Solely in terms of UKBA entry visa requirements you don't need one.
The new requirements for TB screening certification are required to be complied with BEFORE visa application is made.
HHaving said that, if you will be arriving at Heathrow airport or Gatwick airport you may be questioned about X-Ray but will not encounter any problems being admitted entry. You may be asked to register later for TB screening in UK and given a form to fill out