Suspected appendicitis in children: focused CT technique for evaluation.

PURPOSE: To determine the accuracy of a focused computed tomographic (CT) technique with oral and intravenous contrast materials for the diagnosis of appendicitis. MATERIALS AND METHODS: Ninety-three abdominal-pelvic contrast material-enhanced CT scans obtained during 6 years in 54 girls and 39 boys (age range, 1-18 years) with right lower quadrant pain were retrospectively reviewed. The detected abnormal findings were recorded as being in the region above the upper pole of the right kidney, between the upper pole of the right kidney and the lower pole of the right kidney (RLP), or below the iliac crest. Sensitivity, specificity, and positive and negative predictive values were calculated. chi(2) analysis was performed to determine whether there were significant differences among patient groups according to region of detected disease. RESULTS: Fifty-five scans were abnormal: 38 showed appendicitis; and 17, other diseases. No scans, except two that showed pneumonia, had key findings above the RLP. Nineteen scans showed key findings between the RLP and the iliac crest. Thirty-three scans had diagnostic findings only below the iliac crest. The sensitivity (97%), specificity (93%), positive predictive value (90%), and negative predictive value (98%) of interpretation with all images for the diagnosis of appendicitis were the same as those of interpretation with only the focused images. CONCLUSION: CT performed to diagnose appendicitis can be limited to the region below the RLP.

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.

Interrupted aortic arch: diagnosis with gadolinium-enhanced 3D MRA.

PURPOSE: Our goal was to describe the use of gadolinium-enhanced 3D MR angiography (MRA) in the diagnosis of interrupted aortic arch (IAA). METHOD: A review of our MR data base from a 1 year period yielded three patients (1 day, 8 days, and 16 years old) with IAA. All were referred for evaluation of aortic arch abnormalities, only one of whom had suspected IAA. Patients were imaged at 1.5 T with a 3D spoiled gradient echo pulse sequence (TR/TE 3.8-8/1.3-2.7 ms) following the administration of intravenous gadolinium chelates. Surgical correlation was available in all cases. RESULTS: In the patient with clinically suspected IAA, a previously unsuspected aberrant right subclavian artery was identified that was not seen on preoperative echocardiography. In another patient with a history of previous mediastinal surgery, IAA was diagnosed without concomitant cardiac anomalies, suggesting surgical ligation. In the remaining patient, IAA was detected as well as a patent truncus arteriosus. CONCLUSION: Gadolinium-enhanced 3D MRA may provide for a rapid diagnosis of IAA that may not be possible with other noninvasive modalities. The rapid acquisition time enables unstable pediatric patients to spend minimal time in the MR suite.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Congenital anomalies of the lungs in adults: MR diagnosis.

Over an 18-month period, 11 adults with congenital pulmonary anomalies within the sequestration spectrum, identified either surgically or radiographically by CT and/or angiography, were evaluated with MR. These included seven patients with bronchogenic cysts, two with intralobar pulmonary sequestrations, one with scimitar syndrome, and one with bronchial atresia. In each case, MR showed at least some findings indicative of the correct diagnosis. MR proved especially effective in the detection of abnormal fluid collections (nine cases) and the identification of anomalous vessels (three cases). Fluid collections were easily identified in all cases, including four cases with high-density collections on CT (two with bronchogenic cysts and two with intralobar pulmonary sequestration), especially when single-level, multiecho T2-weighted sequences were obtained. Calculated T2 values ranged from 78 to 439 msec (average, 223 +/- 123 msec). Although T2 values were statistically significant for differentiating fluid from muscle (p = .0012) and fat (p = .0046), they were not sufficiently specific to allow precise fluid characterization. Significant limitations were also apparent, such as an inability to detect alterations in the parenchymal architecture of the lungs (three cases) or intrapulmonary vascularity (one case). Despite this, we conclude that MR may be of considerable value in the assessment of congenital pulmonary anomalies and in select cases obviate more invasive diagnostic procedures.