النقطه الثانيه حبيت اذكرها وهو موضوع تكرر في التجمع اكثر من مرره عن وظائف الاشعه والبطاله
هذي مجموعه تغريدات قدمها الدكتور عبد الرحمن الفريح عبر حسابه في تويتر

جميله جدا وتستحق القراءه
https://twitter.com/amalfuraih/status/970259318133182464?s=21

#CT_Scan


💎 سلسلة مصطلحات3 أشعة مقطعية : -


🔹Calibration of a CT scanner:
Correction procedures
used to take account of variations in beam intensity or detector efficiency in order to achieve homogeneity within the field of view and accuracy of CT number.
Calibration procedures include scanning air or an appropriate test phantom .

🔸Collimation: Geometrical limitation of the extent of the radiation beam in the z-direction.

🔹Computed tomography dose index (CTDI):
Integral along a line parallel to the axis of rotation (z) of the
dose profile (D(z)), measured free-in-air or in a CT dosimetry phantom for a single slice, divided by the nominal slice thickness (T) .
In practice, it is convenient to use a pencil ionisation chamber with an active length of 100 mm so as to provide a measurement ofCTDI100 (mGy to air) .

🔹Computed tomography number (CT number):
Number used to represent the mean X-ray attenuation associated with each elemental area of the CT image.
Numbers are normally expressed in terms of Hounsfield unit (HU). Measured values of attenuation are transformed into CT numbers using the international Where μ is the effective linear attenuation coefficient for the X-ray beam.
The CT number scale is defined so that water has a value of 0 HU and air a
value of -1000 HU .

🔹Couch increment:
Distance by which position of patient couch (table) is changed between individual
slices in serial scanning or the distance the couch position is changed during one 360° rotation of the tube during helical scanning.

🔹Computed tomography dose index (CTDI):
Integral along a line parallel to the axis of rotation (z) of the
dose profile (D(z)), measured free-in-air or in a CT dosimetry phantom for a single slice, divided by the nominal slice thickness (T) .

🔸CT dosimetry phantoms:
Cylinders of polymethylmethacrylate (PMMA) used for standard measurements of dose in CT, having a diameter of 16 cm (head
phantom) or 32 cm (body phantom) and a length of at least 14 cm.
The phantoms are constructed with removable inserts parallel to the axis to allow the positioning of a dosimeter at the centre and 1 cm from the outer surface (periphery).

🔸CT number:
Abbreviation for computed tomography number.

🔹CTDI:
Abbreviation for computed tomography dose index.

🔸CTDI air:
Value of CTDI determined free-in-air

🔹Detector array:
The entire assembly of detectors, including their interspace material, arranged along an
arc or circumference (depending on scanner
technology) of a circle centred on the axis of rotation.

🔸Detector efficiency:
For each detector contained in a detector array, the ratio between the number of pulses
recorded and the number of X-ray photons incident on the detector.

🔹Detector width:
In a detector array, the distance between the two opposite faces of any single detector.

kamal alkebsi

#CT

#CT_Anatomy

💎brain anatomy 3

1 - Superior sagittal sinus.
2 - Frontal bone.
3 - Lateral ventricle anterior horn .
4 - Caudate nucleus head.
5 - Putamen/Globus pallidus.
6 - Third ventricle.
7 - Choroid plexus.
8 - Parietal bone.
9 -Internal occipital.
protuberence.
10 - Cerebellar vermis.
11 - Pineal body.
12- Thalamus.
13 - Internal capsule.
14 - Temporal bone.

#CT_anatomy

💎 brain anatomy 4

1 - Falx cerebri.
2. Frontal bone.
3. Corpous callosum.
4 - Caudate nucleus.
5. Parietal bone.
6. Confluence of sinuses (torcula).
7. Occipital lobe.
8. Choroid plexus.
9 - Lateral ventricle, body .
10. Temporal bone .
11. Corona radiata.
12. Straight sinus .

#CT_anatomy

💎 Brain anatomy 5

1 - Frontal lobe
2 - Superior sagittal sinus
3 - Precentral gyrus
4 - Central suicus
5 - Falx cerebri
6 - Parietal lobe
7 - Parietal bone
8 - Temporal bone
9 - Scalp
10 - Frontal bone

#CT_Scan


💎 سلسلة رموز وإختصارات2 أشعة مقطعية : -

▪MTF - modulation transfer function.
▪PSF - point spread function.
▪FOV - field of view.
▪MDCT - multidetector row CT .
▪DLP - Dose-length product.
▪ICRP - International Commission on Radiological Protection.
▪NCRP - National Council for Radiation Protection .
▪FWHM - Full width at half maximum.
▪MSAD - Multiple scan average dose .

▪PMMA
Polymethylmethacrylate.

▪DAS - Data acquisition system .
▪OC -Operator Console.
▪MOD -Magnetic Optical Disk .
▪ANR -Advanced noise reduction .
▪HRCT - High Resolution Computed Tomography .
▪AP -Arterial phase.
▪DP - Delayed phase.
▪MPR - MULTIPLANAR RECONSTRUCTION.
▪LOCM - Low-osmolar contrast media.
▪ HOCM -
high-osmolar
contrast media.
▪QCT - quantitative computed tomography.
▪CTDI - Computed tomography dose index.


Kamal alkebsi

#CT

Bachelors Degree/Diploma in Radiology with 1-2 year experience.     

http://careers.mouwasat.com/ar/career/view?name=mri-technician