Detection of intraventricular hemorrhage (IVH) by transcephalic impedance (TCZ) in premature infants.

Transcephalic impedance was measured serially in 45 preterm infants less than 1500 g birth weight in order to test the method for the early detection of intraventricular hemorrhage. TCZ increased in all seventeen (38%) infants who developed IVH diagnosed by CT-scan or autopsy. Five of 8 infants monitored 4-8 weeks following confirmed IVH developed hydrocephalus documented by repeat CT-scans; all 5 were discovered early by the TCZ-method 2-3 weeks before physical findings or an increasing head circumference indicated the possibility of hydrocephalus. TCZ appears to be a useful non-invasive clinical guide to the occurrence and course of IVH in the newborn.

Pseudomyxoma peritonei: computed tomography and sonography.

Computed tomography was used to evaluate four patients with pseudomyxoma peritonei. Sonography was used to evaluate two of these patients. In three of four cases, the findings of liver scalloping and/or ascitis septations suggested the diagnosis. The differential diagnosis fo widespread peritoneal processes is considered.

Pitfalls in the diagnosis of extraadrenal pheochromocytoma.

Precise localization of pheochromocytomas is an essential part of their preoperative management. As a significant number of these tumors may be extraadrenal multiple, or hypovascular, they may not be detected by computerized body tomography (CBT) or arteriography without film subtraction. In seven patients with extraadrenal pheochromocytomas, all tumors were demonstrated by arteriography. In two cases, subtraction films revealed tumors that had not been visualized on the non-subtraction films. CBT, performed in four patients, demonstrated a mass in two but failed to visualized tumors in the other two.

Traumatic aortic aneurysm: validity of esophageal tube displacement sign.

Displacement of the nasogastric tube to the right as a new sign in the diagnosis of an acute traumatic rupture of the thoracic aorta was reevaluated by statistical analysis in 28 patients (seven patients with a traumatic aortic aneurysm and 21 patients with normal aortas). This new sign was compared with the commonly used chest radiographic findings in 46 patients (eight patients with a traumatic aortic aneurysm and 38 with normal aortas). This study showed that when both the trachea and the nasogastric tube were shifted to the right, as seen on the chest radiograph, the patient had a 96% probability of having an acute rupture of the thoracic aorta.

Pseudopathologic hip fracture: anatomic explanation.

Fracture of the hip may result in external rotation of the femoral diaphysis. When this occurs the proximal diaphysis may appear homogeneously dense, particularly in elderly woman. Computed tomography shows that the misleading appearance is due to variations in cortical thickness anteroposteriorly and mediolaterally. This finding is important as this appearance of the femur must be distinguished from a pathologic fracture.

Nuclear magnetic resonance and computed tomography: comparison of normal human body images.

Normal human body images of the thorax and abdomen were obtained using nuclear magnetic resonance (NMR) and computed tomography. Correlation of the images allowed precise anatomic identification of organs and structures. Differences between the images appear to be significant. NMR has potential as a methodology for assessing and imaging nuclear composition. Certain clinical implications from this technique are discussed.

CT of ascites: differential diagnosis.

Forty-three patients with ascites were evaluated with computed tomography (CT). Neoplasm accounted for 72% of the cases; the remainder included inflammatory processes (10%), cirrhosis (8%), trauma (2%), renal transplant (2%), congestive heart failure (2%), and unknown (4%). An accuracy of 93% was achieved in correctly predicting the presence of ascites alone or together with a mass. The potential for diagnostic error when mass lesions coexist with ascites is discussed and parameters are described to help avoid such errors. These include: (1) knowledge of the normal anatomy of the fluid-filled intraperitoneal space and fluid flow patterns; (2) inspection of the intra-/extraperitoneal interface; and (3) evaluation of the bowel-mesentery pattern.

Diagnostic imaging in pediatric emergencies.

Evaluation of pediatric emergencies by diagnostic imaging technics can involve both invasive and noninvasive procedures. Nuclear medicine, conventional radiography, ultrasound, computerized axial tomography, and xeroradiography are the major nonangiographic diagnostic technics available for patient evaluation. Appropriate decisions regarding choice of these imagining technics can be made only if the advantages and limitations of each are known. We will emphasize the use of computerized axial tomography, nuclear medicine, xeroradiography, and ultrsound in the evaluation of emergencies in the pediatric age group. Basic principles with specific reference to clinical disorders will be presented. Since the radiologist is the primary consultant with regard to diagnostic imaging, his knowledge of these modalities can greatly influence patient care and clinical results.

Intracranial ring lesions: can we differentiate by computed tomography?

The ability to differentiate brain abscess, brain tumor (primary and metastatic), and cerebral vascular accident (CVA) using the patient's age, ten ring lesion image-parameters, and two mathematical algorithms (Bayes theorem and linear discriminant function analysis) was evaluated. From the eleven patients/image parameters, a subset of six parameters was found which could partially separate the patients having those three diseases in which ring lesions occurred. The correctness of the individual disease classifications was as follows: abscess (84% accuracy), tumor (96% accuracy), and CVA (17% accuracy). The ordered list of parameters which were found to be best for separating the diseases were 1) ring thickness variability, 2) patient's age, 3) outside ring diameter, 4) average value of CT numbers in ring center, 5) maximum ring thickness, and 6) lesion (edema)-to-ring ratio. The overall classification accuracy was 86%. Three additional subsets of six parameters were identified which were disease-specific; each subset, however, was slightly different for each disease. These data are useful both for diagnosis and for identifying lesion parameters which are disease-specific and therefore deserving of further experimental or observational analysis.

Intracaval extension of renal cell carcinoma.

Intravenous extension occurs in many patients with renal cell carcinoma. Preoperative recognition is essential as venous involvement alters the surgical approach and clinical staging of the tumours. The venous extension of tumor has a characteristic arteriographic appearance, the recognition of which should prompt venacavography. Computerized body tomography (CBT) may also detect renal vein and caval extension and provide evidence of early ascites from the Budd Chiari syndrome associated with hepatic vein obstruction from intracaval tumor extension. However, it may be difficult to distinguish intracaval blood clot and tumor on the basis of CBT criteria alone. Of the four patients with intracaval growth of renal cell carcinoma, three received preoperative therapeutic tumor embolization, a procedure that carried no additional risk of tumor detachment and embolization.

Physical and dosimetric aspects of diagnostic geometrical and computer-assisted tomographic procedures.

Tomographic systems offer potential for visualizing sections of the body that are ambiguously imaged by "flat" detection systems. Effective utilization involves the synergistic combining of various considerations, including appropriate motion, contrast, and extent of the anatomic region of interest; cost-benefit considerations; assurance of correct electromechanical operation; and benefit-risk analysis of patient exposure.