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Biomedical subjects

D C Kushner

Publications and source records attributed to D C Kushner.

At least 19 recordsLinked to original sources

Posttraumatic shock in children: CT findings associated with hemodynamic instability.

Twenty-seven of 1,018 children evaluated with contrast material-enhanced computed tomography (CT) after blunt trauma demonstrated a characteristic hypoperfusion complex. This complex was usually seen in young children (median age, 2 years). CT findings in all 27 patients included a dilated, fluid-filled bowel and abnormally intense enhancement of the bowel wall, mesentery, kidneys, aorta, and inferior vena cava. Twenty-four percent of all children with a Trauma Score of 10 or less and 20% with a Glasgow Coma Score of 6 or less had the hypoperfusion complex. All 27 patients had a normal blood pressure immediately before CT, but five (19%) became hypotensive within 10 minutes of intravenous contrast material administration. Twenty-three children (85%) died. Of 16 children who survived 24 hours, four (25%) developed renal insufficiency. The intense multiorgan enhancement pattern seen in the hypoperfusion complex indicates tenuous hemodynamic stability. Recognition that the constellation of CT findings is due to hypovolemic shock and not to injured viscera helps avoid unnecessary laparotomy.

Abdominal Injuries

Blunt pancreatic trauma in children: CT diagnosis.

The purpose of this study is to determine the efficacy of CT in the diagnosis of pancreatic injury after blunt abdominal trauma in children. Pancreatic injury was diagnosed at surgery, at autopsy, or on the basis of the development of clinical pancreatitis or a pseudocyst on follow-up imaging evaluation in 18 of 1045 consecutive children examined with CT after blunt trauma. Types of pancreatic injury included laceration in 11 children, transection in two, contusion in one, and tumor with hemorrhage in one. Three children had clinical pancreatitis without a pancreatic abnormality noted on CT. The pancreatic injury was prospectively identified on CT in 12 children (67%). The presence of fluid in the lesser sac was a useful marker for injury to the pancreas. This was noted in 13 children with pancreatic injury, whereas it was observed in only six (1%) of 1028 children in the absence of pancreatic injury (sensitivity, 72%; specificity, 99%). Fluid in the anterior pararenal space was less helpful in establishing the diagnosis of pancreatic injury (sensitivity, 44%; specificity, 98%). A pancreatic pseudocyst developed in four of the 11 survivors. Our experience shows that direct signs of pancreatic trauma may be difficult to identify on CT. Recognition of the limitations of CT diagnosis of pancreatic injury is important in helping to reduce errors of interpretation.

Child

Posttraumatic adrenal hemorrhage in children: CT findings in 34 patients.

The medical records and CT scans of 34 children with posttraumatic adrenal hemorrhage were reviewed. Adrenal hemorrhage was unilateral in 32 children; most injuries were on the right side. Bilateral hemorrhage was present in two children. The injured gland was oval in 27 cases and triangular in nine. Gland size ranged from 7 to 45 mm long and 4 to 30 mm wide. All adrenal hemorrhages had decreased attenuation relative to liver and spleen on contrast-enhanced CT. Ipsilateral diaphragmatic crural thickening was a frequent (61%) associated finding. Ipsilateral intraabdominal (61%) and intrathoracic (44%) injuries were often present. Clinical signs of adrenocortical insufficiency were not observed in any child. In summary, posttraumatic adrenal hemorrhage is uncommon in children. The hemorrhage is usually unilateral, right sided, and associated with ipsilateral visceral injury.

Abdominal Injuries

Sonography in neonatal congenital adrenal hyperplasia.

Adrenal gland size was evaluated in six infants with congenital adrenal hyperplasia. All of the infants had a severe deficiency of the 21-hydroxylase enzyme resulting in the salt-losing form of congenital adrenal hyperplasia. The adrenal measurements were compared with those of 40 consecutive age-matched, asymptomatic infants. Mean adrenal length was 14.4 mm and width was 1.9 mm in asymptomatic infants, whereas in infants with congenital adrenal hyperplasia mean adrenal length was 23.7 mm and width was 5.3 mm. Although infants with congenital adrenal hyperplasia may have normal-sized adrenal glands, mean length measurements of 20 mm or greater and mean width measurements of 4 mm or greater suggest the diagnosis.

Adrenal Glands

Retrograde colostomy and ileostomy enemas in neonates and infants: a simple combination of techniques.

A combination of previously known techniques for retrograde opacification of ileostomies and colostomies has been used successfully in neonates and infants. This combination of techniques used on very small stomas allows easy retrograde opacification of bowel. The technique uses a small feeding tube, a larger Foley catheter with an inflatable balloon, and a Lucite compression device, the construction and use of which are discussed here.

Barium Sulfate

Three-dimensional volumetric assessment of response to treatment: stage I and II diffuse large cell lymphoma of the mediastinum.

From 1981 to 1986, 12 patients with Stage I and II diffuse large cell lymphoma of the mediastinum were treated with 4 or more cycles of multiagent chemotherapy and for nine patients this was followed by mediastinal irradiation. The response to treatment was assessed by three-dimensional volumetric analysis utilizing thoracic CT scans. The initial mean tumor volume of the five patients relapsing was 540 ml in contrast to an initial mean tumor volume of 360 ml for the seven patients remaining in remission. Of the eight patients in whom mediastinal lymphoma volumes could be assessed 1-2 months after chemotherapy prior to mediastinal irradiation, the three patients who have relapsed had volumes of 292, 92, and 50 ml (mean volume 145 ml) in contrast to five patients who have remained in remission with residual volume abnormalities of 4-87 ml (mean volume 32 ml). Four patients in prolonged remission with CT scans taken one year after treatment have been noted to have mediastinal tumor volumes of 0-28 ml with a mean value of 10 ml. This volumetric technique to assess the extent of mediastinal large cell lymphoma from thoracic CT scans appears to be a useful method to quantitate the amount of disease at presentation as well as objectively monitor response to treatment.

Adolescent

Determination of leg length discrepancy. A comparison of weight-bearing and supine imaging.

Leg length discrepancy (LLD) may be determined by comparison of leg (lower extremity) lengths measured during physical examination or by radiographic means. Leg lengths may be measured with the patient in standing, weight-bearing position or in supine position. We used a low dose digital radiographic unit to test the hypothesis that there is a difference in LLD determined from radiographs obtained with the patient standing and those obtained with the patient supine. Conventional physical examination measurements also were compared with the radiographic measurements. The amount of LLD that is clinically meaningful has not been established, although 10 to 12 mm has been used as a threshold difference of clinical meaningfulness in the past. Analysis of our data, using 10 mm as the threshold of difference, reveals high level correlation by linear regression analysis and no significant difference by t-test between measurements obtained from standing and supine radiographs. A weak correlation and statistical difference existed between each set of radiographic measurements and physical examination measurements.

Adult

Lung lesions: correlation between viewing time and detection.

The influence of viewing time on the detectability of subtle and obvious lung cancers was studied. Frontal chest radiographs of 40 patients with subtle cancers, 40 patients with obvious cancers, and 40 healthy control subjects were shown to four observers for four different viewing times (0.25 second, 1 second, 4 seconds, and unlimited time). Receiver operating characteristic analysis was used to compare the detectability of lesions. Performance was degraded as viewing time decreased. The true-positive fractions for subtle and obvious cancers were 30% and 70% at 0.25 second and 74% and 98% at unlimited viewing time, respectively, for a given false-positive fraction of 20%. Thus, even with unlimited viewing time, the false-negative fraction for subtle cancers was 26%. The difference in detectability between subtle and obvious lung cancers was exaggerated at 1.0 second compared with 4 seconds and unlimited viewing time. The following conclusions were reached: (a) a substantial proportion of subtle lung lesions are missed, even with unlimited viewing time; (b) a large proportion of obvious lung cancers are detected with flash viewing; (c) the detectability of lesions decreases considerably as viewing time becomes less than 4 seconds; and (d) differences in detectability are exaggerated by short viewing times.

False Negative Reactions

Subtle lung cancers: impact of edge enhancement and gray scale reversal on detection with digitized chest radiographs.

The authors studied the impact of edge enhancement and gray scale polarity reversal on the detection of subtle lung cancers. Three experienced readers reviewed 46 biopsy-proved subtle lung cancers and 46 normal controls on chest radiographs that had been digitized into a 1,024 X 1,536-pixel matrix 8 bits deep. Receiver-operating characteristics (ROC) analysis of 1,656 pooled observations indicated that performance was best with the unmodified images (ROC area = 0.83), degraded by moderate enhancement of medium frequencies (ROC area = 0.80), and markedly impaired by severe enhancement of low frequencies (ROC area = 0.69). Gray scale polarity reversal further degraded performance (unenhanced ROC area = 0.74; moderately enhanced ROC area = 0.76; severely enhanced ROC area = 0.76). The authors conclude that edge enhancement and gray scale polarity reversal can impair the detectability of subtle lung cancers on digitized radiographs of medium resolution.

Humans

Hematologic bone marrow disorders: quantitative chemical shift MR imaging.

Twenty-one in vivo studies of bone marrow of the lumbar spine were performed with a 0.6-T commercial MR imager and proton chemical shift imaging techniques. Six healthy volunteers served as controls. Multiple measurements in the volunteers demonstrated reproducibility within errors of 5% for fat fraction and 6% for T1 of water. Ten patients who had histologically proved leukemia or aplastic anemia were then examined. The data show that changes in fat fraction represent the underlying reason for many of the changes observed in conventional spin-echo (SE) images of these disorders. Although both conventional and chemical shift images showed differences among the pathologic groups and healthy volunteers, fat fraction determined with chemical shift imaging was the single best discriminator among them. A two-point estimate of fat fraction was also evaluated. This rapid imaging protocol performed almost as well as the complete quantitative analysis in discriminating between pathologic and healthy tissue and showed improved discrimination compared with conventional SE techniques.

Adipose Tissue

Impact of sex steroids and their suppression on skeletal growth and maturation.

Forty girls with central precocious puberty (CPP) were studied before and during 1-3 yr of luteinizing hormone-releasing factor (LHRH) agonist (LHRHa) administration to examine the impact of gonadal steroid secretion and its suppression on skeletal growth and maturation. Pubertal growth velocity (GV) was 10.1 +/- 0.7 (SE) cm/yr and, when normalized for chronological age (CA) and bone age (BA), demonstrated that the effects of sex steroids were most profound in patients with the youngest CA and BA. GV decreased significantly to 5.8 +/- 0.3 (n = 40), 4.6 +/- 0.3 (n = 30), and 3.2 +/- 0.6 cm/yr (n = 12) during 3 yr of gonadal suppression and correlated negatively with starting BA. Skeletal maturation was markedly accelerated by premature sex steroid secretion (BA/CA = 1.8 +/- 0.1), was slowed significantly with gonadal suppression (mean delta BA/delta CA less than 1), and also was negatively correlated with the starting BA. Cumulative increases in predicted adult height were observed regardless of starting BA and averaged +2.0 +/- 0.4, +5.2 +/- 0.5, and +6.7 +/- 1.2 cm after 1, 2, and 3 yr of gonadal suppression. The comparable changes in height predictions across all BAs despite highly variable GVs underscore the need for use of developmental (i.e., BA-based) rather than CA-based standards in the analysis of growth during gonadal steroid exposure and suppression in childhood.

Body Height

Stage IA to IIB mediastinal Hodgkin's disease: three-dimensional volumetric assessment of response to treatment.

From 1979 to 1986, the response to treatment of 53 patients with stage IA to IIB mediastinal Hodgkin's disease was evaluated by three-dimensional volumetric analysis using thoracic computed tomographic (CT) scans. The mean initial volume of mediastinal disease in 34 patients treated with mantle and para-aortic irradiation was 166 mL, whereas for 19 patients treated with two to six cycles of multiagent chemotherapy and mantle and para-aortic irradiation the mean initial volume was 446 mL. Preliminary data suggested that patients with mediastinal volumes of less than 200 mL had a lower mediastinal relapse rate (13%) than patients with volumes greater than 200 mL (32%). For 12 patients receiving six cycles of nitrogen mustard, vincristine, procarbazine, and prednisone (MOPP), those with a greater than 85% reduction in volume 1 to 2 months after chemotherapy had a lower incidence of mediastinal relapse (zero of six, 0%) compared with patients having 85% or less reduction in volume (four of six, 67%). The primary value of this technique is that it provides a sensitive assessment of response to treatment and may aid in monitoring the effectiveness of a given treatment.

Adolescent

The effect of the respiratory cycle on mediastinal and lung dimensions in Hodgkin's disease. Implications for radiotherapy gated to respiration.

Changes in mediastinal and lung dimensions during respiration were studied to assess the potential of radiotherapy gated to respiration to minimize normal tissue irradiation. Twelve patients with mediastinal Hodgkin's disease were assessed using chest radiographs and thoracic computed tomography (CT) scans both during quiet breathing and at maximum inspiration in the standing, supine, and prone positions. A simple measure of the bulk of mediastinal disease, the ratio of the width of mediastinal mass to thoracic diameter, was determined from posteroanterior (PA) chest radiographs. The volumes of mediastinum, irradiated and protected lung if anteroposterior (AP) and PA mantle fields were used were determined from sequential thoracic CT scans and three-dimensional treatment planning and compared at quiet breathing and deep inspiration. The mediastinal width to thoracic diameter ratio decreased from quiet breathing to deep inspiration an average of 3%, 9%, and 11% for the standing, supine, and prone positions, respectively. Lung volumes as measured from the thoracic CT scans showed that on average, 8% more lung was protected at deep inspiration than at quiet breathing, independent of treatment position. The maximum increase in the percentage of protected lung from quiet breathing to deep inspiration was seen in patients with extensive mediastinal adenopathy suggesting that radiotherapy gated to respiration may be most advantageous in the subset of patients.

Hodgkin Disease

The evolution of neonatal herpes encephalitis as demonstrated by cranial ultrasound with CT correlation.

Three neonates with herpes encephalitis had serial cranial ultrasound and CT studies performed during their hospitalization. Initially, subtle changes of diffuse brain edema were present but with no ventricular compression. A second phase revealed progressive brain edema with ventricular compression. A third phase with enlarging ventricles indicates developing encephalomalacia. Occasionally cyst formation may be noted within the cerebral white matter, a phenomenon initially more readily evident by ultrasound.

Brain

Low-dose flying spot digital radiography of the chest: sensitivity studies.

Standard film examinations of the chest were compared with low-dose flying spot digital radiographic examinations obtained with a prototype unit in 174 patients. Analysis of pooled data from a double-blind study of 120 patients showed that film was more sensitive than digital images in the detection of pulmonary parenchymal abnormalities, that is, abnormal opacities, atelectasis, scar, and interstitial lung disease (P less than .05). Analysis of pooled data from a side-by-side study of 54 patients showed that the digital images were more sensitive than film in the detection of normal mediastinal and pleural soft-tissue contours, including the azygoesophageal recess, paraspinal line, and vertebral disk spaces (P less than .05). However, film was more sensitive than digital images in the detection of abnormalities of the lung, including scar, interstitial lung disease, septal lines, and the presence of vascular catheters (P less than .05). These findings suggest that low-dose flying spot digital radiography of the chest, as performed with this specific prototype unit, is not adequate to replace film in the detection of abnormalities of the lung parenchyma.

Adolescent