Safety of ventilation/perfusion single photon emission computed tomography for pulmonary embolism diagnosis.
OBJECTIVE
The aim of this management outcome study was to assess the safety of ventilation/perfusion single photon emission computed tomography (V/Q SPECT) for the diagnosis of pulmonary embolism (PE) using for interpretation the criteria proposed in the European Association of Nuclear Medicine (EANM) guidelines for V/Q scintigraphy.


METHODS
A total of 393 patients with clinically suspected PE referred to the Nuclear Medicine Department of Brest University Hospital from April 2011 to March 2013, with either a high clinical probability or a low or intermediate clinical probability but positive D-dimer, were retrospectively analysed. V/Q SPECT were interpreted by the attending nuclear medicine physician using a diagnostic cut-off of one segmental or two subsegmental mismatches. The final diagnostic conclusion was established by the physician responsible for patient care, based on clinical symptoms, laboratory test, V/Q SPECT and other imaging procedures performed. Patients in whom PE was deemed absent were not treated with anticoagulants and were followed up for 3 months.


RESULTS
Of the 393 patients, the prevalence of PE was 28 %. V/Q SPECT was positive for PE in 110 patients (28 %) and negative in 283 patients (72 %). Of the 110 patients with a positive V/Q SPECT, 78 (71 %) had at least one additional imaging test (computed tomography pulmonary angiography or ultrasound) and the diagnosis of PE was eventually excluded in one patient. Of the 283 patients with a negative V/Q SPECT, 74 (26 %) patients had another test. The diagnosis of PE was finally retained in one patient and excluded in 282 patients. The 3-month thromboembolic risk in the patients not treated with anticoagulants was 1/262: 0.38 % (95 % confidence interval 0.07-2.13).


CONCLUSIONS
A diagnostic management including V/Q SPECT interpreted with a diagnostic cut-off of "one segmental or two subsegmental mismatches" appears safe to exclude PE.
Université Européenne de Bretagne, Brest, France.
Pierre-Yves
PY
Le Roux
Xavier
X
Palard
Philippe
P
Robin
Aurélien
A
Delluc
Ronan
R
Abgral
Solène
S
Querellou
Francis
F
Couturaud
Grégoire
G
Le Gal
Pierre-Yves
PY
Salaun
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000009:adverse effects*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011875:Radionuclide Angiography / Q000009:adverse effects; D015899:Tomography, Emission-Computed, Single-Photon / Q000009:adverse effects*; D014463:Ultrasonography; D014692:Ventilation-Perfusion Ratio