X-rays -What is New ?

What is the new about X-rays: Teaching points by Dr MGK Murthy

1. No consensus  exists  as to how many radiological examinations are carried out per day in the  world,  however most agree the two commonest examinations done  daily  account for nearly 80-90%of work. These are Chest and Abdominal X-rays , followed by extremities .

Very small % of the work (apps 5%) is attributed to Ultrasonography and balance consists of CT/MRI /Nuclear medicine  etc 

2. In USA, 59% of Xray work is carried out by DR systems, 40%by CR systems and  less than 1% by analog system using films , presently (as of 2016)

3. DR systems use detectors and these are of two varieties 

(a) Flatpanel detectors

i) Amorphous silicon-- indirect detectors (where X-rays fall on the  outer scintillator of Cesium Iodide which converts them to light) . Light travels to Amorphous silicon detector , which  converts to digital signal (Charge) (Indirect FPDs) . Most systems use this technology.

ii) Another variety where  X-rays directly get  converted by amorphous selenium in to digital signal , with outer layer in these types , formed by high voltage  electrode .(Direct FPDs) 

(b) A high-density line-scan solid state detector composed of a photostimulable barium fluorobromide doped with europium (BaFBr:Eu) or caesium bromide (CsBr) phosphor 

The phosphor detector records the X-ray energy during exposure and is scanned by a  laser diode , to excite the stored energy which is released and read out by a digital image capture array of a CCD.

4. Conversion of CR to DR systems reduced radiation by 30-50% , increases efficiency (3 minutes average for CR  Vs  40 secs for DR)

5. All X-rays systems work for average 10-15 years with tubes needing change 5-10 years (average 20-30000 exposures) 

6. Obama care 2017 suggests reduction in physician remuneration for Analog and CR reads as compared to DR reads to encourage conversion

7.Recent advances in technology  brings innovations like  Konica Minolta model  is water Resistant Xray system, Siemens Multitom Robotic system combines Xray or fluoroscopy and angiography in to one machine  and Fujis FDR  D-EVO permits acquisition of full length extremity in one  exposure