Page No.

 

Safety Considerations                                                                                                                 4-5

      (Attached:  2 pages re: Glucophage)                                                             between pp. 5-6

General Considerations                                                                                                                  6

Selective Use of Non-Ionic Contrast Material                                                                             7-8

      (Attached:    Contrast Agent Data Form

                           Alphabetical Drug List

                           ABCD Approach for Patient Evaluation

                           Categories of Reactions                                                             between pp. 8-9

Chest                                                                                                                                       9-10

Pulmonary Artery CTA                                                                                                                11

High Resolution Chest CT                                                                                                            12

Abdominal Aortic Aneurysm Rupture                                                                                           13

Aortic Dissection                                                                                                                         14

Esophagus - For Tumor Work-up                                                                                                15

Chest and Abdomen                                                                                                                    16

Chest/Abdomen/Pelvis                                                                                                                 17

Routine Abdomen/Pelvis Survey (or Abdomen)                                                                            18

Triple-Phase Studies (Liver)                                                                                                         19

Pancreas                                                                                                                                      20

Trauma: Abdomen/Pelvis Survey                                                                                                  21

CT Cystography for Bladder Injury After Trauma                                                                         22

Acute Abdominal/Pelvic Pain (Abdomen and Pelvis)                                                                     23

Pelvic Malignancy, Gynecologic Abnormality                                                                                24

Kidney                                                                                                                                        25

Stone Search                                                                                                                               26

Liver-Hemangioma Study                                                                                                             27

Abdominal Angiography (Potential Renal Artery Donor)                                                               28

Renal Artery Stenosis                                                                                                                   29

Abdominal Aortic Aneurysm                                                                                                        30

CT Scanogram for Leg Length                                                                                                     31

CT Portogram                                                                                                                             32

CT Hepatic Angiogram                                                                                                                33

CT Pelvimetry                                                                                                                              34

      (Attached:  pp. 1215-1216 from Moss et al)                                              between pp. 34-35

Adrenal Scan                                                                                                                               35

Endovascular Aneurysms                                                                                                             36

CT for Patients with Prostate Cancer                                                                                            37

Appendix A:  Safety Considerations (added to P&P, March 2003)                                               38

      (Attached:  four articles on safety)                                                                  following p. 38

 

A.        For Power Injections:

 

            1.         Venipuncture:  20 or 22 gauge, 1 inch angiocatheter preferably in an antecubital location.  Forearm and dorsum of hand are second and third choice sites respectively.

 

            2.         Check for palpable "thrill" as bolus begins but before images.

 

            3.         Avoid:  butterfly needles, sites of unsuccessful venipuncture and hyperalimentation lines (contrast may precipitate).

 

            4.         May use:  central lines, Hickman catheters and Mediports if necessary.  use pre and post heparin flush (100 u/m) and decrease delay time approximately 10 seconds.

 

            5.         If patient has poor venous access and must receive contrast, use a small butterfly and hand inject (resident).

 

            6.         Do not use Power Injector for children less than 100 lbs.

 

B.         Oral Contrast Preparation:

 

            1.         Water soluble contrast for emergencies, trauma, possible perforation:

 

                        a.         20 gm Hypaque with 16 oz. juice 3 hours before

                        b.         repeat at time of study

 

            2.         Other patients:

 

                        a.         16 oz. pre-mixed Redi-CAT-2 three hours before

                        b.         repeat at time of study

 

            3.         All outpatients should be NPO 3 hours prior to study.

 

            4.         Inpatients are NPO depending upon history and radiologist's decision.

 

C.        Steroid Preparation if prior contrast reaction to intravenous contrast

 

            a.         Day before study:

 

                        i.          6:00 p.m. and 12:00 midnight:      Prednisone 50 mg p.o.

 

            b.         Day of study:

 

                        i.          6:00 a.m.:                              Prednisone 50 mg p.o.

 

                        ii.          One hour before study:          Benadryl 50 mg p.o.

                                                                                 Axid 150 mg (1 cap) p.o.

 

            c.         Use non-ionic contrast

 

D.        Glucophage® (Revised labeling - June 1998)

 

            1.         Glucophage® (metformin hydrochloride tablets) should be stopped at the time of or prior to the procedure involving intravascular administration of iodinated contrast materials.

 

            2.         Assure normal renal function 48 hours after procedure before restarting Glucophage® therapy. 

 

            3.         Attached: 2 pages from Bristol-Myers Squibb Company re: Glucophage®

 

E.         Subcutaneous extravasation of iodinated contrast:

 

            Though very large volumes of extravasated contrast can occasionally lead to skin ulceration and necrosis, fortunately most extravasations are small, causing only mild pain and swelling, which resolve.  A variety of medical treatments have been proposed (hot or cold applications, injection of steroids, etc.), but most have no effect.  Recent animal studies suggest that local injection of saline at the extravasation site decreases tissue injury.  Non-ionic contrast does seem to be less toxic than ionic contrast on an anecdotal basis.

 

            If extravasation occurs:

 

            a.         Elevate arm and apply hot or cold as per patient preference

 

            b.         Have patient/family observe carefully because maximum inflammation may not occur for 12-24 hours.  Symptoms should subside in 2-3 days.

 

F.         See "Safety Consideration" articles in Appendix A

 

1.         When both CT scanners (Hi-Speed and Hi-Lite Advantage) are in use, the following body studies may be performed on the non-helical (Hi-Lite):

 

            a.         Search for retroperitoneal bleed or abscess

            b.         High resolution chest CT.

 

2.         If helical scanner is not functioning, all other body studies can be performed on the Hi-Lite Advantage with modified protocols, with the exception of - all CT angiography.

 

3.         Lung windows from abdomen study should be filmed 20 on 1

 

4.         Liver windows filmed 20 on 1

 

5.         Use appropriate field of view for each patient.

 

6.         Always check technique of prior studies and try to keep field of view uniform.

 

7.         Remove all items from scanning field which will cast artifacts.

 

8.         All CT pulmonary angiograms during the day must have an immediate resident and staff reading.  After hours the resident must give a stat reading with staff support as necessary.  The study should be shown to the staff promptly in the morning.

 

9.         Twice a day, once in the morning and once in the late afternoon, all inpatient requests for body CTs will be brought to the resident/staff for protocols.  All outpatient studies shall be protocolled prior to the day of the study.

 

10.       See next section:  "Selective Use of Non-ionic Contrast Material"

 

 

A.        Contrast Agent Data Form

 

"Contrast Agent Data Form" is filled out by the technologist at the time of every study.  The radiologist shall review the patient request, records, if available, and the Data Form and will also question the patient personally as to allergic and other pertinent medical history. (copy of "Contrast Agent Data Form" attached)

 

B.         Policy

 

The type and amount of intravenous contrast material will be selected by the responsible radiologist, according to the Procedure outlined below.  Please see "D" for guidelines for pediatric patients.

 

C.        Procedure

 

            Note:   Please note that because of the lack of an acute care hospital in close proximity to Einstein Elkins Park Radiology (EPRA) and Einstein Center One Radiology (CORA), that non-ionic intravenous contrast material will be used exclusively at these out-patient centers.

 

            1.         Patients with a history of a previous adverse reaction to contrast material, with the exception of the sensation of heat, flushing or a single episode of nausea or vomiting.

 

            2.         Patients with a history of asthma or allergy.

 

            3.         Patients with known cardiac dysfunction, including recent or potentially imminent cardiac decompensation, severe arrhythmia, unstable angina, recent myocardial infarction and pulmonary hypertension.

 

            4.         Patients with generalized severe debilitation.

 

            5.         Any other circumstances where, after due consideration, the radiologist believes there is a specific indication for the use of non-ionic contrast agents.  Examples of this include but are not restricted to:  sickle cell disease; patients at increased risk for aspiration (such as those in body casts or traction devices);  patients who are manifestly very anxious about the contrast procedure;  patients with whom communication cannot be established in order to determine the presence or absence of risk factor;  patients who request or demand the use of non-ionic contrast agents.

 

D.        Pediatric Patients

 

            1.         Isovue 300:  for patients NB to 12 years of age (see "C" [Procedure] for Guidelines for patients 13 years of age and older)

 

            2.         Renografin 60 or Isovue 300:  age 13 years and older according to ACR criteria

 

E.         Attached:

 

            1.   Contrast Agent Data Form

 

            2.   Alphabetical Drug List

 

            3.   ABCD Approach for Patient Evaluation and Treatment

 

            4.   Iodinated Contrast Media:  Categories of Reactions

 

 

 

A.        Non-contrast

 

            Rule out metastases (excluding lymphoma, lung, breast), parenchymal lung disease, possible nodule on CXR

 

            1.         If looking for lung metastases, helical scan with 7 mm collimation using 1 or 2 helices if possible.  Hyperventilate patient as necessary.  Pitch 1:1

           

            2.         Others:  10 mm contiguous slices, with thinner sections for small nodule as necessary.

 

            3.         Scan from thoracic inlet to dome of diaphragm.

 

B.         Contrast Nodule Protocol

 

 

 

            1.         After nodule is localized on routine scan, inject 100 cc contrast at 2 cc/sec.

            2.         Slice thickness 2 mm

            3.         Obtain six scans every 30 sec

            4.         Print with density readings

                        (Average enhancement for carcinoma = 40 H.U.  [20-108])

                        (Average enhancement for benign = 12 H.U. [0-50]

 

C.        Routine Contrast Chest CT

 

            Staging of lung cancer, lymphoma, abscess, empyema, thoracic aneurysm, mediastinal mass

 

            1.         Technique:  helical 1:1 pitch, collimation 7 mm

 

            2.         Contrast:

 

                        a.         IV contrast 2.0 ml/sec for 100 ml

 

                        b.         Delay:  25 sec (30 sec if > 70 yrs or history of heart disease)

 

            3.         Scan from thoracic inlet to diaphragm, include adrenal glands if there is a history of lung cancer.  If thoracic aneurysm is present at level of diaphragm continue into upper abdomen to image entire aneurysm.

 

            4.         Three high resolution slices:  aortic arch, carina, and just above hemidiaphragms.  Print lung windows only.

 

 

A.        Scout should be at same phase of respiration as scans (inspiration if possibility of hyperventilation).  If unable to hold breath, quiet respiration may be used.

 

            Note:  Ventilated patients must be paralyzed and sedated.

 

B.         Test Dose

 

            1.         18 or 20 gauge IV

 

            2.         5 mm scan at level of main pulmonary artery every 2 seconds for a total of 20 seconds

 

            3.         20 cc non-ionic contrast 4 cc/sec - Delay:

 

                        a.         4 sec for antecubital site

                       

                        b.         2 sec for central line

 

C.        Scanning

 

            1.         Hyperventilate patient before scanning.  One breath hold if possible.

 

            2.         Coverage - from diaphragm to top of arch

 

            3.         Rate - 4 cc/sec

 

            4.         Delay - Calculate from test dose (Avg 12-14 seconds) time to maximum enhancement

 

            5.         Collimation - 3 mm;  Pitch - 2:1

 

            6.         Recon - every 2 mm - 24 DFOV

 

            7.         150 cc IV contrast (non-ionic)

 

D.        Chest

 

            1.         Re-scan helically routine chest (10 mm) immediately to follow - breath hold if possible

 

E.         Print lung windows of CTA scan.  Immediately network reconstructed image set to CT #2.  Do not delete from there without checking.  Fill out information sheet!

 

A.        Indications

 

            1.         Diffuse parenchymal lung disease

 

            2.         Bronchiectasis, emphysema, sarcoidosis, etc.

 

B.         Technique

 

            1.         Axial scans:  1 mm thick sections every 20 mm

 

            2.         Bone algorithm

 

            3.         Thoracic inlet to hemidiaphragms

 

            4.         No IV contrast, unless suspected mediastinal pathology

 

            5.         Patient position:  Supine (if dependent densities appear significant, try getting patient to make greater inspiratory effort, or turn prone)

 

            6.         Film lung windows (whole chest) zoomed up, 6 on 1

 

            7.         If this is the first study for a patient, do routine chest without IV contrast, and then 6 selected high resolution images.

 

            8.         Ask if expiratory scans should be done.

 

A.        Indications:

 

            Signs of rupture include: retroperitoneal hematoma, high attenuating crescent, indistinct aortic wall, break in the intimal calcifications, and extravasation of intravenous contrast material.

 

            When there is no frank leak, the best sign of impending rupture is the high attenuating peripheral crescent sign which represents acute dissection of blood within mural thrombus and/or aneurysm wall.  This sign is best seen on unenhanced scans.

 

B.         Procedure:

 

1.         Spiral imaging from the diaphragm through the pelvis with 7 mm thick slices to aortic bifurcation and 1 cm slices in pelvis.  No oral or IV contrast.

 

2.         If results are equivocal, repeat with intravenous contrast as per Aortic Dissection protocol.

 

C.        References:

 

1.         Mehard WB et al:  High-attenuating crescent in abdominal aortic aneurysm wall at CT:  A sign of acute or impending rupture.  Radiology 192:359-362, 1994.

 

2.         Arita T et al:  Abdominal aortic aneurysm:  Rupture associated with the high-attenuating crescent sign.  Radiology 204:765-768, 1997.

 

Aortic Dissection – Revised - February 2003

 

 

A.        Technique

 

            1.         Un-enhanced images - with 10 mm collimation and pitch of 1.5 from 2 cm above aortic arch through diaphragm or to aortic bifurcation, depending upon the clinical concern.  The purpose is to look for acute hemorrhage in the pleural, mediastinal and pericardial spaces as well as for intramural hematoma in a thrombosed dissection.

 

            2.         Contrast:  Full bolus of 150 cc for large patients and less for smaller patients.  Inject at rate of 3-4 cc per second.  Begin scanning just as bolus injection ends.  Collimation of 3-5 mm depending upon patient size and pitch of 1.5.  Study should begin 2 cm above aortic arch and extend into iliac arteries.

 

            3.         Reformatting: axial images are usually sufficient to diagnose the presence, location and extent of flap.  Multiplanar reformats, with shaded surface display or maximum intensity projections help to provide an overview of the dissection and the relationship to branch vessels.  These can be sagittal, coronal, oblique, or curved reformats.  These would only be necessary in positive cases.

 

4.         No oral contrast.

 

 

 

 

Suggested reading:

 

Batra P, et al: Pitfalls in the diagnosis of thoracic aortic dissection at CT angiography.  RadioGraphics 2000; 20:309-320

 

Sebastia C, et al: Aortic dissection: Diagnosis and follow-up with helical CT.  RadioGraphics 1999; 19:45-60

 

 

 

 

 

A.        Technique

 

            1.         Helical

 

            2.         1:1 pitch

 

B.         Contrast

 

            1.         IV contrast:  2.0 cc/sec for total of 150 cc

 

            2.         Delay:  20 sec (25-30 sec if > 70 yrs or history of heart disease)

 

            3.         Give one bottle oral contrast immediately before scanning

 

C.        Collimation

 

            1.         7 mm from lung apices through liver, to include celiac axis

 

            2.         May finish liver with axial clusters

 

 

A.        Technique

 

            1.         Helical with axial clusters as needed

 

            2.         Start with chest and proceed continuously through abdomen

 

            3.         Pitch 1:1

 

B.         Collimation

 

            1.         7 mm section

 

C.        Contrast

 

            1.         Contrast:  1.5 cc/sec for 150 cc

 

            2.         Delay:  25 sec (greater if > 70 yrs, or history of heart disease)

 

            3.         Routine oral contrast

 

 

A.        Indications

 

            1.         Routine survey, lymphoma, widespread metastatic disease.

 

            2.         If history of hypervascular tumor (breast, melanoma, carcinoid, islet cell, renal cell, hepatoma, pheochromocytoma, etc.), get non-contrast axial images through liver, 7 mm thick contiguous slices.  (Consider triple phase)

 

B.         Technique

 

            1.         Helical through chest and liver if possible

 

            2.         Pitch 1:1

 

C.        Collimation

 

            1.         7 mm sections through liver

 

            2.         7 mm sections through liver

 

            3.         10 mm through remainder of study

 

D.        Contrast

 

            1.         Contrast:  1.5 cc/sec for 150 cc

 

            2.         Delay:  25 sec (greater if > 70 yrs, or history of heart disease)

 

            3.         Routine oral contrast

 

 

A.        Indications

 

            1.         Non-specific pain

 

            2.         Possible metastases

 

            3.         Weight loss

 

            4.         Bowel obstruction

 

            5.         Perforation

 

            6.         Abscess

 

B.         Technique

 

            1.         Helical 1:1 pitch through liver

 

            2.         Axial clusters

 

C.        Collimation

 

            1.         7 mm thick during helical portion

 

            2.         10 mm for axial images

 

D.        Contrast

 

            1.         Radiologist should evaluate case for use of IV contrast.  For example, outpatients with non-specific symptoms could be scanned without IV contrast, checked, and rescanned with IV contrast if necessary to ellucidate a finding.

 

            2.         IV contrast: 150 cc at 2 cc/secwith 20 g angiocath (if 22 g angiocath, rate is 1.8 cc/sec)

 

            3.         Delay:  70 sec routine, 80 sec or greater  if > 70 yrs or history of heart disease

 

            4.         Routine oral contrast, except use water soluble if possible perforation (i.e., trauma, obstruction)

 

 

A.        Indications

 

            1.         Hypervascular tumors:  breast, renal cell, carcinoid, islet cell (insulinoma, glucagonoma), melanoma, hepatocellular carcinoma

 

            2.         Cirrhotic livers

 

            3.         Pre-transplantation livers

 

B.         Technique

 

            1.         Noncontrast liver:  Axial, 7 mm

 

            2.         Arterial phase:  Helical, 7 mm, 1:1 pitch, 25 sec breathhold, delay 20 sec, with patient breathing

 

            3.         Portal venous phase:  Helical, 7 mm, 1:1 pitch, two 15 sec breathholds, scan at 90 seconds

 

            4.         Finish the rest of abdomen and pelvis with axial 10 mm sections

 

C.        Contrast

 

            1.         IV:  150 cc

 

            2.         Non-ionic  -     20 g IV, 3 cc/sec, delay 25 sec

                                                18 g IV, 4 cc/sec, delay 20 sec - Preferred

 

            3.         Routine oral contrast

 

 

Note:  Film liver windows on the arterial phase.

 

 

 

 

A.        Indications

 

            1.         Pancreatic tumors

 

            2.         Pancreatitis

 

B.         Technique

 

            1.         One or more non-contrast axial scout slices at lower mA to localize uncinate process of pancreas/duodenal sweep (approx. L3).

 

            2.         Scan superiorly from bottom of pancreas to top of liver with IV contrast

 

            3.         Helical, 1:1 pitch, 5 mm through pancreas (20 sec breathhold), 7 mm to top of liver

 

            4.         Axial cluster:  10 mm contiguous sections from bottom of pancreas to symphysis

 

            5.         Film in reverse of scanning

 

C.        Contrast

 

            1.         IV: 150 cc, 50 second scan delay

 

                        a.         20g angiocatheter; Biphasic - 3.0 ml/sec (60 ml) then 1.5 ml/sec (90 ml)

 

                        b.         22g angiocatheter; Biphasic - 1.5 ml/sec (50 ml) then 1.0 ml/sec (100 ml)

 

            2.         Routine oral contrast

 

 

 

A.        Technique

 

            1.         Helical

 

            2.         1:1 pitch  (If patient cannot hold breath, is moving, or on ventilator, increase pitch to 1:1.5)

 

            3.         7 mm sections through liver and kidneys

 

            4.         10 mm axial clusters to symphysis

 

B.         Contrast

 

            1.         IV contrast:

 

                        a.         20g angiocatheter:  2 cc/sec for 150 cc with 70 sec delay

 

                        b.         22g angiocatheter:  1.5 cc/sec for 150 cc with 80 second delay

 

            Note:   Radiologist must check images and rescan kidneys as necessary, particularly if suspicion of renal trauma.  If signs of renal or bladder trauma, repeat images through respective areas 2-3 minutes later to look for extravasation. 

 

            2.         Oral contrast - water soluble

 

A.        Reason for Study:

 

            1.         Bladder injury after trauma

 

            2.         After completion of a routine examination of the abdomen and pelvis using the Trauma protocol, proceed to the following protocol.

 

B.         Procedure:

 

            1.         Prepare 500 cc of a dilute contrast solution (example, dilute Renograffin 20 to 1).

 

            2.         Instill 350-400 ml of this solution under gravity flow via the Foley catheter into the bladder.

 

            3.         Clamp the Foley catheter to maintain bladder distention and re-image the pelvis with 10 mm sections from the top of the iliac crest to the pubic symphysis.

 

C.        Findings:

 

            1.         Extraperitoneal bladder injury is present if new or increasing extraperitoneal contrast material is visualized within the perivesicle space, extending from the bladder.

 

            2.         Intraperitoneal bladder rupture is present if new extraluminal contrast material is visualized along the paracolic gutters or surrounding bowel loops.

 

            Note:  If one experiences difficulty distinguishing intraperitoneal from extraperitoneal bladder rupture, delayed scanning or repeated injection of additional contrast into the bladder may help.

 

D.        References:

 

            1.         Peng MY et al: CT cystography versus conventional cytography in evaluation of bladder injury.  AJR 173:1269-1272, 1999.

 

            2.         Scott MH, Porter JR: Extraperitoneal bladder rupture: Pitfall in CT cystography.  AJR 168:1232, 1997.

 

            3.         Sivit CJ et al: CT diagnosis and localization of rupture of the bladder in children with blunt abdominal trauma: Significance of contrast material extravasation in the pelvis.  AJR 164:1242, 1995.

           

 

A.        Indications

            1.         Appendicitis

            2.         Diverticulitis

            3.         Crohn's disease

            4.         Ulcerative colitis

            5.         Nonspecific right or left lower quadrant pain

 

B.         Technique

            1.         Appendicitis:

                        a.         Helical pitch 1:1.5, 5 mm sections through pelvis

            2.         Other

            a.         Helical, 1:1, 7 mm sections through liver

            b.         Axial clusters:  7 mm sections to symphysis

 

C.        Contrast

 

            1.         IV contrast:

 

                        a.         20g angiocatheter:  2 cc/sec for 150 cc with 70 sec delay

 

                        b.         22g angiocatheter:  1.5 cc/sec for 150 cc with 80 second delay

            2.         Routine oral contrast

 

            3.         If study is for appendicitis or Crohn's disease, do one non-contrast axial scan at level of iliac crest.  If no contrast in right colon, delay scanning at least 30 minutes

 

            4.         Rectal contrast routinely for these patients (approx. 100 cc).

 

 

A.        Indications

            1.         Recto-sigmoid carcinoma

            2.         Gynecologic malignancies

            3.         Uterine or adnexal masses

            4.         Prostate carcinoma

 

B.         Technique

            1.         Helical, 1:1, 10 mm from liver to iliac crest

            2.         Axial cluster:  5 mm every 7 mm to symphysis

            3.         Use tampon in women

 

C.        Contrast

            1.         150 cc, biphasic:  2 cc/sec for 100 cc with 70 sec delay

            2.         At 90 sec give 1 cc/sec for 50 cc (during pelvic scanning)

            3.         Routine rectal contrast (100 cc)

 

 

A.        Indications

 

            1.         Suspected neoplasm

 

            2.         Characterization of mass seen by other imaging study

 

            3.         Follow-up of unproven lesion

 

B.         Technique

 

            1.         Non-contrast, axial cluster:  5 or 7 mm contiguous through kidneys (depends on size of mass if known for prior study).  If study is to characterize a specific lesion, slice thickness must be less than half the diameter of the lesion.

 

            2.         Helical, 1:1, 5-7 mm contiguous through kidneys, STOP.

 

3.         Wait 2-3 minutes, re-image kidneys by 7 mm and remainder of pelvis by 10 mm.

 

            4.         If patient is very large, and thin slices are needed, do all axial instead of helical

 

C.        Contrast

 

            1.         IV: 2 cc/sec at 150 cc

 

            2.         90 second delay

 

D.        Kidneys for pyelonephritis or other infections

 

            1.         Non contrast not necessary.

 

            2.         Just do 2 contrast phases as above.

 

 

A.        Indications

 

            1.         Acute flank pain

 

            2.         Possible ureteral calculus

 

B.         Technique

 

            1.         Helical pitch 1:1, 5 mm from top of kidneys to bottom of bladder

 

            2.         Reconstruct images every 3 mm (delete overlap images) and save with 5 mm images on Data Acquisition Tapes for possible reformatting.

 

            3.         Film only 5 mm images in soft tissue

 

            4.         Enlarge CT scout radiograph, optimize window/level to visualize stones

 

            5.         Magnify image with ureteral calculus and measure.

 

C.        Contrast

 

            1.         No oral or intravenous for initial scan.

 

            2.         Subsequent oral, rectal or intravenous contrast at discretion of radiologist.

 

            3.         If IV contrast is given to opacify the ureters, delay at least 3 minutes before re-imaging.  If moderate/severe hydronephrosis, increase delay as per radiologist.

 

 

 

 

A.        Technique

 

            1.         Axial

 

            2.         Localize lesion on unenhanced scan

 

B.         Contrast

 

            1.         150 cc at 2 cc/sec

 

            2.         Begin scanning with 20 sec delay (arterial phase)

 

            3.         Image at 15, 30, 45 sec and 1, 2, 3, 5, 10 minutes (the 5 and 10 min scans depend on size of lesion)

 

            4.         Further scans at discretion of radiologist.

 

            5.         Be very careful with patient breathing to avoid misregistration (Have patient practice breathholds;  end expiration may be easier)

 

            6.         Oral contrast - none

 

A.        Contrast

 

            1.         No oral contrast agent

 

B.         First set of scans:  After abdominal scout view, obtain contiguous unenhanced images of kidneys (non-helical) at 10 mm collimation.  These scans are necessary to localize scanning volume of interest and detect any calculi.

 

C.        Second set of scans:  These images are to identify peak enhancement in the aorta.  Find level at renal arteries.  Give 20 cc non-ionic contrast via 20g catheter at 4 cc/sec

 

            1.         Collimation 10 mm

 

            2.         End inspiration

 

            3.         Single breath hold; 10 sec delay following injection with 15 axial scan cluster (not spiral).  Place region of interest in abdominal aorta to determine time to peak enhancement.  Use this time as the delay for next set of scans.  Scans are obtained without table incrementation.

 

D.        Third set of scans: (Helical scan for angiography)

 

            1.         mAS 260-280 (may be lower as necessary)

 

            2.         Level - start just above kidneys at least to aortic bifurcation.  If possible go 3 cm below bifurcation to demonstrate any inferior accessory arteries

 

            3.         IV contrast - 120-160 cc at 4 cc/sec for 30-40 sec.  Use smaller amounts of contrast in patients less than 50 kg

 

            4.         Delay - time to peak aortic enhancement from previous scan

 

            5.         Collimation - 3 mm with pitch of 1.3 to 2.0 depending on required length of scan

 

            6.         Duration - 30-40 sec helical scan after hyperventilation

 

            7.         Reconstruct scan every 1.0 mm at 22 cm FOV and send to work station

 

E.         After patient relaxes, reimage kidneys with axial clusters at 10 mm collimation (2-3 min after contrast administration).  These images are to look for any other pathology, e.g., masses, etc.

 

A.        See Protocol for “Abdominal Angiography (Potential Renal Artery Donor)”

 

            1.         Omit first set of noncontrast images

 

            2.         Perform scans to determine peak contrast in aorta at level of renal arteries

 

            3.         Scan through kidneys at 1 mm collimation with pitch of 2 (3 mm if needed)

 

 

A.        See Protocol for “Abdominal Angiography (Potential Renal Artery Donor)”

 

            1.         Omit first set of noncontrast images

 

            2.         Perform scans to determine peak contrast in aorta at level of renal arteries

 

            3.         Begin second scan for angiography at celiac axis.  Proceed as for renal donor protocol

 

            4.         After patient relaxes, starting 2 m below last scan, image through midpelvis using 10 mm collimation and 1:1 pitch.  use these images to check iliac arteries.

 

 

A.        Procedure:

            1.         Place patient supine on CT table – feet first

            2.         Patient to hold lower legs in anatomic position – tape feet together if necessary

            3.         Obtain scout AP of pelvis to feet

            4.         Obtain measurements off scout CT of right and left legs:

                        a.         1^st measurement: top of femoral head to distal medial femoral condyle.

                        b.         2^nd measurement: taken from medial femoral condyle to distal tibia epiphysis (mid plane at level of tibia talor surface)

                        c.         Film taken with measurements and cursors.

 

 

A.        Indications

 

            1.         Metastatic disease

 

B.         Technique:    

 

            1.         Patient will come from Specials Section with catheter in superior mesenteric artery

 

            2.         Non-contrast:  axial, 7 mm slices every 7 mm

 

            3.         With contrast (1):

 

                        a.         Helical, 1:1 pitch, 7 mm

 

                                    i.          25 sec delay

 

                                    ii.          Either two 15 sec breathholds or three ten sec breathholds (8 sec in between breathholds)

 

            4.         With contrast  (2):

 

                        a.         Axial, 7 mm slices every 7 mm

 

                                    i.          Three 10 sec breathholds

 

                        Note:   Perform these images immediately after helical scan

 

            5.         IV contrast:  100 ml at 1.5 ml/sec

 

 

 

A.        Indications

 

            1.         Hepatoma

 

B.         Technique

 

            1.         Patient will come from angiography section with catheter in hepatic artery.

 

            2.         Non-contrast - axial, 7 mm, pitch 1:1

 

            3.         Contrast (1)

 

                        a.         Helical - pitch 7 mm, pitch 1:1

 

                        b.         8-9 sec delay

 

            4.         Contrast (2)

 

                        a.         Axial - 7 mm, pitch 1:1

 

                        b.         IV contrast

 

            5.         Non-ionic 40-50 cc @ 3 cc/sec

 

 

 

 

 

 

A.        Obtain lateral digital radiograph of pelvis.

 

            1.         Pelvic inlet (or true conjugate) is measured on lateral scout view from sacral promontory to upper portion of symphysis pubis.

 

           2.         Normal > 11.0 cm

 

B.         Obtain antero-posterior digital radiograph of pelvis.

           

            1.         Measure largest transverse diameter of the pelvis:

 

                        a.         Normal > 12.0 cm

 

C.        Axial scan at level of ischial spines

 

            1.         Interspinous distance (midpelvic diameter) is measured between two points connecting ischial spines on CT obtained at level of fovae of femoral heads.  Use them as landmark on AP digital radiograph to choose level for axial CT section.

 

            2.         Normal > 10 cm

 

D.        Attached:  pp. 1215-1216 from Moss, Gamsu, Genant, Vol. 3, 2nd Ed.

 Adrenal Scan – Revised - February 2003

 

 

A.        Indications

 

            1.         Rule out mass (patient with symptoms of Cushing's or Cohn's syndrome), follow-up of a mass, hemorrhage, pheochromocytoma

            2.         Work up of potential adenoma

 

B.         Technique

 

            1.         Pitch 1:1;  3-5 mm collimation

            2.         Film with small field of view

            3.         If a mass is present, measure size and attenuation.

            4.         If the study is to distinguish a benign adenoma, and the density of the mass is < 10 HU, no further imaging is required.

            5.         If attenuation value is > 10 HU, contrast enhanced and delayed contrast enhanced imaging is performed.

 

C.        Contrast

 

            1.         Oral, give 500 to 750 cc one hour prior to study and 250 cc just before imaging

            2.         If IV contrast is required, use collimation of 5 mm, pitch 1:1.  Use 150 cc bolus @ 2-3 mL/sec

            3.         Obtain at least 2 measurements of mass during each phase of study.

            4.         Image with 60 sec delay and then @ 15 min delay for delayed washout

 

                        Calculations of washout and relative washout:

 

                                                                                                atten. @ enh. CT – atten. @ delayed CT

                        a)   % enhancement  washout             =  100  x  ------------------------------------------------

                                                                                                atten. @ enh. CT – atten. @ unenh. CT

 

 

                                                                                                atten. @ enh. CT – atten. @ delayed CT

                        b)   relative % enhancement washout  =  100  x  ------------------------------------------------

                                                                                                atten. @ enh. CT

 

 

                              Threshold value of 60% or higher for absolute % enhancement washout

 

                                                                              or

 

                              Threshold value of 40% of higher for relative % enhancement washout

 

(indicates a benign adenoma)

 

 

 

Suggested Reading:

 

Caoili EM, et al:  Adrenal masses: Characterization with combined unenhanced and delayed enhanced CT.  Radiology 222:629-633, March 2002.

 

 

A.        Measurements

 

            1.         Length of the neck of the aneurysm from the lowest renal artery to the beginning of the aneurysm

 

            2.         AP and transverse diameter of the neck of the aneurysm

 

            3.         Length of abdominal aorta from lowest renal artery to aortic bifurcation

 

            4.         Length of each iliac artery to the bifurcation

 

            5.         Diameter of each iliac artery proximal, mid and distal (usually a measurement at 3 cm from the bifurcation)

Added to P&P - March 2003

 

 

A.        Diagnostic study (for initial staging and follow up of patients with prostate Ca).

These are patients who are not in the body mold.

 

1.         Scan with IV contrast if appropriate.

 

2.         Standard protocol, per CT P&P Manual

 

3.         Standard injection delay.

 

B.        Combined diagnostic and theraputic planning study.

These patients are in the body mold.

 

           1.         Scan with IV contrast.

 

           2.         Standard delay after injection.

 

           3.         7 mm scans from diaphragm to iliac crests.

 

           4.         Wait until 5 minutes after injection began.

 

           5.         5 mm scans from iliac crests to ischial tuberosities. Make sure there is contrast in the bladder. If not, wait a few more minutes and scan by 5 mm through the bladder base and prostate.

 

           6.         Reconstruct using large FOV to ensure that all of the patient's skin is included on the images.

 

           7.         Load images onto a disc for the Radiation Therapy department.

 

C.        Theraputic planning scan only.

These patients are in the body mold. This is a scan of the pelvis only.

 

            1.         Inject 25 cc of contrast IV and wait at least 5 minutes before scanning..  This injection can be made before the patient is put on the CT table.  Then the time involved with aligning the patient will account for the waiting time for the contrast.

 

            2.         5 mm scans from iliac crests to ischial tuberosities. Make sure there is contrast in the bladder. If not, wait a few more minutes and scan by 5mm through the bladder base and prostate.

 

            3.         Reconstruct using large FOV to ensure that all of the patient's skin is included on the images.

 

            4.         Load images onto a disc for the Radiation Therapy department.

 

            5.         If there are any questions about which scan is to be done, contact Radiation Therapy physician if it is one of their patients. Otherwise, ask Body CT radiologist.

 

 

A.        Attached:

 

1.         Cohan RH, Dunnick NR, Leder RA, Baker ME:  Extravasation of nonionic radiologic contrast media:  Efficacy of conservative treatment.  Radiology 176:65-67, 1990.

 

2.         Sistrom CL, Gay SB, Peffley L:  Extravasation of iopamidol and iohexol during contrast-enhanced CT:  Report of 28 cases.  Radiology 180:707-710, 1991.

 

3.         Park KS, Kim SH, Park JH, et al:  Methods for mitigating soft-tissue injury after subcutaneous injection of water soluble contrast media.  Invest Radiol 28:332-334, April 1993.

 

4.         Miles SG, Rasmussen JF, Litwiller T, Osik A:  Safe use of an intravenous power injector for CT:  Experience and protocol.  Radiology 176:69-70, 1990.