Measurement of pulmonary density by means of X-ray computerized tomography. Relation to pulmonary mechanics in normal subjects

We examined the relationship between pulmonary density, measured with computerized tomography, and pulmonary mechanics (static pulmonary volume; pulmonary resistance) in 39 normal subjects (20 nonsmokers and 19 smokers). Pulmonary density decreased with increasing static elastic recoil pressure, and smokers consistently showed higher pulmonary density than nonsmokers. Pulmonary density, measured at full inspiration, correlated inversely with total lung capacity. Pulmonary density showed a ventrodorsal gradient, which was greater at low elastic recoil pressure than at high recoil pressure. The study shows that pulmonary density is related to the mechanical properties of the lung in normal subjects. Increased pulmonary density appears to be a sensitive indicator of pulmonary damage induced by smoking. Further studies of the relationship between pulmonary density and pulmonary mechanics in disease seem warranted

Percutaneous transluminal angioplasty of crural arteries: diabetes and other factors influencing outcome

OBJECTIVE: to evaluate the efficacy of percutaneous transluminal angioplasty (PTA) of the crural arteries. PATIENTS AND METHODS: a retrospective review of patients treated with PTA of at least one crural artery during an 8-year period (1990--1997). RESULTS: one hundred and fifty-five legs in 140 consecutive patients (mean age 74 years, range 38--91 years) were treated. In 76% a more proximal lesion was also treated. After 1 year, results were significantly better in non-diabetics (improvement rate of 66% vs 32%p <0.05). The outcome for patients with a combination of diabetes, heart disease and renal disease was significantly worse compared to all other patients with an improvement rate of only 9% after 1 year. Patients alive and not amputated at 1 year were significantly more common (p <0.05) among non-diabetics (90%), compared to diabetics (66%). The 1-year mortality for the whole group was 15%, significantly higher for diabetic patients (p =0.04). CONCLUSION: PTA of crural arteries produces reasonably good results in non-diabetic patients. Diabetic patients were doing worse than non-diabetics after a year, though 1-month results were not significantly different. Patients with diabetes, heart disease and renal disease make a high-risk group that has a significantly worse outcome

Measurement of lung density by x-ray computed tomography. Relation to lung mechanics in workers exposed to asbestos cement

We measured lung density by means of x-ray computed tomography and lung mechanics in 33 workers exposed to asbestos cement and in 39 normal subjects. The exposed group showed evidence of lung fibrosis with reduced static lung volumes and lung compliance, although only three subjects had signs of interstitial fibrosis at standard chest radiography. Lung density was significantly increased in the exposed workers compared to control subjects, with greater differences between nonsmokers than between smokers. Lung density correlated inversely with static lung volumes. There was no appreciable difference in the regional distribution of lung density between exposed workers and control subjects. We conclude that lung density is often increased in workers with mild asbestosis, even in the presence of a normal chest radiograph. Measurement of lung density may be of value in the evaluation of asbestos-exposed workers for assessment of the extent of parenchymal disease

MR evaluation ex vivo and in vivo of a covered stent-graft for abdominal aortic aneurysms: ferromagnetism, heating, artifacts, and velocity mapping

Magnetic resonance imaging (MRI) safety was evaluated at 1.5 T in a covered nickel titanium stent-graft (Vanguard) used for endovascular treatment of abdominal aortic aneurysms (AAAs). Imaging artifacts were assessed on MRI with contrast-enhanced (CE) three-dimensional (3D) MR angiography (MRA) and spiral computed tomography (CT) in 10 patients as well as ex vivo. Velocity mapping was performed in the suprarenal aorta and femoral arteries in 14 patients before and after stent-graft placement. For comparison it was also performed in six healthy volunteers. No ferromagnetism or heating was detected. Metal artifacts caused minimal image distortion on MRI/MRA. The artifacts disturbed image evaluation on CT at the graft bifurcation and graft limb junction. No significant differences in mean flow were found in patients before and after stent-graft placement. Our study indicates that MRI at 1.5 T may be performed safely in patients with the (Vanguard) stent-graft. MRI/MRA provides diagnostic image information. Velocity mapping is not included in our routine protocol