The clinical application of X-Rays was started almost immediately after the discovery by Sir Wilhelm Conrad Roentgen on 8 November 1895. Since 1895, diagnostic X-Ray equipment has placed their presence in each clinician’s center. Discovery of X-Rays tremendously changed the medicine world and worked as eye opener for each clinician & surgeon. As technology get going improved day by day, as the quality of X-Ray images getting improved (1). In New Delhi India, the 1st X-Ray equipment was installed at Lady Hardinge hospital in 1918 and a radiology department was established in 1923 in the hospital (2). The role of spine radiography has importance in trauma, lower backache, jerk cases (Sudden or sharp movements of spine), Heavy weight lifting, radiating lower limb pain on either one side or both sides, and in case of metastatic diseases (3).
This study is hypothesized that the role of Body Mass Index (BMI) in the Lumbo-Sacral (L.S) Spine AP & LAT radiography may help in improvement of imaging quality and reduce the amount of patient absorbed dose. This will be beneficial for not only the patients but it will also help the radiographer or radiologist to choose optimum radiation exposure parameters. Which can help in to decrease the amount of radiation dose in each patient and can archive quality X-Rays images. Low or high radiation dose to patient is harmful, So the responsibility of radiographer is to choose the appropriate radiation exposure for each patient. The major responsibility of the radiographer is to avoid the unnecessary or extra radiation exposure to the patient (4). In the diagnostics, poor X-Ray imaging quality may lead to repeat exposure or false/mis-diagnosis of patient’s the disease. The radiation dose in a L.S Spine AP & LAT radiograph for adult is approximately 0.06 mSv (5) and this radiation dose is differ from patient to patient.
The density of the tissues at L.S Spine region is different in AP position and it is different in Lateral position. Blindly selection of radiation exposure parameters may lead to unprofessional behavior of the radiographer. Good contrast images are required in each X-Ray procedure. Contrast of the x-ray image was defined according to the different density levels of tissues between the lighter shade to darker shades of gray scale (6). Ionizing radiation has sufficient energy to affect the atoms of living cells and also can damage their genetic material (DNA). Radiation interactions with genetic material of living cell may produce direct and indirect biologic effects (7). It involves rupture of cell membrane and breakdown of chromosomes structure and that is known as DNA strands break (8). For radiation protection radiographer must follow the term “ALARA” (As Low As Reasonably Achievable), and TDS (Time Distance Shielding) principals in his routine practice (9).
In the Anatomy of L.S Spine X-Ray Figure 1a AP view showing the 1. Lower chest ribs. 2. Transverse process, 3. Pedicle, 4. Spinous process, 5. Sacrum, 6. Sacroiliac joint and Figure 1.b lateral view showing the 1. Sacrum, 2. Spinous process, 3. Vertebral body, 4. Intervertebral disc space, 5. Intervertebral foramen, 6. Pedicle, 7. Inferior articular process, 8. Superior articular process, 9. Lower Chest Ribs. All these anatomical regions should be clearly visualized in X-Ray image (10).
Body Mass Index (BMI) values are the key index of the relationship in weight and height of the human beings. BMI is calculated as, weight kg/height m2. This is commonly use to surrogate in diagnosis of the obesity and fat distribution. As the fat increases or decreases near or at the lumbar region, on the basis of BMI values calculation patient can consider as fatty/obese or normal patient as shown in Table 1. On the basis of BMI values radiographer can adjust the radiation exposure parameter to the optimum level to achieve the good quality of radiographs also can eliminate the extra radiation absorbed dose to patients (11, 12).
Vasileios I. et al. conducted a study and says that the dose audit is important in the optimization of the patient’s radiation protection in diagnostic. In this study, the effect of body mass index (BMI) on radiation dose were calculated. Total 1869 adult patients underwent chest, abdomen, lumbar spine, kidneys and urinary bladder (KUB) and pelvis radiography. All procedures was done for both, overweight and obese patients and compared with normal patients through Mann–Whitney test (p < 0.0001) and were found significantly positive relationship between patient body size and exposure factor (13).
Patrick Knott, et al. performed a study on reducing the X-Rays exposure in pediatric patient’s scoliosis patients. In this study, such significant advance changes have been made in current diagnostic techniques. In general, adolescents are exposed to less radiation dose for radiographic imaging, and proved that newer imaging techniques are able to decrease the amount of radiation exposure. Researcher well explained that it should be noted the rates of cancer secondary to primary radiation exposure are not specific in scoliosis patients. Dosages for the spine radiograph were reduced from 1/6th to 1/9th from the standard amount of radiation dose. By following the standard exposure chart as suggested by researcher (9), the radiation dose to patient in higher BMI (Pre-obese and obese) vales, can be minimized by 30-40% without compromise the quality, contrast and resolution of radiographic images (14).
Need of this study- In routine X-Ray procedures, maximum number of patients underwent for spine radiography and took high radiation dose exposure. In which some of them also get repeated exam due to the lack of optimum radiation exposure or poor image quality radiograph and if not repeated then radiologist need to compromised with the poor image quality radiograph and diagnosis has to made for patient. To optimize the radiation dose and improve the image quality of spine radiograph, some bull’s eye technique is required. No any study has been yet published in “India” on spine radiograph with consideration of BMI values before performing the examination. BMI values may provide an idea to choose appropriate radiation exposure factors, which can be help to radiographer to minimize the amount of radiation dose to patient.
Aim: To evaluate the role of BMI values before each L. S. spine radiograph and to choose the optimum radiation exposure factors without compromised the radiographic image quality.