CT proseduresCT prosedures

• CT ColonographyCT Colonography• CT UrographyCT Urography• CT AngiographyCT Angiography• CT PerfusionCT Perfusion

CT ColonographyCT ColonographyWhy?Why?• Looking for cancer in the Looking for cancer in the

coloncolonHow?How?• Air or COAir or CO22 gets pumped in gets pumped in

the patients colon, the the patients colon, the doctor feels the patients doctor feels the patients stomach and desides if a stomach and desides if a topogram should be made. topogram should be made. By looking at this topogram By looking at this topogram he/she then desides if there he/she then desides if there is enough air in the colon to is enough air in the colon to start scanning.start scanning.

• Use BuscopanUse Buscopan• Scan both in supine and Scan both in supine and

prone positioning.prone positioning.• 120 kV/50 mAs120 kV/50 mAs• No I.V contrastNo I.V contrast

CT ColonographyCT Colonography

Comments:Comments:• It’s important that the patient It’s important that the patient

has gone trough a thorough has gone trough a thorough preparation with taking preparation with taking laxidents and not eating. laxidents and not eating.

• They should also take fecalie- They should also take fecalie- taggingtagging

• Equipment for pumping the air Equipment for pumping the air in could be the same as a in could be the same as a convensionel x-ray examination convensionel x-ray examination of the colon.of the colon.

• Equipment for using COEquipment for using CO22 is is very expensive.very expensive.

• Always be aware that the Always be aware that the patient can feel dizzy and sick patient can feel dizzy and sick after the exam. The preparation after the exam. The preparation for the exam is hard for them!for the exam is hard for them!

3D of colon after putting the CT images into another 3D of colon after putting the CT images into another computer hardware. This image can be flipped and computer hardware. This image can be flipped and viewed in all angles.viewed in all angles.

Image to the right is how the colon looks in Image to the right is how the colon looks in MSCT,in the middle the image shows how you MSCT,in the middle the image shows how you can look at the colon from inside using 3D can look at the colon from inside using 3D computer hardware, and to the left the image computer hardware, and to the left the image is also 3D, but it’s subtracted so that you only is also 3D, but it’s subtracted so that you only see the wall of the colon in grayscale. Both 3D see the wall of the colon in grayscale. Both 3D images can be flipped and viewed from all images can be flipped and viewed from all angles.angles.

CT scan of colon. The arrow shows a CT scan of colon. The arrow shows a flebolitis which can indicate colon flebolitis which can indicate colon cancer.cancer.

CT UrographyCT UrographyWhy?Why?• Hematuri, kidney- and urotelcancer, Hematuri, kidney- and urotelcancer,

difficult stone- exams.difficult stone- exams.How?How?• First one scan in prone positioning. First one scan in prone positioning.

This is to look for stones. By laying This is to look for stones. By laying in prone position the stones are in prone position the stones are easyer to confirm. If the patient is easyer to confirm. If the patient is laying in a suping position flebolitis laying in a suping position flebolitis could look like stones.could look like stones.

• I.V contrast- Omnipaque 300 mg/ml- I.V contrast- Omnipaque 300 mg/ml- after weight. Flow: 3ml/safter weight. Flow: 3ml/s

• Second scan is done after 100 s to Second scan is done after 100 s to get the contrast in pharemcym-fase.get the contrast in pharemcym-fase.

• After that you give the patient 250 After that you give the patient 250 ml of NaCl, which goes I.V over 10 ml of NaCl, which goes I.V over 10 minutes, and take the third scan. minutes, and take the third scan. Then it’s possible to follow the Then it’s possible to follow the ureter all the way from the kidneys ureter all the way from the kidneys to the bladder. to the bladder.

• First scan: 120 kV/ 145 mAsFirst scan: 120 kV/ 145 mAs• Second/Third scan: 120 kV/ 300 mAsSecond/Third scan: 120 kV/ 300 mAs

CT UrographyCT Urography

Comments:Comments:• ALARAALARA

• Depending on the problemDepending on the problem of of the patient, you and the the patient, you and the doctor should always think if doctor should always think if this type of examination this type of examination would come to the patients would come to the patients benefits. benefits.

• Studies has shown that CT Studies has shown that CT gives more dose to patient gives more dose to patient than conventionel than conventionel examitations of this type. But examitations of this type. But in some cases the CT in some cases the CT Urography will give more Urography will give more answers to a problematic answers to a problematic case.case.

Image shows the uretertrackt and the bladder. Image shows the uretertrackt and the bladder. The CT image is transfered into 3D. Can be The CT image is transfered into 3D. Can be flipped and viewed from all angles.flipped and viewed from all angles.

MSCT scan of kidneys after I.V.CMSCT scan of kidneys after I.V.CThe arrow indicates an obstruction in the left The arrow indicates an obstruction in the left kidney. The delay after contrast is 100 s.kidney. The delay after contrast is 100 s.

CT AngiographyCT AngiographyWhy?Why?• To look for occluded To look for occluded

vessles in head, neck and vessles in head, neck and body.body.

How?How?• Dipending on the Dipending on the

examination you use 50 ml examination you use 50 ml -100 ml Omnipaque (or -100 ml Omnipaque (or other) 350 mg/ml. Flow is other) 350 mg/ml. Flow is 4 ml/s. 4 ml/s.

• 120 kV and 300 mAs also 120 kV and 300 mAs also depending on the depending on the examination.examination.

• Bolus tracking.Bolus tracking.

CT angiography of the head in sagittal view.CT angiography of the head in sagittal view. I.V.C used. In frontal you can se 2 occlusions I.V.C used. In frontal you can se 2 occlusions in the major vessles.in the major vessles.

Axial scan of CT angiography. This scan is Axial scan of CT angiography. This scan is over the circle of willis, where all major over the circle of willis, where all major arteries in the brain meet.arteries in the brain meet.

CT PerfusionCT PerfusionWhy?Why?• Brain infarction / Brain infarction /

thrombolysisthrombolysis

When?When?• After a standard brainscan, After a standard brainscan,

when there’s no bleeding.when there’s no bleeding.• Only done when the Only done when the

neurologist and the neurologist and the radiologist agree that it’s radiologist agree that it’s the best choise. the best choise.

Further scans?Further scans?• If the exam is positive, it If the exam is positive, it

can be descussed if CT can be descussed if CT angio of carotis and brain angio of carotis and brain should be done.should be done.

CT PerfusionCT Perfusion

How?How?• Patient needs a large Patient needs a large

venefloneveneflone• First take a regular scan of First take a regular scan of

the brainthe brain• Perfusion scan should be Perfusion scan should be

done over the circle of willisdone over the circle of willis• Orbita should NOT be in the Orbita should NOT be in the

scanscan• CT brain – 120 kV/ 380mAsCT brain – 120 kV/ 380mAs• CTperfusion – 80kV / 270mAsCTperfusion – 80kV / 270mAs• I.V contrast – 40 ml Omipaque I.V contrast – 40 ml Omipaque

350 mg/ml350 mg/ml• Flow rate 7 ml/sFlow rate 7 ml/s• NaCl 20 ml – bolus.NaCl 20 ml – bolus.• Repeated scans over one area.Repeated scans over one area.

Images to the left show a brainscan where the Images to the left show a brainscan where the arrows point to a dark area. arrows point to a dark area. Image to the right is the same as on the left, Image to the right is the same as on the left, but it has been convertet using a computer but it has been convertet using a computer hardware –PERFUSION.hardware –PERFUSION.The read area indicates low perfusion in this The read area indicates low perfusion in this part of the brain.part of the brain.

Upper picture to the left shows a normal CT Upper picture to the left shows a normal CT image using perfusion protocoll. The other image using perfusion protocoll. The other

images show different ways to use the images show different ways to use the computer hardware – PERFUSION.computer hardware – PERFUSION.

CT PerfusionCT PerfusionComments:Comments:• All patients that are submitted to All patients that are submitted to

the dep. of neurology with the dep. of neurology with suspision of acute brain infarction, suspision of acute brain infarction, and has symphtoms less than 24 and has symphtoms less than 24 hours old, should get a cerebral CT hours old, should get a cerebral CT as soon as they come to the as soon as they come to the hospital.hospital.

• CT perfusion should be done CT perfusion should be done imidiatly after regular cerebral CT imidiatly after regular cerebral CT scan when there’s no bleeding/ it scan when there’s no bleeding/ it has been less than 6 hours sinse has been less than 6 hours sinse the symphtoms started/ symphtoms the symphtoms started/ symphtoms point to a non-lacunar infarction/ point to a non-lacunar infarction/ the patient doesn’t have the patient doesn’t have kidneyfailure. kidneyfailure.

• If there is an area with decreased If there is an area with decreased perfusion, CT angiography can be perfusion, CT angiography can be done to find the vessel that caused done to find the vessel that caused the infarction. the infarction.

• The following day cerebral MRI can The following day cerebral MRI can be done if there’s still suspision of be done if there’s still suspision of infarction that has not been infarction that has not been resolved.resolved.

Questions?