Chest
Clinical InvestigationsClinical Validity of a Normal Perfusion Lung Scan in Patients with Suspected Pulmonary Embolism
Section snippets
Patients
Between 1981 and 1988, 1,420 consecutive patients with clinically suspected pulmonary embolism were referred to the Thromboembolism Service at Chedoke-McMaster Hospitals and were studied prospectively. The 515 (36 percent) of these patients who had normal perfusion lung scans are the subject of this report. The findings in the patients with abnormal perfusion scans have been described previously.9, 10, 11
Study Protocol
Each patient was examined on the day of referral by the consultant physician and the study
Patients
The 515 consecutive patients with clinically suspected pulmonary embolism and normal perfusion scans ranged in age from 14 to 93 years (mean, 45 years); 154 (30 percent) were men and 361 (70 percent) were women. Their clinical characteristics are shown in Table 1. Of the 515 patients, 361 patients (70 percent) were outpatients at the time of presentation and 154 (30 percent) were inpatients.
Findings by Impedance Plethysmography at Presentation
Impedance plethysmography was performed successfully in 493 of the 515 patients (it could not be
DISCUSSION
The results indicate that patients with suspected pulmonary embolism and a normal perfusion lung scan have an excellent prognosis without anticoagulant therapy. Symptomatic venous thromboembolism was rare on follow-up in our patients with normal perfusion scans (0.6 percent [three of 515 patients]). Further, two of the three patients with venous thromboembolism on follow-up had predisposing factors which placed them at continued risk for venous thromboembolism. The results on follow-up indicate
ACKNOWLEDGMENTS
We gratefully acknowledge the support of the members of the sections of Emergency Medicine, Family Practice, Medicine, Surgery, Obstetrics and Gynecology, Critical Care and Diagnostic Imaging at Chedoke-McMaster Hospitals; the members of the undergraduate and postgraduate training programs of McMaster University; D. Sackett, M.D.; J. Freiburger, M.A., T.W.; and N. Anderson, Ph.D.
In particular, the contributions of the members of the Regional Thromboembolism Program including J. Hirsh, M.D., and
REFERENCES (25)
- et al.
Long-term follow-up of patients with suspected pulmonary embolism and a normal lung scan
Chest
(1982) - et al.
Anticoagulant drugs in the treatment of pulmonary embolism: a controlled trial
Lancet
(1960) - et al.
Diagnostic value of ventilation-perfusion lung scanning in patients with suspected pulmonary embolism
Chest
(1985) - et al.
Natural history of post-operative deep-vein thrombosis
Lancet
(1969) - et al.
Perfusion and ventilation radioisotope lung scans in stenosis of the pulmonary arteries and their branches
Am Heart J
(1969) - et al.
The role of non-invasive tests versus pulmonary angiography in the diagnosis of pulmonary embolism
Am J Med
(1981) - et al.
The clinical features of submassive and massive pulmonary emboli
Am J Med
(1977) - et al.
Diagnosis of massive pulmonary embolism in man by radioisotope scanning
N Engl J Med
(1964) - et al.
Ventilation-perfusion lung imaging and selective pulmonary angiography in dogs with experimental pulmonary embolism
J Nucl Med
(1978) - et al.
Assessment of pulmonary photoscanning and angiography in experimental pulmonary embolism
Circulation
(1969)
On purple emperors, pulmonary embolism, and venous thrombosis
Ann Intern Med
Warfarin sodium versus low-dose heparin in the long-term treatment of venous thromboembolism
N Engl J Med
Cited by (189)
Pulmonary Thromboembolism
2015, Murray and Nadel's Textbook of Respiratory Medicine: Volume 1,2, Sixth EditionAcute and Chronic Pulmonary Embolism: An In-depth Review for Radiologists Through the Use of Frequently Asked Questions
2012, Seminars in Ultrasound, CT and MRICitation Excerpt :Perfusion scintigraphy combined with chest radiography has been shown to have the same diagnostic accuracy as MDCTPA and V/Q scintigraphy,70 and a normal perfusion scan excludes PE with an NPV close to 100%.71-73 Thus, the ventilation portion of the examination can be eliminated without decreasing diagnostic accuracy.69-72,74,75 Perfusion scintigraphy may eventually become the modality of choice in young and pregnant women with normal chest radiographs.10
Noninvasive diagnosis of pulmonary embolism
2011, ChestDiagnosis: Imaging techniques
2010, Clinics in Chest MedicineCitation Excerpt :Interpretation schemes based on high probability patterns (PE present), normal or nearly normal patterns (PE absent), with the remaining patterns termed nondiagnostic, provide effective communication for clinicians.95 At least 2 studies have shown that it is safe to withhold anticoagulants when a technically satisfactory perfusion lung scan shows no perfusion defects.96,97 In one large well-designed study, anticoagulants were withheld or discontinued following evaluation of 515 consecutive patients who had a normal perfusion lung scan and clinically suspected acute PE.97
Nuclear Medicine Imaging in Thoracic Surgery
2010, Medical Management of the Thoracic Surgery PatientNuclear Medicine Imaging in Thoracic Surgery
2009, Medical Management of the Thoracic Surgery Patient
This work was supported by grants from the Ontario Ministry of Health, the Heart and Stroke Foundation of Ontario, and the Canadian Heart Foundation
Manuscript received April 27; accepted May 2.