CORRELATION STATISTICS  (1989 - PRESENT)

Advanced Mobile Diagnostics, Inc. has been documenting quality assurance data for cerebrovascular and extremity arterial non-invasive evaluations since 1989. 

The following tables demonstrate the results of vascular laboratory examinations, which correlate with radiographic results or surgical or pathological findings for Extracranial and Extremity Arterial Examinations.  Radiographic data include conventional arteriograms, Magnetic Resonance Imaging or Computer Tomography angiography.  Typically, radiographic procedures are performed on patients with greater than 70% carotid artery stenosis or suspected ulceration/intraplaque hemorrhage and patients with hemodynamically significant extremity arterial disease in the lower and upper extremities (as defined by the ordering physician). 

Every effort was made to gather Gold Standard radiographic data for comparison.  The following tables represent the cases in which correlation data was available.

The extremity venous exams demonstrate the results of comparing follow-up exams in patients who have previously been diagnosed with deep vein thrombosis by noninvasive means.   

Visceral Vascular data (ultrasound exams of the aorta-iliac system, Superior Mesenteric Artery exams and Renal Duplex exams) was not included due to the relatively small number of Gold Standard radiographic exams used for comparison in relation to the number of Visceral Vascular exams that were performed.                                        

DEFINITIONS

Accuracy is defined as the percentage of all the studies in the group that were correctly predicted by the test compared with the Gold Standard – for instance, the arteriogram.

Sensitivity is the ability of the test to actually detect a disease process – in other words, how well it can show an abnormality.

Specificity is the ability of the test to declare a vessel to be normal or without disease – in other words, how well it can detect normal vessels.

PPV or Positive Predictive Value is the percentage of studies in the group that are abnormal by both the noninvasive test and the Gold Standard.

online view            QA-pdf