Page No.

 

Routine Head                                                                                                                            3-4

 

Orbits                                                                                                                                       5-6

 

Trauma - Sinuses and Facial Bones                                                                                           7-8     

 

Petrous Bones                                                                                                                         9-11

 

Basilar Skull Fracture                                                                                                                  12

 

Sella Turcica                                                                                                                         13-14

 

Paranasal Sinuses                                                                                                                  15-16     

 

Cervical Spine                                                                                                                       17-19

 

Thoracic Spine             20                                                                                                             

 

Lumbar Spine                                                                                                                             21

           

Lumbar Myelogram                                                                                                                    22     

 

Cervical Myelogram                                                                                                                   23     

 

Thoracic Myelogram                                                                                                                   24     

 

Techniques for Myelograms                                                                                                        25     

 

Neck                                                                                                                                          26     

 

Larynx (Vocal Cords)                                                                                                                 27

 

DentaScan                                                                                                                                  28

 

CT Angiography                                                                                                                   29-31

 

Windows Workstation Processing of Vascular Structures:                                                              

Surface Rendered Images                                                                                                      32-33

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            General survey scan of the head done to rule out:

            1.         CVA

            2.         TIA

            3.         RIND

            4.         Tumor

            5.         Hemorrhage

            6.         AVM

            7.         Dementia

            8.         Hydrocephalus

            9.         Shunt placement

            10.       Trauma

            11.       Post surgical/radiation changes

            12.       Metastatic disease

            13.       Abscess

            14.       Seizure disorder

 

B.        Preparation

 

            1.         None for unenhanced scans

            2.         NPO 2 hours for enhanced scans

 

C.        Technical Guidelines

 

            1.         Enhanced Only Scan:  IV contrast given for:

 

                        a.         Tumor

                        b.         AVM

                        c.         Metastatic disease

                        d.         Abscess

                        e.         Seizure disorder

 

            2.         Unenhanced Only Scan for:

 

                        a.         CVA

                        b.         TIA

                        c.         RIND

                        d.         Dementia

                        e.         Hydrocephalus

                        f.          Shunt placement

                        g.         Acute/chronic trauma

                        h.         Subarachnoid hemorrhage

 

            3.         Both Unenhanced and Enhanced Scan for:

 

                        a.         Pediatric cases

                        b.         Post-surgical/radiation changes

                        c.         Sedated patients who cannot tolerate further studies

 

D.        Intravenous Contrast

 

            1.         Pediatrics:

 

                        a.         Pediatric doses according to pediatric chart already outlined

                        b.         Give dose and start scanning immediately

 

            2.         Adults:

 

                        a.         Start infusion and allow 50 cc to infuse before scanning

                        b.         Remaining 100 cc infuse during the scan

 

            Note:   For metastatic disease cases, allow 150 cc to infuse before scanning.

 

E.         Scanning

 

            Note:   First cut - line from posterior aspect of foramen magnum to base of frontal sinus.

 

            1.         0-8 year old:

 

                        a.         Do 5 mm slice thickness, 5 mm slice increments from foramen magnum to vertex.

 

            Note:   If you do not see the fourth ventricle, do thin cuts through the area.

 

            2.         8 years to adult:

 

                        a.         Cuts taken are 3 mm thickness, 3 mm increments from the foramen magnum through the suprasellar cistern. 

 

                        b.         Subsequent cuts after the cistern are 10 mm thickness, 10 mm increments to the vertex of the skull.

 

            3.         Do bone windows for all trauma cases and metastatic disease cases.

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Rule out:

 

                        a.         Intraconal lesions

                        b.         Extraconal lesions

                        c.         Retroorbital lesions

                        d.         Trauma

                        e.         Hyperthyroidism

                        f.          Graves disease

                        g.         Orbital pseudo tumor

 

B.        Preparation

 

            1.         Trauma and Graves disease  -  none

            2.         Tumor search  -  NPO 2 hours

           

            Note:   For multiple myeloma  -  no contrast

 

C.        Tumor Search

 

            1.         Technical Guidelines

 

                        a.         Enhanced scans only

                        b.         Axial and coronal

                        c.         Instruct patient to close their eyes for both sets

 

            2.         Scanning

 

                        a.         Do coronals first

                        b.         IOML is perpendicular to scanning plane

                        c.         3 mm thickness, 3 mm increments

                        d.         Following the surview, depress "Head Coronal" key

 

                                    Menu should read:

Reconstruction Filter - Bone

Image Matrix - 512 x 512

Image Center x/y - Omm, Omm

Image Rotation Angle - - degrees

Image Zoom Factor - 14

Image Dump

 

                                    Note:   For coronals, make sure menu reads "-1" for slice increments

 

                        e.         When first image is processed, use graphic zoom with cursor to set Zoom factor at 14 centering orbits bilaterally

 

                        f.          Axials:  Remove needle if infusion is complete

 

                        g.         Depress "Contrast" key again before obtaining surview

 

                        h.         IOML should be parallel to scanning plane for orbit images and OML should be parallel to plane for routine head images

 

                        i.          Do 3 mm thickness, 3 mm increments from mid-maxillary antrum through supraorbital rim.

 

                                    Note:   If soft tissue density is seen on first image, start lower

 

                        j.          Scan through orbits, stop sequence and type "N" for next sequence and proceed to brain.  Change technical factors to 200 mAs, 10 mm thickness, 10 mm increments, filter standard.

 

D.        Facial Bones and Sinuses

 

            1.         For all facial bone trauma cases, use a spiral CT at 3 mm with 1:1 pitch.  No angulation.  Then recon with 1 mm thick slices and send over to the workstation.  This system will enable us to make usable coronal images.  Feel free to reformat the image for the radiologist and film reformatted images at 3 mm intervals.

 

            2.         For sinus studies where patient cannot maintain an extended neck position, use a spiral CT at 3 mm with 1:1 pitch.  No angulation.  Then recon with 1 mm thick slices and send over to the workstation.  This system will enable us to make usable coronal images.  Feel free to reformat the image for the radiologist and film reformatted images at 3 mm intervals.

 

 

A.        Technical Guidelines

 

            1.         Unenhanced scans only

 

            2.         Axials

 

                        a.         IOML parallel to scanning plane

                        b.         3 thickness, 3 mm increments

                        c.         Scan from floor of maxillary antrum through frontal sinuses

 

            3.         Coronals

 

                        a.         IOML perpendicular to scanning plane

                        b.         3 mm thickness, 3 mm increments from frontal sinuses through sphenoid sinuses.

 

B.        Batch Reconstruction - for Coronals

 

            1.         Use program to formulate Bone

            2.         Image x/y center like scanning sequence

            3.         D.F.O.V. - 15

            4.         Image Matrix - 512 x 512

 

C.        Filming

 

            1.         Follow Protocol for "Routine Brain"

 

            2.         Soft tissue technique for axials and coronals of zoomer images:

                        a.         Windows width  =  350 - 400

                        b.         Windows center  =  25 - 50

 

            3.         Bone technique for non-trauma images:

                        a.         Window width  =  2000

                        b.         Window center  =  300

 

            4.         Trauma bone techniques:

                        a.         Window width  =  2500

                        b.         Window center  =  350 - 400

 

            Note:   If patient cannot lie supine head extended for coronal views or prone for coronals, patient must be scanned axial/Helical with a 1:1 pitch.  Images reconstructed by 1 mm and sent to workstation for reformatted images.

 

D.        Trauma Facial Bones and Orbits

 

            1.         Trauma facial bones and orbits are to be scanned helically (axial views) with no gantry tilt;  by 3's then reconstructed by 1's and network* images to workstation (for 3-D reconstruction)

 

                        a.         Log cases in network station book

                        b.         Film study by 3's

                        c.         If unable to do coronal views reformat coronals by 3's and film

                        d.         If patient is able to do coronal views, still do as per routine

 

            *  Be sure network station is on!!

 

 

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         "Attention CP angle"

            2.         Acoustic neuroma

            3.         Cholesteatoma

            4.         Inflammatory disease

            5.         Hearing loss

            6.         Tinnitus

            7.         Vertigo

 

B.        Preparation

 

            1.         NPO 2 hours prior to scan

 

C.        Technical Guidelines

 

            1.         Enhanced Scans Only:  IV contrast given for:

 

                        a.         Tumor

                        b.         AVM

                        c.         Metastatic disease

                        d.         Abscess

 

D.        Scanning:  "Attention CP Angle" and Acoustic Neuroma

 

            1.         Axial images only - Helical scanner only

 

            2.         IOML should be parallel to the scanning plane

 

            3.         Do 1 mm / 1 mm from foramen magnum to EAM canal, then switch to 1.2 thickness every 1 mm and scan through semi-circular canals.

 

            4.         After through canals, change back to 2.5 mm / 2 mm through petrous bones.

 

            5.         Start study as previously described and do surview.

 

            6.         Depress "Head Protocol" key to bring up menus and enable you to scan.

 

            7.         Depress "Sinuses" key to initiate exposure.

 

            8.         Scan through petrous bones.

 

            9.         OML is now parallel to scanning plane per surview plan.

 

            10.       Do Routine Head:

 

                        Menu should read:

 

Scan FOV Head (25 cm)

Scan Time - 1 sec

Technical Factors - 120 KV 220 mA

Sampling Density - Normal

Slice Width - 3 mm

Slice increments - 3 mm out

No. of slices - determined by surview plan

Patient Position - head in, face up

Reconstruction Filter - Bone

Image Matrix - 512 x 512

Image Center x/y - Omm, Omm.

Image Rotation Angle -  0 degrees

Display FOV - 15

Image Dump - Dat and Disk

 

E.         Scanning:  Cholesteatoma

 

            1.         Remove dental hardware.

 

            2.         Axials and coronals (do coronal scans first)

 

            3.         Scanning plane should be perpendicular to IOML for coronals and parallel to IOML for axials.

 

            4.         Coronals - start anterior EAM and scan through mastoids

 

            5.         Axials

 

                        a.         Axial images only

 

                        b.         IOML should be parallel to the scanning plane

 

                        c.         Do 3 mm / 3 mm from foramen magnum to EAM canal, then switch to 1.2 thickness every 1 mm and scan through semi-circular canals.

 

                        d.         After through canals, change back to 2.5 mm / 2 mm through petrous bones.

 

            6.         Cuts should be 1.0 mm thickness, 1 mm increments for axials and coronals

 

            7.         Following the surview, depress "Head Coronal" key

 

            8.         Scan through mastoid air cells and stop sequence.

 

            9.         Remove intravenous needle if infusion is complete and proceed to axial scans.

 

            10.       Follow same parameters for axial images as described in Acoustic Neuroma Protocol.

 

            11.       Batch reconstruction:  Use program for axial and coronal images:

 

                        a.         Coronal

 

                                    i.          Use program to formulate images with "C" filter and 512 x 512 matrix.

 

                                    ii.          See scanning sequence for x and y Image Center and Image Zoom factor.

 

                        b.         Axial

 

                                    i.          Use program to Zoom image:  change filter to "C," and 512 x 512 matrix.

 

            Note:   Prior to entering program access image from directory and zoom it like done in CP Angle Protocol.  Note x and y numbers and zoom factor so that they can be typed in for the Batch Reconstruction program.

 

            12.       Axial and coronal images should have identical zoom factors.

 

F.         Filming

 

            1.         Coronal "C" Filter Images and Axial "C" Filter Images:

 

                        a.         Window Width = 3000

                        b.         Window Center = 450-500

 

            2.         Coronal "B" Filter Images and Axial "B" Filter Images:

 

                        a.         Window Width = 150-200

                        b.         Window Center = 25-50

 

            3.         Routine Head done as previously described.

 

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Trauma to skull base

            2.         Hemotympanum

            3.         Post-traumatic hearing loss

            4.         CSF otorrhea)

 

B.        Preparation

 

            1.         None

 

C.        Scanning

 

            1.         Axial and coronal

 

            2.         IOML parallel to scanning plane.

 

            3.         1 mm thickness, 1 mm increments from foramen magnum through petrous bones.

 

            4.         Menu should read: (same as Petrous Bones Protocol using C filter):

 

Scan Mode - normal 382 deg

Scan Diameter - Head

Scan Time - 2.1 sec

Technical Factors - 120 KV 200 mA

Sampling Density - Normal

Slice width - 1.0 mm

Slice increments - 1 out  +1

Number of slices - # according to surview plan

Patient position - head in, face up

Reconstruction filter - Bone

Image Matrix - 512 x 512

Image Center s/y - Omm, Omm

Image Rotation Angle - 0 degrees

Image Zoom Factor - 1

Image Dump - Dat and disk

Raw Dump - no

 

                        Note:   Resolution - Bone.

 

 

Note:

Try to get an MRI first if not looking for acute hemorrhage

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Micro adenoma

            2.         Elevated prolactin level

            3.         Amenorrhea

            4.         Visual field defect

            5.         Hypothalamic disease, e.g., diabetes inspidis

            6.         Macro adenoma

 

B.        Preparation

 

            1.         NPO 2 hours prior to examination

 

C.        Microadenoma

 

            1.         Technical Guidelines

 

                        a.         Enhanced coronal scans only

 

                        b.         Intravenous contrast given by Radiologist with a 50 cc bolus of Reno-M 60 followed by an infusion of 100 cc Reno-M 60

 

                        Note:   If there is any contraindication for use of Reno, non-ionic IV contrast may be used.

 

            2.         Scanning

 

                        a.         Scanning plane should be perpendicular to the floor of the sella along the same plane as the dorsum sella

 

                        b.         Scan 1 mm thickness, 1 mm increments

 

                        c.         Following the surview, depress "Head Coronal" key

 

                                    Note:   For coronals, make sure menu reads "-1" for slice increments

 

                        e.         After first image is processed, use graphic zoom with cursor to D.F.O.V. 15.  Center in the middle of the sella.

 

D.        Parasella or Optic Chiasm

 

            1.         Technical Guidelines

 

                        a.         Enhanced coronal axial scans

 

            2.         Scanning

 

                        a.         Coronal

 

                                    i.          Use program to formulate images with Bone filter and 512 x 512 matrix.

 

                                    ii.          See scanning sequence for x and y Image Center and Image Zoom factor.

 

                        b.         Axial

 

            Note:   Prior to entering program access image from directory and zoom it like done in CP Angle Protocol.  Note x and y numbers and zoom factor so that they can be typed in for the Batch Reconstruction program.

 

                        c.         For axial image:

 

                                    i.          Scanning plane should be parallel to the floor of the sella

 

                                    ii.          1 mm thickness, 1 mm increments

 

                                    ii.          Zoom factor D.F.O.V. 15  like coronal images.

 

                        d.         Scans must be checked prior to the patient leaving to determine if lateral and AP radiographs should be obtained of the sella turcica

 

            3.         Filming

 

                        a.         Axial and coronal soft tissue techniques:

 

                                    i.          Window width  =  150 - 200

 

                                    ii.          Window center  =  35 - 50

 

                        b.         Bone technique:

 

                                    i.          Window width  =  1300 - 1500

 

                                    ii.          Window center  =  300 – 350

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Trauma

            2.         Rule out tumor or polyps

            3.         Sinusitis

            4.         Follow-up sinusitis studies:  Coronals only

 

B.        Preparation

 

            1.         For trauma - no preparation

            2.         For tumor, polyp or sinusitis - NPO 2 hours

 

C.        Scanning

 

            1.         Axials

 

                        a.         IOML parallel to scanning plane

                        b.         3 mm thickness, 3 mm increments

                        c.         Scan from floor of maxillary antrum through frontal sinuses

 

            2.         Coronals

 

                        a.         IOML perpendicular to scanning plane

                        b.         3 mm thickness, 3 mm increments from frontal sinuses through sphenoid sinuses.

 

            3.         Coronals are done first

 

                        a.         Following surview depress "Head Coronal" key

                        b.         See "Cholesteatoma" Protocol for menu details

                        c.         Change slice width to 3 mm

                        d.         After first image is processed, use graphic zoom program with cursor to set zoom factor at 14

                        e.         Center midway between the orbits

 

            4.         Axials

 

                        a.         Following surview depress "Head PF" key

                        b.         Change slide width to 3 mm

                        c.         See "Routine Head" Protocol for menu details

                        d.         After first image is processed use graphic zoom program with cursor to set zoom factor at 15.

                        e.         Center midway between anterior borders of the skull and posterior maxillary antrum borders.

 

D.        Filming

 

            1.         Bone windows and soft tissue windows must be filmed

 

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Degenerative disease

            2.         Disc disease

            3.         Trauma

            4.         Tumor

            5.         Low back pain

            6.         Radiculopathy

 

B.        Preparation

 

            1.         Routine AP and lateral radiographs within past month; if not, have them done now

            2.         Myelogram preparation when scan is being done in conjunction with a myelogram

            3.         Completed cervical spine questionnaire

 

C.        Degenerative / Disc Disease

 

            1.         Technical Guidelines

 

                        a.         Patient supine on table to enter the gantry head first, arms down by sides with restraints in place to pull should down towards the feet

                        b.         Tape chin so it is extended away from C1

                        c.         Centering light horizontally is 1 cm below the sternal notch and vertically to the level of the cervical spine

                        d.         Routine levels to be scanned are C3-C7

                        e.         3 mm thickness, 3 mm increments

 

            2.         Scanning

 

                        a.         Include levels to be scanned under comments when entering the patient information

                        b.         After first image is processed use the graphic zoom program to set the zoom factor at 12 by placing the cursor in the middle of the spinal cord

 

                        Note:   If patient is breathing hard, instruct them to hold their breath for each exposure.  Be sure they are breathing the same way each time or your levels will be off.

 

                        c.         Increase mAs for people with broad shoulders as you approach C7

 

D.        Trauma

 

            1.         Technical Guidelines

 

                        a.         Done to clear C7-T1

                        b.         If multiple levels are requested, do C1 through T1 without skipping levels

 

            2.         Scanning

 

                        a.         Scan C5-T1 starting mid C5 and continuing to T1

                        b.         3 mm thickness, 3 mm increments (1:1 pitch)

                        c.         No gantry tilt  (tilt gantry only if marked "kyphosis")

                        d.         Patient supine on table to enter the gantry head first, arms down by sides with restraints in place to pull should down towards the feet

                        e.         Centering light horizontally is 1 cm below the sternal notch and vertically to the level of the cervical spine

                        f.          Helical scanning is preferred

                        g.         Recon images 1 mm bone technique

                        h.         Send to workstation for "Sag-Cor" reconstruction

 

            3.         Filming

 

                        a.         Include levels to be scanned under comments when entering the patient information

                        b.         DFOV to 12

 

                        Note:   If patient is breathing hard, instruct them to hold their breath for each exposure.  Be sure they are breathing the same way each time or your levels will be off.

 

                        c.         Increase mAs for people with broad shoulders as you approach C7

                        d.         Reconstruct images with bone algorithm

                        e.         Make sure peristalsis is "off"

                        f.          Reconstruct at 1 mm increments

                        g.         Send 1 mm images to workstation

 

            4.         Include "Sag-Cor" reconstruction:

 

                        a.         Access axial image from the disc

                        b.         Go to Image Analysis

                        c.         Load data set

                        d.         Reconstruct sagittal or coronal as needed

                        e.         Film image on 1 on 1 format with bone and soft tissue technique as previously described, 20 on 1 page

 

            5.         For C1/C2 trauma

 

                        a.         3 mm thickness, 3 mm increments (1:1 pitch)

                        b.         Coronal/sagittal reconstruction needed

                        c.         Recon images 1 mm bone technique

 

            6.         For trauma to any other level

 

                        a.         Same as above

                        b.         Helical is preferred

                        c.         Recon images and send to workstation for possible "Sag-Cor" reconstruction

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Degenerative disease

            2.         Disc trauma

            3.         Tumor

 

B.        Preparation

 

            1.         None except with myelogram

            2.         Routine AP and lateral radiographs to localize specific levels

 

C.        Technical Guidelines

 

            1.         Patient supine on table so feet will enter the gantry first

 

            2.         Centering light horizontally is 1 cm above the sternal notch and vertically to the level of the thoracic spine

 

            3.         Levels and thickness incrementation will be determined by the radiologist

 

            4.         Include levels under comments when entering the patient information to start study

 

            5.         Following the surview, depress "Spine" key.  Only differences will include patient position, increments or thickness or cuts

 

            6.         After first image is processed graphic zoom the image by placing the cursor in the middle of the spinal cord and zoom it 1.2.  Set parameters and archive the image on tape and disk.

 

            Note:   If patient is breathing hard, suspend respiration for each exposure and instruct them to breathe as quietly as they can so that the levels are correct.

 

            7.         Bone and soft tissue windows must be filmed.

 

            8.         Slice thickness:

 

                        a.         5 mm thick if scanning entire thoracic spine

                        b.         3 mm for localized areas

 

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Herniated nucleus pulposus (HNP)

            2.         Degenerative disease

            3.         Stenosis

            4.         Trauma

            5.         Tumor

            6.         Low back pain

            7.         Radiculopathy

 

B.        Preparation

 

            1.         No barium studies one week prior to exam

            2.         Routine AP and lateral radiographs of the lumbar spine within past month; if not, have them done now

            3.         Myelogram preparation if myelogram is being done in conjunction with the CT scan.  Otherwise no preparation necessary.

 

C.        Technical Guidelines

 

            1.         Have patient complete the lumbar spine questionnaire

 

D.        Scanning

 

            1.         Patient supine on the table so the head will enter the gantry first.  Place arms above the head for the surview.  Put cushion under the knees to reduce the lordotic curvature of the spine.  (It also reduces the air gap between the table and the patient to reduce artifacts.)

            2.         Centering light horizontally is at the xyphoid and vertically to the level of the lumbar spine

            3.         Note levels to be included in the study when starting the study under comments.

            4.         3 / 3 mm pedicle to pedicle L2/S1

            5.         When planning study, angle parallel to disc space.

 

            Note:   Because of severe lordosis of the spine, sometimes you may end the study before getting through the anterior portion of the disc at L5-S1.

 

            6.         Following the surview, depress the "Spine" key.  Make changes of patient position, increments.

            7.         Bone and soft tissue windows must be filmed.

 

A.        Contraindications

 

            1.         Patient receiving phenothiazine derivatives, e.g., Thorazine

            2.         Patient with contrast allergies

            3.         Patient with renal failure

            4.         Glucophage - stop 48 hours prior and start 48 hours post myelogram

 

B.        Preparation

 

            1.         100 mg phenobarbital I.M. on call to x-ray

            2.         Clear liquids only until 3 hours before study

            3.         IV drip with D5/W started prior to study (optional)

 

C.        Routine Filming  (to cover L2-3, L3-4, L4-5, L5-31)

 

            1.         A-P   (prone fluoro spots 8 x 10)

            2.         25-30o obliques  (prone oblique fluoro spots 8 x 10)

            3.         Cross table lateral with patient 45-90o erect

            4.         Cross table lateral with patient prone

            5.         Prone, overhead 10 x 12 (or 14 x 17) lumbar spine

 

D.        Contrast

 

            1.         Non-ionic (Isovue), 200 mg/ml, 15 cc (not to exceed 3000 mg)

 

E.         CT of L-spine

 

            1.         Optional at discretion of physician.

            2.         CT done prone.

            3.         CT levels decided at time of myelogram

 

F.         Post-Myelogram

 

            1.         Patient semi-erect OOB as tolerated

            2.         Force fluids PO or IV

            3.         Phenobarbital 100 mg IM or PO at conclusion of study and h.s.

 

 

A.        Contraindications

 

            1.         Patient receiving phenothiazine derivatives, e.g., Thorazine

            2.         Patient with contrast allergies

            3.         Patient with renal failure

            4.         Glucophage - stop 48 hours prior and start 48 hours post myelogram

 

B.        Preparation

 

            1.         100 mg phenobarbital I.M. on call to x-ray

            2.         Clear liquids only until 3 hours before study

            3.         IV drip with D5/W started prior to study (optional)

 

C.        Filming - to cover foramen magnum through T1

 

            1.         Fluoro, spots, prone - A-P on 8 x 10

            2.         Cross table lateral  10 x 12

            3.         Swimmer's cross table lateral 10 x 12

            4.         Overhead 10 x 12  P-A prone

 

D.        CT of C-Spine - patient supine

 

            1.         Optional at discretion of physician

 

E.         Contrast

 

            1.         Non-ionic 300 mg/ml  (e.g., Isovue) -

                        Maximum of 3000 mgm

 

F.         Post-Myelogram:

 

            1.         Patient semi-erect OOB as tolerated

            2.         Force fluids PO or IV

            3.         Phenobarbital 100 mg IM or PO at conclusion of study and h.s.

 

A.        Contraindications

 

            1.         Patient receiving phenothiazine derivatives, e.g., Thorazine

            2.         Patient with contrast allergies

            3.         Patient with renal failure

            4.         Glucophage - stop 48 hours prior and start 48 hours post myelogram

 

B.        Preparation

 

            1.         100 mg phenobarbital I.M. on call to x-ray

            2.         Clear liquids only until 3 hours before study

            3.         IV drip with D5/W started prior to study

 

C.        Filming

 

            1.         A-P,  14 x 17,  supine

            2.         Lateral,  14 x 17,  supine,  cross table

            3.         Fluoro spots prone

 

D.        CT of T-Spine

 

            1.         Optional at discretion of physician

 

E.         Contrast

 

            1.         Non-ionic 300 mg/ml  (e.g., Isovue)

                        Maximum of 3000 mgm

 

F.         Post-Myelogram:

 

            1.         Patient semi-erect OOB as tolerated

            2.         Force fluids PO or IV

            3.         Phenobarbital 100 mg IM or PO at conclusion of study and h.s.

 

 

 

 

                                                                            KV              MA                 Time               

C-spine:

 

10 x 12  cross table lateral                                80                100                  .3

 

10 x 12  swimmers                                           75                100                  3 seconds

 

10 x 12  PA                                                     70                100                  Phototimer

 

Fluoro spots  9 x 9                                           80                200                  Phototimer

 

                                                                                                                                               

 

 

 

                                                                            KV              MA                 Time               

T-spine:

 

14 x 17 cross table lateral                                 75                200                  .6

 

14 x 17  AP                                                     70                200                  Phototimer

 

Fluoro spots 9 x 9                                            85                200                  Phototimer

 

                                                                                                                                               

 

 

 

                                                                            KV              MA                 Time               

L-spine:

 

10 x 12 cross table lateral                                 85                200                  .8

 

14 x 17 PA                                                      75                200                  Phototimer

 

Fluoro spots (PA, obliques)              85                    200                  Phototimer

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Rule out soft tissue mass to include lymph nodes

            2.         Larynx

            3.         Vocal cords

            4.         Pyriform sinuses

 

B.        Preparation

 

            1.         NPO 2 hours

 

C.        Technical Guidelines

 

            1.         Power injected enhanced scans only

           

D.        Scanning

 

            1.         Patient supine on the table so the patient's head will enter the gantry first.  Arms down by sides with restraints in place to pull shoulders down to the feet.  Extend the chin away from C1 and immobilize head and chin with tape.

 

            2.         Centering light horizontally is 1 cm below the sternal notch and vertically to the midcoronal plane of the neck

 

            3.         Do 3 mm thickness and 3 mm increments from nasopharynx to sternal notch (unless otherwise requested)

 

            4.         Scans should be done with the patient quietly breathing

 

            5.         Soft tissue technique and bone technique is needed on all CT neck studies.

 

            6.         Scan Helical using 1.3 pitch.  Reconstruct images every 3 mm to film in Bone and soft tissue.

 

            7.         IV contrast - Bolus injection

 

            8.         Bone and soft tissue filming needed

           

 

A.        Clinical Indications (Indications for study may be added by radiologist; indications given are not complete but are samples.)

 

            1.         Voice changes

            2.         Hoarseness

 

B.        Preparation

 

            1.         NPO 2 hours

 

C.        Technical Guidelines

 

            1.         Power injected

 

D.        Scanning

 

            1.         Patient supine on the table so the patient's head will enter the gantry first.  Arms down by sides with restraints in place to pull shoulders down to the feet.  Extend the chin away from C1 and immobilize head and chin with tape.

 

            2.         Centering light horizontally is 1 cm below the sternal notch and vertically to the midcoronal plane of the neck

 

            3.         1 cm above and 1 cm below vocal cords (1.0 pitch)

 

            4.         Soft tissue technique and bone windows on study

 

            5.         Have patient softly say the letter "E" while scanning.      

 

 

A.        Scout

 

            1.         Head first

            2.         Patient supine

            3.         No angle of patient's chin

 

B.        Axial Images

 

            1.         No tilt of gantry

            2.         D.F.O.V. 15.4

            3.         1 mm thickness; 1 mm spacing

            4.         For maxilla scanning - plan scout from middle frontal sinuses to bottom of teeth

            5.         For mandible scanning - plan scout from bottom of hard palate to tip of chin

 

C.        Send Images to Workstation

 

            1.         Select Denta protocol

            2.         After model is built - select image which includes most of object you are interested in (i.e., mandible to include entire mandible)

            3.         Depress shift key and trace entire object

            4.         Depress Panorex Key.*  Images will start to form model.  Before saving model, make sure that mandibular canal is on all images.

            5.         Select 3-D

            6.         Select the Bone model

            7.         After model is built, depress modify modes, then threshold.  using shift key in addition to select trace around area to be removed;  select apply cut.

 

D.        Filming

 

            1.         3-D reconstruction images are to be filmed 6 images on one sheet:

 

                        Anterior                        15° superior anterior                 15° inferior anterior

                        Rt oblique                     Rt oblique                                 Rt oblique

                        Lt oblique                     Lt oblique                                 Lt oblique

                                           Superior                                Inferior

 

            2.         DentaScan images are to be filmed 4 images on one sheet.

 

 

 

*  Axial images need not be filmed.  Must be saved on Dat.

 

 

 

A.        Cervical Carotids

 

            1.         Preparation

 

                        a.         A large bore IV - preferably a 20 gauge - is inserted by the technologist.  ONLY NONIONICS (300 mg% Omnipaque) are used because of the rapid bolus.

 

                        b.         The patient should be lying flat on the table with a sponge behind the neck to elevate the chin.

 

                        c.         The technologist will take a lateral view.  Make sure the chin is elevated enough so that fillings or permanent dentures are not in the way.

 

                        d.         A test injection of 18 cc at three cc/sec is then performed using a 18 FOV, 10 mm x 10 mm slices, and an eight second prep delay.  Images should be obtained starting at the clavicles extending superiorly to C1.  KV used is 120.  Use the minimum MA possible, i.e., 140 since we don't need a great deal of detail on the test.

 

                        e.         From the test injection:

 

                                    i.          Calculate the approximate scan delay - 1st image is 8 seconds, plus 2 seconds for each additional image until contrast appears.  Example:  Contrast first appears on the third image.  This results in an approximate delay of 8 + 2 + 2 = 12 seconds.  The longest delay should be 26 seconds in a patient with poor cardiac output.

 

                                    ii.          Locate the carotid bifurcation on both sides.  You will start the CT angiogram approximately 15 mm below the most inferior bifurcation.

 

            2.         CT Angiogram

 

                        a.         Use a 1 mm thick spiral (collimation) at a pitch (table speed) of 2 with a FOV of 18.  Please use the maximum MA available, generally around 280.  Try not to use less than 250.

 

                        b.         Start location is 10-15 mm below the bifurcation.  Each complete spiral takes 1 second and the number of spirals in a single acquisition is 30.  The patient will hold their breath for the thirty second injection if possible.  The total length covered by the spiral scan will be 6 cm using a pitch of 2.

 

            pitch  x  collimation  x  # spirals  =  length

            (example:  2  x  1  x  30 spirals  =  60 mm)

 

                                    Therefore, the end location will be 60 mm above your start location.  Always scan in Caudal to Cranial direction.

 

                        c.         Inject 3 cc/second for a total of 90 cc.  This will result in a 30 second injection.  Begin the scanning at the calculated scan delay.  Have the patient hold their breath at the start of the scanning not at the start of the injection.  Have the patient take several deep breaths just prior to holding their breath.  If a patient will not be able to hold their breath, have them breath shallowly.  In all cases patients must be instructed not to swallow.

 

                        d.         Have the technologists reconstruct the images at a 10 centimeter FOV at .7 mm slice thickness.  Only a single window needs to be pictured that separates the contrast from calcification.  Generally, a window 800 and a level 230-280.

 

                        e.         The technologists will then transfer this data to the Windows workstation.

 

B.        Aortic Arch

 

            1.         Preparation

 

                        a.         A large bore IV is inserted into the Right antecubital vein.  NONIONICS are only used (300 mg Omnipaque) because of the rapid bolus.  Arms above head.

 

                        b.         The technician will scout the upper chest AP.

 

                        c.         A test injection of 3 cc/sec for a total of 20 cc is used using an 8 second prep delay.  Scan using 10 x 10 mm slices with a 20 FOV from the tracheal bifurcation to approximately C5.  Always scan caudal to cranial!!!

 

                        d.         From the test injection:

 

                                    i.          Calculate the timing in the same way as for the carotids (see above)

 

                                    ii.          Check that the origins of the great vessels will be well identified.

 

            2.         CT Angiogram

 

                        a.         Scan approximately the same area covered on the test injection using a 3 mm spiral with a pitch of 1.7-2.  Try to scan in no longer than thirty seconds.

 

                        b.         Inject 4 cc/sec for a total of 120 cc (30 sec).  The patient holds their breath during as much of the scanning as possible followed by quiet breathing.  If the patient cannot hold their breath  SHALLOW breathing is OK.  This should result in adequate coverage through the aortic arch and origins of the great vessels.

 

                        c.         The technologist must then reconstruct this data by 2 mm with a smaller field of view (12-16).  This will then be transferred to the Windows workstation.

 

                        d.         Only a single window needs to be pictured that separates the contrast from calcification.  Generally, a window around 800 and a level 230-280.

 

C.        Intracranial CTA

 

            1.         No test injection is needed unless there is a need to see the cavernous carotid.

 

            2.         Position the patient chin down to minimize base of skull cuts.

 

            3.         Do a non contrast brain to localize the AVM or circle of Willis.

 

            4.         After the area to be covered  has been determined, use a 1 mm collimated spiral with a pitch of 1.0-2 to cover the area in 40 seconds or less.  Use the maximum MA possible, i.e., 280.  You may be able to use up to 60 seconds over at COB or on the third floor.

 

            5.         Use a 25 second prep delay.  Inject 3 cc/sec for 120 cc.  The patient may breath while the scan is performed.

 

            6.         Always scan caudal to cranial!!!

 

            7.         The technologist should reformat the images using a smaller FOV and at .7 mm thickness.

 

            8.         These RETRO images should then be transferred to the Windows workstation.

 

            9.         See "Windows Workstation Processing of Vascular Structures: Surface Rendered Images" (on following page).

 

The following is the basic method to process angios on the Windows workstation.  Use the left mouse button unless otherwise stated for all operations.  The surface rendering technique is best for vessels with complex spatial relationship, i.e., aneurysms and AVMs.  It is not a good technique to evaluate for stenosis.  You also cannot use a threshold technique to subtract out bone - it must be cut away.  There is a way to do this by switching from MIP to Surface rendered in the custom model. 

 

A.        Transfer retro images to work station from the CT scanner or MRI if not already on.

 

            1.         Network

 

                        a.         Select the host (see the key at the workstation)

                        b.         Select Query Host

                        c.         Select exam - patient name

                        d.         Get

 

B.         Once the exam is on the workstation, build the 3D model - Surface rendered images - appropriate for intracranial aneurysms and AVMs.

 

            1.         Highlight the patient and series you want to examine

 

            2.         Select 3D (on right)

 

            3.         Select Custom when the window opens up

 

            4.         Select 95 for the lower threshold on CTA and 250 for the lower threshold on an MRA

 

            5.         Select Build Model

 

            6.         The images will load and an image will appear in the upper left box.

 

C.        To isolate the region of interest for the 3D images

 

            1.         Select I projection to allow you to view from the inferior aspect

 

            2.         Select Modify Model

 

            3.         Select Threshold VOI

 

            4.         Select Outside Cut for everything to disappear outside the trace.  Select Inside Cut for everything to disappear inside the trace

 

            5.         Put your cursor at your starting point and press both the left mouse button and the shift key on the keyboard to draw your area of interest.

 

            6.         Select Apply Cut

 

            7.         Select Clear trace to remove the residual lines

 

            8.         Rotate and perform the same maneuver repeatedly until you have the proper residual picture.

 

            9.         You can magnify the image by pointing to the FOV and pressing the left mouse button to magnify and the right mouse button to minify.

 

            10.       It is wise to save the modified image periodically as you progress by dragging the image to the lower left corner.  Keep the image in the lower left window until it is no longer needed.  You can delete it later by pointing to it with the right mouse button since you can only save 3 at any one time.

 

D.        Once the image is in its final form, you may rotate the image to bring out the abnormalities.  Screen save each image that you feel is important or just do a set of rotated images.

 

E.         Close the program to print the images you made.  Reselect your patient in Browser.  There will now be a new series that has all the screen saved images or the rotated series.