CTA Chest if GFR >60
V/Q scan if GFR <60
Will be nondiagnostic if patient has effusion, pneumonia, or other airspace disease
If imaging negative,<unk> rform additional diagnostic testing (e.g. lower extremity Doppler US, V/Q scan, and/or traditional<unk>  angiogram) prior to exclusion of VTE (ACEP Level C)
A negative d-dimer in combination with a negative CTA theoretically provides a post-test probability of VTE less than 1%
Will be nondiagnostic if patient has effusion, pneumonia, or other airspace disease
A negative d-dimer in combination with a negative CTA theoretically provides a post-test probability of VTE less than 1%
ECG (abnormal in 70% of<unk>   and associated with an adverse prognosis)
T-wave inversions (34%)
Anterior/septal leads (V1-V4) and inferior leads
T-wave flattening (30%)
Sinus Tachycardia (27%)
Right axis deviation (11%)
ST-segment changes in V1-V4 (9%)
S1Q3T3 RV strain pattern (4%)
New-onset atrial arrhythmias (e.g. atrial fibrillation)
New RBBB (complete or incomplete) 
QR pattern in V1
CXR (abnormal in 70%)
Atelectasis is most common (esp >24 hrs after onset of symptoms)
Pleural effusion
Hampton's Hump
Westermark's sign
Formal transthoracic echo or bedside cardiac ultrasound
Can help diagnosis in equivocal cases
May see signs of right heart strain (bowing of septum into LV; Aka D Sign)
Right ventricular strain is associated with statistically significant worse outcome
McConnell's sign- Right ventricular free wall akinesis that spares the apex
Lateral right ventricular wall diameter of <5mm is suggestive of acute<unk>  hypertension while >5mm is suggestive of chronic<unk>  hypertension
SPECT
Combination of non-contrast CT chest with V/Q scan
Avoidance of contrast for patients with renal injury
As sensitive as CTPA and more sensitive than planar V/Q scanning
T-wave inversions (34%)
Anterior/septal leads (V1-V4) and inferior leads
T-wave flattening (30%)
Sinus Tachycardia (27%)
Right axis deviation (11%)
ST-segment changes in V1-V4 (9%)
S1Q3T3 RV strain pattern (4%)
New-onset atrial arrhythmias (e.g. atrial fibrillation)
New RBBB (complete or incomplete) 
QR pattern in V1
Anterior/septal leads (V1-V4) and inferior leads
Atelectasis is most common (esp >24 hrs after onset of symptoms)
Pleural effusion
Hampton's Hump
Westermark's sign
Can help diagnosis in equivocal cases
May see signs of right heart strain (bowing of septum into LV; Aka D Sign)
Right ventricular strain is associated with statistically significant worse outcome
McConnell's sign- Right ventricular free wall akinesis that spares the apex
Lateral right ventricular wall diameter of <5mm is suggestive of acute<unk>  hypertension while >5mm is suggestive of chronic<unk>  hypertension
Right ventricular strain is associated with statistically significant worse outcome
Combination of non-contrast CT chest with V/Q scan
Avoidance of contrast for patients with renal injury
As sensitive as CTPA and more sensitive than planar V/Q scanning
Pulmonary embolism
Acute coronary syndromes 
Pleural effusion
STEMI
Arterial gas embolism
Non-STEMI
Pleuritis
Unstable angina