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Purpose: To assess the uptake of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) in common and uncommon tumors in children and to develop a method for performing positron emission tomography (PET) studies in children with malignant neoplasms., Materials and Methods: Twenty-two pediatric patients with known or suspected malignancies (27 scans) underwent FDG PET. Tumor uptake of FDG was measured on PET scans., Results: Tumor uptake of FDG was detected in 17 of 21 patients with malignant disease. Neuroblastomas and their metastases (including those that did not absorb metaiodobenzylguanidine) intensely accumulated FDG. In a patient with Ewing sarcoma, FDG PET showed two foci of metastatic disease not evident on bone scans. In two patients, PET showed that large areas of the tumor were necrotic., Conclusion: FDG PET is feasible, is useful in the study of tumors in children, and may provide unique, clinically important information.

Purpose: To determine whether a lower radiation dose technique can be used for computed tomography (CT) of the pediatric pelvis without significant loss of diagnostic image quality., Materials and Methods: Thirty-six pediatric patients underwent CT at 80 mAs (experimental group), and 42 underwent CT at 240 mAs (control group). Anatomic details, image quality, and the degree of confidence in reaching a diagnosis were graded on a scale of 1 (poor) to 4 (excellent)., Results: The difference in perceived image quality between the experimental and control groups was not statistically significant. The mean scores for scans evaluated by the first reader were 3.88 for the experimental group and 3.92 for the control group (P = .2804). The mean scores for the second reader were 3.78 and 3.77 for the experimental and control groups, respectively (P = .8131)., Conclusion: A substantial dose reduction can be achieved if pelvic CT is performed at 80 mAs, without a recognizable deterioration of diagnostic image quality.

A fast gradient-recalled-echo sequence with cardiac-triggered segmented acquisition (fastcard) was compared with a standard T1-weighted spin-echo sequence with cardiac gating and respiratory compensation in the evaluation of pediatric patients with thoracic cardiovascular anomalies. Twenty patients aged 1 week to 24 years (median age, 9 months) with various abnormalities underwent magnetic resonance (MR) imaging. In 18 patients, MR imaging was performed with both gated spin-echo and fastcard. Two observers rated the clinical utility of each sequence. Fastcard images were superior to spin-echo images in 10 patients, equivalent in seven, and inferior in one. Two additional patients with suspected pulmonary vascular lesions were accurately evaluated with the fastcard technique. The fastcard technique provides superior demonstration of thoracic cardiovascular structures and turbulent flow and enables imaging in multiple phases of the cardiac cycle.

Objective: The purpose of this study was to describe the musculoskeletal MR findings in childhood dermatomyositis and to correlate MR findings with indicators of disease activity such as muscle strength and serum levels of muscle enzymes., Subjects and Methods: This prospective study included 24 children: 19 children with dermatomyositis and five control subjects. The diagnosis of dermatomyositis was established by clinical findings and serum levels of muscle enzymes in all patients, electromyography in six patients, and biopsy in four patients. At the time of the initial MR evaluation, patients were classified on the basis of clinical findings as having active (n = 15) or inactive (n = 4) disease. A total of 44 MR evaluations of patients with dermatomyositis were included in the study: 19 initial MR examinations and 12 examinations repeated after 4-6 months of therapy in patients with active disease. An additional 13 examinations were performed on five patients. Conventional T1-weighted (SE 600/20) and T2-weighted (SE 2500/80) spin-echo and fat-suppressed MR images were obtained. The T2-weighted images (TE = 80) were used for comparison. In addition to the visual assessment, ratios between the signal intensity of muscles (gluteus, adductors, quadriceps, and hamstrings) and the signal intensity of subcutaneous fat in the same tomographic section were calculated., Results: All patients with clinically active disease (n = 15) had abnormal findings on MR studies, whereas those with inactive disease (n = 4) had normal MR findings. Signal-intensity ratios of patients with active disease were greater than those in control subjects, whereas the ratios in patients with inactive disease were not different from those in control subjects. After 4-6 months of therapy, the average signal-intensity ratios of treated patients with repeated MR evaluations (n = 12) differed from ratios obtained before therapy in the same patients, but were not different from the ratios in control subjects. Other MR findings observed were perimuscular edema, enhancement of the chemical-shift artifact, and inflammatory changes of subcutaneous fat. Fat-suppressed imaging enhanced visualization of abnormalities. Markedly abnormal signal intensities of muscle were associated with marked elevations of serum levels of muscle enzymes; however, abnormal MR findings were visualized with normal serum levels of muscle enzymes., Conclusion: Findings of active childhood dermatomyositis on T2-weighted MR images include increased signal intensity in affected muscle, perimuscular edema, enhanced chemical-shift artifact, and increased signal intensity in subcutaneous fat. After therapy, signal intensity of muscle returns to normal. These MR findings are enhanced on fat-suppressed images.(ABSTRACT TRUNCATED AT 400 WORDS)

The role that imaging plays in the evaluation of the child with hypertension depends in large part on the results of thorough historical, physical, and laboratory examinations. How aggressively one searches for an underlying renal parenchymal or renovascular disorder must be individualized in each child. An individualized approach to renal imaging in children with hypertension is presented.

We reviewed the applications of CT, sonography, and MR imaging in diseases of the musculoskeletal system in children. Unique advantages of each technique are discussed, and common disease entities and practical applications of the three imaging methods are stressed. Evaluation of congenital dysplasia of the hip, hip effusion, and soft-tissue foreign bodies with sonography are emphasized. The role of CT in imaging patients with congenital dysplasia of the hip, tarsal coalition, osteomyelitis, and benign and malignant bone tumors is stressed. Common applications of MR that are emphasized include imaging of osteomyelitis, musculoskeletal tumors, normal bone marrow, and avascular necrosis. Innovations are briefly discussed, including evaluation of dermatomyositis with MR and imaging sternoclavicular dislocation, congenital vertical talus, and fractures and dislocations with sonography.

A hybrid fat-suppression sequence in magnetic resonance (MR) imaging was used to evaluate inflammatory muscle disorders in seven children: five patients with dermatomyositis, one patient with vasculitis, and one patient with viral myositis. Fat-suppressed multisection axial images obtained with the same repetition and echo times as those used to obtain standard spin-echo (SE) images enabled direct comparison of images, with little variation of T1 and T2 weighting. In six patients, the contrast on images obtained with T2 fat suppression was 15%-20% greater than contrast on conventional T2-weighted SE images. In all seven patients, the subjective judgment was that T2-weighted fat-suppression sequences improved visualization of muscle abnormalities. It is concluded that T2 fat suppression is useful in evaluation of inflammatory muscle disorders in children because it increases contrast and eliminates fat as a cause of muscle abnormality.

Magnetic resonance imaging (MRI) was used to follow the course of juvenile dermatomyositis from the onset of disease through resolution of a primary relapse. The signal intensity of the T2-weighted image of involved muscles was elevated during periods of disease activity, and returned to approximately normal levels with effective suppression of disease activity. T1-weighted images of involved muscles remained approximately normal despite disease activity.

Sonographic measurement of renal length is used commonly to evaluate growth of the kidneys in children. However, no previous studies have been performed to determine the degree of interobserver and intraobserver variability in such determinations. We measured the interobserver and intraobserver error in sonographic measurements of renal length obtained independently by three experienced imagers in 21 children (41 kidneys). The mean interobserver variation between any two imagers ranged from 3.87 to 5.49 mm. The mean intraobserver variation was 0.87 to 3.61 mm. The observed variability in sonographic measurement of renal length is comparable to the expected annual increase in length of the kidneys during childhood (2.2-5.7 mm per year). Therefore, caution is suggested when using sonography to evaluate renal growth in children during a year's time.

Skeletal maturation is marked by an orderly and reproducible sequence of recognizable changes in the appearance of the skeleton during childhood. Such changes include the timing and sequence of the appearance of the centers of ossification, specific alterations in the contours of the bones, and the timing and sequence of the ultimate closure of the growth plates. Radiographically, skeletal maturity can be assessed by comparing the radiographic appearance of portions of an individual child's skeleton with the standardized appearance in a comparable population of children at various stages in their progress toward maturity. Radiographic assessment of skeletal maturity in the child is most frequently based on the appearance of the hand and wrist. Considerable normative data are available for this examination. The Greulich-Pyle atlas is the system which is most frequently used in the United States. Assessment of skeletal maturity can be useful in the evaluation and management of children with various endocrinopathies (especially those involving the pituitary, thyroid, and gonads) and in children with malformation syndromes. Skeletal maturity assessment is also frequently requested as part of the evaluation of children who are either too tall or too short for their chronologic age and can be used to predict height at maturity. Such assessment can also be useful in planning orthopedic procedures in which the outcome may be influenced by subsequent growth of the child (e.g., surgical management of scoliosis or leg-length discrepancy).

Compression of the left renal vein (LRV) between the superior mesenteric artery and the aorta is thought to be a cause of hematuria, periureteral and gonadal varices, and varicocele ("Nutcracker phenomenon"). Previous investigators have suggested that this diagnosis can be made on computed tomography when the LRV ratio greater than or equal to 1.5 (the diameter of the LRV proximal to the aorto-mesenteric angle divided by the diameter of the LRV distal to the aorto-mesenteric angle). This study was designed to establish the normal range for the LRV ratio on CT in children. The LRV ratio was measured in thirty-nine consecutive children undergoing intravenously enhanced CT of the abdomen. None of the children had hematuria on urinalysis immediately before or after the CT. Children with any known abnormality involving the kidneys, adrenal glands, IVC, or renal or gonadal veins were excluded. The patients ranged in age from 3.4 to 18.5 years (mean = 10.6 years). LRV ratio ranged from 0.78 to 2.00 (mean = 1.46; S.D. = 0.312). Twenty of the 39 children (51.3%) had a LRV ratio greater than or equal to 1.50. The conclusion is that the normal range for the LRV ration is too wide for it to be useful in diagnosing LRV entrapment and that a LRV ratio greater than or equal to 1.5 on CT is normal in children.

Clinical observation suggested an association between an increased cardiothoracic ratio (CT) and growth retardation (IUGR) in the premature neonate. To investigate this hypothesis, a case-control study was performed. Study subjects included 23 cases (IUGR) and 55 control (appropriate for gestational age [AGA]) premature infants with birthweights 2000 gm or less; Apgar scores greater than 5 at 5 minutes; no congenital heart disease; no polycythemia; no toxoplasmosis, rubella, cytomegalovirus, or herpes infection. In random order, the first chest radiograph of each infant (less than 24 hours) was reviewed by a single radiologist, unaware of the infant's growth status. The CT ratio was computed after measuring the widest internal width of the bony thorax and the cardiac diameter. Mean birthweight (+/- 1 SD) of the IUGR infants was 1161 +/- 289 g and of AGA infants was 1401 +/- 401 g (p less than 0.002); the mean gestational ages (+/- 1 SD) were 33.2 +/- 2.8 and 30.8 +/- 2.5 weeks (p less than 0.001). Mean CT for IUGR infants was 0.57 +/- 0.07 (+/- 1 SD) versus AGA infants, 0.51 +/- 0.04 (+/- 1 SD), p less than 0.001. When the infants were stratified by growth status and CT ratio, 11 of 23 IUGR and 1 of 55 AGA infants had an increased CT ratio p less than 0.0001. When birthweight and gestational age were covaried, growth status remained the best predictor of CT, p = 0.005. There is a strong association of increased CT and growth retardation in premature infants with birthweights 2000 gm or less.

Double chambered left ventricle is a very rare anomaly within the broader category of "subdivision of the left ventricular cavity," which includes the relatively more common congenital aneurysms and diverticulae. We report a case of an adolescent with double chambered left ventricle that MR clearly delineated, resulting in successful surgical correction.

Documentation of muscle involvement in a child thought to have dermatomyositis may require the performance of invasive procedures such as electromyography and/or muscle biopsy. We describe four patients with dermatomyositis in whom magnetic resonance imaging (MRI) demonstrated the muscle involvement. The involved muscles had increased signal intensity on the T2-weighted images (SE 2500/80) and normal appearance on the T1-weighted images (SE 600/20). The involvement of the muscles was not uniform. There was good correlation between the distribution of muscle involvement by MRI and functional testing. Follow-up MRI scans in patients with favorable outcome demonstrated that the affected muscles had returned to normal signal intensity. Although the MRI findings are not specific, in the proper clinical context they may be helpful in establishing the diagnosis of dermatomyositis. MRI may also be used in establishing an appropriate muscle biopsy site. In addition, MRI may be used for monitoring the progress of the disease.

The authors review techniques available to image the airway, normal radiographic airway anatomy, pitfalls in imaging the airway, and radiographic findings in various pathologic processes that may cause airway obstruction. A brief discussion of the application of imaging in the child with sleep apnea is included.

An unusual case of omental cyst is described. The child initially presented with a unilocular intraperitoneal fluid collection on CT. After paracentesis, CT showed freely layering peritoneal fluid, with eventual complete resolution of fluid. CT eight months later demonstrated re-appearance of a multi-septated cystic mass. At surgery, an omental cyst was found.

We have observed soft-tissue calcification of the chest in 4 of 54 patients following thoracotomy in the neonatal period for a Blalock-Taussig or a Blalock-Hanlon procedure. The time of appearance ranged from 2 weeks to 11 months. This calcification is similar to myositis ossificans in having a traumatic origin. In one of the patients, it resolved spontaneously.

The postnatal development of 3H-5-HT specific binding sites has been studied in rat brain. Experimental conditions allowed the characterization of the class of sites corresponding to the synaptosomal receptor for 5-HT. The related affinity constant and maximal binding were measured at various ages after birth. During the second week after birth, the serotonin receptor system developed explosively, the maximal number of sites increasing from a nonsignificant value to that observed in adult rats. Lesion of the presynaptic neurons using 5,6-DHT led to a significant increase of the number of sites.

Three cases of talocalcaneal and two calcaneonavicular tarsal coalitions were evaluated with plain radiography and computed tomography (CT). Four of five of the patients' plain films were read as normal. Two of three patients had a Harris view performed for the talocalcaneal middle facet coalitions. One was read as negative, the second as positive after five attempts at obtaining the correct angle. In addition, two of three patients with talocalcaneal middle facet coalition had conventional tomography. One was read as positive, the other as negative. Arthrography was done in one case of calcaneonavicular coalition and was suspicious for the coalition. CT was diagnostic in all five cases. It provided an accurate depiction of the coalition site. In addition, the width of the bony bar at the coalition site could be determined to help plan surgical treatment. In patients presenting with painful feet, in whom tarsal coalition is suspected, plain radiographs should be the initial screening procedure. If secondary signs are present, CT is recommended as the best imaging modality to investigate further for tarsal coalition. Also, if plain films are normal but the index of suspicion is high, CT is thought to be the next most valuable test for diagnosing tarsal coalition.

To evaluate the effect of aluminum on growing bone in the presence of normal renal function, the following experiment was performed. Eight littermate pair-fed pigs (5 weeks old) were randomly assigned to one of two study groups: control C, n = 4, or aluminum treated Al, n = 4. Daily intravenous injections of either aluminum 1.5 mg/kg/day (Al group) or vehicle only (C group) were given during the 8-week duration of the study. The radiographic findings which appeared in the aluminum-treated group and not in the controls consisted of areas of sclerosis in the submetaphyseal regions and the periphery of epiphyses. In addition there was separation of the anterior tibial tubercle. The growth plates did not increase in width despite the presence of osteomalacia and histologic evidence of extensive deposition of aluminum in bone. The area of sclerosis visualized in the radiographs correlated histologically with thickened bony trabeculae. The increased width of these trabeculae is attributable to an increase in primary spongiosum and broadened seams of osteoid.

This report describes the course and prognosis of four patients with Noonan syndrome and associated pulmonary lymphangiectasia. All patients had (1) superior deviation of the QRS axis in the frontal plane of the electrocardiogram; (2) moderate to severe valvular pulmonary stenosis, with an additional atrial septal defect secundum type present in two and a small ventricular septal defect in one; and (3) bilateral prominence of the pulmonary interstitial markings (dilated lymphatics), with or without accompanying pleural effusions on the chest radiographs. Surgical repair of the cardiac lesion may cause undue morbidity because of the interruption of the engorged pleural or mediastinal lymphatics.

Concentric reduction of a dislocated hip can be evaluated by anteroposterior views or linear tomography. Anterior relationships, however, may be difficult to evaluate from a frontal radiograph despite good visibility. Computed tomography (CT), because of its cross-sectional imaging capabilities, is superior in demonstrating these relationships. The CT appearance of two types of dislocations (posterior and lateral) is described. A posterior dislocation should be suspected if the femoral metaphysis approximates the acetabulum, a mass projects behind the ischium, or the fat plane anterior to the gluteus maximus is deformed or displaced posteriorly.

Congenital tracheal stenosis is an intrinsic narrowing of the tracheal lumen due to complete cartilaginous rings. We evaluated the role of the chest radiograph, high kV films, CT and bronchoscopy in five patients with congenital tracheal stenosis. CT was superior to chest radiography and high kV films in the evaluation of the presence and extent of the stenosis. CT was superior to bronchoscopy in the evaluation of the distal extent of the stenosis in two patients. In addition, CT is useful in ruling out external compression of the trachea by a mass or associated vascular anomaly.

The majority of children with traumatic injuries of the brachial plexus recover with only minor sequelae. Some patients develop residual deformity, however. This deformity may consist only of internal rotation contractures, but in some patients subluxation of the humeral head may be present. CT is useful in the evaluation of: the presence or absence of subluxation, deformity of the glenoid and the proper placement of the humeral head in plaster or orthotic devices.

The role of computed tomography (CT) in the evaluation of the gluteal region was assessed. Six cases of gluteal masses were studied preoperatively by CT; several were also studied with conventional radiographic methods, including barium enema, cystogram, and intravenous urogram. Our case material included an epithelioid sarcoma, Ewing's sarcoma, endodermal sinus tumor, cystic hygroma, neurofibromatosis, and a normal variant. The conventional radiologic studies were normal or demonstrated nonspecific soft tissue density mass effect. By comparison, CT, with its cross-sectional imaging capability, provided unique diagnostic information. CT depicted the presence and origin of a mass, provided tissue characterization, and showed the extent of the lesion, often demonstrating the gluteal mass as an extension of an intrapelvic lesion. CT was valuable in monitoring tumor response to therapy, detecting recurrences, and excluding normal variants as the cause for a gluteal mass. The information provided by CT was important in treatment planning.

The distance between the midpoint of the distal radial epiphyseal growth plate and the proximal end of the third metacarpal offers a useful measure for determining wrist size. Standards of this distance as compared to intermetacarpal width and second metacarpal length are presented. These measures (or ratios) should be useful in evaluating patients with juvenile rheumatoid arthritis and a number of congenital malformation syndromes, particularly when the carpals are still not fully ossified. Shortening of the carpus occurs in multiple epiphyseal dysplasia, the otopalatodigital syndromes, Turner syndrome, arthrogryposis, and in juvenile rheumatoid arthritis. A relatively large carpus is present in achondroplasia.

[(3)H]5-HT specific binding sites have been characterized in the rat spinal cord. Experimental conditions allowed us to study a single class of sites possibly related to the postsynaptic receptor for 5-HT. Binding constants (KD and Bmax) are described for adult and developing animals. No substantial changes in affinity were observed but the number of receptors increased from birth up to day 20 postnatally, stabilizing thereafter. The developmental pattern of a presynaptic marker, tryptophan-5-hydroxylase, was similar to that of binding sites., (Copyright © 1984. Published by Elsevier Ltd.)

Three cases of pulmonary sequestration evaluated by bolus dynamic computed tomography are described. The computed tomography appearance and the differential diagnosis are discussed. It is important to recognize the advantages of the bolus dynamic technique in the evaluation of pulmonary sequestration as it may eliminate the need for further studies.

Hypothyroidism affects linear growth less than it affects skeletal maturation, while hypopituitarism linear growth is more severely affected. By determining the mean age for the length of the second metacarpal and dividing by the skeletal age, a ratio R was obtained in 15 hypothyroid children and in 33 with hypopituitarism. R was more than 1 in most hypothyroids and less than 1 in most children with hypopituitarism. Thus, a distinction between these two entities can be made simply from a hand radiograph and appropriate reference sources for determining second metacarpal length age and skeletal age.

The presence of gastrointestinal (GI) tract hemangiomatosis was demonstrated by computed tomography in two children who presented with lower GI tract bleeding. Marked vascular enhancement of the bowel during rapid intravenous administration of contrast material and dynamic scanning is characteristic, similar to that seen with hemangiomas elsewhere in the body. Barium examinations demonstrate submucosal lesions within the bowel and are useful to approximate the length of bowel involvement.

Twelve children (aged 4-15 years) with suspected coarctation of the aorta or restenosis of the aorta after previous coarctation repair were considered for balloon angioplasty. Gated magnetic resonance (MR) imaging and cineangiography of the aorta were performed before angioplasty in all 12 children. In six of the nine children treated with angioplasty, MR imaging was performed between 1 day and 4 months later. Correlation with cineangiography showed that MR imaging accurately delineated the site and characteristics of the coarctation before balloon angioplasty. After balloon dilation, MR demonstrated a significant increase in the diameter of the aorta at the coarctation site in four patients and no change in two patients. No complications such as aneurysm formation, dissection, or hematoma were detected as a result of balloon angioplasty in the follow-up MR studies. A decrease in the number and size of collateral vessels was identified in successfully treated patients. MR was useful in identifying patients who were unlikely to benefit from angioplasty, determining the appropriate balloon size for angioplasty, and noninvasively monitoring patients who underwent angioplasty.

The purpose of this prospective study was to assess and compare the roles of CT, sonography, and cineangiography in the evaluation of the central pulmonary arteries. Twenty patients with severe cyanotic congenital heart disease were evaluated. In six patients, cineangiography failed to identify pulmonary arteries (four right, two left) that were seen by CT. Narrowing within the right pulmonary artery was seen more clearly by CT and sonography than by cineangiography in one-third of patients. By contrast, narrowing of the origin of the left pulmonary artery shown by cineangiography was not detected by either CT or sonography in four of four patients. CT has a complementary role and should be performed when the pulmonary arteries are not well seen by cineangiography or sonography, confirmation of the patency and adequacy of the pulmonary arteries is necessary before complete repair, or documentation of interval growth of the pulmonary arteries is desired after palliative surgery.

CT and MR join echocardiography in the noninvasive evaluation of the child with congenital heart disease. This article discusses the uses of these modalities in the assessment of the cardiovascular system in children.

The presentation of a foregut cyst may vary from an asymptomatic mass discovered as an incidental finding in a chest radiograph, to signs or symptoms secondary to airway compression by the cyst. The radiographic evaluation of a child with a possible foregut cyst usually consists of a chest radiograph and barium esophagogram. Although this approach is often sufficient, in other instances delay of treatment occurs or unnecessary workups are performed due to the inadequacy of the approach. CT is useful for depicting cryptic foregut cysts, clarifying abnormal radiographs, avoiding unnecessary workup of patients by establishing the precise location of the mass, and defining the cystic nature of the mass and excluding other etiologies.

Femoral torsion has been measured in infants and children by computed tomography. The method requires two scans, one through the femoral neck, another through the femoral condyles. A specially designed device and packing about the knees assures immobilization of the legs. Slight variations in the positions of the sections in the neck and condyles do not alter the measurement significantly. Intraobserver and interobserver errors are low, 2 degrees and 3 degrees mean error, respectively. The radiation required involves small tissue volumes at about 1.7 R (4.4 x 10(-4) C/kg). Measurements are more difficult when the femoral necks are short or vertically oriented. The method appears to have sufficient accuracy for clinical purposes.

CT plays an important role in the management of children with congenital dislocation of the hip and torsional abnormalities of the femur. In addition, CT is also useful in evaluating children with inflammatory, neoplastic, and traumatic abnormalities of the pelvis.

The diagnosis of osteomyelitis is usually clear by a constellation of clinical, radiographic, and/or scintigraphic findings. Computed tomography may be used to clarify the nature of a bony process. In addition to the CT findings already described, an additional finding is reported, consisting of the visualization of a small sequestrum. This finding has to be differentiated from the similar appearance in osteoid osteoma, intraosseous lipoma, fibrous dysplasia, and osteogenic sarcoma.

Children and young adults with hemolytic anemias requiring frequent transfusions develop increased liver iron content. We evaluated 15 chronically transfused children with sickle cell disease to determine whether spin-echo magnetic resonance (MR) imaging was useful in assessing the degree of iron overload. Quantitative MR parameters were correlated with liver biopsy iron determinations and serum ferritin levels. The best predictor of liver iron was the ratio of the intensities between the liver and paraspinal musculature on somewhat T1 weighted sequence (repetition time 0.5 s, echo time 28 ms), R2 = 0.58. Magnetic resonance was able to separate those patients with liver iron levels greater than 100 micrograms/mg (intensity ratios approximately 0.4), from those with levels less than 100 micrograms/mg (intensity ratios near 1). However, MR was unable to quantitate liver iron in patients with values ranging from 100 to 400 micrograms/mg since similar intensity ratios were present in this range. Thus, MR provides a qualitative rather than quantitative assessment of liver iron overload.

Compression of the bronchi by vertebral bodies is an uncommon cause of atelectasis. This report describes a patient with such a compression and the important role of CT in establishing the etiology.

Among 216 primary renal tumors collected from a pediatric population in metropolitan Chicago, 6 instances corresponded in multiloculated cystic masses conforming to the diagnostic criteria of so-called cystic nephroma. Histopathologically, the component tissues were entirely mature in 2 cases, but in the remaining 4 the septa between cysts contained variable amounts of primitive or embryonic tissues; in one of these, a grossly visible mass formed a nodule of typical Wilms tumor. Our experience agrees with previous reports that favor closer structural similarity of these lesions to nephroblastoma than to any known form of cystic malformation. This concept has important consequences on the therapeutic approach to preoperatively diagnosed multilocular cystic masses of the kidney, and supports the idea that nephrectomy is the treatment of choice. Metastases or local recurrence have not been reported in cases of cystic nephroma.

We have performed over 200 examinations in children with congenital dislocation of the hip during a 3-year period. From this experience, we conclude that computed tomography is useful in the evaluation of: (a) concentricity of closed reduction; (b) obstacles to closed reduction, such as infolding of the capsule, secondary to a tight iliopsoas tendon; (c) femoral torsion; (d) intraarticular obstacles contributing to persistent subluxation, such as (1) hypertrophy of the pulvinar, (2) intraarticular soft-tissue interposition, and (3) iatrogenic obstacles, such as metallic pins penetrating into the joint space; and (e) acetabular configuration, specifically (1) anterior or posterior lip of the acetabulum, (2) capacity of the acetabulum, and (3) acetabular torsion.

Serial concentrations of basal serum LH, FSH, testosterone, and LH and FSH responses to intravenous gonadotropin-releasing hormone were measured before and during six months of administration of fluoxymesterone or oxandrolone in 14 boys with constitutionally delayed growth and adolescence, in order to assess the effects of these androgens on maturation of the hypothalamic-pituitary-gonadal axis. Before therapy all boys had normal hormonal responses based on bone age. At the end of six months therapy 10 of the 14 boys had lower LH responses (34 to 89% reduction) to GnRH without consistent changes in FSH responses. With both androgens, there there was significant suppression of both basal serum FSH and testosterone. Eleven boys were restudied six months after completion of therapy; basal serum LH, FSH, and testosterone and responses to GnRH were equal to or greater than pretreatment levels, indicating recovery or progressive maturation of the HPGA. All boys had increased growth velocity and imporved weight gain without excessive bone age advancement; all had improved psychosocial adjustment.

The iliopsoas tendon can interpose between the femoral head and the acetabulum, preventing reduction or stability of reduction of a dislocated hip by a closed method. The tendon produces an infolding of the capsule and labrum. This infolding of the capsule and labrum creates an "isthmus" between the capital and the acetabular parts of the capsule. This deformity of the capsule was recognizable on computed tomography (CT) in 10 patients, all of whom had surgical confirmation of the findings. The presence of hypertrophied pulvinar can also be recognized by CT.