Tissue Sampling FAQs

Below is a list of some frequently asked questions, but please feel free to contact us if you need additional information. We are always pleased to assist you.

Percutaneous Needle Biopsy and Aspiration

Sinus Tract Injection

Arthrogram and Joint Aspirations/Injection

What is tissue sampling?

Tissue sampling refers to various procedures to obtain bodily fluids or tissue (e.g. bone, muscle, etc.) for analysis.

Who performs these procedures?

Percutaneous needle biopsies and aspirations, sinus tract aspiration/injections, arthrograms and joint aspirations/injections are performed with imaging guidance by healthcare workers of various specialties and expertise. A board certified radiologist is a physician specializing in radiology and other imaging modalities including MRI, ultrasound and CT. Radiologists are trained in the variable sensitivity and specificity of each imaging technique, and in the potential for hazards related to the examination that could cause harm and must be avoided. Radiologists specialize in the imaging and diagnosis of disease. Interpretation of a radiograph MRI, CT or ultrasound examination requires expertise in pattern recognition and in the identification of potential artifacts that may otherwise be mistaken for pathology. All of the radiologists at Hospital for Special Surgery are board certified by the American Board of Radiology, have years of experience in the imaging of musculoskeletal disorders, and a majority have additional formal fellowship training beyond residency in musculoskeletal or body imaging.

What should I do to prepare for the procedure?

  • Allergies:
    If you have any allergies, especially to medications, contrast agents, local anesthesia, or latex, be sure to indicate the situation at the time of scheduling the procedure and be sure to inform the x-ray technologist and radiologist at the start of the procedure.
  • Laboratory Tests:
    Blood tests may be ordered within two weeks of the procedure in order to evaluate your blood count and to check your clotting profile. If you are taking a blood thinner (anti-coagulant medication) such as Coumadin, Heparin or Lovenox, be sure to inform your doctor when the radiographic examination is scheduled so that arrangements can be made to stop the medications before the procedure, if indicated (for Coumadin this may be as long as 2 or 3 days). Your can resume taking your medication after the procedure with an appropriate delay (usually 24 hours) for safety reasons. Aspirin and nonsteroidal anti-inflammatory medication may also need to be stopped at least 2 days prior to the procedure. Your physician should be contacted before stopping any prescribed medication.
  • Pregnancy:
    If you are pregnant or think that you might be pregnant, be sure to inform your physician, the technologist, and the radiologist prior to the procedure. Most procedures/examinations using x-rays will not be performed on pregnant women unless the benefits of the procedure/examination are felt to outweigh the risks of radiation exposure to the fetus. Procedures utilizing ultrasound can be performed safely.

What are the risks?

  • Infection:
    Anytime a needle is placed through the skin, there is a risk of introducing bacteria that can cause infection. Sterile technique and sterile equipment are used to minimize the possibility of introducing infection. The risk of infection as a complication is very low. If you experience continued swelling, redness, and/or fever and chills after your procedure, be sure to contact your doctor for an evaluation.
  • Bleeding:
    Bleeding may occur at the site of needle placement and result in soft tissue swelling and/or a black and blue appearance. Bleeding at the biopsy or aspiration site may produce compression of nearby structures such as nerves or blood vessels. Any numbness, tingling or swelling should be reported to your physician.
  • Soreness:
    Discomfort at the needle puncture site is not unusual and usually lasts no more than a few hours. In the case of an arthrogram, the joint capsule (pseudo capsule if there has been a joint replacement) is distended which may result in discomfort, pain or stiffness that lasts a few hours to a day or two.
  • Fracture:
    This is a very uncommon complication of bone biopsies but may occur, especially in bones that are weakened by an underlying disease process.
  • Contrast Reaction:
    The risk of contrast reaction is extremely low. Contrast reactions include itching, hives, and in some cases cardiac and respiratory failure.

What happens with the results?

A board certified radiologist will generate a written report which will be sent to the doctor who referred you for the examination. This report becomes part of your medical record. If fluid or tissue is removed, it will be sent to the laboratory for analysis. The results of the laboratory analysis may take several days and will be sent to your referring physician. Copies of the report can be obtained through your referring physician's office. Your physician can call the file room at 212.606.1015. A copy of the report can be faxed or mailed free of charge to their office. The radiographs are the property of the institution as are biopsy slides or blood samples. Copies of the radiographs can be obtained by contacting the file room. There is a charge for obtaining film copies and mailing them to your physician.

Percutaneous Needle Biopsy and Aspiration

What is a percutaneous needle biopsy/aspiration?

Biopsies and aspirations use specialized needles that pass through the skin (percutaneous) to obtain a sample of tissue (biopsy) or fluid (aspiration).

Why did my physician order a percutaneous needle biopsy and/or aspiration?

Samples obtained from percutaneous needle biopsies and aspirations provide valuable information regarding the presence or absence of tumor, infection or metabolic abnormality.

How are percutaneous needle biopsies and aspirations performed?

The site for needle entry is determined using imaging (fluoroscopic or x-ray, ultrasound, or CT) guidance. These procedures are performed using sterile technique and local anesthesia. The tissue or fluid sample is collected. The needle is removed and the tissue or fluid sent for laboratory analysis. Occasionally, cavities are injected with iodinated contrast agent to determine their size, extent, or to see if they communicate with other structures or cavities.

What should I do to prepare for the procedure?

If you are not an in-patient, have someone accompany you to assure your safe trip home. If you are taking pain medication, bring your medication with you. If anesthesia other than local anesthesia (such as conscious sedation) is planned for the procedure you will receive instructions from the anesthesiologist.

What are the alternatives?

Open surgical biopsy or aspiration are the main alternatives. Blood loss, anesthesia requirements, and time required for recovery from a percutaneous study are less than in open surgical procedures of the same nature. In some cases, percutaneous needle biopsy (or aspiration) is not possible because of the location of the abnormality such as when vital structures are in the path of the needle or because of the nature of the specific abnormality.

What can I expect after the procedure?

Pain or soreness at the biopsy site usually lasts from hours to, in some cases, several days. Soft tissue swelling, possibly accompanied by a black and blue area, may occur and can last anywhere from a few hours to a week.

Sinus Tract Injection

What is a sinus tract injection?

A sinus tract is a channel in the soft tissues that may communicate with the skin. A sinus tract injection/aspiration is a procedure in which an iodinated contrast agent is injected into a sinus tract to determine where the tract goes. Fluid may be aspirated at the time of injection. If so, it will be sent to the laboratory for analysis. Routine radiographs or CT images are obtained before, during and after the injection.

Why did my doctor order a sinus tract injection?

A sinus tract injection can help determine the source of unexplained fluid oozing. In the case of infection, it can help determine if there is communication with vital structures (e.g. the spinal canal and nerve roots, bowel or other organs, or to the underlying bone or joint).

How is a sinus tract injection performed?

A sinus tract injection is performed under sterile conditions. A sterile catheter (tube) is placed into the sinus tract under imaging guidance and advanced as far as it will go without resistance. Then contrast is injected and additional images are obtained. You may be placed in various positions to see if gravity changes the distribution of the contrast material. Aspirated fluid samples are sent for laboratory analysis.

What should I do to prepare for the procedure?

If you are not a hospital in-patient, be sure you have someone to escort you home safely. If you are taking medication, bring your medication with you.

What are the alternatives?

It is not unusual to have routine radiographs, CT, ultrasound or MRI examinations done before or after sinus tract injections. There are no alternatives for determining the extent of the infection.

What can I expect after the procedure?

Drainage of contrast material may occur over a period of minutes to hours after the procedure. Gauze dressings should be replaced with reasonable frequency during this period. You can expect drainage from the sinus tract to otherwise continue as before the procedure.

Arthrogram and Joint Aspirations/Injection

What is an arthrogram/joint aspiration/injection?

An arthrogram involves the needle placement into a joint and the injection of an iodinated contrast agent. If ultrasound is used for the procedure, no contrast is necessary. Sometimes air is injected into the joint instead of, or along with, the contrast agent. An aspiration can be performed during an arthrogram or independently with imaging guidance in order to permit precise placement of the needle tip. Aspirated fluid is sent for laboratory analysis.

Why did my physician order these studies?

An arthrogram is used to diagnose internal derangements of joints such as cartilage, ligament and capsular tears; help confirm arthritic conditions; and to evaluate a joint replacement for loosening or infection. An aspiration can be used to determine if a joint is infected or if an inflammatory condition is present, and also to decrease the amount of swelling. A joint injection can be used to treat a symptomatic joint disorder in an attempt to relieve or decrease symptoms and also as a test to locate or confirm the origin of your symptoms.

How are these procedures performed?

These examinations are performed under sterile conditions using local anesthesia combined with contrast injection and imaging guidance. Fluid is aspirated and contrast agent (with or without air) is injected. If ultrasound is used for guidance, contrast is not necessary. If ordered, medication would be injected. Additional x-ray images are usually obtained, sometimes in multiple positions or from multiple angles, after the needle has been removed.

What should I do to prepare for the procedure?

You do not have to undergo any special preparation.

What are the alternatives?

MRI of a joint can provide detailed information about the intra-articular structures. The arthrogram has a special role in cases that require an aspiration, injection, or examination of joints with joint replacements for evidence of loosening or infection.

What can I expect after the procedure?

If air is injected, you may experience crepitus (a crackling or popping sensation that may be heard or felt) during the first 24 hours after the procedure. In a minority of patients, the injection of steroid compounds and in some individuals the injection of contrast material may result in a painful inflammation, which can last a few days.


Department of Radiology and Imaging
Hospital for Special Surgery

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