Occupational Ethnography Analysis

Characterization of peripheral arterial diseases can be broadly performed noninvasively and invasively by computed tomography angiography (CTA), magnetic resonance (MR), digital subtraction angiography as well as Doppler ultrasonography (Stanford 2005). Invasive digital subtraction angiography has been classified as a gold standard method to evaluate the lower extremity vascular diseases (Ota et al 2004). However in a certain circumstances due to limitation of this technique it is seemly inapplicable for some cases.
A 76 years old patient was requested for interventional angiography with clinical detail of peripheral arterial disease. Patient has rest pain with duration of 4 weeks. ABI (ankle brachial index) test showed a value less than 0.9 which indicates significant peripheral arterial diseases. Conventional angiogram was requested to confirm the location and degrees of stenosis before revascularisation.
However, during the procedure, patient looked quite uncomfortable as he needed to maintain the access site straight

for long period of time. As the endotable is hard and flat giving more discomfort for patient. Moreover because of movement of patient, there were some artifacts presented which affected the resolution of images. In my opinion, although interventional angiogram is a standard method it is not suitable for old patients especially for old patient. CT angiography can be considered as a better technique due to several reasons.
Firstly CT angiogram is a non-invasive and rapidly fast examination (Kibbe 2010). The images are obtained when contrast in the first pass phase of arteries (Al-Qais et al 2009). For some old patients with difficulty to hold breath or maintain the position for long time, CTA is more appropriate and helpful compared to digital subtraction angiography. Also as it is a quick scan, it becomes more useful tool in detecting claudication and critical limb ischemia which revascularization is urgently necessary (Fleischmann et al 2006).Secondly digital subtraction angiography can result in iatrogenic arterial injury (Kibbe 2010). This is relatively risky for elderly patients who are great risk from stroke (Al-Qais et al 2009). Therefore non-invasive CT angiogram has less complication for patient (Radiologyinfor 2014).
Beside according to the previous studies, CT angiogram provides excellent spatial resolution to show exquisite detailed of vasculatures (Chin & Rubin 2006).

It has been reported that sensitivity and specificity of CT angiogram was greater than 90% in detecting stenosis, calcification or occlusion (Suzuki & Tanaka 2013). Moreover Pollak et al (2012) has proved that the accuracy of diagnostic performance was greater than 95%, sensitivity of 99% and specificity at 97% and no evidences of decreased performance down to popliteocrural branches. Regardless of the location, accurate characteristics can be assessed in aortoiliac vessels with sensitivity 96%, and specificity 98%, femoropopliteal with sensitivity 97% and specificity 94%, and tibial arteries with sensitivity 95% and specificity 91%. Conventionally, the precise of evaluation in tibial disease is poorer than the aorta-iliac and femoral levels, particularly if vessels are heavily

calcified.
Furthermore, the efficacy of CT angiography in diagnosing peripheral artery disease is evidenced by using 3D reconstruction program and various post-processing algorithm (Maximum Intensity projection, volume rendering, multiplanar reconstruction, vessel density ratio, etc.). These facility radiographic analysis (Al-Qaisi et al 2009).
With 64 multi-detector MDCT, it makes CT angiography more a disable tool for assessment of vasculatures. The procedure can be performed in short time with less contrast. Thus sufficient contrast is achieved without venous circulation (Oztekin et al 2013). According to Ota et al (2004) study, eccentric stenosis can be evaluated accurately via cross sectional MDCT angiogram whereas additional views – oblique and lateral are required in digital subtraction angiography. It is possible to show immediately the segments distal to the occlusion in MDCT which are not opacified on digital subtraction angiography. CTA also is beneficial in term of cost effectiveness. Current literatures showed that CTA reduces the diagnostic cost when compared to DSA with comparable clinical utility and patient’s outcomes (Chin& Rubin 2006).
In conclusion, CT angiogram is a useful alternative technique to evaluate peripheral vascular diseases. With modern 64 MDCT, it produces high resolution diagnostic images whilst lessen complications, lower cost and radiation dose for patients compared to digital subtraction angiography. Hence it can play a significant role in diagnosing vascular problems.