What is the diagnosis based on the following X-ray?

Multiple bladder calculi. Four oval radiopaque bladder stones are visible centrally in the pelvis. Most bladder calculi are round or oval, but they may also be amorphous, laminated, or even spiculated. Bladder stones are small mineral deposits that can form in the bladder. In most cases bladder stones develop when the urine becomes very concentrated or when one is dehydrated. This allows for minerals, such as calcium or magnesium salts, to crystallize and form stones. In some cases bladder stones do not cause any symptoms and are discovered as an incidental finding on a plain radiograph. Bladder stones vary in their size, shape and texture- some are small, hard and smooth whereas others are huge, spiked and very soft. One can have one or multiple stones. Bladder stones are somewhat more common in men who have prostate enlargement. The large prostate presses on the urethra and makes it difficult to pass urine. Over time, stagnant urine collects in the bladder and minerals like calcium sta to precipitate REF : DAVID SUTTON 6TH ED