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Biomedical subjects

B C Lee

Publications and source records attributed to B C Lee.

At least 217 records · Page 12Linked to original sources
PubMed1979

Neonatal intraventricular hemorrhage: a serial computed tomography study.

Thirty infants weighing less than 1,500 g at birth and requiring assisted ventilation were studied by computed tomography (CT) as soon as possible after birth and at intervals thereafter. Hemorrhage were frequently detected within the first 48 hr of birth. Two infants had normal scans initially but developed intraventricular hemorrhage later. One infant had subependymal hemorrhage that later ruptured into the ventricles. Six deaths were due directly to intracranial hemorrhages. Hydrocephalus developed in seven and atrophy in two survivors. There was poor correlation between CT scan and clinical evidence of intracranial hemorrhage.

Brain Diseases↗
PubMed1979

Intracranial cysts.

While CT scanning is useful for diagnosis of hydrocephalus and fluid-containing intracranial cysts, air studies are often necessary to determine whether the cysts communicate with the ventricular or subarachnoid space. When obstructive hydrocephalus results, decompression of the cyst is normally adequate. Hydrocephalus not caused by a cyst still requires decompression, but in addition the cyst has to be treated. Until the exact pathways of absorption of water-soluble contrast media such as metrizamide are fully understood, it may be advisable not to administer them into the ventricles in patients with obstructive hydrocephalus. A combination of CT and air studies may offer information not obtainable with either modality alone.

Adolescent↗
PubMed1979

Site of pulmonary edema after unilateral microembolization.

The effect of unilateral pulmonary microembolization on regional lung extravascular fluid accumulation was determined in dogs. Embolization was produced by injecting 100-micrometer-diam glass beads (0.25 g/kg) into the right pulmonary artery. After embolization of one lung, pulmonary arterial pressure (Ppa) and pulmonary vascular resistance increased (P less than 0.05) from base-line values of 11.7 +/- 1.3 to 17.9 +/- 1.3 Torr and of 3.4 +/- 0.5 to 5.5 +/- 0.5 Torr/(1/min). Blood flow to embolized lung measured with labeled microspheres decreased from 104.2 +/- 24.9 to 35.2 +/- 9.2 ml/min.g bloodless lung after embolization, whereas flow to the normal lung increased from 43.1 +/- 5.6 to 71.2 +/- 19.2 ml/min.g bloodless lung. Extravascular lung water-to-bloodless dry lung weight ratio (W/D) of 4.97 +/- 0.32 was greater (P less than 0.001) in the embolized lung than the value of 3.34 +/- 0.15 in nonembolized lung. In six dogs pretreated with 500 U/kg of heparin, a similar degree of duration of embolization and similar hemodynamic changes did not result in significant differences in W/D (3.88 +/- 0.18 in right lung vs. 3.02 +/- 0.53 in the left lung), and the right lung ratio was less (P less than 0.05) than the value in the heparinized dogs, suggesting that humoral mechanisms contribute to the genesis of pulmonary edema after regional embolization. Therefore, unilateral embolization leads to a greater increase in extravascular content in the embolized lung than in the nonembolized lung. Because Ppa was in the normal range after embolization, regional pulmonary edema may be due partly to the local release of factors that increase lung vascular permeability.

Animals↗
PubMed1979

Pulmonary transvascular fluid dynamics in sheep during hemorrhage.

The effects of hemorrhage on pulmonary hemodynamics and lung transvascular fluid dynamics were studied in sheep. We found that 2 hr of hemorrhage caused a fall in lung lymph flow (p less than 0.05) and no significant change in lymph protein concentration. The fall in lymph flow was not due to decreased vascular surface area since the regional distribution of pulmonary perfusion was not altered during hemorrhage; however, the decrease in lymph flow was associated with decrease (p less than 0.05) in the calculated pulmonary microvascular pressure. The extravascular lung water lung content per g bloodless dry lung was increased (p less than 0.05) in the hemorrhaged sheep from the control values. Pulmonary edema was not due to increased lung vascular endothelial permeability since the net transvascular protein flux was not increased. The finding that pulmonary edema occurred despite the consistent decreases in lymph flow suggests that edema may be due to hemorrhage-induced lymphatic "failure" or that edema fluid is sequestered in spaces (e.g., endothelial cells) where if cannot be drained by the lymphatics.

Animals↗
PubMed1978

Tuberous sclerosis. Comparison of computed tomography and conventional neuroradiology.

Sixty-two patients with tuberous sclerosis were studied by skull radiography. In addition, 16 had CT scanning, 26 had air studies, and 5 had cerebral angiography. Both subependymal and parenchymal tubers were shown on CT; all had a higher density than the brain and none were enhanced by contrast material. CT showed tubers in 13 of 16 patients, including 4 of 6 patients with glioma and hydrocephalus. Air studies showed subependymal tubers in 12 of 26 patients. Four other patients had intraventricular gliomas but no tubers. Skull radiographs showed spotty calcification, compatible with tuberous sclerosis, in 30 cases. Four patients had calcification compatible with tumor. Angiograms were nonspecific, showing intraventricular masses but no tubers.

Air↗
PubMed1978

Computed tomography of the spine and spinal cord.

Configurations of 50 normal lumbar canals at each vertebral level were assessed and the dimensions of the canal at these levels measured. The appearances of the contents of the canal and their absorption values were carefully analyzed in the lumbar, cervical, and thoracic regions. Of 75 scans of patients with specific spinal symptoms, 38 showed abnormalities representing 19 pathological entities. The appearances of these lesions on scans are compared with normal scans, and the usefulness of CT scans in assessing lesions of the bone and within the canal is discussed.

Cervical Vertebrae↗
PubMed1978

Ventricular opacification after intravascular injections of contrast material.

The cerebral ventricles of two neonates were demonstrated on CT scans and plain radiographs after the intra-arterial injection of contrast material. Leakage of contrast material into the ventricles after intravenous injection probably indicates damage of the blood-brain barrier. Breakdown of this barrier results only from severe and prolonged anoxia because cerebral vessels are much more resistant to anoxia than neuronal tissues. The authors have not observed ventricular opacification in adults.

Cerebral Ventriculography↗
PubMed1976

Intercostal pulmonary hernia.

In five cases of intercostal pulmonary hernia, the hernia occurred following blunt chest trauma in two cases, after tube thoracostomy drainage in two, and following rib resection in one. Surgical repair was accomplished in three cases with good results, while in the remaining two the hernia underwent spontaneous regression.

Adult↗
PubMed1976

Computerized tomography and angiography in subarachnoid haemorrhage.

Our study of 100 multiple aneurysm cases show that 66 survivied the initial danger period either with surgery, or by conservative treatment. Of these only one may have died subsequently from bleeding from an incidental aneurysm, during a continuing follow-up period now averaging more than seven years. In a separate series of 75 patients presenting clinically with subarachnoid haemorrhage it was possible to lateralize or approximately localize the site of bleeding by CAT in 56; 31 were from aneurysms and 13 from arteriovenous malformations. In the remaining 19 cases CAT was unhelpful in indicating the site of haemorrhage; 12 had aneurysms; no cause was found in the remainder. CAT was more valuable in localization in the seven days following the haemorrhage (86 per cent) than later (34 per cent). The low risk of bleeding from incidental aneurysms makes us feel that treatment confined to the lesion which is responsible for the subarachnoid haemorrhage is not an unreasonable policy in the large majority of these patients. Detailed angiographic study of the site of haemorrhage is performed, but once this has been achieved, more extensive angiography is not routine, but is determined by the requirements of the surgery directed at the site of haemorrhage.

Cerebral Angiography↗
PubMed1976

Flexible fiberoptic bronchoscopy and endobronchial tamponade in the management of massive hemoptysis.

Flexible fiberoptic bronchoscopic examination with systematic bronchial lavage was performed in ten patients with massive hemoptysis. Localization of the bleeding to the distal segments of the bronchial tree and endobronchial balloon tamponade were achieved in all cases. The technique is rapid, simple, and effective in controlling life-threatening hemoptysis in patients who are unsuitable for resection due to inadequate pulmonary reserve or other causes.

Adult↗