Examination Techniques CT-Scan Head

A. Indications Examination (BONTRAGER, 2001)

    Tumors, masses and lesions
    Brain metastases
    Intra-cranial bleeding
    Aneurysms
    Abscess
    Brain atrophy
    Post-trauma disorders (epidural and subdural hematoma)
    Congenital Abnormalities
B. Examination preparation a. Preparation No special preparation of patients for patients, only instruksui-instruction regarding patient positioning and inspection procedures should be clearly known, especially if the examination using contrast media. Objects accessories such as false teeth, wigs, earrings, hair penjempit, and hearing aids must be removed first before the examination because it will lead to patient comfort artefak.Untuk recall examinations performed on air-conditioned room the patient should be given blankets (Brooker, 1986) b. Preparation tools and bahanAlat and materials used for examination of the head can be divided into two, namely: 1. Sterile equipment:

    The means of injecting
    Syringe.
    Gauze and cotton
    Alcohol
2. Non-sterile equipment

    CT-Scan plane
    Contrast media
    Oxygen tank
c. Preparation of contrast media and drug-obatanDalam a CT-scan of the head in pediatric need nonionic contrast media due to pressure reactions to contrast media such as dizziness, nausea and vomiting, and anesthetic drugs if needed. Contrast media used for the body's anatomical structures like blood vessels and other organs organism can be distinguished clearly. In addition to the use of contrast media can reveal the presence of abnormalities in the body such as the existence tumor.Teknik injection Intra Venous (Seeram, 2001)

    Types of contrast media: omnipaque, Visipaque
    Volume usage: 2-3 mm / kg, maximum 150 m
    Injection rate: 1-3 mm / sec
C. Examination Technique

    Position the patient: Patient supine on an exam table with your head close to the gantry.
    Object Position: Head hiperfleksi and diletkkan on the head holder. The head is positioned so that the mid sagittal plane of the body parallel to the indicator lights and interpupilary longitudinal line parallel to the horizontal indicator lights. Patient's arm is placed over the abdomen or in addition to the body. To reduce the movement of the forehead and the patient's body should difikasasi with a special belt on the head holder and the examination table. Knees were given a booster for patient comfort (Nesseth, 2000).

      Scan Parameters

        Scanogram: lateral head
        Range: range I of the base until the pars petrosum cranii and II of pars petrosum range up to the vertex.
        Slice Thickness: 2-5 mm (range I) and 5-10 mm (range II)
        FOV: 24 cm
        Gantry tilt: gantry angle depends on the size of the angle formed by the orbito meatal line with vertical lines.
        kV: 120
        mA: 250
        Reconstruksion Algorithm: soft tissue
        Window width: 00-90 HU (supratentorial brain); 110-160 HU (brain in posterior fossa); 2000-3000 HU (bone)
        Window Level: 40-45 HU (supratentorial brain); 30-40 HU (brain in posterior fossa); 200-400 HU (bones)

    Photos before and after entry of contrast media
        In general, a CT-scan of the head takes 6-10 axial slices. However, such measures can vary depending on the purposes of diagnosis. For cases such as a tumor then the number of slices will reach twice that of having made the images before and after contrast medium income. The goal made the images before and after contrast medium income is to be able to distinguish clearly whether the organ abnormalities or not.
    The resulting images in a CT-scan of the head in general:
        Pieces Axial I
            Is the most superior part of the brain called the hemisphere. Criteria picture is apparent:


a. The anterior part of superior sagittal sinus b. Centrum semi-ovale (which contain material cerebrum) c. Longitudinal fissure (part of falks cerebri) d. Sulcus e. Gyrus f. The posterior superior sagittal sinus

        Axial Pieces IV
            An axial slice of the four so-called medial ventricular rate. Criteria picture looks:

a. Anterior corpus collosum b. Anterior horn of the left lateral ventricle c. Caudate nucleus d. Thalamus e. Third ventricle f. Pineal gland (a bit less calcified) g. Posterior horn of the left lateral ventricle

        Pieces Axial V
            Describing the brain tissue in the medial third ventricle. Criteria for images that look:

a. Anterior corpus collosum b. Left lateral ventricle anterior horn c. Third ventricle d. Pineal gland e. Protuberantia internal occipital

        Axial Pieces VII
            Sliced ​​into seven is a depiction of the field of orbital tissue. The structure of the slices is difficult to properly revealed in the CT-scan. Modifications of the position angle head is done to get the picture looks:

  a. Eyeball / occular bulb b. Right optic nerve c. Optic Chiasma d. Temporal lobe e. Midbrain f. Cerebellum g. Lobe oksipitalis h. Water mastoid cell i. Or ethmoid sinus and sphenoid sinus