Biomedical subjects
Publications and source records attributed to A Daneman.
A case of lumbar osteoid osteoma is presented in which computed tomography (CT) demonstrated ipsilateral fatty replacement of the psoas and paraspinal muscles. This association has not been documented on CT previously. The fatty replacement of muscle may be related to atrophy.
The use of CT in the evaluation of intrinsic laryngeal and tracheal lesions in 42 children is reported. Computed tomography accurately defined the caliber of the airway and documented the site and extent of narrowed segments as well as revealed detailed information about tissues adjacent to the airway. Documentation of a normal or slightly narrowed airway on CT may obviate the need for more invasive endoscopic procedures. Computed tomography may reveal valuable anatomical information prior to endoscopy and can delineate the length of narrowed segments when endoscopy fails to do so.
The clinical and radiologic findings in seven children with synovial sarcoma are described. The five boys and two girls had a mean age at presentation of 4.4 years. All seven had the lesion situated in an extremity. Plain radiographs in four revealed the presence of a soft-tissue mass with no calcification or bone and joint involvement. In two patients studied with computed tomography (CT), the primary lesions had peripheral irregular areas of enhancement with central areas of poor enhancement, reflecting the necrotic, cystic, and hemorrhagic changes found in the centers of these tumors. Although the exact margins of these lesions were difficult to define accurately even with intravenous contrast enhancement, CT is still recommended as the best imaging method for assessing the local extent of the primary tumor and is a useful tool in the planning of appropriate therapy as well as the gauging of tumor response to ongoing treatment.
The clinical and radiographic findings in 10 children with neuroblastoma presenting with opsomyoclonus are described and the literature is reviewed. Children with opsomyoclonus are often a diagnostic dilemma, as they may not have a palpable tumor or increased urinary catecholamines. Computed tomography (CT) is the most sensitive imaging method in locating tumors (100%) compared with plain radiography of the chest and abdomen (sensitivity 40%), excretory urography (50%), and 99mTc radionuclide bone scans (50%). The use of body CT significantly shortened the interval between initial presentation and final diagnosis and avoided multiple hospitalizations and unnecessary investigations for patients with persistent opsomyoclonus. Since most neuroblastomas are solitary lesions that may arise in the adrenal glands or along the sympathetic chain from the neck down into the pelvis, our policy is to use plain radiography, sonography, and 99mTc methylene diphosphonate (MDP) bone scans for the preliminary investigation of patients with opsomyoclonus. Body CT can then be tailored to suit the needs of the individual patients.
A patient with Menkes' syndrome is reported. This patient has survived to the age of six years without mental retardation, and shows previously unreported computed tomographic (CT) findings of tortuous vessels and unusual osseous manifestations of undertubulation of long bones and posterior vertebral body scalloping.
Endodermal sinus tumors (EST) are highly malignant lesions with a tendency to recur locally and with a high incidence of metastatic disease at the time of diagnosis. The clinical and radiographic spectra of 24 patients with extragonadal EST are reported. There were 17 females and seven males and the mean age of presentation was 21 months. The primary lesion occurred in the sacrococcygeal region in 16 patients; in the vagina in two patients; in the anterior mediastinum in two patients; and in the bladder, liver, nasopharynx and posterior cranial fossa in one patient each. Computed tomography (CT) is the most accurate study in delineating the extent of primary lesions particularly in the pelvis and head and neck and also for demonstrating metastatic disease in the lungs. Significant improvement in survival rates is obtained with a combination of surgery, chemotherapy and radiotherapy.
The clinical and radiographic findings in a neonate with adenocarcinoma of the head of the pancreas are presented. CT revealed the mass to be well defined, with an inhomogeneous density before and after intravenous contrast enhancement. Ultrasound revealed the mass to be mainly densely echogenic with small, irregular echo-free areas. The portal vein was intimately applied to the posterior aspect of the mass. The literature concerning adenocarcinoma of the pancreas in the pediatric age group is reviewed.
Seventeen children with adrenocortical neoplasms (13 carcinomas: four adenomas) are reviewed and attention is focused on the value of the newer imaging modalities in the management of these children. All the lesions were functioning tumors. CT is the single most important modality in assessing primary and metastatic disease at diagnosis and during follow-up. In children suspected of having an adrenal lesion, high resolution CT will promptly localize the lesion to an adrenal. Since the only curative treatment is complete surgical removal CT plays an important role in defining the extent of the primary lesion pre-operatively. Large carcinomas have an inhomogeneous density on CT and a complex echo pattern on ultrasound reflecting the areas of hemorrhage and necrosis seen macroscopically in these lesions. Smaller lesions have a more homogeneous density on CT but benign and malignant disease could not be differentiated by this modality. Ultrasound is useful in screening the adrenal area in those patients in whom there is a low clinical index of suspicion for an adrenal tumor and also in the post-operative period.
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A previously unreported pattern of enhancement of the liver on CT in a 7-month-old female with cirrhosis is illustrated. Precontrast scans showed the liver to have a normal homogeneous density throughout. Scans performed immediately after rapid bolus injection of contrast showed an uneven enhancement of the entire liver. Bands of enhancing tissue (thought to represent vascular fibrous tissue) surrounded more extensive areas that enhanced less markedly. Delayed post-injection scans revealed again an even level of density throughout the liver.
Ultrasound has been used in 11 neonates whose history or clinical features suggested the possibility of hypoxic/ischaemic lesions. The ultrasound findings were correlated with computed tomographic findings in nine infants and with pathological findings in two. On ultrasound scan, areas of increased echoes represented both hypoxic/ischaemic and haemorrhagic lesions. However, the distinction between them could not be made with certainty. Cystic changes were shown clearly by ultrasound as were cerebral vascular pulsations in and adjacent to the areas of increased echoes. With computed tomography, hypoxic/ischaemic lesions were represented by areas of decreased density and haemorrhagic lesions by areas of increased density. Computed tomography failed to clearly demonstrate the cystic changes. Three types of lesions, viz. diffuse, focal and periventricular were based on the location of brain injury, the former two occurring in term infants and the latter in premature infants. Ultrasound has been shown to be of value for definition of the site and extent of hypoxic/ischaemic cerebral lesions in the newborn and for observation of their evolution.
This paper illustrates the previously unreported sonographic changes in the biliary tract in metachromatic leukodystrophy (MLD). Gallbladder wall thickening due to sulfatide deposition, intraluminal globules of sulfatide or papillomatosis may cause symptoms referrable to the biliary tract in these patients. A series of patients whom we have studied is briefly alluded to in order to bring to the attention of the radiologist MLD as a rare cause of biliary disease in children.
Renal cell carcinoma occurs rarely in the first two decades of life. This paper reviews the clinical and radiographic features of 17 such patients (10F: 7M, mean age = 12 years) seen in a 24 year period. The almost equal sex incidence contrasts with the male preponderance in adults. All patients presented with symptoms and signs referable to the primary lesion. In comparison to Wilms' tumor, renal cell carcinoma in childhood and adolescence usually presents with a smaller abdominal mass which is frequently not palpable or visible on plain abdominal radiographs. Ultrasound and CT showed non-specific solid intrarenal masses. This rare tumor of childhood should be included in the differential diagnosis of intrarenal mass lesions, particularly in older children with hematuria and renal calcification on plain radiographs. One child in this series had tuberous sclerosis. The prognosis depends on the stage of disease at presentation.
Two children who developed cardiac metastases from osteogenic sarcoma are described, and the value of computed tomography in making an antemortem diagnosis is illustrated. Computed tomographic images with a narrow window width will reveal the presence of calcification within the cardiac metastases. Images in this mode should always be studied in patients with osteogenic sarcoma who are undergoing chest computed tomography scans to detect pulmonary metastases.
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Three children with aggressive fibromatosis are presented and the value of computed tomography in defining the extent of the lesions and for follow-up and treatment planning is discussed. Aggressive fibromatosis is a nonmetastasizing fibrous lesion with a propensity for local invasion and recurrence after surgery. The lesions usually have a poorly defined margin on computed tomography and the attenuation coefficient is less than that of muscle with poor enhancement following intravenous administration of contrast material.
In 17 children with Hodgkin's disease, abdominal computed tomography (CT) and bipedal lymphangiography findings were correlated in an attempt to assess the accuracy of CT in excluding the presence of retroperitoneal and pelvic lymphadenopathy. There was excellent correlation in 14 (82%) patients. In 13 of these, both studies were negative; in one, enlarged nodes were noted in the pelvis on both studies, which otherwise revealed no abnormality in the remainder of the abdomen. In one other patient, CT revealed lymphadenopathy high in the abdomen and these nodes were not filled with contrast medium at lymphangiography. Lymphangiography revealed pelvic lymphadenopathy in 2 (12%) patients in whom the CT scan was initially interpreted as normal. If strict attention is paid to adequate opacification of the bowel and retroperitoneal vasculature, CT is an accurate modality for excluding retroperitoneal and pelvic lymphadenopathy, particularly in older children.
Thyroid ultrasound findings in 55 patients aged 6 days to 19 years were reviewed to assess the importance of this technique in evaluating childhood thyroid disorders. Findings were correlated with the available clinical, radionuclide, and pathologic data. In 25 patients with diffuse thyroid lesions (thyroiditis, Graves disease, euthyroid goiter, iodine-induced goiter, goitrous cretinism), ultrasound revealed only homogeneous thyroid enlargement or a nonspecific patchy echo pattern. In two infants with poorly visualized glands on radionuclide scans, ultrasound confirmed the presence of anatomically normal thyroid tissue. Twenty patients had at least one focal thyroid lesion seen by ultrasound, including nodules not detected by palpation in one child or by technetium scan in three. Thyroid malignancies were found in four of 13 patients with solitary thyroid nodules, occurring in two of four patients with echogenic nodules, two of five children with complex lesions, and none of four with echofree nodules. Thyroid ultrasound is a sensitive, noninvasive means of evaluating thyroid anatomy. Because it can detect thyroid tissue in the neck not seen on radionuclide scan in patients at all ages and can define the number and consistency of focal lesions, this technique offers definite advantages in assessing a variety of childhood thyroid disorders.