IMPORTANCE OF AN ACCURATE DIAGNOSIS

INITIAL STEPS

These efforts are the initial steps towards the goal of diagnostic precision. In the instances where a significant Brain problem is suspected, conditions such as Brain Tumors, Aneurysms, Arteriovenous Malformations (AVM) and Congenital Abnormalities may very well share some common symptoms. An accurate diagnosis of the disease process producing the symptoms becomes an imperative. It is fundamental to successful outcomes for the physician to determine, before surgery, the precise location, size and anatomical configuration of any Tumor, Aneurysm, AVM or Congenital Abnormalities along with its relationship to vital contiguous structures.

The same concepts apply for Neurological problems that are generated by pathological conditions of the Spine and/or Spinal Cord with its Nerve Roots. Any mass lesion (meaning a pathological entity that takes up space within the Skull or Spinal Canal) has the capacity to compress the Brain, Spinal Cord or Nerve Roots against the surrounding bone structure (Skull and/or Vertebral elements). The knowledge and understanding of the precise anatomical location and configuration of the pathological process and its relationship to the Brain, Spinal Cord or Nerve Roots, as well as the surrounding anatomical structures (blood vessels, nerves, bone, etc.) is of considerable importance to the Neurosurgeon, as he/she develops an understanding of the projected natural history (what will happen if one leaves this pathological process untreated), the alternative methods of treatment with their relative risks and limitations, and then arrives at a recommendation for dealing with the process.

NEURO-IMAGING

NON-INVASIVE TECHNOLOGIES

We are fortunate to have several non-invasive and painless methods for evaluating and visualizing Brain, Skull, Spinal Cord, Spinal Column, arteries, veins, nerves, joints and muscle in extraordinary detail. Computed Tomography scans (CT scans) and/or Magnetic Resonance Imaging (MRI) scans provide vital information for diagnosing and assessing the patient's unique situation.

Both technologies provide information about bone and soft tissue, however, CT scanning provides exquisite accuracy in the evaluation of bone structure, whereas MRI scanning provides superior details for "soft tissue".

Figure 1A (Left): MRI Scan (Transaxial View) of a Left Petrous "lesion" (Arrow) at level of the Internal Auditory Canals. Figure 1B (Right): CT Scan (Transaxial View-same patient & level) The bone detail of the "Lesion" (Arrows) is far greater than the MRI Scan. COMMENT: Compare the two sides of the Skull Base and note the differences in the bone structure.

Figure 2A (Left-Below): MRI Scan (Transaxial View) 38 year old female with a Left Petrous Tumor (Curved Arrow). The details of the 8th Cranial Nerve is apparent as it enters the Internal Auditory Canal (Slender Arrow). Figure 2B (Center): MRI Scan (Same patient-Gadolinium enhanced). Note the difference "appearance" and characteristics of the tumor (Curved Arrow). Figure 2C (Right): CT Scan (Transaxial View-same patient). There is no change in the bone underlying the tumor (Curved Arrow). Compare to Figure 2A.

Modern MRI and CT scanning methods have experienced major technological advances that permit the Team of Neurological Physicians and Surgeons to evaluate anatomical details with considerable precision as well as allowing for the examination of some Neurological functions.

CT & MR "Angiography"

Figure 3 A (Left): 3-D CT Angiogram. Advanced computer technology permits the Neuroradiologists & Neurosurgeons to "manipulate" the images as is represented here with the "face" of the patient being "tilted upwards" as compared to Figure 3B (Right) which represents a "straight Transaxial" view with the nose at the lower portion of each image. The arteries and major veins are clearly identified.

Figure 4 A (Left): MRA (Coronal View) of patient with Right Glossopharyngeal Neuralgia demonstrates unusual tortuosity (Curved arrow) of the Right Posterior Inferior Cerebellar Artery (PICA). Figure 4 B (Right): Operative Photo (Same Patient) Tortuous PICA (Arrow) compresses and distorts the Right Glossopharyngeal Nerve Root at its entry zone to the Brain Stem.

Figure 5 A (Left): Pre-operative MRI Scan (Gadolinium Enhanced-Transaxial View) demonstrates a very large, partially cystic High Grade Glioma with considerable Right to Left shift of the midline with compression and distortion of the Ventricular system. Figure 5B (Center): 2 year Post-operative MRI Scan (Gadolinium Enhanced-Transaxial View). There is no evidence of residual tumor after an extensive Right Frontal Lobectomy, aggressive tumor resection & modern chemotherapy/radiation. Figure 5C (Right): 2 year Post-operative Functional MRI (FMRI) Scan (Transaxial View-Same Patient-almost identical "Slice")

PET/CT Scan

Figure 6: PET/CT Scan. The "dark" areas represent increased "uptake" of the radioisotope indicating metastatic tumor (Arrows).

INVASIVE TECHNOLOGIES

There are times when certain disease processes require even more accurate anatomical understanding such as occurs with blood vessel problems inside the Skull or Spinal Canal. In cases of Aneurysms, AVM's or Skull Base Tumors, the precision of the CT and MRI may be insufficient. In these situations, Cerebral Angiography may be required. This is an "invasive" test conducted by a Neuroradiologist. A catheter is inserted into a blood vessel, usually in the groin, and threaded, under x-ray monitoring, into the large artery (Aorta) in the abdomen and chest, until it reaches the blood vessels that supply blood to the Brain. The catheters and techniques are exquisitely accurate. A dye substance is injected into the blood vessels and x-rays obtained resulting in high resolution images of the anatomy.

	Figure 7A (Left): Vertebral Angiogram (Lateral View) of a Basilar Artery "Tip" Aneurysm (Arrow). Figure 7B (Below): Post-operative Vertebral Angiogram (Same patient). The Aneurysm has been successfully "clipped" (Arrow) with preservation of the vital adjacent vessels.

Myelogram/Post-myelographic CT Scan

Myelograms are usually conducted by the Neuroradiologist who inserts a small needle into the Spinal Canal and injects a fluid dye substance which can then flow within the Spinal Canal and be "photographed" with several x-ray techniques including CT scanning.

Figure 8A (Left): MRI Scan (Sagittal View) Multi-level Cervical Spinal Stenosis Figure 8B (Right): Post-myelographic CT Scan (Sagittal View) The bone details are far more graphically demonstrated on this CT Scan than the comparable MRI Scan. COMMENT: These DETAILS are critically important in the planning of the surgical repair of problems such as this.

Your Neurosurgeon's diagnostic accuracy is directly related to having the vital information provided by these investigations.

Return to Top of Page

This page last edited on 2/19