Relationship between the extent of deep venous thrombosis and the extent of acute pulmonary embolism as assessed by CT angiography.

The aim of our study is to investigate prospectively the quantitative relationship between deep venous thrombosis (DVT) and acute pulmonary embolism (PE). 110 patients clinically suspected of having venous thromboembolic disease underwent combined CT pulmonary angiography (CTPA) and venography of lower limb veins. 44 patients presented with clinical signs of DVT and positive ultrasonography or ascending venography, but no clinical sign of PE (Group 1). 66 patients presented with clinical signs of PE and positive CTPA (Group 2). Clot load in lower limb veins and pulmonary arteries were scored by two independent readers, each using two separate systems for DVT and two for PE. 27 (61%) patients in Group 1 also had PE, and 55 (83%) patients in Group 2 also had DVT. Correlations between PE and DVT scores were weak but statistically significant in Group 2 (r(s) ranging from 0.470-0.520; p< or =0.001), but only some were significant in Group 1 (r(s) ranging from 0.253-0.318; p-values ranging from 0.035-0.097). In conclusion, although PE occurs in a majority of patients with DVT, and vice versa, the amount/burden of clot load in one condition does not necessarily indicate - or indicates only weakly - the degree of burden in the other condition.

Computed tomographic pulmonary angiography and prognostic significance in patients with acute pulmonary embolism.

BACKGROUND: Patients with acute pulmonary embolism (APE) present with a broad spectrum of prognoses. Computed tomographic pulmonary angiography (CTPA) has progressively been established as a first line test in the APE diagnostic algorithm, but estimation of short term prognosis by this method remains to be explored. METHODS: Eighty two patients admitted with APE were divided into three groups according to their clinical presentation: pulmonary infarction (n = 21), prominent dyspnoea (n = 29), and circulatory failure (n = 32). CTPA studies included assessment of both pulmonary obstruction index and right heart overload. Haemodynamic evaluation was based on systolic aortic blood pressure, heart rate, and systolic pulmonary arterial pressure obtained non-invasively by echocardiography at the time of diagnosis of pulmonary embolism. RESULTS: The mortality rate was 0%, 13.8% and 25% in the three groups, respectively. Neither the pulmonary obstruction index nor the pulmonary artery pressure could predict patient outcome. In contrast, a significant correlation with mortality was found using the systolic blood pressure (p<0.001) and heart rate (p<0.05), as well as from imaging parameters including right to left ventricle minor axis ratio (p<0.005), proximal superior vena cava diameter (p<0.001), azygos vein diameter (p<0.001), and presence of contrast regurgitation into the inferior vena cava (p = 0.001). Analysis from logistic regression aimed at testing for mortality prediction revealed true reclassification of 89% using radiological variables. CONCLUSION: These results suggest that CTPA quantification of right ventricular strain is an accurate predictor of in-hospital death related to pulmonary embolism.

Evaluation of CT time-density curves of lower-limb veins.

UNLABELLED: Szapiro D, Ghaye B, Willems V, et al. Evaluation of CT time-density curves of lower-limb veins. Invest Radiol 2001;36:164-169. RATIONALE AND OBJECTIVES: To evaluate time-density curves of the lower-limb veins for optimization of CT venography. METHODS: Fifty patients referred for chest CT were randomized into five equal groups. Five anatomic levels (abdomen, pelvis, proximal thigh, knee, and midcalf) were evaluated by a dynamic acquisition during 7 minutes. Computed tomography attenuation values of the veins, arteries, and adjacent muscles were measured for each level and plotted into curves versus time. Venous enhancement was also assessed qualitatively. RESULTS: Mean peak enhancement values of the inferior vena cava and the iliac, femoral, popliteal, anterior tibial, posterior tibial, and peroneal veins were, respectively, 112 +/- 16, 103 +/- 17, 93 +/- 23, 98 +/- 30, 112 +/- 28, 137 +/- 28, and 124 +/- 29 Hounsfield units. These were reached at 93 +/- 9.5, 129 +/- 15, 135 +/- 20, 147 +/- 57, 124 +/- 32, 123 +/- 17, and 123 +/- 18 seconds. Homogeneous opacification was obtained after 210 seconds. An optimal time window for CT venography was obtained between 210 and 240 seconds for the calf level and between 180 and 300 seconds for above-knee veins. CONCLUSIONS: For sequential CT venography, a caudocranial acquisition of the lower-limb veins, starting at 210 seconds, should allow optimal clot detection.

Combined CT venography of the lower limbs and spiral CT angiography of pulmonary arteries in acute pulmonary embolism: preliminary results of a prospective study.

PURPOSE: To determine the clinical accuracy of combined CT venography (CTV) and spiral CT angiography (SCTA) in patients suspicious of acute pulmonary thrombo-embolism. MATERIALS AND METHODS: 278 consecutive patients referred for SCTA for suspicion of acute pulmonary embolism (APE) underwent subsequent evaluation of the veins of the lower limbs and abdomen (CTV) within one examination without additional injection of contrast medium. Sixty-nine patients had no further study. Two hundred and nine patients were included in the study, 199 had US and 51 phlebography (PG) within 48 hours from SCTA-CTV. The investigators were blinded to the results of CT. When results of CTV and US were discordant, phlebography was indicated. RESULTS: SCTA was positive in 89 patients, negative in 119 and indeterminate in 1. CTV was positive in 99 patients, negative in 103 and indeterminate in 7. US was positive in 87 patients, negative in 97 and indeterminate in 15. PG was positive in 21 patients, negative in 29 and indeterminate in 1. Excellent correlation was found between CTV and US (k = 0.84) and moderate correlation between CTV and PG, and US and PG (k = 0.53). CONCLUSIONS: Combined SCTA and CTV is a rapid and accurate one-session examination in patients suspicious of acute pulmonary thrombo-embolism.

[The biological properties of the HIV isolated from a virus carrier living in the Byelorussian SSR]. / Biologicheskie svoistva VICh, vydelennogo ot virusonositelia, prozhivaiushchego v BSSR.

Biological properties of an AIDS agent first isolated from a native citizen in the USSR are presented. The source of the virus was a young Byelorussian woman who in the near past had had sexual contacts with a citizen from one of the Central Africa countries. The isolate is thought to be of HIV-I type. It replicated perfectly in many continuous lymphocyte lines and had HIV-characteristic morphology. The protein spectrum of the isolate was gp120, gp41, p65/51, p55, p32, p24, p17. Reverse transcriptase activity was detected in the culture fluid of the virus-containing cell cultures. The isolate was designated HIV-IZ.