Many laboratory personnel have made great strides in correlating
extracranial cerebrovascular examinations with angiographic reports.
However, correlating lower extremity arterial examinations remains a
challenging aspect of the quality assurance program in many departments!

The ICAVL Essentials and Standards state that correlation and confirmation
of test results is necessary. In regard to correlating lower extremity
arterial examinations, success may be achieved by comparing the level of
disease identified in the arterial exam with similar diagnostic findings
noted in radiographic reports. Focusing one's attention on the primary
lesion in each extremity will keep the QA program manageable. The
comparisons can then be entered into a matrix, which breaks the arterial
and the radiographic results into diagnostic segments, such as aorto-iliac,
femoral-popliteal and tibial vessels. For accurate comparison, the
diagnostic segments in each half of the matrix should match. A matrix may
provide a more valuable comparative study, as opposed to a two-by-two
table, in that laboratory personnel can identify more specific areas for
improvement. For instance, if the majority of the 'mismatches' occur at the
tibial level, then the testing technique and the interpretation criteria
for that level of the examination can be further reviewed.

Laboratory personnel may also attempt to correlate arterial examinations
with radiographic results on the basis of severity of disease. This is
potentially a much more subjective review, in that a qualitative assessment
of both the arterial and the radiographic test results must be determined.
Severity of arterial disease can be defined as an overall qualitative
assessment of the test results, such as 'normal, mild, moderate or severe.'
 If this approach is used, then the matrix would again have matching
categories.

Other avenues for correlation and confirmation of test results include
matching the arterial test results to operative notes, pathological
findings, clinical outcome and repeat arterial examinations. Ambitious
individuals may also want to set up a mechanism of internal peer review,
which could involve both the technologists and the physicians. When time
permits, portions of examinations can be repeated, to see if different
techs obtain the same diagnostic results. Also, physicians may 'over-read'
the final interpretations, to see if the diagnostic criteria are being
applied to the diagnostic findings in a consistent manner.

These last several ideas can also be applied to confirming the accuracy of
venous duplex examinations, since venograms have essentially gone the way
of the dinosaurs.

We have additional articles regarding correlation and confirmation at the
ICAVL, and would be happy to fax or mail them to interested individuals.
Please do not hesitate to contact us if you have additional comments or
questions.