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Biomedical subjects

A Daneman

Publications and source records attributed to A Daneman.

At least 73 records · Page 4Linked to original sources
PubMed1992

Sonography of multinodular thyroid gland in children and adolescents.

Multinodular disease of the thyroid gland is uncommon in children and adolescents, and has received little attention in the recent literature. This article reviews the clinical, sonographic, and pathologic findings in 16 children with multinodular disease of the thyroid gland, and draws attention to the high incidence of other associated clinical findings. This condition was associated with a triad including renal and digital anomalies in three patients, with McCune-Albright syndrome in two patients, with Hashimoto's thyroiditis in three patients, and with thyroid carcinoma in four patients. Three of five patients with a history of previous radiation therapy had thyroid carcinoma. Sonography is a proven valuable imaging modality for the study of thyroid disease in children and has contributed to our understanding of multinodular disease of the thyroid gland in this age group.

Adolescent↗
PubMed1992

Sonographic findings of testicular teratoma with pathologic correlation.

Testicular teratoma is a rare tumor in children. We recently encountered two boys, aged 18 months and 2 years respectively, with this tumor. Sonography revealed an intratesticular mass in both. The first revealed a predominantly cystic lesion with echogenic components along its wall. The second showed a complex mass occupying most of the right testicle, and containing several areas of calcifications and cysts. Excellent pathologic correlation was obtained in both. Preoperative diagnosis of testicular teratoma is possible if the characteristic features are recognized. The prognosis is good following orchiectomy in the pediatric patients.

Child, Preschool↗
PubMed1992

Subspecialization in pediatric radiology.

Within radiology there is an increasing trend towards specialization in North America [1]. Although some radiologists still consider themselves as generalists, every radiologist has eliminated some aspect of imaging from his repertoire [2]. Within some specialty areas of radiology further subspecialization is beginning to take place. This subspecialization is being affected by conflicting forces, some of which are pushing us towards increased subspecialization in our daily clinical work, while other forces are inhibiting such subspecialization.

Medicine↗
PubMed1992

Pneumatic reduction of intussusception: 5-year experience.

Pneumatic reduction of 246 intussusceptions was attempted in 219 patients over a 5-year period. The mean age of the patients was 15.4 months. Successful reduction was achieved in 199 cases (80.9%). Bowel perforation occurred in seven cases (2.8%), requiring needle decompression of tension pneumoperitoneum in one case. Recurrence of intussusception occurred in 27 cases (11%). The mean fluoroscopy time was 3.5 minutes +/- 0.2 in successful reductions and 9.3 minutes +/- 0.9 in failed reductions (P less than .001). Logistic regression analysis helped identify four independent predictors of failure, as follows: (a) ileoileocolic intussusception (P less than .001), (b) long duration of symptoms (P less than .001), (c) rectal bleeding (P less than .01), and (d) failed reduction with barium at another institution (P less than .05). Predictors of bowel perforation were a younger age (P less than .05) and long duration of symptoms (P less than .05). Surgery was performed in 48 cases (19.5%), 16 of which required bowel resection. Transmural necrosis of bowel wall was found in nine specimens. The most important predictor of outcome in this series was a long duration of symptoms. Pneumatic reduction is a useful substitute for barium in the management of pediatric intussusception.

Air↗
PubMed1992

Sonography in thyroid carcinoma in children.

This paper reviews the clinical, sonographic and pathological findings of 20 children with thyroid carcinoma in an attempt to determine the value and limitations of sonography in thyroid neoplasms in this age group. Although sonography is an excellent technique for the evaluation of thyroid disorders and masses, certain limitations must be kept in mind. Microscopic foci of tumour might be missed and sonography cannot predictably differentiate benign from malignant disease. Previous radiation exposure should increase the level of suspicion for malignancy.

Adenocarcinoma↗
PubMed1992

Infradiaphragmatic pulmonary sequestration.

The authors describe two patients with intra-abdominal pulmonary sequestration presenting as a suprarenal mass in antenatal ultrasonography (US) images. In both cases the suprarenal mass was echogenic, and in one the mass also contained small hypoechoic areas. US and computed tomography performed after birth demonstrated feeding vessels in the suprarenal mass of one neonate; colour-flow Doppler US demonstrated the smaller feeding vessels to greater advantage.

Abdominal Neoplasms↗
PubMed1991

Traumatic aortic rupture in the pediatric population. Role of plain film, CT and angiography in the diagnosis.

A retrospective review was undertaken to determine the incidence of, and radiologic findings associated with aortic rupture resulting from blunt chest trauma in children. Records and imaging data of 54 consecutive pediatric patients admitted over a 2 year period to a pediatric trauma center after sustaining blunt chest trauma were reviewed. Four of 54 (7.4%) had a documented aortic tear. Plain films were evaluated for 7 radiographic signs described in the adult literature as sensitive indicators of aortic rupture, including abnormal aortic contour and mediastinal widening. Two groups of patients were defined: Group 1 (n = 4) had aortic rupture confirmed by angiography or operation and Group 2 (n = 50) with no angiographic investigation. All patients in Group 1 demonstrated mediastinal widening and abnormal aortic contour; however, 50 percent of patients in Group 2 had similar findings. Computed tomograms of the thorax where obtained were reviewed, including 1 patient from Group 1 and 6 patients from Group 2. The aortic tear was well demonstrated in the one patient from Group 1; however, the remaining computed tomograms were deemed inadequate for reliable exclusion of significant aortic injury. Plain chest radiographic findings in 5 consecutive children who underwent aortography in the two years subsequent to this series, including 2 additional patients with aortic rupture, were also reviewed, with similar results. In conclusion, traumatic aortic rupture in the pediatric population may be more common than previously reported. Plain film findings of aortic rupture in children are similar to those in adults, and are sensitive but non-specific. Currently, at least in our institution, this injury may be underinvestigated. Angiography remains the modality of choice in the diagnosis of aortic tears in children.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiography↗
PubMed1991

Multiple gastrointestinal atresias: sonography of associated biliary abnormalities.

The pre-operative finding of biliary ductal dilatation in the setting of multiple gastrointestinal atresias has not been previously reported. This paper illustrates the sonographic findings in two neonates with multiple gastrointestinal atresias from the prepyloric region to the rectum. Biliary ductal dilatation was seen in both patients and highly echogenic, mobile intraluminal bowel debris secondary to calcified meconium was evident in one. Post-operative biliary gas was demonstrated on sonography in one case.

Bile Duct Diseases↗
PubMed1991

Marshall-Smith syndrome: new radiographic, clinical, and pathologic observations.

Radiographic, clinical, and histologic findings in two infants and a neonate with a syndrome of profoundly accelerated skeletal maturation included features closely resembling those of Marshall-Smith (MS) syndrome, but patients had dysmorphic ears as well as distinctive generalized skeletal abnormalities suggestive of a bone dysplasia. Among these was an instability at the craniocervical junction with severe spinal stenosis. These previously unrecognized abnormalities may represent uncommon manifestations within the spectrum of MS syndrome or indicate the existence of a separate disorder.

Atlanto-Axial Joint↗
PubMed1991

Radiographic manifestations of renal anomalies.

Intrauterine sonography has revolutionized the detection of renal anomalies. Previously unavailable demonstrations of abnormalities pose a new challenge to those responsible for the care of these patients. Optimal management is dependent on knowledge of the natural history of the demonstrated abnormality, the sequelae, and also the results and the complications of the various forms of available treatment.

Female↗
PubMed1990

Cerebral blood-flow velocity patterns in post-hemorrhagic ventricular dilation.

To evaluate the effect of ventricular dilation (VD) on cerebral hemodynamics, serial cerebral bloodflow velocity patterns from the anterior and middle cerebral, and circle of Willis arteries were examined by range-gated, pulsed Doppler sonography in premature infants developing post-hemorrhagic VD. Nine infants (25 to 30 weeks gestation) without a patent ductus arteriosus were studied until resolution of VD. Forty-nine cranial sonograms from all nine infants were reviewed independently and grouped cross-sectionally into mild, moderate and severe VD prior to shunt. The corresponding pulsatility index (PI) showed a consistent trend of increase with VD in all three studied vessels. In six infants, absent or reversed diastolic flow was observed at the height of VD. Four of these infants required V-P shunt. Immediate fall in PI occurred in all three vessels. Serial measurement of PI during VD reflects global changes in cerebrovascular resistance. Results confirmed PI could be a useful index in monitoring cerebral hemodynamic changes.

Cerebral Hemorrhage↗
PubMed1990

The value of Doppler sonography in the detection of major vessel thrombosis in the neonatal abdomen.

Duplex spectral or color Doppler sonography demonstrated major abdominal vessel blocks affecting 18 vessels in 16 infants aged between 23 and 56 weeks postconceptional age. The portal vein was affected in 8 infants, the renal vein in 3, the renal vein and inferior vena cava in 1, the renal artery in 1, the inferior vena cava and hepatic vein in 1, and the aorta in 2 infants. Doppler sonography confirmed the grey-scale findings and often demonstrated the extent of vascular flow, providing functional information not available from the grey-scale scan. It facilitated the follow-up of thrombosis during therapy. Most important of all, in many instances it enabled a rapid and reliable specific diagnosis often not possible on the grey-scale study alone and hence altered patient management.

Abdomen↗
PubMed1990

Regional cerebral blood flow velocity patterns in newborn infants.

Using range-gated pulsed Doppler sonography, cerebral blood flow velocity (CBFV) waveforms from the anterior cerebral artery (ACA), middle cerebral artery (MCA) and circle of Willis artery (CW) were examined in a total of 34 newborn infants. We compared the pulsatility index (PI) from the three cerebral arteries sampled in 10 term and 10 preterm (29 +/- 2 weeks) newborn infants without a history of perinatal asphyxia or intracranial pathology. The Pl in the ACA ranged from 0.60 to 1.03. There were no significant differences in Pl between the three vessels by paired comparisons. The Pl of the MCA differed from that of the ACA by 0.00 +/- 0.05. The variation coefficient (CV) was 7%. For CW with ACA, the difference was 0.00 +/- 0.04 and CV was 6%. Both intra- and interexaminer variation in Pl measurements were studied in another 14 infants. The variation coefficients were 5-8% for all three cerebral arteries. We showed that CBFV waveform patterns were similar in regional cerebral arteries, with Pl being a consistent CBFV index. In normal cerebral circulation, the intervessel Pl differences were within observer variations. Deviation from this may suggest abnormal regional cerebral haemodynamics.

Blood Flow Velocity↗
PubMed1990

Widened subarachnoid space in pre-discharge cranial ultrasound: evidence of cerebral atrophy in immature infants?

The authors examined the incidence of widened subarachnoid spaces (SAS) among 75 infants with birthweights less than or equal to 1250g, and their significance in developmental outcome. Nine of 30 infants with gestations less than or equal to 27 weeks had widened SAS in their pre-discharge ultrasound scans. Three of the nine, including two with periventricular leukomalacia (PVL), had late-onset ventricular enlargement, unrelated to intraventricular haemorrhage (IVH): all three were developmentally impaired. The other six infants without ventricular enlargement developed normally, including one with IVH. Five of the remaining 21 infants with gestations less than or equal to 27 weeks and without widened SAS were developmentally impaired. Widened SAS was not associated with a significantly increased risk of developmental impairment; ventricular enlargement and PVL were the only significant factors. The authors conclude that an isolated finding of widened SAS is not predictive of impairment in immature infants.

Atrophy↗
PubMed1990

Malignant carcinoid within a recurrent sacrococcygeal teratoma in childhood.

Sacrococcygeal teratomas are uncommon tumors of childhood carrying a good prognosis if histologically benign and completely excised, especially if the coccyx is also excised. Carcinoids are also rare in children and only rarely associated with teratomas. We report the findings in a girl who had a malignant carcinoid within a recurrent malignant sacrococcygeal teratoma following its incomplete excision in the neonatal period. We believe that this is the first such case occurring in childhood.

Carcinoid Tumor↗
PubMed1989

Duplex Doppler sonography for renal artery stenosis in the post-transplant pediatric patient.

Of 60 renal transplant patients who underwent 134 duplex Doppler sonograms, 38 had normal frequency shift profiles and 8 showed only minimal disturbances, within normal post-transplantation limits. Fourteen patients had hypertension and showed a very abnormal profile. In 3 of the 14 the hypertension was controllable medically, and the remaining 11 underwent angiography. Duplex Doppler sonography showed gross turbulence (spectral broadening, bidirectional flow) and high frequency shift confirmed on angiography to represent 50 to 75% main renal artery stenosis in 8 of these 11, and major renal intrahilar vessel stenosis in 2. In the remaining patient, no Doppler signal was found and 95% stenosis was present. In 1 patient with intrahilar stenosis, arterial signals detected in the renal veins indicated the presence of a post-biopsy arteriovenous fistula. One patient with main renal artery stenosis also had a fistula, which was masked by a 70% stenosis. All patients with angiographically proven renal artery stenosis had a distinctive abnormality of the Doppler arterial flow pattern.

Adolescent↗
PubMed1989

An assessment of sonography in the diagnosis and management of neonatal renal candidiasis.

The renal sonographic findings in six cases of neonatal candidiasis and 13 cases previously reported in the literature are reviewed. Focal and diffuse parenchymal changes and obstruction due to mycetoma formation were frequent features. In the current series the sonographic changes were found to bear an inconstant relationship to the probable time of onset of the infection. In addition, apparent sonographic deterioration occurred in neonates well after adequate antifungal treatment was initiated. In view of the potential toxicity of systemic antifungal therapy, sonographic renal parenchymal changes are not considered an adequate indication for either its initiation or its continuation.

Candidiasis↗