD) in very preterm infants, we sought to identify the IVH characteristics that predict WMD. HYPOTHESES We evaluated variations on the null hypothesis that infants with IVH are no more likely than infants without IVH to have WMD. These variations dealt with characteristics of the IVH (presence or absence of ventriculomegaly) or characteristics of the WMD (size, localization, and laterality). METHODS A total of 1605 infants weighing 500 to 1500 g at birth between January 1991 and December 1993 underwent standardized cranial ultrasound studies with 6 standard coronal and 5 sagittal views at postnatal days 1 to 3, 7 to 10, and at 3 to 8 weeks. RESULTS A total of 129 (8%) infants had WMD, either an echodensity alone (n = 59), an echolucency alone (n = 18), or both (n = 52). In analyses that controlled for gestational age, IVH was associated with a fivefold to ninefold increased risk of WMD regardless of size, laterality, or extent of lesions (P </=.0005). Compared with infants with neither IVH nor ventriculomegaly, infants with both were at 18- to 29-fold greater risk of WMD (P </=.0005). CONCLUSIONS In this study IVH and ventriculomegaly were powerful predictors of WMD occurrence, whether small or large, unilateral or bilateral, localized or diffuse.

The echographic characteristics of fatty tissues and tumors.

Fatty tissues and tumors have been described as characteristically cyst-like on ultrasound examination, with relatively few internal echoes. The authors offer several examples of lipomatous masses and tissues which are markedly echogenic. In vitro studies suggest that this is an inherent property of body fat and is not due to coexistent fibrous tissue or tumor vascularity. The echogenicity of fat has important implications for diagnostic ultrasound: (a) the presence of fat in tissues and masses may be demonstrated by ultrasound, and (b) because the high-level internal echoes blend with the echo pattern of bowel gas and retroperitoneal fat, lipomatous abdominal masses may easily be overlooked.

Computed tomography can guide focused exploration in select patients with primary hyperparathyroidism and negative sestamibi scanning

BACKGROUND The aim of this study was to analyze the utility of preoperative thin cut (2.5 mm) computed tomography (CT) in patients with primary hyperparathyroidism (PHPT) and negative sestamibi scans. METHODS A retrospective review of patients with PHPT was conducted from the prospective parathyroid registries of 2 tertiary referral centers. Of 482 patients, 63 with negative sestamibi scanning underwent thin cut CT of the neck and were included in the final analysis. RESULTS CT was 85% sensitive and 94% specific for correctly lateralizing the side(s) of diseased glands and 66% sensitive and 89% specific for predicting exactly the location of diseased glands. Sixty-six percent of patients underwent focused explorations, and 87% of patients underwent parathyroidectomy under local anesthesia. Pathology revealed a single adenoma in 83%, multigland disease in 14%, carcinoma in 1%, and no pathology in 2%. Average operative time was 73 minutes overall, but only 55 minutes in patients with precise CT localization (P = .02). CONCLUSION Thin cut CT is a helpful adjunct to preoperative workup in PHPT patients who have negative sestamibi localization and permits a focused neck exploration in a high percentage of those patients.

Intraoperative Sonography: Application in Renal Cell Carcinoma

Our ability to detect and potentially to treat renal tumors earlier has increased exponentially during recent years, in part owing to the introduction of more sophisticated imaging modalities. We report 2 cases in which intraoperative sonography was used to localize tumors not palpable at operation. In both cases surgery was performed on solitary kidneys for renal cell carcinoma in otherwise healthy patients.

Parathyroid localization with modified 4D-computed tomography and ultrasonography for patients with primary hyperparathyroidism†

In this article, we report our decade‐long experience in using modified 4D‐computed tomography in combination with ultrasonography (Mod 4D‐CT/US) to localize abnormal parathyroid glands in patients with primary hyperparathyroidism.

Topography of cerebral white-matter disease of prematurity studied prospectively in 1607 very-low-birthweight infants.

The objective of this study was to evaluate to what extent (1) the characteristics of localization, distribution, and size of echodense and echolucent abnormalities enable individuals to be designated as having either periventricular hemorrhagic infarction or periventricular leukomalacia and (2) the characteristics of periventricular hemorrhagic infarction and periventricular leukomalacia are independent occurrences. The population for this study consisted of 1607 infants with birthweights of 500 to 1500 g, born between January 1991 and December 1993, who had at least one cranial ultrasound scan read independently by at least two ultrasonographers. The ultrasound data collection form diagrammed six standard coronal views. The cerebrum was divided into 17 zones in each hemisphere. All abnormalities were described as being echodense or echolucent and were classified on the basis of their size, laterality, location, and evolution. Eight percent (134/1607) of infants had at least one white-matter abnormality. The prevalence of white-matter disease decreased with increasing gestational age. Most abnormalities were small or medium sized and unilateral; only large echodensities tended to be bilateral and asymmetric. Large abnormalities, whether echodense or echolucent, were more likely than smaller abnormalities to be widespread, and the extent of cerebral involvement was independent of whether abnormalities were unilateral or bilateral. Large abnormalities were relatively more likely than small abnormalities to involve anterior planes. Small abnormalities, whether echodense or echolucent, or whether unilateral or bilateral, preferentially occurred near the trigone. Using the characteristics of location, size, and laterality/symmetry, we were able to allocate only 53% of infants with white-matter abnormalities to periventricular hemorrhagic infarction or periventricular leukomalacia. Assuming that periventricular leukomalacia and periventricular hemorrhagic infarction are independent and do not share risk factors, and that each occurs in approximately 5% of infants, we would have expected 0.25%, or about 4 individuals, to have abnormalities with characteristics of both periventricular leukomalacia and periventricular hemorrhagic infarction, whereas we found 63 such infants. Most infants with white-matter disease could not be clearly designated as having periventricular hemorrhagic infarction or periventricular leukomalacia only. Periventricular hemorrhagic infarction contributes to the risk of periventricular leukomalacia occurrence, or the two sorts of abnormalities share common risk antecedent factors. The descriptive term echodense or echolucent and the generic term white-matter disease of prematurity should be used instead of periventricular leukomalacia or periventricular hemorrhagic infarction when referring to sonographically defined white-matter abnormalities. (J Child Neurol 2001;16:401-408).

Appendiceal CT in 140 cases diagnostic criteria for acute and necrotizing appendicitis

Computed tomography (CT) was performed in 140 patients with suspected acute appendicitis. Thin collimation (5 mm), intravenous contrast enhancement, 1-second scan times, and supplementary cecal air insufflation were emphasized. CT accuracy was 98% overall (137/140), and 99% in the 124 cases with early surgery. Necrotizing appendicitis was diagnosed by CT with 86% accuracy and 90% positive predictive value.

A review of 100 renal and perinephric sonograms with anatomic diagnoses.

Sonography is a non-invasive safe, convenient, quick and pain-free diagnostic modality, which can differentiate fluid masses from solid tumors and give a 3-dimensional representation of organs and masses in the retroperitoneum by biplanar sections. Sonography depends on the fact that high frequency sound has many characteristics of light and is, in fact, a sophisticated method of transillumination. A review of the first 100 consecutive patients who had sonography and anatomic diagnosis of the renal or perinephric abnormality shows the versatility and potentials of sonography. Of these 100 sonograms of renal and perinephric abnormalities 92 were correct by anatomic diagnosis.