Brain Tumor CT-Scan Examination Techniques

CT examination was carried out acts specifically on the head. Not only performed on patients suffering from head trauma, but it turns out this examination can detect various abnormalities in the patient's head is:     Tumors, masses and lesions. In the brain tumors,the sulci may also be obligated by expanding lesions within the brain suck as a tumor or an absecess. In addition to mechanical compression of the sulci, associated swelling of the surrounding gyri from oedema leads to appearance of complete obliteration of the sulci as shown in the figure. To summaries , we have learn that the brain surface consist of gyri and that sulci normally filled with brain cerebrospinal fluid (CSF),which get replaced by blood or is squeezed out by swelling of the brain from oedema or expanding mass

Before the examination by means of CT, the officer must give the position instructions and inspection procedures to patients. Especially if the examination using contrast media. Also explained that the object of accessories such as false teeth, false hair, earrings, hair accessories, and hearing aids must be removed first. Because it will cause artefak. The patient should the patient be given a blanket because the room was very cold.Preparation tools and materials used for the examination of the head is divided into two, namely:1. Sterile equipment:

• Injection tools
• Syringe.
• Gauze and cotton
• Alcohol 

Non-sterile equipment

• Plane CT-Scan
• Contrast media
• Oxygen tube

CT-scan of the head of pediatricshould using nonionic contrast media  . This function is to suppress reactions to contrast media such as dizziness, nausea and vomiting. Anesthetic drugs may be used if needed. Contrast media used for anatomical structures can be distinguished clearly distinguishable. (Such as blood vessels and other body organs). Contrast media can reveal the presence of abnormalities in the body like a tumor. (Seeram, 2001) This type of contrast media, among others omnipaque, Visipaque with volume usage: 2-3 mm / kg, maximum 150 m. While the injection rate: 1-3 mm / secExamination TechniquesPosition the patient in CT Scanning is the patient supine on the examination table with your head close to the gantry. While the Object Position is the head hiperfleksi and take the head holder. Head is positioned so that the mid sagittal plane of the body parallel to the longitudinal indicator lights. While Interpupilary line parallel to the horizontal indicator lights. The patient's arm is placed on the abdomen or in addition to the body. To reduce the movement of the forehead and the patient should fixation use a special belt holder on the head. The knees were given a booster for the convenience of the patient (Nesseth, 2000).

 Setting of Scan Parameters

• Use the type of scanogram on  lateral head. Then take the range I of the basis cranii to pars petrosum and range II of pars petrosum to the vertex. The slice Thickness is 2-5 mm (range I) and 5-10 mm (range II) with FOV: 24 cm. The gantry tilt angle depends on the size of the angle formed by the orbito meatal line with vertical lines.
• Sett your power machine use kV: 120 an mA: 250 and the algorithm reconstruction are on soft tissue mode.
• Window width: 0-90 HU (supratentorial brain); 110-160 HU (posterior fossa brain); 2000-3000 HU (bone)
•  Window Level: 40-45 HU (supratentorial brain); 30-40 HU (posterior fossa brain); 200-400 HU (bone)

Contrast media can reveal the presence of abnormalities in the body like a tumor. Taking photos must before and after intake of contrast medium. In general, a CT-scan of the head takes 6-10 axial slices. But such measures can vary depending on the purpose of diagnosis. For cases such as tumor, the number will reach two time slices because they have made images before and after introduction of contrast media. Purposes made income before and after shots of contrast media is to be able to distinguish clearly whether the organ is abnormal or not.

• Axial pieces I was most superior part of the brain called the hemisphere.
• Axial IV pieces to the four axial slices is called the medial ventricle.
• Axiak  V Describe the brain tissue in the medial third ventricle.
• Axial pieces VII is a seven slices to a depiction of the field of orbital tissues. Structures in this slice is difficult to be revealed by both the CT-scan. 

The right-sided small lesion and oedema are squeezing neighboring sulci and gyri similar to schematic illustration. Note the density of the oedema surrounding the lesion. The white matter normally appears less dense than the cortex as seen on the left hemisphere in this scan. It is referred to as grey white differentiation on the ct scn. But the odedema from the lesion is darker than the normal white matter low density and it is not brain cerebrospinal fluid (CSF).

Drawing of the effect of an extra axial mass on brain and a CT scan showing an ISODENSE mass. Can you detect asymmetry in two halves of the scan?Can you make out where the tomour is?