introduction to radiological devices Xray

                                                                                                        Diseases are as old as

 mankind  .   As long as man existed there was disease , injury and  man thought  they were due to curse from the gods  .  But as  humans progressed  he realized that  disease is caused due  to various  changes occurring in the human body .  The work of  Andreas Vesalius  helped to understand the normal structure of the body  and  later  the  abnormal changes occurring in the body were described  . These changes could be seen only after the  person is dead  due to the disease or when the  person is cut open  to treat the disease .But  waiting to diagnose  whether a  person has a fracture of the skull , if we have to wait till the person is dead  what is the use of diagnosis and treatment  .  So the treatments in 19 th century  was like the  hunter who shoots  with eyes blindfolded at a charging tiger  .  Sometimes the disease gets cured but often  the disease got worse by the wrong treatment  .                                                                                In  1895  ,   a man was doing some experiments with a Crookes  tube  .He  bombarded a  tungsten target with  high voltage electrons   .  He discovered that some invisible rays were coming from that tube which  penetrates  substances  and cause a  fluorescence on photographic plate kept at a distance  .

He  kept  his  wifes  hand  with  her wedding ring  between the  tube and the photographic plate and to his amazement  saw  the  bones  inside  her hand   on the photographic plate with the wedding ring  .  This  was the first time the inside of the body was seen without cutting open with a knife  .  He called these  rays  coming from the Crookes  tube as X rays  as X stood for unknown rays  .   This  is  the  famous Xray which we are using even now in modern medicine after more than 100 years and the man was Wilhelm Rontgen a German scientist   .  Soon  it was found  that  Xrays was useful to diagnose the breaks in bones called fractures  .  It was  useful to  find lung diseases like pneumonia  . Though it was the first radiologic investigation invented  ,  it is still the most common investigation done in the world  . Xray of the  chest is the most common investigation in the world and it is possible that the  reader  might have  got a  xray for cough or  an injury after an accident  .  As  the  years  advanced Xray machines became more sophisticated . We now have  Xrays which are  mobile which can go to the bedside of the patient and take Xrays , we  have  dental Xrays for teeth  to check whether they have tooth infection  . There  are  digital Xrays nowadays where the  process is Computerized  . The  Xray  coming out of the machine  is  still similar to the Roentgen’s Xrays but the  amount  of  Xrays  can be  regulated automatically by using computer control . This results  in highest quality of the Xray pictures(called a Radiograph)  while using  the minimum amount of radiation  . 

                                                                 Still  people could not see  the inside of intestine , the bronchus , or  the kidneys  using Xrays  as only  bones could stop the Xray beam and produce a picture  . Scientists discovered that substances like barium sulfate could be used  to  see  the inside of intestines  . This  was because  when swallowed  the barium coats the  intestine and when xray pass through the body the outline of barium  shows the outline of intestine  .  This technique helped in diagnosing various diseases of stomach and intestine  like  cancer  , ulcer  etc  These studies were called barium studies ..   Similarly it was discovered  that  injection of iodine contained dye was excreted by the kidneys  and  iodine being dense  could be shown by passing xrays . This technique was called  IVP or intravenous pyelography  .