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Biomedical subjects

N B Genieser

Publications and source records attributed to N B Genieser.

At least 19 recordsLinked to original sources

Obstructive jaundice caused by placement of a nasoenteric feeding tube.

Nasoenteric feeding tubes are a safe and effective means for providing nutritional support to the critically ill patient. Serious complications have been reported, but usually are the result of an improper path of the tube during placement. The authors report a case of ampullary obstruction and jaundice caused by a nasoenteric feeding tube, presumably caused by coiling of the tube in the duodenum. This report represents the first such case in the literature.

Child, Preschool

MR findings in Shone's complex of left heart obstructive lesions.

BACKGROUND: Shone's complex is a series of four obstructive or potentially obstructive left-sided cardiac lesions (supravalvular mitral ring, parachute deformity of the mitral value, subaortic stenosis, and coarctation of the aorta). Both the complete form (all four lesions) and incomplete forms (less than four lesions) have been described. OBJECTIVE: To determine which abnormalities of Shone's complex could be characterized by MR. MATERIALS AND METHODS: MR examinations in three patients (one complete, two incomplete) were retrospectively reviewed. RESULTS: A supravalvular mitral ring, found at surgery in one patient, was not identified. Regurgitant and stenotic flow across the mitral valve, abnormal motion of the valve leaflets and abnormalities of the papillary muscles were identified. Individual chordal attachments were difficult to resolve. Narrowing in the subaortic region and abnormal flow from the subaortic region through the valve plane were demonstrated. A discrete subaortic diaphragm in one patient was not resolved. Both focal and diffuse types of coarctation of the aorta were well characterized. CONCLUSION: MR imaging is suited to evaluation of patients with Shone's complex. Individual chordal attachments and thin diaphragms of the mitral and aortic valves were difficult to resolve.

Aortic Coarctation

Resonance imaging of a ruptured aneurysm of the sinus of Valsalva.

Ruptured aneurysm of an aortic sinus of Valsalva is a rare cause of left-to-right shunting. We show how resonance imaging can be used to make the diagnosis. This technique can successfully characterize the shunt as well as determine the presence of associated anomalies, such as ventricular septation and aortic regurgitation. It may be the only study required prior to therapeutic intervention.

Adolescent

Pediatric hepatic CT: an injection protocol.

OBJECTIVE: To determine an injection protocol for pediatric hepatic CT and to investigate the use of power injection. MATERIALS AND METHODS: Eighty-seven studies were prospectively performed using ioversol (320 mg iodine per cc) at 2 cc/kg. Three techniques were used: helical (1 s/slice); dynamic, non-breath-hold (5.5 s/slice); dynamic, breath-hold (10 s/slice) scans. The liver-scan time for each study was determined. Scan initiation ranged from 25 to 80 s. An injection duration (50-100 seconds) was selected. From the contrast volume (2 cc/kg x kg body wt) and injection duration, the injection rate (cc/s) was calculated for each patient. Each study was grouped by injection rate corrected for body weight (cc/kg/min) into: 1.2-1.5, 1.51-2.0, and 2.01-2.4. The aortic/liver attenuation curves were plotted for each group. RESULTS: Liver-scan time for helical studies was a mean of 26 s, for dynamic, non-breath-hold studies 75 s, dynamic breath-hold scans were 154 s. Injection rates of 1.2-1.5 cc/kg/min produced a scanning interval of 165 s. Injection rates of 1.51-2.0 cc/kg/min produced a scanning interval of 120 s. Injection rates of 2.01-2.4 cc/kg/min produced a scanning interval of 90 s. There was no increase in hepatic attenuation for the injection rates 2.01-2.4 cc/kg/min compared with 1.51-2.0 cc/kg/min. There was one complication related to injection through a central line. CONCLUSIONS: An injection protocol was determined for helical studies with injection rates of 1.7-2.0 cc/kg/min with initiation at 60 s; for dynamic, non-breath-hold studies with injection rates of 1.5-1.7 cc/kg/min with initiation at 50 s; and for dynamic breath-hold studies with injection rates of 1.2-1.5 cc/kg/min with initiation at 45 s. Power injection was used safely in our population.

Adolescent

Application of thin-section low-dose chest CT (TSCT) in the management of pediatric AIDS.

The aim of this study was to evaluate the usefulness of thin-section low-dose computed tomography (TSCT) in the management of children with AIDS, as chest radiographs (CXR) often fail to adequately explain the patients' clinical status. We performed 54 noncontrast TSCTs on 32 children. The patients aged from 3 months to 14.6 years, were diagnosed as having bacterial pneumonia, lumphocytic interstitial pneumonitis (LIP), Pneumocystis carinii pneumonia (PCP), or Mycobacterium avium-intracellulare infection (MAI). The scans were correlated with the clinical diagnosis, T-lymphocyte-subset percentages, and p24-antigen levels. Subsegmental consolidations were seen in patients with LIP, PCP, and MAI, and as an isolated finding in those with only bacterial pneumonia. Ground-glass haziness was seen exclusively with acute PCP. Reticulonodular thickening was identified only in patients with LIP. Mosaic perfusion was seen with MAI, LIP, and pneumonia. The presence of adenopathy correlated with CD4+ T-cell subset percentages. The greatest value of CT in this study was in detecting new disease when chest films failed to correlate with a patient's clinical state, and in demonstrating acute/subacute disease in patients with severe baseline chest-film changes. Recurrent pneumonias may represent progression of "smoldering" disease, rather than true recurrent disease following complete clearing. Adenopathy with low CD4+ levels should suggest lymphoma or infection with MAI.

AIDS-Related Opportunistic Infections

Traumatic abdominal pseudoaneurysm secondary to child abuse.

Traumatic injury to the descending thoracic and abdominal aorta is uncommon in children and is usually secondary to recognized blunt trauma. Child abuse has not been previously reported as a cause. We report a 3-year-old boy who was kicked in the abdomen by his father. A resulting pseudoaneurysm was successfully resected.

Abdominal Injuries

Feasibility of high-resolution, low-dose chest CT in evaluating the pediatric chest.

Thin-section, high-resolution (1.0/1.5 mm thick slices), low-dose chest CT scans were performed in 55 infants and children. The studies were carried out with 1- and 2-s scan (data acquisition) times using a high-resolution (bone) algorithm. Although there was some motion artifact, the studies provided valuable information for evaluating diffuse parenchymal lung disease. The thin slices provided finer detail and more diagnostic information than images representing thicker sections. Most studies were performed using between 40 and 80 mAs. It is estimated that the patients' radiation exposure was 20% that of conventional high-resolution CT (HRCT) and 57% that of routine chest CT. Diagnostic HRCT scans can be obtained in infants and young children without the need for suspended respiration or specialized ultrafast CT scanners.

Adolescent

Monitoring of girls undergoing medical therapy for isosexual precocious puberty.

We evaluated the use of sonography in monitoring the efficacy of suppressive therapy with a gonadotropin releasing hormone analogue in girls being treated for isosexual precocious puberty. Ten girls 5 to 9 years of age underwent serial sonography and hormonal stimulation tests on the same day. Sonographic trends of decreasing ovarian volume and uterine length indicated early suppression even when absolute values were above threshold. Changes in ovarian volume were the most sensitive predictor of pituitary-gonadal suppression. Sonography is a sensitive and accurate method of monitoring medical therapy; ovarian volume and analysis of interval change are the most sensitive barometers of change.

Child

Opportunistic infections and tumors in immunocompromised children.

HIV infection is responsible for a major proportion of the immunodeficiency disease seen in the pediatric population. The radiologic findings are varied and generally non-specific. The development of secondary neoplasms may present new diagnostic and therapeutic challenges as therapy for superimposed infections becomes more successful.

Child

Pictorial essay. Current evaluation of the patient with abnormal visceroatrial situs.

Patients suspected of having derangement of solitus asymmetry should be evaluated individually to determine abdominal visceral and vascular arrangement and to investigate associated problems. This evaluation should begin with plain films to assess cardiac and gastric positions and pulmonary vascularity. Assessment of the bronchial branching patterns should be attempted in all cases. Sonography will delineate the presence or absence of splenic tissue and the anatomy and relationships of the cava and the portal vein. When no spleen is found and the pulmonary vascularity appears congested, a subdiaphragmatic total anomalous pulmonary venous connection should be suspected and verified. If there are splenuli in the retrogastric area, particular attention should be paid to the status of the gallbladder, especially in children who do not have congenital heart disease. Selective spleen scans can confirm the presence of splenic tissue. The high cost and sedation requirement of MR would suggest that it be reserved for cases in which sonography is unable to answer the pertinent questions.

Heart

Spondylothoracic dysplasia. Clinical and sonographic diagnosis.

Spondylothoracic dysplasia, also known as short-trunk dwarfism or Jarcho-Levin syndrome, is a fatal autosomal recessive disorder characterized by vertebral and spinal defects with a short thorax. Until recently, in utero diagnosis could only be made radiographically. Sonographic criteria for antenatal diagnosis are discussed in conjunction with a review of the literature.

Abnormalities, Multiple

Sonography of the simple and complicated ipsilateral fused kidney.

Anomalies of renal fusion and their sonographic findings can be straightforward or quite complex. Sonograms of eight cases of simple and complicated anomalies of renal fusion in pediatric patients are reviewed to determine characteristic sonographic findings in such cases. The correct diagnosis can be suspected by evaluation of the following parameters: (1) the echoic texture of the renal "mass"; (2) the differential orientation of the renal pelves; (3) the content of the contralateral renal fossa; (4) the size of the ipsilateral kidney; (5) extension of the isthmus medially anterior to the spine; and (6) presence of a deep anteroposterior notch. Utilizing these parameters, a rationale for diagnosis and for selecting the appropriate sequence of further studies is suggested.

Child

Magnetic resonance imaging of cor triatriatum.

Magnetic resonance imaging utilizing spin echo sequences was used to demonstrate cor triatriatum in an 18-year-old boy. Phase map images aided the diagnosis by demonstrating the presence of slowly flowing blood in the accessory atrial chamber. Magnetic resonance is an excellent modality for the noninvasive diagnosis of cor triatriatum.

Adolescent

Brain tumors in infants less than a year of age.

A retrospective examination of brain tumors in infants less than a year of age was undertaken by reviewing their charts and CT scans. In contradistinction to brain tumors found in older children, most tumors were supratentorial in location. The most common histologic types included: astrocytoma, ganglioglioma and primative neuroectodermal tumors. Apart from their larger size at the time of presentation, these tumors were radiologically and pathologically similar to analogous tumors found in adults.

Brain Neoplasms

Cardiovascular disease: evaluation with MR phase imaging.

Magnetic resonance phase images are derived from conventional spin-echo (SE) pulse sequences and display properties of proton movement that occurs with blood flow. SE magnitude and phase images were obtained and retrospectively evaluated in 21 patients referred for potential cardiovascular abnormalities in which intracardiac or intravascular signal was detected. Abnormalities included intravascular and intracardiac thrombus, aneurysm, aortic dissection, flow alteration, atherosclerotic disease, and congenital cardiac anomaly. Thrombosis (six cases) was successfully differentiated from flow-related signal (15 cases) by comparing phase images with SE magnitude images; in cases of thrombosis, there was no phase shift in corresponding areas of increased signal intensity. In comparison, SE magnitude signal intensities alone were not an accurate indicator in differentiating thrombus from flow-related enhancement. Because phase images are sensitive for identifying flow, the SE magnitude signal of intravascular tumor or thrombus can be differentiated from that of flow effects with more clinical confidence.

Adolescent