Yes, chest CTA absolutely evaluates pulmonary abnormalities beyond pulmonary embolism
A chest CTA performed for suspected PE should routinely assess and report multiple pulmonary and thoracic findings beyond just the presence or absence of emboli. This is explicitly recommended by the most recent international consensus guidelines 1, 2.
What Else Does Chest CTA Evaluate?
Parenchymal Lung Findings
The CTA protocol includes lung window imaging that allows comprehensive assessment of:
- Pulmonary infarcts - appearing as peripheral airspace opacities with heterogeneous enhancement, sometimes showing the "reversed halo sign" 1
- Lung nodules - detected in approximately 13-14% of PE-protocol CTAs 3, 4
- Consolidation or lobar collapse - found in about 8% of cases 5
- Pleural effusions and pleural abnormalities - identified in 2-4% 5
- Emphysema - noted in approximately 6% 5
Cardiac and Vascular Findings
The CTA inherently images the entire thorax and provides critical information about:
- Right ventricular overload indicators - RV/LV ratio, PA trunk diameter, septal deviation (these predict early hemodynamic collapse and death) 1
- Cardiac abnormalities - cardiomegaly (41%), atrial dilatation (18%), RV hypertrophy 5
- Aortic pathology - aortic dissection, aneurysm, or other differential diagnoses for chest pain 2
- Coronary and valvular calcification - coronary calcification (46%), mitral annulus calcification (15%) 5
Signs of Chronic Thromboembolic Disease
The guidelines specifically emphasize looking for features suggesting chronic thromboembolic pulmonary hypertension (CTEPH):
- Organized mural thrombi
- Complete arterial occlusion
- Intravascular webs or bands
- Pulmonary artery retraction
- Bronchial artery dilatation - this is why simultaneous opacification of both pulmonary and systemic circulation is recommended rather than exclusive pulmonary arterial phase imaging 2
Lymphadenopathy and Other Findings
- Mediastinal and hilar lymphadenopathy - found in approximately 9% of cases 4
- Abdominal organ abnormalities - when the scan extends to include potential embolic sources 1
Critical Clinical Implications
High Yield of Incidental Findings
Research demonstrates that chest CTAs ordered for PE evaluation are more than twice as likely to identify an incidental pulmonary nodule or adenopathy than an actual PE 4. In one study, only 9% had PE, while 24% had new incidental findings requiring diagnostic follow-up 4.
Limitations of Early Arterial Phase
Important caveat: The early arterial phase of CTPA may not optimally visualize certain structures compared to standard portal venous phase CT. Studies show significantly more pleural, peritoneal, solid organ abnormalities, and abdominal lymphadenopathy are identified on standard CT compared to CTPA alone 3. However, this does not mean these structures are not evaluated—they are simply better seen on delayed phase imaging.
Alternative Diagnoses
Approximately 33% of chest CTAs performed for suspected PE reveal findings that provide alternative explanations for acute symptoms 4, making the comprehensive evaluation essential for patient care.
Recommended Reporting Approach
The 2025 consensus guidelines 1, 2 mandate that radiologists report a core set of 11 specific CTA findings routinely, including PE location, RV overload signs, and features suggesting chronic disease. The scan protocol should include simultaneous opacification of both pulmonary and systemic circulation to avoid missing bronchial artery hypertrophy (a sign of CTEPH) and to evaluate for aortic pathology 2.
Follow-up Burden
Clinicians must be prepared: using current guidelines, follow-up CT or another procedure would be recommended for 96% of patients with newly identified incidental pulmonary nodules 4. This creates a substantial clinical management burden that requires systematic approaches.