Ct head protocols

MAAJIDMOHIUDDINMALIK
LECTURERCOPMS,ADESHUNIVERSITY
BATHINDAPUNJAB
CT HEAD PROTOCOLS

COMPUTED TOMOGRAPHY (CT) - HEAD
Computed tomography (CT) of the head uses special x-ray
equipment to help assess head injuries, severe headaches,
dizziness, and other symptoms of aneurysm, bleeding, stroke,
and brain tumors. It also helps to evaluate your face, sinuses,
and skull or to plan radiation therapy for brain cancer. In
emergency cases, it can reveal internal injuries and bleeding
quickly enough to help save lives.

WHAT IS CT SCANNING OF THE HEAD?
 Computed tomography, more commonly known as a CT or CAT scan,
is a diagnostic medical imaging test. Like traditional x-rays, it produces
multiple images or pictures of the inside of the body.
 The cross-sectional images generated during a CT scan can be
reformatted in multiple planes. They can even generate three-
dimensional images. These images can be viewed on a computer
monitor, printed on film or by a 3D printer, or transferred to a CD or
DVD.

CONTINUE...
CT images of internal organs, bones, soft tissue and
blood vessels provide greater detail than traditional x-
rays, particularly of soft tissues and blood vessels.
CT scanning provides more detailed information on head
injuries, stroke brain tumors and other brain diseases
than regular radiographs (x-rays).

PREPARATION
 You should wear comfortable, loose-fitting clothing to your exam. You
may need to wear a gown during the procedure.
 Metal objects, including jewelry, eyeglasses, dentures and hairpins, may
affect the CT images. Leave them at home or remove them prior to your
exam. You may also be asked to remove hearing aids and removable
dental work. Women will be asked to remove bras containing metal
underwire. You may be asked to remove any piercings, if possible.

CONTINUE...
 You will be asked not to eat or drink anything for a few hours beforehand, if contrast
material will be used in your exam. You should inform your physician of all
medications you are taking and if you have any allergies. If you have a known allergy
to contrast material, your doctor may prescribe medications (usually a steroid) to
reduce the risk of an allergic reaction. To avoid unnecessary delays, contact your
doctor before the exact time of your exam.
 Also inform your doctor of any recent illnesses or other medical conditions and
whether you have a history of heart disease, asthma, diabetes, kidney disease or
thyroid problems. Any of these conditions may increase the risk of an adverse effect.

WHATARE SOME COMMON USES OF THE PROCEDURE?
 CT scanning of the head is typically used to detect:
 Bleeding, brain injury and skull fractures in patients with head
injuries.
 Bleeding caused by a ruptured or leaking aneurysm in a patient with a
sudden severe headache.
 A blood clot or bleeding within the brain shortly after a patient exhibits
symptoms of a stroke.

CONTINUE...
 A stroke, especially with a technique called CT Perfusion of the Head.
 Brain tumors.
 Enlarged brain cavities (ventricles) in patients with hydrocephalus.
 Diseases or malformations of the skull.
CT scanning is also performed to:
 Evaluate the extent of bone and soft tissue damage in patients with
facial trauma, and planning surgical reconstruction.
 Diagnose diseases of the temporal bone on the side of the skull, which
may be causing hearing problems.

CONTINUE...
Determine whether inflammation or other changes are
present in the paranasal sinuses.
Plan radiation therapy for cancer of the brain or other
tissues.
Guide the passage of a needle used to obtain a tissue
sample (biopsy) from the brain.
Assess aneurysms, arteriovenous malformations, and
blood vessels through a technique called CT
angiography.

WHAT ARE THE BENEFITS VS. RISKS?
Benefits
 CT scanning is painless, noninvasive and accurate.
 A major advantage of CT is its ability to image bone, soft tissue and blood vessels all at
the same time.
 Unlike conventional x-rays, CT scanning provides very detailed images of many types
of tissue as well as the lungs, bones, and blood vessels.
 CT examinations are fast and simple; in emergency cases, they can reveal internal
injuries and bleeding quickly enough to help save lives.

CONTINUE...
 CT has been shown to be a cost-effective imaging tool for a wide range of clinical
problems.
 CT is less sensitive to patient movement than MRI.
 CT can be performed if you have an implanted medical device of any kind, unlike
MRI.
 A diagnosis determined by CT scanning may eliminate the need for exploratory
surgery and surgical biopsy.
 No radiation remains in a patient's body after a CT examination.
 X-rays used in CT scans should have no immediate side effects.

RISKS
 There is always a slight chance of cancer from excessive exposure to
radiation. However, the benefit of an accurate diagnosis far outweighs
the risk.
 The effective radiation dose for this procedure varies. See the Radiation
Dose in X-Ray and CT Exams page for more information about
radiation dose.
 Women should always tell their doctor and x-ray or CT technologist if
there is any chance they are pregnant. See the Safety in X-ray,
Interventional Radiology and Nuclear Medicine Procedures page for
more information about pregnancy and x-rays.

CONTINUE...
 CT scanning is, in general, not recommended for pregnant women unless medically
necessary because of potential risk to the baby. This risk is, however, minimal with
head CT scanning.
 IV contrast manufacturers indicate mothers should not breastfeed their babies for 24-
48 hours after contrast material is given. However, the most recent American College
of Radiology (ACR) Manual on Contrast Media reports that studies show the amount
of contrast absorbed by the infant during breastfeeding is extremely low. For further
information please consult the ACR Manual on Contrast Media and its references.

CONTINUE...
 The risk of serious allergic reaction to contrast materials that contain
iodine is extremely rare, and radiology departments are well-equipped
to deal with them.
 Because children are more sensitive to radiation, they should have a CT
exam only if it is essential for making a diagnosis and should not have
repeated CT exams unless absolutely necessary. CT scans in children
should always be done with low-dose technique.

CT ROUTINE ADULT HEAD (NCCT BRAIN)
PROTOCOL
Indications:
Acute head trauma
Stroke
Intracranial bleed
Headache
Epilepsy
Neoplasms- Pre or
postoperative
evaluation
Hydrocephalus
Abscess

CONTRAINDICATIONS
Pregnancy
Hypersensitivity to iodinated contrast media.
Renal impairment (Creatinine >1.5mg/dl )

POSITION
 Patient Position: Spine with head
first arms bilaterally downwards, with
the head in the head holder. Center
the table height such that external
auditory meatus (EAM) is at center of
the gantry. To decrease the ocular
lens exposure, the scan angle should
be parallel to a line created by the
supraorbital ridge and the inner table
of the posterior margin of the foramen
magnum.
 Topogram Direction: Craniocaudal
 Scan Type: Axial
 Position/Landmark: 2-3cm
(20-30mm) above the vertex.
 Start Location: Skull base.
 End Location: Skull vertex.
 Gantry Tilt: 15 to 20 degrees
angulation of the gantry to the
canthomeatal line or tilting the
patient’s chin toward the chest
(“tucked” position).
 DFOV: 22cm

CONTINUE….
 Contrast: Nil
 Slice Thickness: 2-5 mm
 Algorithm: standard, bone
 Respiratory Phase: None
 Tube Voltage (Kv): 120
 Tube Current (mAs): 300-
450
Rotation Time (s): 1
Pitch: 10.65 mm
Contrast: Nil
Image Format: DICOM

Topogram of head with scan lines
showing the plane and scan range
Axial NCCThead showingEDH

CONTRASTENHANCED CT HEADPROTOCOL
Indications:
Suspicion of mass
Known primary
tumour
Metastases
Aneurysm
Abscesses
Meningitis
 Patient Position: Spine with head
the gantry. To decrease the ocular
lens exposure, the scan angle should
be parallel to a line created by the
supraorbital ridge and the inner table
of the posterior margin of the foramen
magnum
 Topogram Direction: Craniocaudal

CONTINUE….
 Scan Type: Helical
 Position/Landmark: 2-3 cm (20-30
mm) above the vertex.
 Start Location: 1 cm inferior to Skull
base.
 End Location: 1 cm superior to Skull
vertex.
canthomeatal line or tilting the
patient’s chin toward the chest
(“tucked” position).
 DFOV: 25cm
 Contrast: Nonionic low
osmolar Iodinated
Contrast media
 Contrast Administration:
IV
 Volume: 60-100 ml
 Rate of Injection: 2-3 ml
/s

CONTINUE….
Scan Delay: 30-50sec
Algorithm: Standard,
Soft tissue
Recons and
Reformations: MPR,
MIP
Respiratory Phase:
Any
Tube Voltage (Kv):
135-240
Tube Current (mAs):
150-220
Rotation Time (s): 0.5-
0.7
Image Format: DICOM

Topogram of head with scan
lines showing the plane and
scan range
CECT axial image showing
normal brain

CT TEMPORAL BONES PROTOCOL
Indications:
Inflammatory middle ear diseases
Cholesteatoma
Hearing Loss
Trauma

CONTINUE….
Mastoiditis
Neoplastic lesions
Congenital anomalies

AXIAL PROJECTION
Patient Position: Spine with head first, head in head
rest.
Topogram Direction: Craniocaudal in axial plane or in
spine position.
Scan type: Helical
Position /landmark: Midforehead in axial plane.
Start Location: Skull base
End Location: Superior margin of petrous temporal
bone

CONTINUE….
 Gantry Tilt: No tilt in axial
plane.
 DFOV: 20 cm
 Scan field of view: 25 cm
 Contrast Administration: IV
 Rate of Injection: 2-3 ml /s
 Scan Delay: 30-40 sec
 Algorithm: Bone
 Slice Thickness: 1-2mm
 Tube Current (mAs): 350
 Rotation Time (s): 0.5
 Image Format: DICOM

CORONAL PROJECTION
 Patient Position: Prone with
head first, with extended neck
and chin on chin rest.
 Topogram Direction: Posterior
to anterior in coronal plane or in
prone position
 Scan Type: Helical
 Position/Landmark: 2-3 cm
(20-30 mm) anterior to the
forehead in coronal plane.
 Start Location: Anterior margin
of petrous temporal bone
 End Location: Posterior
margin of petrous temporal
bone
 Gantry Tilt: 17-23 degrees to
make the scanning plane
perpendicular to bony palate in
coronal plane.
 DFOV: 18 cm

CONTINUE….
osmolar Iodinated Contrast
media
 Algorithm: Standard, Bone
 Recons and Reformations:
MPR, MIP
 Slice Thickness: 1-3mm
350

Topogramof temporal bone showingscan range Coronal sectionof temporal bone

CT PITUITARY GLAND PROTOCOL
Indications:
Pituitary adenoma
Suspected/ known pituitary mass
Inflammation
Pituitary tumor
Contraindications to MRI

PROTOCOL
 Patient/Position: Spine with
IOML perpendicular to table and
head in a symmetrical position.
 Topogram Direction:
Caudocranial
 Position/Landmark:
 Start Location: Bottom of sella
 End Location: Hypothalamus
 Breath hold: None
 DFOV: 22 cm
media

CONTINUE….
 Rate of Injection: 3-3.5 ml
/s
 Algorithm: Standard, soft
tissue, bone,
 Recons and
Reformations: MPR, MIP
 Scan Delay: 30 sec
 Tube Voltage (Kv): 130-
150
250

Topogramof sellashowing scan range CT axialimageof pituitaryglandshowspituitary
adenomas

CT CEREBRAL PERFUSION PROTOCOL
Indications:
 Acute stroke
 Evaluate vasospasm
 Suspected cerebral
infarction
 Vasculitis
 Brain tumor
 Transient ischemic attack
 Follow up after ischemic
stroke
 Assessment of reperfusion
after treatment of acute
stroke

PROTOCOL
 Patient/Position: Spine with head
the gantry.
 Topogram Direction: Caudocranial
 Position/Landmark: At the level of
the canthomeatal line
 Start Location: 1cm inferior to skull
base
 End Location: Skull vertex
canthomeatal line is advisable if
possible or tilting the patient’s chin
toward the chest (“tucked” position).
 Breath hold: None
 DFOV: 20 cm
 Contrast: Nonionic low osmolar
Iodinated Contrast media

CONTINUE….
tissue
 Recons and Reformations:
MPR, MIP, SSD
 Tube Voltage (Kv): 80-100
150

CT CEREBRAL VENOGRAMPROTOCOL
Indications:
Cerebral venous
thrombosis
 Patient/Position: Spine with head
the gantry.
 Topogram Direction: Caudocranial
 Position/Landmark: 2-3 cm (20-30
mm) above the vertex.

CONTINUE….
 Start Location: 1cm
inferior to skull base
 End Location: skull vertex
 Breath hold: Any
 DFOV: 18 cm
media
 Contrast Administration:
IV
 Rate of Injection: 5.00 ml
/s
tissue
 Recons and
Reformations: MPR, MIP,
VRT, SSD

CONTINUE….
 Scan Delay: 45 sec
 Slice Thickness: 1-1.5 mm
 Tube Voltage (Kv): 130-150
 Tube Current (mAs): 220-450

CEREBRAL VENOUS THROMBOSIS IN ADULTS

Multi-section CT Venographyof the Dural Sinuses and Cerebral Veins by Using Matched Mask Bone
Elimination

Ct head protocols

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