There are no recommended tests to diagnose CNS tumors. The tumor is usually found when patients develop symptoms and visit the doctor. The first step in diagnosis is usually a neurological exam, including tests for reflexes, muscle strength, vision and eye movements, and balance and alertness. If the results are abnormal, additional tests carried out by a specialist such as a neurosurgeon or a neurologist may be recommended. Adults and children both undergo a similar set of tests to diagnose CNS tumors, including: * Medical history * Blood test * Urine test * Medical imaging * X-ray * CT scan * MRI * Biopsy Most patients who have CNS tumors do not have a family record of the disease. Imaging Imaging is an important method for diagnosing CNS tumors and determining their location. The location is informative both for identifying the type of tumor and for determining how to treat it. Magnetic resonance imaging (MRI) and computed tomography (CT) scans are the most commonly used imaging technologies for diagnosis of CNS tumors. MRI provides better detail and detection of tumor-infiltrated areas. Examples of CNS tumors imaged using positron emission tomography (PET). Magnetic Resonance Imaging Magnetic resonance imaging uses strong magnetic fields, magnetic field gradients, and radio waves to generate images of the structure of the brain. In perfusion MRI a contrast agent, such as gadolinium compounds, may be used to study the structure of the blood vessels around the tumor that provide nutrients and remove waste. The contrast agent may be taken by mouth or injected into the patient before the scan. Magnetic Resonance Spectroscopy Magnetic resonance spectroscopy (MRS) is a variant of MRI used to measure biochemical changes in the brain. Comparing the metabolites detected in normal brain tissue with those in affected brain tissue can help determine the type of tumor and estimate how quickly it is growing. Computed tomography Computed tomography (CT) technologies include X-ray CT, positron emission tomography (PET) and single-photon emission computed tomography (SPECT). X-ray CT scans take many X-ray measurements from different angles to produce virtual "slices" of specific areas of a scanned object that can then be reassembled into a complete image of the object. Such scans can detect tumors by the swelling and anatomical distortion they cause, or by surrounding edema. While CT scans are widely available and produce images rapidly, MRI scans provide better anatomic detail of brain structures and detection of tumor-infiltrated areas. Biopsy A biopsy is the definitive way to diagnose CNS tumors. Because of the difficulty of accessing brain tissue, and the risk of damage to the brain, biopsies may be guided by computer and imaging in a stereotactic surgery procedure. A stereotactic biopsy is performed under local anesthesia or general anesthesia. After the MRI or a CT scan, the scalp or scalp contours are marked to show the position of where to drill or cut the scalp. An image guidance system is then used to provide assistance in directing a needle into the tumor to collect a small tissue sample. The sample is analyzed by a pathologist or neuropathologist to determine whether the tumor is benign or malignant and identify the type of tumor. Biopsies can also be performed as part of an operation to remove the tumor mass. Blood tests Blood tests such as a complete blood count (CBC) can provide insight into the progress of a tumor by measuring the number of blood cell types such as white blood cells, red blood cells and platelets. Blood chemistry is also used to check the health of the liver, kidneys and other organs. Many tumors shed microscopic extracellular vesicles into the bloodstream that can be used to monitor the progress of a cancer or its response to therapy.
Central nervous system tumor
Brain tumor
Spinal tumor
Brain stem tumor
Basal ganglia disease
Central nervous system viral disease
Spinal cord injury
Central nervous system cyst