Biomedical subjects
Publications and source records attributed to G Horev.
Seventeen of 55 children and adolescents with Gaucher's disease presented with upper limb pain. Seven had nonspecific pain, 11 had bone crisis, and 2 had arthritis symptoms in the proximal interphalangeal joints. X-ray films of both hands showed osteopenia and thinning of the cortex in half of the patients.
The syndrome of Albright hereditary osteodystrophy (AHO), pseudohypoparathyroidism (PHP) and pseudopseudohypoparathyroidism (PPHP) is clinically and genetically heterogeneous. Classically, patients with PHP have the skeletal features of AHO, resistance to multiple hormones that work via cAMP such as parathyroid hormone and thyroid stimulating hormone, and deficient activity of Gs protein, the guanine nucleotide-binding protein that stimulates adenylate cyclase. However, patients without hormone resistance but with AHO and Gs deficiency were described (PPHP), as well as patients with multiple hormone resistance but without AHO or Gs deficiency. In a few patients with deficient Gs activity, hypothyroidism rather than hypocalcemia was the initial presentation of the disorder. We describe here a new variant of the syndrome, affecting 5 individuals in a 3 generation family with AHO, normal Gs activity and hypothyroidism. In the first 2 generations, mild features of AHO were present. The 2 sibs in the third generation had severe manifestations of AHO, including mild mental retardation as well as hypothyroidism. Diagnosis of congenital osteoma cutis at birth of the proband led to the diagnosis of the family. Elucidation of the molecular defect will shed light on the relationship between hormone resistance and AHO, as well as on the physiological mechanism of hormonal signal transduction.
The bubble sign (BS) in the gasless abdomen of the newborn is a helpful clue in the diagnosis of an upper gastrointestinal obstruction. The already swallowed air serves as the natural contrast agent. The single, double and triple BS are described in view of 23 cases indicating the level of the obstruction, and its differential diagnosis is discussed. The presence of BS in the gasless abdomen of the newborn is an indication for surgery until proved otherwise. With the increasing experience by ultrasonography, this modality should be considered as the first bed-side procedure when suspecting upper gastrointestinal obstruction, and then be confirmed by radiograms.
The signals obtained from mediastinal cystic lesions in children by magnetic resonance imaging (MRI) have been analysed. The advantages and pitfalls in establishing the final diagnosis by MRI are compared to the conventional radiographic technique and to computed tomography.
In 63 patients with various congenital heart defects, lung perfusion was evaluated with technetium-99mm macroaggregated albumin. Right lung perfusion abnormalities were documented in 34 patients (54%). A particularly high incidence occurred in patients who had undergone a systemic to pulmonary artery shunt operation as an initial palliative procedure or who had had right ventricular outflow reconstruction and in those with bilateral pulmonary artery stenosis. Serial studies were helpful in evaluating the functional results of different transcatheter interventions for optimizing pulmonary blood flow. The quantitative relative perfusion radionuclide method was a more sensitive means of detecting cases of abnormal lung perfusion than was chest radiology.
We describe a case of inflammatory pseudotumor of the lower abdomen in a young child. The urinary bladder and abdominal wall were involved, and the pseudotumor simulated a malignant sarcomatous tumor. Surgical excision was undertaken, and the outcome was favorable. This rare tumor simulates a true neoplasm both clinically and morphologically and presents a diagnostic and therapeutic dilemma. Our case and a review of the literature indicate that an effort should be made to perform a radical excision. This is considered the treatment of choice except if it requires a mutilating procedure.
Children suffering from Gaucher's disease were examined by magnetic resonance imaging (MRI) during a characteristic episode of "bone crisis". An unexpectedly high intramedullary as well as subperiosteal signal was observed on both the T1- and T2-weighted sequences in 5 patients, suggesting a subacute hemorrhage or hematoma. It is conceivable that such a painful hemorrhage is an important component of the "bone crisis" phenomenon. Furthermore, in these cases this is a specific sign which may enable differentiation of bone crises from other types of bone pain associated with Gaucher's disease.
Liver candidiasis is characterised by small abscesses spread throughout the organ at random. These lesions may be identified sonographically. In the active phase of the disease, hepatomegaly is seen together with the "wheel in wheel" phenomenon, the "wagon wheel" appearance and/or the "bull's eye" lesion. Later on, hypoechoic defects develop. When the echogenic foci are revealed, the healing phase is initiated. These manifestations are demonstrated in 4 pediatric oncology patients. The sonographic patterns as well as its differential diagnosis from primary liver tumors, metastatic infiltrations or other abscess formations are discussed.
The use of GD-DTPA was introduced recently for MR imaging of the body. This paper presents our experience with GD-DTPA enhanced MRI in the evaluation of neuroblastoma in children. The characteristics of the tumor-enhancement are described, its contribution to the diagnosis and the follow-up of this disease are discussed.
Atlanto-occipital subluxation (AOS) in individuals with Down syndrome is discussed using five new cases and nine patients previously presented in the literature. Although AOS is likely due to ligamentous laxity, it was associated with atlantoaxial instability in only two youngsters. Reducible C1-C2 rotary subluxation was present in a third. Posterior movement of the occiput with respect to C1 occurred on extension and reduced on flexion in all but one individual who demonstrated anterior subluxation. Neurological problems are described in only two individuals: one with severe atlantoaxial subluxation (AAS) and the other with multiple cervical spine anomalies. Since AOS is usually detected on films obtained to screen children with Down syndrome for AAS, the atlanto-occipital joint should be carefully studied on these radiographs. The clinical significance of AOS needs to be determined.
Iron deposits demonstrate characteristically shortened T2 relaxation times. Several previously published studies reported poor correlation between the in vivo hepatic 1/T2 measurements made by means of midfield magnetic resonance (MR) units and the hepatic iron content of iron-overloaded patients. In this study, the authors assessed the use of in vivo 1/T2 measurements obtained by means of MR imaging at 0.5 T using short echo times (13.4 and 30 msec) and single-echo-sequences as well as computed tomographic (CT) attenuation as a measure of liver iron concentration in 10 severely iron-overloaded patients with beta-thalassemia major. The iron concentrations in surgical wedge biopsy samples of the liver, which varied between 3 and 9 mg/g of wet weight (normal, less than or equal to 0.5 mg/g), correlated well (r = .93, P less than or equal to .0001) with the preoperative in vivo hepatic 1/T2 measurements. The CT attenuation did not correlate with liver iron concentration. Quantitative MR imaging is a readily available noninvasive method for the assessment of hepatic iron concentration in iron-overloaded patients, reducing the need for needle biopsies of the liver.
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Of thirty-four occurrences of bone pain in seventeen children and young adults who had type-I Gaucher disease, twenty-five were finally diagnosed as bone crises. On the basis of a bone scan with technetium-99m methylene diphosphonate, a correct diagnosis of bone crisis was made for twenty-three occurrences, with a sensitivity of 0.92. At the onset of a crisis, the bone scan typically showed decreased uptake of radionuclide at the involved site. After six weeks, a repeat bone scan of the long bones showed a ring of increased uptake surrounding an area of decreased uptake. At six months, the appearance of the bones on the radionuclide scan was normal.
Computed tomography of the normal female pelvis may show the presence of a tiny air bubble within the vagina. Among 2,800 female abdomino-pelvic CTs, 27 were found to contain large amounts of intravaginal air. Twenty-three patients suffered from pelvic malignancy while in 4, non-tumorous pelvic pathology was present. Detection of air bubbles in the vagina is abnormal and indicates, in the majority of cases, an intrapelvic malignancy.
We describe an infant with an enteric thoraco-abdominal duplication arising in the proximal jejunum and associated with a dorsal meningocele, dextrocardia, agenesis of ribs and hypoplasia of the left arm. Diagnosis was reached post-operatively and the infant died of cytomegalovirus pneumonitis. Results of the postmortem examination are presented. Awareness of this rare malformation is required in order to reach a timely diagnosis and to plan a suitable operative approach.
Cortical thickening and/or periosteal reaction in long bones of children and adolescents continue to present a diagnostic difficulty for the pediatric radiologist. A history of physical activity points to the possibility of stress fracture, nevertheless bone malignancy or chronic inflammatory changes have to be excluded. The MRI findings in recent cases of stress fractures were confusing. An extensive metadiaphyseal abnormal signal from the medullary cavity was observed. Only the meticulous correlation between the various imaging modalities established the correct diagnosis. Stress fractures can occur in a normal bone that is subjected to repeated trauma, with the strain being less than that which causes an acute fracture. Localized pain is the presenting symptom. This kind of fracture is encountered in adolescents who are often involved in competitive physical exercise. The conventional radiographic examination shows the evidence of the fracture repair rather than the fracture itself: localized periosteal reaction and endosteal thickening. A radiolucent cortical fracture-line is usually not demonstrated. The radiologic appearance can be problematic in the pediatric age and necessitates differentiation from osteomyelitis or bone malignancy. The diagnostic investigation includes multidirectional bone radiographs. Tcm99 polyphosphate bone scintigraphy and computerized tomography. Recently MRI has been added to the diagnostic armamentarium. This paper presents the experience gained in the diagnosis of pediatric stress fractures which were investigated and followed up by MRI. It was found that this modality did not contribute to the establishment of the final diagnosis of stress fracture.
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The installation of the ventriculo-peritoneal shunt (VPS) is on the rise in the pediatric age. Its obstruction is a major cause for further deterioration of the already present hydrocephalus. Distal VPS obstruction may be due to a pseudocyst, an infected pseudocyst or an abscess-formation within the peritoneal cavity. These pathologies are identified through an abdominal radiograph and ultrasonography. The sonographic signs are described and its differential diagnosis is discussed in relation to 6 diagnosed cases. One VPS was obstructed by Ascaris lumbricoides clinging to its tip within an abscess.