Pulmonary Embolism: Comprehensive Diagnosis by Using Electron-Beam CT for Detection of Emboli and Assessment of Pulmonary Blood Flow1
U. Joseph Schoepf, MD,
Roland Bruening, MD,
Hita Konschitzky, BS,
Christoph R. Becker, MD,
Andreas Knez, MD,
Juergen Weber, MS,
Olaf Muehling, MD,
Peter Herzog, BS,
Armin Huber, MD,
Ralph Haberl, MD and
Maximilian F. Reiser, MD
1 From the Departments of Clinical Radiology (U.J.S., R.B., H.K., C.R.B., J.W., P.H., A.H., M.F.R.) and Internal Medicine I-Cardiology (A.K., O.M., R.H.), Klinikum Grosshadern, University of Munich, Marchioninistrasse 15, 81377, Germany. Received October 14, 1999; revision requested November 18; final revision received February 23, 2000; accepted February 28. Address correspondence to U.J.S. (e-mail: schoepf@ikra.med.uni-muenchen.de).
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Figure 2a. (a) Two consecutive transverse electron-beam CT sections obtained in the patient in Figure 1 after heparin therapy. The thromboembolism in the upper lobe of the left lung has completely resolved. (b) Dynamic CT scan obtained in the same patient at the same level as in Figure 1d shows the flow void in the apicoposterior segment has resolved.
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Figure 2b. (a) Two consecutive transverse electron-beam CT sections obtained in the patient in Figure 1 after heparin therapy. The thromboembolism in the upper lobe of the left lung has completely resolved. (b) Dynamic CT scan obtained in the same patient at the same level as in Figure 1d shows the flow void in the apicoposterior segment has resolved.
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Figure 3a. Initial suspicion of pulmonary embolism in a 52-year-old man with chest pain. (a) Three consecutive transverse electron-beam CT volume scans show a mediastinal soft-tissue mass (arrows) encasing the upper lobe artery of the left lung. Biopsy later revealed small-cell lung cancer. (b) On the corresponding dynamic electron-beam CT scan, a flow void (arrows) in the upper lobe of the left lung, due to obstruction of the feeding vessel by the soft-tissue mass, is seen. Blood flow in the lower lobe of the left lung and in the right lung was maintained. Scintigraphy results would have revealed a ventilation-perfusion mismatch in the upper lobe of the left lung, which would have been compatible with lobar pulmonary embolism.
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Figure 3b. Initial suspicion of pulmonary embolism in a 52-year-old man with chest pain. (a) Three consecutive transverse electron-beam CT volume scans show a mediastinal soft-tissue mass (arrows) encasing the upper lobe artery of the left lung. Biopsy later revealed small-cell lung cancer. (b) On the corresponding dynamic electron-beam CT scan, a flow void (arrows) in the upper lobe of the left lung, due to obstruction of the feeding vessel by the soft-tissue mass, is seen. Blood flow in the lower lobe of the left lung and in the right lung was maintained. Scintigraphy results would have revealed a ventilation-perfusion mismatch in the upper lobe of the left lung, which would have been compatible with lobar pulmonary embolism.
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Figure 4a. Antithrombin III deficiency in a 36-year-old man. (a) Transverse electron-beam CT volume scan shows an isolated nonoccluding segmental embolus (arrow) in segmental artery 10 in the lower lobe of the right lung. The vessel shows signs of reperfusion, with a rim of contrast enhancement next to the thromboembolism. (b) Dynamic transverse electron-beam CT scan shows a false-negative result, presumably caused by partial occlusion of the segmental vessel in a. No flow void is evident on the color-coded map, because perfusion is maintained despite the presence of intravascular thrombi.
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Figure 4b. Antithrombin III deficiency in a 36-year-old man. (a) Transverse electron-beam CT volume scan shows an isolated nonoccluding segmental embolus (arrow) in segmental artery 10 in the lower lobe of the right lung. The vessel shows signs of reperfusion, with a rim of contrast enhancement next to the thromboembolism. (b) Dynamic transverse electron-beam CT scan shows a false-negative result, presumably caused by partial occlusion of the segmental vessel in a. No flow void is evident on the color-coded map, because perfusion is maintained despite the presence of intravascular thrombi.
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Copyright © 2000 by the Radiological Society of North America.
) has been placed in the main pulmonary artery to measure the arterial input for estimation of PBF. Data from the time-attenuation curve were fit by using a 
-variate function. (c) At another level on the dynamic CT scan, parenchymal time-attenuation curves in the occluded apicoposterior segment of the upper lobe of the left lung (L) and the nonoccluded corresponding segment in the upper lobe of the right lung (R) are seen. PBF in the occluded segment was 0.15 mL/min/mL versus 1.48 mL/min/mL in the nonoccluded segment. In our study, the mean PBF in occluded vessels was 0.63 mL/min/mL versus 2.27 mL/min/mL in nonoccluded segments (P = .002). (d) Color-coded map at the level of the upper lobes of the lungs at dynamic electron-beam CT. Cold spectrum colors delineate the perfusion deficit in the apicoposterior segment (arrows).
