A bone survey, also known as a skeletal survey, is a diagnostic imaging procedure that uses X-rays to create images of multiple bones throughout the body. Its primary goal is to identify widespread or localized abnormalities within the bones, serving as a diagnostic tool for various medical conditions.
Why a Bone Survey is Performed
Bone surveys are performed to detect and assess the spread of certain cancers to the bones, a process known as metastasis. Cancers originating in the breast, prostate, lung, kidney, or thyroid can spread to the bones, and a bone survey helps identify these metastatic lesions. It is particularly useful in diagnosing and monitoring multiple myeloma, a type of cancer that affects plasma cells and can cause “punched-out” lesions or holes in the bones, guiding treatment decisions and prognosis.
The survey also plays a role in identifying various metabolic bone diseases. Conditions such as rickets, osteomalacia, or advanced osteoporosis, which involve widespread changes in bone density or structure, can be evaluated through a bone survey. These X-rays can reveal loss or thinning of bone, as seen in osteoporosis or osteopenia, and can also show past or current bone fractures.
In pediatric cases, a bone survey is a tool for investigating suspected non-accidental trauma or child abuse. It can uncover occult fractures—those not immediately obvious—or other injuries that might suggest abuse, especially in children under two years old. The findings from a bone survey in such situations can even be used as evidence in legal proceedings.
Bone surveys also assist in diagnosing skeletal dysplasias, which are genetic disorders affecting bone growth and development. These conditions often present with widespread skeletal abnormalities, making a comprehensive X-ray series suitable for their identification and characterization.
What to Expect During a Bone Survey
Preparation for a bone survey is minimal, with no specific dietary restrictions like fasting required beforehand. Patients need to remove any jewelry, metal objects, or clothing containing metal components, as these materials can interfere with the X-ray images. A hospital gown is provided to ensure clear imaging of the bones.
During the procedure, a radiology technician will guide the patient through various positions, either standing or lying down, to capture multiple X-ray images of different body parts. A typical skeletal survey involves approximately 20 individual X-rays, covering areas such as the skull, entire spine, ribs, pelvis, and the long bones of the arms and legs. Each X-ray image is captured quickly, and the technician will reposition the patient to ensure all necessary views are obtained.
The technician operates the X-ray machine from a separate area to minimize their own radiation exposure, though they remain nearby to provide instructions and monitor the patient. Lead shielding may be used to protect sensitive areas of the body that are not being imaged. The entire procedure takes about one hour. After the survey is complete, patients can resume their normal activities immediately, as it is an outpatient procedure.
Bone Survey vs. Other Imaging Tests
A bone survey differs from a single X-ray in its scope; while a single X-ray focuses on one specific area of concern, a bone survey involves multiple X-rays to provide a comprehensive view of the entire skeleton or large regions of it. This broader approach allows for the detection of widespread or systemic bone issues that a localized X-ray might miss.
A bone survey also stands apart from a bone scan, which is a nuclear medicine test. A bone survey uses standard X-ray technology to visualize the bone structure directly. In contrast, a bone scan involves injecting a small amount of radioactive tracer into a vein, which then travels through the bloodstream and accumulates in areas of increased bone metabolism, indicating active bone formation or destruction. While both can detect bone involvement by cancer, infection, or trauma, bone scans are often employed for more subtle or metabolically active lesions, whereas bone surveys highlight structural changes.
Other imaging modalities like Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scans offer different types of information. MRI provides detailed images of soft tissues, bone marrow, and subtle bone injuries not visible on X-rays, using powerful magnets and radio waves without ionizing radiation. CT scans use X-rays to create detailed cross-sectional, 360-degree views of bones and soft tissues, offering a higher level of detail than a standard X-ray and being faster than MRI. While MRI and CT can detect bone involvement by cancer, a bone survey remains a standard method for a comprehensive skeletal overview, particularly for conditions like multiple myeloma.