The study was conducted in the Department of Radiology at Guru Gobind Singh Hospital,
Jamnagar from September 2010 to August 2012.
NECT Brain and CT angiography examinations of 28 patients were performed who fulfilled below mentioned inclusion and exclusion criteria.
Images were analyzed on dedicated workstations and correlated mutually.
The images were acquired with a helical 16 slice MDCT scanner (General Electric,
Brightspeed).
Acquisitions were performed without injection of contrast medium,
from the base of the skull to the vertex in the plane parallel to the canthomeatal line.
In all patients a 5 mm section thickness was used.
- MDCT Angiography for carotid
The angiographic CT examinations were performed with a helical 16 slice MDCT machine (General Electric,
Brightspeed).
A lateral scout image is acquired initially to define the correct field of view (FOV).
Patients are placed in the supine position,
with the head tilted back.
Patients are also instructed not to breathe or swallow during the acquisition.
A 5 mm plain spiral acquisition from C2 to C6 was obtained to determine the presence of calcifications.
The angiographic study is acquired after the injection of 110 ml non-ionic iodinated contrast material (Omnipaque,
General Electric) at flow rate of 4 ml/s using a power injector through a 16-18 G intravenous catheter inserted into the antecubital vein.
Scanning parameters:
The acquisition timing was individualized for each patient using automatic bolus tracking techniques.
The CT acquisition parameters included: matrix 512 X 512,
FOV 11X19 cm; 180-200 mAs; 120-140 kV; section thickness 3.2 mm,
increment 1.6 mm.
The source data was reformatted in multiple planes using slice thickness of 0.75 mm.
The angiographic acquisition started at C7 level and proceeded as far cephalic ascircle of willis including the carotid siphon.
The images were transferred to independent workstations to produce MPR (multiplanar reconstruction),
MIP (maximum intensity projection) and VR (volume rendering) reconstructions.
Axial source images were used in grading the degree of carotid artery stenosis with MIP reconstructions aiding in road mapping the vessel.
Inclusion criteria: Patients fulfilling either of below mentioned criteria were included in the study group.
After detailed informed consent and written undertaking patient underwent carotid CT angiography
- Acute or subacute infarct on CT brain/ normal CT brain with recently described TIA or stroke (an arbitrary cut off of 10 days is used from the time of patient onset)
- Ultrasound (USG) examination is showing a pathological stenosis and/or plaque alteration.
Exclusion criteria: Patient with any of the below mentioned condition is excluded from study group.
- Age less than 45 years (choice of age is relatively arbitrary and primary aimed to exclude cases of stroke in young)
- Hemorrhagic stroke/ combined hemorrhagic and ischemic stroke including ischemic infarct with hemorrhagic transformation
- Isolated posterior circulation stroke
- Familial stroke (family history positive in more than 2 relatives)
- k/c/o vasculitis
- pregnant women/ post partum women
- Diagnosed or suspected atrial fibrillation/valvular heart disease/recent myocardial infarction (ischemic heart disease is NOT a contraindication).
- Patients with re-stenosis after carotid endarterectomy (CEA) with tandem lesions.
- Patients with carotid occlusion/complete thrombosis/ILT (intraluminal thrombosis).
- Known allergy to iodinated contrast media or abnormal renal function (creatinine >1.2).
In this study observations were recorded for each patient (combining two separate angiography data sets- right and left).
In cases of significant difference in findings between right and left angiography data,
side with greater pathology (fatty plaque,
higher grade of stenosis) is given predominance over less affected side (for ease of statistical purpose),
assuming more affected side is the likely cause of clinical manifested disease.