How do I identify bacteria biofilm and phleboliths/calcification for UTI symptoms in bladder x-ray?

An Xray of the Kidneys, Ureters and Bladder (KUB Xray) is done to look for stones, which may cause UTI or symptoms similar to UTI such as pain on passing urine or abdominal pain.

Biofilms are a collection of microorganism on a surface. Their formation begins when free-floating bacteria come in contact with an appropriate surface such as the inner lining of the bladder and begins attach to this surface. This enables the bacteria in a biofilm to stick together. Attachment is followed by a period of growth. Biofilm increases the resistance of bacteria to the host immune response and to antibiotics. Biofilms are microscopic, so they will not be visible on x-rays.

Phleboliths are small round calcifications located in veins. They are more common in the pelvis, and their significance is that they can be mistaken for stones on xrays. Phleboliths typically do not move and are harmless.

The difference between phleboliths and stones in the ureter are: 1) Round shape (stones are not typically round and have jagged edges), Position, Presence of central lucency. In some cases, a CT scan may be needed to differentiate between a stone and phlebolith.

To answer this question, we first need to discuss briefly how X-rays work.

When X-rays travel through the body, they are absorbed in different amounts by different tissues, depending on the properties of these tissues, in particular, how radiologically dense these tissues are.

Structures such as bone contain calcium which helps them absorb X-rays more readily. This, in turn, produces high contrast on the X-ray detector causing bony structures to appear whiter than other tissues on an X-ray image.

Conversely, X-rays travel more easily through less radiologically dense tissues such as fat and muscle, as well as structures that are air-filled, like our lungs. These structures are displayed in shades of grey on a radiograph.

Phleboliths and calcification have differing radiologic densities and, depending on how white they appear on a film, radiologists are usually able to guess at their likely consistency and, hence, what they are likely to be when a white image appears on a bladder X-ray.

Unfortunately, bacterial biofilms are too small and aren't radiologically dense. Hence, they would not appear as an image on an X-ray.

Identifying phleboliths/calcifications is important for UTIs because they are a nidus for infection to grow (which can result in recurrent infections). Calcifications in the wrong places (like the ureter) can also result in discomfort, obstruction and infection and, depending on size and location, may even require surgical removal.