Bone scan

Bone scans can help identify hidden fractures that cannot be seen in regular x-rays, they can also help detect bone cancer, arthritis, reason for mysterious bone pain and bone infections. In a normal x-ray, the radiation passes through the body and creates an image on the x-ray placed on the other side of the body, whereas in a bone scan the radiation travels to the surface of the body that is in turn detected by a camera. All metal items in contact with the body have to be removed before a bone scan. There are no restrictions on eating and drinking. Bone scans are not performed on pregnant women. You have to arrive 4 hours before the scan and let the tracer settle well into your body.Bone scan procedure involves:

• An injection with tracers is injected into the vein in your arm.
  
• After this you have to wait for 2-4 hours to allow the tracers to circulate and become absorbed by your bones. In organs and tissues such as the bones, this radio nuclide gets accumulated.
  
• You will be asked to drink lots of water to pass out the unabsorbed radioactive material through the urine. The absorbed radioactive material will flush out through the urine by 24 hours.
  
• During the bone scan, you will be made to lie motionless on the table, as a device with an arm-like gadget holding the gamma camera passes above the body. When the tracers enter the body, they emit gamma waves of radiation that can be detected by a special camera.
  
• The camera in turn generates images that can be inferred by radiologists or nuclear medicine specialists.
  
• The scan takes about 30-60 minutes for the entire skeletal and even less if only for specified areas.

When no abnormal area is seen with high or low accumulation of the tracers, the radioactive material is evenly distributed. This indicates that the bone area that is scanned is normal. In abnormal cases, radioactive material accumulates in a particular area of the bone. This is known as a hot spot. Hot spots can indicate a healing fracture, bone cancer, bone infection, arthritis or a disease of an abnormal bone metabolism. Certain spots may indicate less absorption of the radioactive material, they are called cold spots. This could indicate cancer or lack of blood supply to the bone.

Bone biopsy

Bone biopsy is a medical procedure during which a small sample of bone tissue is taken and examined for the presence of cancer cells, infections or any other bone disorders. Bone biopsy involves removing the hard outer portion of the bone from the compact tissue, unlike bone marrow biopsy procedure where the innermost sponge-like material containing marrow is removed to assess for abnormalities.

Why is bone biopsy conducted?

Tests like x rays and bone scans may reveal a tumor, but whether it is benign or malignant and if it is malignant, the type of cancer cell is detected accurately by bone biopsy. Bone biopsy determines the presence of benign tumors like Fibroma, Osteoblastoma, Osteoid osteoma and cysts and cancerous tumors like Ewing's sarcoma, Multiple myeloma and Osteosarcoma. Apart from tumors, bone biopsies are also used to identify the bone infections like osteomyelitis and abnormal bone structures that may be causing persistent pain and tenderness.

Types of bone biopsy

Closed biopsy or needle biopsy involves inserting a needle through the skin into the bone to draw a small bone tissue with the needle. Closed biopsy is performed under imaging guidance using a variety of modalities such as fluoroscopy, CT and MRI. Firstly the doctor will choose the bone, mostly the one that is closer to the surface such as hip bone, but biopsy can be performed on any bone. The area is sterilized with antiseptic lotion and local anesthesia is administered. It is important for the patient to remain motionless during the procedure; he may be strapped or belted to restrict movement.

A small incision is made at the site through which the needle is drilled till it finds bone. Needle will be wriggled into the bone to obtain the sample. After the needle is withdrawn, gentle pressure is applied on the site to control the bleeding; finally, the area is cleaned and covered with the bandage. The tissue sample is sent to the laboratory for analysis.

Open biopsy procedure takes place during surgery after administering general anesthesia. Here, the size of the incision is relatively larger as a small piece of bone is removed from the patient's body for further examination.

The patient is required to undergo few blood tests before the procedure to assess the blood clotting and the functioning of kidneys and liver. Medications like blood thinners and anti platelet drugs may need to be stopped temporarily. The site of the biopsy may feel sore and tender for few days and patient may be given pain relievers. If it is a closed biopsy, the patient can return home within an hour or as soon as he starts feeling comfortable. In the case of open biopsy, the patient will regain consciousness after few minutes but may feel drowsy for few hours after the procedure and is retained in the hospital for the whole day. Whether it is needle or open biopsy, patient should keep the area of biopsy bandaged and dry to avoid infections.

Complications arising from bone biopsy are rare, yet patient should be aware of the risks associated with the bone biopsy. Patient may contact skin infection or suffer from bone infection. There is also a risk of needle breaking the bone and causing injury. Hence whenever there is bleeding, redness or oozing of the pus or fever, pain and chills, it should immediately be brought to the doctor's notice.