All data was obtained through surveys of the AP lumbosacral spine only.
- Seventy-five percent of the chiropractic offices surveyed used screen film systems with speeds of 300 or greater (5% used 100 speed and 20% used 200 speed).
- The distribution of entrance skin exposure values was similar for all facilities (hospitals and non-hospitals, including chiropractors).
- While most facilities used kVps in the 70 to 90 range, about 17% of the chiropractors were using kVps in excess of 90, and 3% were using kVps in excess of 100.
- For processing, almost half (48%) of the chiropractors were underprocessing their films compared to 33% for other private practices, excluding radiologists. Radiologists were underprocessing in only 28% of their facilities. Only 40% of the chiropractors were in the normal processing range with 12% overprocessing. This is the one area of which all users need to be made more aware.
While of continuing concern to reach the maximum balance of ALARA and AHARA, the skin entrance exposure dose (#2 above) appears to be within the currently acceptable range, therefore will be omitted from our following commentary.
The screen film system speed factor appears to be gaining ground in appropriate use. The rare-earth systems can and should now be universally employed by the profession. While specific, select use of non-rare-earth systems may be cited, these are few and far between and should not be encouraged for general use.
The use of kVps outside the 70 to 90 range for the AP LS view is occurring within a small portion (20%) of the facilities tested. The most common reason(s) for this are related to screen-film speed or film processing. The variance, therefore, is in all likelihood a symptom, not a cause of faulty factor selection.
The processing variables (alluded to in #4) are of significant concern and potentially debatable. While quality assurance (QA) in film processing is available, indeed legally required in New York and Ontario, it is typically not employed by most practitioners on a routine basis. (This factor above may soon precipitate more states to adopt mandatory QA programs.) Nonetheless, the problem is of current concern because faulty processing typically is associated with compensatory alteration of factor selection, thus correcting one problem by creating another more serious error.
Hand-tank developing has served the radiological community successfully for many, many years. To imply that it is incorrect is to invite calamity and divisiveness among many of our practitioners, including quite a few radiologists. The truth is that manual processing is prone to faulty QA and prompts ill-advised compensatory practices. Automatic processing of course is not foolproof; it also requires QA. Because most facilities engage an outside service contractor to care for their automatic processor, the percentage of these processing units found in serious violation of QA standards is less than is found with hand-tank processing.
The profession cannot ignore that 60% of our practitioners are outside of the normal processing range. It is painfully obvious that QA is not being maintained or performed, and that in all likelihood the majority of these unacceptable facilities use hand-tank processing.
As with the blanket recommendation that practitioners should now employ rare-earth film-screen systems, so has the time come that automatic processors (hot or cold) should find universal acceptance and use within chiropractic facilities. Only with strict and demonstrable QA systems should hand-tanking continue in general use.
Change for the sake of change only is rarely acceptable. Change based on informed and intellectual reason is usually correct. The suggestions in this article have been made only after prolonged consideration and deep concern for the profession and the public we serve. Your careful perusal and decision making is required and encouraged.
Edward L. Maurer, D.C., D.A.C.B.R.
Kalamazoo, Michigan