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Biomedical subjects

I L Tonkin

Publications and source records attributed to I L Tonkin.

At least 37 records · Page 2Linked to original sources
PubMed1985

Central nervous system hypoxia in children due to near drowning.

Fourteen children who experienced acute, profound central nervous system hypoxia secondary to near drowning, aspiration, or respiratory arrest underwent CT examination. During the first week after the episode, the most frequent finding was a loss of gray-white matter differentiation. Other findings included effacement of sulci and cisterns, focal areas of edema in the cerebral cortex or basal ganglia, and hemorrhagic infarctions of the basal ganglia. Subsequent CT scans obtained from two weeks to five months after the hypoxic episode showed progression of cerebral loss from cortical infarction with gyral hemorrhage and enhancement to global parenchymal atrophy. The prognosis is poor in these patients: seven children experienced severe neurologic deficits and seven died.

Basal Ganglia↗
PubMed1984

Coarctation of the aorta and renal artery stenosis in tuberous sclerosis.

Among neurocutaneous disorders, coarctation of the abdominal aorta and renal artery stenosis have traditionally been associated with neurofibromatosis. We report a 5-year-old girl who, during the evaluation of asymptomatic hypertension, was discovered to have bilateral renal artery stenosis, coarctation of the abdominal aorta, renal cysts and typical skin lesions of tuberous sclerosis. Renal vascular hypertension has not been reported previously in tuberous sclerosis. We conclude that the tuberous sclerosis complex should be expanded to include vascular malformations and that hypertension should not be assumed to be secondary to renal hamartomata or cysts in patients with tuberous sclerosis.

Aortic Coarctation↗
PubMed1984

Ruptured sinus of valsalva aneurysm in children: report of two cases and literature review.

Two children with ruptured sinus of Valsalva aneurysm are described, each with a ventricular septal defect, and in one there was also an associated discrete subvalvular aortic stenosis. The diagnostic appearance of two-dimensional echocardiography and axial angiocardiography are emphasized to allow early diagnosis and surgical repair. A literature review of recent reports in English disclosed that 13 patients under age 20 had been reported to have ruptured sinus of Valsalva aneurysm.

Adolescent↗
PubMed1984

Evaluation of vascular rings with digital subtraction angiography.

Seven patients with vascular rings were evaluated over a 2-year period with intravenous digital subtraction angiography (DSA), which was compared with screen-film aortography or cineangiography. The seven patients were also evaluated with barium esophagography. Six of the seven DSA images were totally diagnostic and one study was only partly diagnostic. Six of the seven vascular anomalies were confirmed surgically. DSA is suggested as an alternative to arteriography in evaluating patients with suspected vascular rings.

Aorta, Thoracic↗
PubMed1983

Advantages of coronal ultrasonography in evaluating the neonatal retroperitoneum.

Good demonstration of retroperitoneal structures in the neonate can be obtained with real-time coronal ultrasonography. Advantages of coronal scanning include limited manipulation of the infant, less hindrance from monitoring devices or tubes when positioning the scanning probe, and improved visualization of retroperitoneal structures due to less interference by bowel gas. Retroperitoneal structures are displayed in conventional frontal anatomic relationships, which may facilitate recognition of renal ectopia and evaluation of abdominal masses. The authors' experience in evaluation of the neonatal retroperitoneum with coronal ultrasonography is presented.

Abdominal Neoplasms↗
PubMed1983

Radiography of diseases involving the aortic valve and thoracic aorta.

This article presents the plain radiographic findings in a variety of conditions that affect the aortic valve and thoracic aorta. For many of the lesions presented in this article, the diagnosis can readily be made by using digital subtraction angiography, computed tomography, and echocardiography. The use of these modalities in conjunction with the chest radiographic findings is emphasized.

Aortic Dissection↗
PubMed1983

Modified Shumacker repair of transposition of the great arteries. Surgical and angiocardiographic considerations.

Sixteen patients with transposition of the great arteries, 8 days to 2 1/2 years of age, underwent intra-atrial transposition of venous return by the modified Shumacker technique. A bipedicle flap of right atrial wall was used to direct vena caval return to the mitral valve, and a hinged viable flap of pericardium was used to form the lateral wall of the pulmonary venous pathway. Thirteen patients survived operation and are well to date. Two of the three nonsurvivors were less than 1 month of age at operation, and the third had an associated inlet ventricular septal defect and a straddling tricuspid valve. Early postoperative chest radiographs were compared with preoperative films in each patient. Postoperative findings included minor right pleural effusion in four, minor pneumothorax in two, and paralyzed right hemidiaphragm in one. Two patients required a permanent pacemaker because of the development of sick sinus syndrome 2 and 4 years postoperatively. Each preoperative angiocardiogram was reviewed and compared with postoperative studies in nine patients. The latter demonstrated absence of caval gradients in each, trivial baffle leaks in four, a moderate baffle leak in one, small residual ventricular septal defects in two, and mild tricuspid regurgitation in two patients.

Angiocardiography↗
PubMed1982

Two-dimensional echocardiographic evaluation of persistent truncus arteriosus.

Using a phased-array, wide angle sector-scanner, 2-dimensional echocardiograms were obtained in 3 patients with persistent truncus arteriosus. Type I was found in 2 patients and type II in 1 patient. In the patient with type II truncal valve stenosis was also present. Using a combination of short-axis views at the cardiac base, within 30 degrees superior transducer angulation and parasternal long-axis views, the truncus arteriosus and the pattern of pulmonary arteries were demonstrated in each case.

Angiocardiography↗
PubMed1982

Visceroatrial situs abnormalities: sonographic and computed tomographic appearance.

Twenty patients with visceroatrial situs abnormalities were examined by sonography or computed tomography (CT). Eighteen patients underwent cardiac catheterization. Left isomerism (polysplenia syndrome) was found in seven patients, right isomerism (asplenia syndrome) in eight, and total situs inversus in five. The abdominal features of polysplenia include interruption of the inferior vena cava with azygous/hemiazygous continuation (100%) and multiple splenules. The diagnostic signs of asplenia include an inferior vena cava and aorta that course together on the same side of the spine with inferior vena cava-atrial communication (100%). In each case, the key differential feature relates to the major abdominal vessels. Sonography or CT examination in cases of situs ambiguus may reveal diagnostic features that can be used with radiographic signs to accurately diagnose the visceroatrial situs.

Adult↗
PubMed1981

Lingular collapse with medial pneumothorax: puzzling image in children.

In addition to paramediastinal lucency, medial pneumothorax on the left may be associated with a confusing localized density about the lateral aspect of the hemithorax. This is primarily caused by superolateral displacement and compression of the lingula. There may be coexistent pulmonary parenchymal abnormality such as hyaline membrane disease or pulmonary contusion that contributes to the density which may simulate pleural fluid or soft tissue mass. In varying degrees this is a common manifestation of medial pneumothorax in children. Of the 20 cases reported herein, nine occurred in newborns with underlying lung disease, six of which were on ventilatory assistance. The second largest group consisted of six postoperative cardiac patients. Other associated causes were blunt chest trauma (two cases), asthma (two) and intrabronchial foreign body (one).

Asthma↗
PubMed1980

Recognition of developing left ventricular outflow tract obstruction in complete transposition of the great arteries.

In the months following balloon atrial septostomy for complete transposition of the great arteries (TGA), clinical deterioration is often ascribed to closure of the septostomy. Of 16 neonates with TGA, 5 showed early clinical deterioration. Each had an adequate septostomy at operation. Deterioration was characterized clinically by increasing cyanosis and radiographically by progressive diminution in pulmonary vascularity. Subsequent catheterization and axial cineangiography demonstrated that pulmonary flow had decreased, probably secondary to a progressive form of left ventricular outflow tract obstruction (LVOTO) characterized by bulging of the ventricular septum with mitral valve apposition. It is important to recognize this phenomenon as an aid in predicting which children will need early surgical intervention.

Cardiomyopathy, Hypertrophic↗
PubMed1980

Concomitant axial cineangiography and barium esophagography in the evaluation of vascular rings.

Six vascular rings were evaluated using axial biplane cineangiography and concomitant barium esophagography. Three patients had a double aortic arch, two had a right aortic arch and aberrant left subclavian artery with a foreshortened left ligamentum arteriosum, and one had a pulmonary vascular sling. Barium was administered in the esophagus of the anesthetized patient followed by cineangiography. Five patients were evaluated using both the standard and four-chamber projection, while the sixth patient with the pulmonary sling was evaluated in the standard and sitting projection. With the four-chamber view, vascular rings were exposed and atypical features such as a small right aortic arch component and branch stenoses of the brachiocephalic arteries were revealed. Axial views with an esophagogram allow easier morphologic analysis and more precise definition of the vascular abnormality than conventional views.

Adult↗