I am a 56-year-old woman. I recently underwent a renal ultrasound scan. The result was that my kidneys are normal, but there was an incidental finding: There were areas showing "coalescence of blood vessels" in the liver; these were called hemangiomas. My doctor explained that hemangiomas cause no symptoms or problems and do not turn into something dangerous. The radiologist recommended, however, that an additional study called a hemangioma scan be carried out to determine whether what she saw on the scan are indeed hemangiomas. I've read that in hemangioma scan a sample of blood is taken from a vein in the patient's arm and is labeled with a radioactive tracer. Thirty minutes later, the blood is reinjected into the patient's vein. Images of the liver are taken immediately after the injection and again 90 to 120 minutes after the injection. I would like to know whether the injected radiotracer causes side effects. How long does it take to eliminate the tracer material from the body? I was told the hemangioma scan is called a "liver scan" and red blood cell liver scan, but the procedure that is done at Hadassah University Medical Center's department of nuclear medicine where I was referred is called a "liver and spleen scan." Why is there a need to scan the spleen as well? - P.T., Jerusalem. Prof. Jonathan Halevy, director-general of Jerusalem's Shaare Zedek Medical Center who is also a senior liver expert, replies: Hemangiomas (dense collections of blood vessels) are common benign findings, mostly discovered incidentally when an ultrasound study of the abdomen is carried out for other reasons. They are, indeed, no cause for concern. They never become malignant, very rarely increase their size progressively and even then, almost never to clinically significant size. Although an experienced ultrasonographist can diagnose hemangiomas at a very high level of certainty, the most accurate diagnosis with definite proof that these are hemangiomas is by a special liver-spleen scan as described in the query or by a dynamic CT study. There are absolutely no side effects to the scan. The amount of radioactivity is negligible and poses no danger whatever. All the names given to the scan are synonymous, including "liver and spleen scan." The tracer is absorbed by the spleen as well as the liver, so the spleen is automatically included in the scan and not because there is any indication to do so. I am a 54-year-old man, and I have noticed that I have to get up in the middle of the night to urinate several times a week. I think I am in good health, but this worries me. What could the problem be? M.N., Haifa Judy Siegel-Itzkovich comments: The Mayo Clinic Health Letter recently covered some of the common causes of frequent urination. An increase in the number of trips to the bathroom - day or night - is a signal it's time to see a physician. Frequent urination often indicates an underlying medical condition. With proper diagnosis and treatment, it's possible to return to normal urinary habits. The key treatment for frequent urination is addressing the underlying condition. Your problem could be caused by urinary tract infection, specifically a bacterial infection of the bladder or the urethra (the tube that allows urine to flow out of the body from the bladder). Symptoms may include burning with urination, foul-smelling urine, fever and pelvic pain. It could be a side effect of medication you are taking: Diuretics and other medications can increase urinary frequency. A weakening of the muscles of the bladder, urethra and pelvic floor many lower the amount of the urine the bladder can store as well as the ability to hold or properly eliminate urine. In men, frequent urination is often connected to prostate problems; if it is enlarged or infected, it can cause urgent and frequent urination, especially at night. Many people your age do not know they suffer from Type 2 diabetes. When excess blood sugar is excreted into urine, it draws water from the body's tissues, increasing the need to urinate. Frequent or urgent urination may also be an early sign of bladder cancer. Bladder stones or bladder inflammation also can cause frequent or painful urination. Diseases that cause kidney decline may affect the kidneys' ability to concentrate urine, increasing the amount of urine produced. It may be nothing serious or it may be something. Go to the doctor immediately. Rx For Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx For Readers, The Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel-Itzkovich at (02) 538-9527, or e-mail it to email@example.com, giving your initials, age and residence.