3.7. Expanding horizons of research

3.7.1. Innovations in approach

Several innovations were constantly being made in field work. For e.g., the conventional method of measuring (reading) tuberculin indurations was the transverse method. Could this be done differently, for e.g., the longitudinal way? In field experiments conducted, experienced tuberculin reaction readers showed that they could fix the perimeter or the edges of the tuberculin indurations and align them to the mantoux ruler more accurately the longitudinal way than the conventional transverse way. The longitudinal diameters were, on the average, slightly larger than the corresponding transverse diameters for all the ranges of reactions. However, considering 10 mm + reactions as infected, the prevalence of infection was similar in either method80.

Yet another example was the development of film loading black boxes. As narrated earlier, the MMR X-ray units were used by the teams in randomly selected study areas. Some times these areas were very remote. The number X-rayed were about 80-100 on the average and touched 200 or more on some days. About 40 X-ray exposures could be made on a 70 mm roll of film. Therefore, on an average two and a half to five rolls would be needed for the day. After each roll was completely exposed, a new roll had to be inserted in the cassette. The imported mobile X-ray units had provided a black cloth bag film loading facility. These were too small for maneuverability. It took a long time for the XT to unload the exposed film and to load a new one. At the end of the day, or on days when the work load was less, a partly exposed roll had to be cut to avoid wastages so that the unexposed film could be utilised the next day. This manoeuver was difficult with the black bag facility. It was modified and replaced by a film loading box.

Not content with the limitations of single picture interpretation of MMR chest, a comparison of the relative value of single and double picture technique was made two years later in 1964, under field conditions. Two mobile X-ray units were used (both had odelca cameras) and two thousand persons were X-rayed on these two units in succession and films were independently read by three readers. In the final analysis, the double picture technique did not offer advantage over the single picture technique. Perhaps it is how carefully the technician takes the X-ray chest and how carefully the radiologist reads and interprets the film that were more important than the number of X-ray films a patient had or the number of X-ray readers reading them81.

About 40-50% of the X-ray equipment were unused all over the country because of inefficient technical understanding, poor selection of equipment, poor planning in housing the unit, inadequate maintenance facility and lack of trained personnel. The estimated losses due to these reasons alone amounted to Rs 71 million in 1969. There was an urgent need for development of infrastructure and better utilisation of the costly and imported equipments. The NTI had gained vast experience and expertise by running its own mobile X-ray fleet and stationery X-ray units, as well as attending to the problems that arose with the stationery units at the DTCs and hospitals. The above is a mere tip of the ice berg of the problems related to the proper functioning of the sophisticated equipments in the country82.