ACRAD37 – Interpretation of CT Pulmonary Angiography (CTPA) for Pulmonary Embolism

Measure Title: Interpretation of CT Pulmonary Angiography (CTPA) for Pulmonary Embolism

Measure Description Percentage of final reports for patients aged 18 years and older undergoing CT pulmonary angiography (CTPA) with a finding of PE that specify the branching order level of the most proximal level of embolus (i.e. main, lobar, interlobar, segmental, sub segmental)

Denominator: All final reports for patients aged 18 years and older undergoing CT pulmonary angiography (CTPA) with a finding of pulmonary embolism

Numerator: Final reports that specify that branching order level of the most proximal level of embolus (i.e. main, lobar, interlobar, segmental, subsegmental)

Denominator Exclusions: None

Denominator Exceptions: None

Numerator Exclusions: None

Published Specialty: Radiology

High Priority Measure: Yes

Measure Type: Process

Include Telehealth: No

Inverse Measure: No

Proportional Measure: Yes

Continuous Variable Measure: No

Ratio Measure: No

Score Range: N/A

Number of Performance Rates: 1

Performance Rate Description: Percentage of final reports for patients aged 18 years and older undergoing CT pulmonary angiography (CTPA) with a finding of PE that specify the branching order level of the most proximal level of embolus (i.e. main, lobar, interlobar, segmental, subsegmental)

Risk Adjusted Status: No

MIPS Reporting Options: Traditional MIPS

Care Setting: Ambulatory; Emergency Department and Services; Hospital Inpatient; Hospital Outpatient; Imaging Facility

Clinical Recommendation Statement: The following evidence statements are quoted verbatim from the referenced clinical guidelines and other sources, where applicable:
Normal CT angiography safely excludes PE in patients with low or intermediate clinical probability or PE-unlikely. (Class I Recommendation; Level of Evidence A) (ESC, 2014)
Normal CT angiography may safely exclude PE in patients with high clinical probability or PE -likely. (Class IIa Recommendation; Level of Evidence B) (ESC, 2014)
CT angiography showing a segmental or more proximal thrombus confirms PE. (Class I Recommendation; Level of Evidence B) (ESC, 2014)
Further testing to confirm PE may be considered in case of isolated sub-segmental clots. (Class IIb Recommendation; Level of Evidence C) (ESC, 2014)

Measure Rationale: Importance:
An estimated 290,000 events of fatal pulmonary embolism (PE) and 230,000 events of nonfatal PE occur in the United States every year. CT pulmonary angiography (CTPA) is the primary imaging modality for evaluating patients suspected of having acute PE. Identification of the embolus and documentation of the location of the embolus influence treatment decisions. Massive central PE increases the risk for right ventricular overload and PE-related mortality. In contrast, subsegmental pulmonary emboli are often noted on CTPA but may not require treatment or follow-up. More appropriate treatment stratification can occur to potentially reduce unnecessary costs and risks for bleeding. Additional level of specification at the subsegmental level will support avoidance of over treatment due to greater degree of prognosis.

Variation in care:
The practice for reporting CTPA varies between reporting only positive or negative PE finding without specifying proximal level of embolus, and inclusion of a more specific level of embolus.

A retrospective analysis of CTPA reports found that of 2,151 consecutive reports, 10% were definitively positive for PE but did not specifically describe the location of the PE. Also, 27% of the reports specifically documented the absence of PE down to the segmental artery level but did not specifically address the presence or absence of subsegmental PE. Anticoagulation treatment is recommended if PE is located proximal to the subsegmental level, whereas anticoagulation is controversial and not always recommended if the only level of PE is subsegmental.

One study (1) found patterns of reporting (from 2151 CTPA reports) varies on the basis of radiologists’ subspecialties, experience and other factors as follows: “” (1) PE conclusively positive (10%), (2) PE conclusively negative (29%), (3) PE negative to segmental arteries (27%), (4) PE negative to central pulmonary arteries (21%), (5) PE negative but suboptimal examination (8%), and (6) nondiagnostic examination (5%)””

Another study (2) indicated that “”the location of emboli seems to be more important in predicting short-term mortality than the percent embolic obstruction of the pulmonary arterial bed. The study also found that specificity of pulmonary hypertension “”increases to 100% if accompanied by findings of a segmental artery-to-bronchus ratio greater than one in three of four pulmonary lobes””.

(1) Abujudeh HH, Kaewlai R, Farsad K, Orr E, Gilman M, Shepard JO. Computed tomography pulmonary angiography: an assessment of the radiology report. Acad Radiology. 2009;16:1309-1315
(2) Do an H, de Roos A, Geleijins J, Huisman MV, Kroft LJM. The role of computed tomography in the diagnosis of acute and chronic pulmonary embolism. Diagn Interv Radiology. 2015;21:307-316.