Intro to Interventional RadiologyJustin McWilliams, MDVersion 1.2Welcome.Responsibilities Read your packet. You are in charge of IR1. Take responsibility for it and make it run smoothly. To that end: Consent inpatients at first opportunity once they appear on the board For outpatients, write their pre-procedure orders the day or night before (charts are with Jackie and Gina until 4 pm, and are in the PTU after that) Relevant things to know for any patient includes history, reason for study, labs (especially INR, platelets, creatinine), consentability, blood thinners, and relevant imaging. Write the procedure note, post-procedure orders, and dictate after the case is done (ask your attending for guidance on what to write/dictate) Follow up with patients at least the next day (if inpatient) or longer if there are ongoing issues Sign out to on-call fellow any relevant issues Keep a log of your patients.Blood thinners should be stopped prior to IR procedures, unless there is a good reason not to. Heparin: 4-6 hours Coumadin: about 4-5 days, check INR Aspirin: 1 week, though recent study suggests that this may not be as crucial as we once thought Plavix: 1 week Lovenox: 12-24 hours Arixtra: 1-2 daysAntibiotics are given prior to some IR procedures. These vary with attending, but here are some oft-used ones: Biliary interventions, non transplant: Ceftriaxone 1 gram IV or Cipro 400 mg IV + Flagyl 500 mg IV Biliary interventions, transplant: Unasyn 3.375 grams IV GU interventions: Ciprofloxacin 400 mg IV or ceftriaxone 1 gram IV Ports: Ancef 1 gram IV; if PCN-allergic use Vancomycin 1 gram IV or Clindamycin 600 mg IV G tubes, Permacaths and Hickmans: Same as Ports, or nothing at all Solid organ embolization (spleen and kidney): Ceftriaxone 1 gram IV TACE and RFA: Variable These doses are for adults only; call pediatric pharmacy for peds doses (x77521)Anesthesia NPO for 8 hours prior to conscious sedation (2 hours for clear liquids). If patient is not NPO, can usually receive “single dose” sedation – either narcotic or sedative but not both General anesthesia, MAC, deep sedation (propofol) – done by anesthesiology, NPO for 8 hours priorTube care Any indwelling tube should be kept dry, in general, to avoid infection Drainage catheters, nephrostomy tubes, biliary tubes may need flushing with 5-10 cc sterile saline BID to help maintain patency – ask your attending Permacaths and temporary dialysis catheters are “locked” with full-strength heparin (1000 units/cc) using a volume sufficient to fill the catheter (printed on the catheter hub); if heparin-allergic, can use tPA at a concentration of 1 mg/mL to fill the catheter PICC lines, Portacaths, Hickmans are “locked” with diluted heparin (100-200 units/cc)Pain management/sedation
Narcotics (all doses listed are for approximate equivalent effect to 2 mg IV morphine) Morphine 2 mg IV = 6 mg PO; duration 4-5 hours; can cause Sphincter of Oddi spasm Dilaudid (hydromorphone) 0.3 mg IV = 1.5 mg PO; duration 4-5 hours Demerol (meperidine) 15 mg IV = 60 mg PO; duration 3-5 hours; often causes nausea, can cause seizures; good for post-procedure rigors; may be less likely to cause Sphincter of Oddi spasm Fentanyl 25 mcg IV; duration 1-2 hours Oxycodone (Oxycontin) 2-4 mg PO; duration 4-5 hours Vicodin RS (500 mg acetaminophen + 5 mg hydrocodone) = 1 tab (approx) Percocet (325 mg acetaminophen + 5 mg oxycodone) = ½ tab (approx) Narcotics are reversed with Naloxone (Narcan). Naloxone can be given IV in 0.4 – 2.0 mg increments for opioid overdose or respiratory/cardiac depression, with dose dependent on severity. 0.2 mg dose can be tried if only partial reversal is desired. Onset of action is 2-3 minutes. If no effect is seen, can repeat dose at several minute intervals. After reversal, keep in mind that the half life of naloxone is only about 60 minutes; so the naloxone may wear off before the narcotic! Sedatives: Versed – usually 1 mg to start, repeat as necessary. Sedative effects at 1-5 minutes, duration 2-6 hours. Benzodiazepines are reversed with flumazenil (Romazicon). Give IV in 0.2 mg increments, injecting over 15 seconds. Onset of action is about 1 minute. If no effect is seen, can repeat dose each minute up to 1.0 mg total dose. Most patients respond to 0.6 – 1.0 mg. Others: Benadryl – has some sedative effect to go along with its antihistamine effect Toradol – a powerful IV NSAID, particularly effective as an anti-inflammatory and often used post-UFEIV contrast: Omnipaque 350 – low-osmolar, cheaper Visipaque 320 – iso-osmolar, slightly more expensive, slightly less risk of contrast nephropathy and contrast reaction Premedication for contrast allergy: Prednisone 32-50 mg PO 12 hours prior and 2 hours prior to procedure; Benadryl 25-50 mg PO 2 hours prior to procedure.Risks to consent for (NOT a comprehensive list, consult your attending) All procedures: Infection, bleeding, target organ damage. Angio procedures: Contrast risks, vessel damage (hematoma, pseudoaneurysm, thrombosis, dissection). Lung procedures: Pneumothorax, systemic air embolism Embolization procedures: Nontarget embolization, post-embolization syndrome Sedation: Respiratory and cardiac depression, allergy PLUS procedure-specific risks: Biopsies: Nondiagnostic sample TACE: Hepatic failure, biloma/abscess GI embolization procedures: Bowel infarction Pelvic embo: Buttock claudication, rectal/bladder ischemia, impotence Biliary procedures: Biliary sepsis, bile leak GU procedures: Urosepsis RFA: Collateral damage to adjacent organs (especially bowel), biliary stricture, abscess, track seeding IVC filter: Migration, perforation, IVC thrombosis Thrombolysis: Severe bleeding including cerebral hemorrhage, reperfusion syndrome, distal embolization G tube: Tube malposition (in peritoneum or colon), bowel damage TIPS: Hepatic failure, encephalopathy, death Venous access (Port, Permacath, Hickman): Air embolism TJ liver biopsy: Capsular perforation (severe bleeding) UFE: Premature menopause, reduced fertility, fibroid expulsion (submucosal)
Radiation safety Most importantly, stand behind your fellow. Not behind me, as I will be standing behind both of you. Keep the image intensifier as close to the patient as possible to reduce scatter. Don’t forget your thyroid shield. Step out of the room, or at least away from the patient, when DSA runs are being performed (higher radiation than regular fluoro) Minimize fluoro in logical situations (don’t fluoro until the wire/catheter is nearing the field of view, etc) Use the hard cones/shutters to reduce radiation when full-screen exposure is unnecessaryLabs For outpatients, the usual lab orders are a CBC, PT/PTT/INR, and BMP. If it is a biliary or liver procedure add LFTs. For HCC cases an AFP may be useful as a pre-treatment baseline. Many patients have recent labs in the system so check PCIMS. Labs within 2 weeks or so may be sufficient, but it depends on the case and the patient. Certainly if the labs were abnormal or if the patient has been on anticoagulation then repeating labs would be prudent. INR: Should be <1.5 for most procedures. Can be repleted with FFP. If related to Coumadin therapy, can also be reversed with Vitamin K, but Vitamin K takes minimum 6-12 hours to begin to take effect. Quick chart on FFP reversal of high INR: Beginning INR How much each unit of FFP will lower the INR (mean) 4.4 – 20 3.5 3.0 – 4.3 0.7 2.4 – 2.9 0.4 1.7 – 2.3 0.2 1.3 – 1.7 0.1 Platelets: Should be >50-75 for most procedures. Can be repleted by giving platelet transfusion (one unit of single-donor platelets raises the platelet count by about 20, but effect is pretty variable). Also, platelets are suspended in plasma, so a unit of platelets gives you close to a unit of FFP. Creatinine: Depends on contrast load expected; higher creatinine increases risk of contrast nephropathy, particularly if dehydrated and in diabetics. In cases of renal insufficiency (Cr >1.5 or so) where more than a token amount of contrast is expected, it is prudent to pre-hydrate with IV fluids (NS is fine, be careful in CHF); additional reasonable measures include bicarbonate and Mucomyst. Bicarbonate protocol: 3 amps of NaHCO3 in 1 L D5W; administer at 3 cc/kg for the hour immediately prior to the procedure, then 1 cc/kg/hr during the procedure and 6 hours after. In diabetics, change the D5W to ½ NS. Mucomyst protocol: 600 mg PO BID the day prior and the day of the procedure Total bilirubin: Except in special circumstances, most liver RFA and TACE procedures are contraindicated by a total bilirubin >3. Be sure your attending is aware. Potassium: High or low potassium levels can predispose to arrhythmias including VFib and asystole. Normal is 3.5 – 5. Hyperkalemia: Particularly worrisome when the K exceeds 5.5-6. Treatment measures include: Insulin: Give 10 units regular insulin + 50 cc of 50% dextrose, moves K back into cells Bicarbonate: 1 amp over 5 minutes, useful when K is related to metabolic acidosis Albuterol: 10-20 mg inhaled by nebulizer, moves K back into cells, caution heart disease Kayexalate: 15-30 grams orally in sorbitol (or by enema), binds K in the gut, takes a few hours to work Calcium gluconate: 10 cc of 10% solution, preferably through a central catheter, decreases myocardial excitability
Furosemide: 40-80 mg IV, increases renal excretion of K (not for patients in renal failure) Dialysis: In patients with renal failure Hypokalemia: Particularly worrisome when the K is less than 3.0. Treat with IV and/or oral K.Dictations: Should be done the day of the procedure whenever possible. PROCEDURE TITLE: Date CLINICAL HISTORY: Be as complete as possible, and be sure you answer why the procedure is needed. INTERVENTIONALISTS: List attending first. CONSENT: After the risks, benefits and alternatives were discussed with the patient, including the likelihood of technical success, and all of the patients questions were answered, written informed consent was obtained for both the procedure and for conscious sedation. SEDATION: Conscious sedation in the amounts of _ mg Versed, _ mcg Fentanyl was administered by the IR nurse, under continuous monitoring by the IR team, including the attending physician. Total duration of time conscious sedation was administered was _ minutes. OTHER MEDICATIONS: Antibiotics, Nitro, etc. CONTRAST: Volume and type. FLUOROSCOPY TIME: PROCEDURE SUMMARY: Numbered list of procedures performed. TECHNIQUE: Be descriptive and complete. FINDINGS: The findings of every relevant picture or run should be described. IMPRESSION: Tie things together, draw conclusions. DISPOSITION: Immediate plan for the patient and follow-up.Achieving hemostasis Arterial puncture: At least 15 minute continuous hold (longer in some circumstances). Most recommend occlusive or near-occlusive pressure on the artery just above and at the access site for the first couple minutes, then slight decrease in pressure so you can feel the thrill of arterial flow beneath your fingers for the remainder of the hold. Remember that the arteriotomy is usually at least 1 cm or so above the skin nick. Release of pressure after 15 minutes should be gradual, not sudden, so as to not dislodge the platelet plug. If there is continued oozing after 15 minutes, pressure should be re-applied; avoid releasing and checking every few minutes. V-pad may be helpful in patients where hemostasis is a concern. Venous puncture: Usually 5-10 minutes is sufficient, depending on the size of the venotomy and clotting status of the patient.Sheaths versus catheters versus guide caths versus microcatheters Sheaths are sized according to what fits through them. So, a 5 French sheath will accommodate a 5 French catheter through it; the outer diameter of a 5 French sheath is between 6 and 7 French. Catheters are sized by their outer diameter. Catheters have a relatively small inner diameter which only accommodates wires and microcatheters. Guide caths are sized by their outer diameter. They have thinner walls and larger inner diameters to allow passage of balloons, stents, etc. Usually the inner diameter is 1-2 French smaller than the listed size of the guide cath; so a 7 French guide cath can accommodate a 5 French catheter. Microcatheters are usually sized by their inner diameter, in inches. Progreat is a 0.028, for example. Microcatheters pass through 5 French catheters, and some pass through 4 French catheters.Reading list (pick 1 or 2) “Handbook of Interventional Radiologic Procedures” by Kandarpa “The Requisites: Vascular and Interventional Radiology” by Kaufman and Lee “Vascular and Interventional Radiology” by ValjiPhone numbers Charge nurse IR3: 310-267-8754
Santa Monica angio: 310-319-4602 st 1 floor CSIR scheduling (Myrna’s desk): x78743 CSIR Charge nurse: x79772 (usually Pat) Beth: x78770 Jackie/Gina (scheduling OP angio cases for WW and SMH): x78751 st IR clinic (1 floor of MP 100) and Ronetta: 310-481-7545 Fax number for angio requisitions: x73891 Fax number for CSIR requisitions: x72694Resident testimonials by some of our success stories:OverviewThe IR rotation at RRH is busy. Dont be fooled by the printed schedule. Add-ons are common, and staying until 7-8pm is the norm. Residents are responsible for all of the cases in room IR1, which may be overwhelming, but itreally is the best way to experience interventional radiology.[Santa Monica and VA: the resident works closely with the fellow on these rotations. This is a great opportunity tolearn bread and butter techniques, and fellows will serve as crucial resources. Ask them to show you the variouswires and catheters that are used, how to consent patients, how to manage the workflow, etc. Once fellows arecomfortable, they will often guide you through various procedures, with the attending observing from outside.]LogisticsArrive at 6:45 am (earlier if you need to write orders, consent or follow-up on inpatients). Pick up the daysschedule from the front desk. You are responsible for making sure that your room runs smoothly. Prior to eachprocedure and as early as possible: consent patients, check labs and imaging, coordinate with anesthesia (ifnecessary) and the rest of the IR team, such as the tech and the nurse.On Wednesdays, lectures begin at 7:00 am. On Thursdays, case conferences begin at 7:30 am. Both are in theconference room by the IR office in RRH.[Santa Monica and VA: not too different from Westwood. Just touch base with your fellow at the end of each dayand make sure you are both on board with what needs to be done. ]Tips*Each night, read up on at least one procedure that you will perform the next day. Kandarpas handbook for IR isespecially practical and useful. Important things to pay attention to arent so much the technical aspects of theprocedure itself, but: the clinical indication, contra-indications, major and minor complications, routine pre andpost-procedure care, such as prophylactic antibiotics and wound care. Knowing these facts will also facilitateconsenting patients.*Review the anatomy relevant to the procedure you are performing. Also always look at prior imaging studies foreach patient.*Use index cards to keep track of your patients. This is an easy way to follow-up on patients and to have a recordof the cases you performed. Also, some patients are repeat fliers, and having their information at your fingertipswill also improve your efficiency and the workflow.Possible format:HEADING: date, patients name, MRN, pt location, procedure, attending.ALLERGIES:BODY: short and pertinent clinical history, indication for procedure, prior IR proceduresOBJECTIVE DATA: pertinent imaging and labs, particularly CBC, Creatinine, Coags; some procedures will also haveother pertinent labs, such as LFTs for TACE.FOLLOW-UP: follow-up on your patients. If they are inpatients, check up on them the next day. If they have been
discharged, followthem up on PCIMS and make sure there are no complications.*Not mandatory, but try to help out the fellows as best you can. This could entail consenting their patients, jottingdown a short note for them, or writing the pre-orders for their next days patients. Talk to the fellows, befriendthem, and see what you can do to make everyones lives easier. It makes for a more collaborative environment,and youll often find that fellows will return the favor.*There is a huge learning curve the first week. The first few times, try and shadow the techs when they prep thepatient and the table. Also, to get a better sense of the technical aspects of IR, try not to rely too heavily on themacros on powerscribe. Instead, print out the templates, and read out the entire dictation. This is a really goodway to remember the steps, wires, catheters, sheaths, etc that are commonly used.*To help the day run smoothly, do as much as you can the day/night prior. This often entails consenting patientsand checking labs/imaging.*scrub in! if there is nothing going on in your room, ask the fellow if you can scrub into their case. Assist whennecessary, but keep in mind that it is the fellows room, and they should be allowed to direct the case. Fellowsshould also show you the same regard.*In many respects, being an IR resident requires that you tap into your intern skills. Figure out what you need to doto make things happen. Also, as best as you can, try to empathize with your patients. Many of them are nervousand need reassurance. As little as 5 extra minutes at the bedside can be enough to assuage their fears and buildrapport.Tips from a second success story:IR is different from any diagnostic radiology rotation. Treat it as you would any surgical rotation that you did inmedical school. This means a couple of things:-Develop a list of patients that you are following with their labs, important info, prior procedures, check boxes ofwhat needs to be done, prior imaging etc-Round on pts in the morning before you start your procedures-Know important info about each pt, meds, vitals, important labs, allergies (keep this in mind when prescribingabx) etc.-I prefill out the H&P with all the info I can find in PCIMS the day before so I can just go in and just verify the infoand do the physical. Also this helps me know everything that could be going on with the patient well in advance.-do everything that you can yourself, even if that means helping the tech or nurse. This will help you learn thebasic things too.-If there is a central line on the floor ie-emergency line in the MICU that they call you about because they cant getaccess, take the ultrasound machine up and go do it (check with attending first). Struggling with the little issuesthat may come up with things like this will teach you how to troubleshoot your way out of situations later.-Dont be afraid to be the clinician. If the BP is up, know how to deal with this (we were all interns once,remember?). Rx some labetalol or nitropaste, or whatever you like to use.-If you have a pt that has had a major procedure (not necessarily ports or permacaths), go and round on themagain before you leave at night.-Remind yourself how to do physical exams (ie-TACE pts- palpate the RUQ, ck for asterixis, etc) and write notes inthe chart if you get a chance.
Basic cathetersSos Omni: For visceral selection, particularly SMA and other acutely angled arteries.Omniflush: For nonselective angiography and selection of contralateral iliac artery.Cobra: For basic visceral selection, particularly celiac and renals.Mickelson: For more difficult selections, particularly bronchials, intercostals and lumbars. Must be reformed.Simmons: Excellent stability for difficult selections. Must be reformed.Progreat microcatheter: 0.028” inner diameter, OK for gelfoam if cut small or well slurried, great for particles upto 900 microns, not as great for 0.018” coils which sometimes (rarely) get bound up in the catheter.Renegade microcatheter: 0.021” inner diameter, a bit small for gelfoam, OK for particles up to 700 microns, goodfor coiling, slightly smaller OD so can get into smaller vessels slightly easier than Progreat
035 wires (in approximate order of most to least used)Amplatz – stiff wire with a floppy straight tip. Great for exchanges, drain placements, also good as a working wirefor vascular interventions. Stiffness can help straighten out tortuous anatomy.Bentson – low-medium stiffness, very floppy tip straight tip, atraumatic. Often used for vascular access, catheterexchanges, etc.Glide – medium stiffness, angled or straight tip, hydrophilic. You can get anywhere you want to go with this wire.You also can get lots of places you don’t want to go. Handle with care to avoid dissection. Not ideal for exchangesas it easily slips between fingers.Rosen – medium stiffness, J tip. Often used as a working wire for vascular interventions (stents and balloons) dueto the atraumatic tip and good stiffness.Stiff glide – same as a glide, but stiffer, and gets even more places you don’t want to go. I like it for GJ exchangesand Permacath exchanges as the smooth hydrophilic surface and stiff body make these long tubes glide in easily;but, keep a good grip on it!Roadrunner – similar to a straight stiff glide, but with a tapered tip. Nice for occlusions that refuse to be crossedany other way.Coons – basically like a stiffer Bentson. Often used for biliary drain exchanges.J wire – comes with the Accustick set, has low-medium stiffness and a J-shaped tip. It is too soft to be a goodexchange wire in my opinion, but may be useful in collections which are too small to get an Amplatz to coil into.Lunderquist – the “coat hanger”. A very stiff wire. Rarely used outside of aortic interventions where extremestiffness is necessary.014 microwiresTransend – good first choice wire, not too expensive, pretty directable, is the only wire needed in mostmicrocatheterizationsSynchro – expensive, extremely floppy and directable tip, if you can’t get somewhere with this wire you probablyjust can’t get thereFathom (actually an 016 wire) – supposedly combines some of the good features of the preceding two wires; Ihave not yet been impressed.018 microwiresCope – comes with the micropuncture kit. Atraumatic, but the spring coil tip is kind of rough and can get caughton the needle, may not advance smoothly, etc.Nitrex – longer than the Cope wire, with more body and a smoother tip. Good choice if the Cope wire isn’t doingwhat it’s supposed to.
Resident Survival Guide to the UCLA CSIR RotationDaily Responsibilities:1) Familiarize yourself with all scheduled cases either the night before or first thing in the morning. Obtain a copy of the scheduled cases for the day from the nurses binder Preview requisition and imaging for all scheduled cases and plan approach2) Consent patients a) The first case usually starts at 7:30 am so consents should be obtained by 7:15 am. b) Prior to seeing the patient, you should: Review the requisition to understand what the referring MD is asking for Review prior imaging Review the medical record Check labs and medications (Inpatients: check cView, Outpatients: ask the patient for their list) c) During the patient encounter, you should: Explain the procedure Detail the benefits and risks Assess for comprehension and answer any questions Review medications, allergies, and obtain H&P if needed3) Complete pre-procedure paperwork. a) Prior to starting the procedure, the following should be completed: H&P short form (not needed if there is an H&P with ROS in the medical record within one month from the date of procedure) Procedure consent Sedation consent Blood transfusion consent (when necessary) Top portion of the procedure note FNA cytopathology, surgical pathology, microbiology, and chemical analyses forms when needed Time out Make sure patient has received appropriate antibiotics, transfusion, etc when necessary4) Scrub in, prep patient, and observe, assist or perform the procedure.5) Complete post-procedure paperwork. a) At the end of the procedure, the following should be completed: Procedure note including: instruments and materials, ablation/specimen description (location, number, volume, analyses requested) Post-procedure orders Dictation: include medication doses, monitored time, fluoroscopy time6) Discharge patient: a) While the patient is being observed in PTU: Review post-procedure imaging (CXR after lung biopsies, MRI after liver/renal RFA) Review results of the procedure with patient and family. b) In consultation with the attending, patients may be discharged if they meet the discharge criteria: Vitals stable, pain well-controlled, able to tolerate PO’s, ambulating c) Give patient instructions: wound care, tube care, pain management, follow-up instructions, return precautions7) Triage new requests throughout the day with fellow Review the requisition Review the imaging and patient record Review labs, meds, time of last PO intake Present case to attending and plan approach8) Sign pre-op orders for the following day’s scheduled cases
9) Sign out to the on-call IR fellow if necessary10) Optional: Ask US techs to page you for thoracenteses and paracenteses11) Optional: Attend clinicConferences: IR Didactics: Wednesday 7:00 am, IR conference room IR Interesting Cases: Thursday 7:30 am, IR conference room GI Interesting Cases: Friday, 8:00 am, RHH 1621 Ablation Conference: Every other Friday, 12:00 pm, RRH 1621 Hepatobiliary Interdisciplinary Conference: Every other Wednesday, 5:30 pm, Radiation Oncology Conference Room, MP 200, B2 LevelReading:1) Texts: Valji, K. Vascular and Interventional Radiology. W. B Saunders, Philadelphia, 2006. Kaufman, J.A. and Lee, M.J. Vascular and Interventional Radiology: The Requisites. Mosby, 2004.2) Liver Ablations Clark et al. Staging and Current Treatment of Hepatocellular Carcinoma. RadioGraphics 2005 25:S3-S23. Mendiratta-Lala, et al. Strategies for Anticipating and Reducing Complications and Treatment Failures in Hepatic Radiofrequency Ablation. RadioGraphics 2010. Park et al. Spectrum of CT Findings after Radiofrequency Ablation of Hepatic Tumors. RadioGraphics 2008 28:379-390.3) Renal Transplants Kobayashi et al. Interventional Radiologic Management of Renal Transplant Dysfunction: Indications, Limitations, and Technical Considerations. RadioGraphics 2007 27:1109-1130.4) Renal Ablations Zagoria RJ. Imaging-guided Radiofrequency Ablation of Renal Masses. RadioGraphics 2004 24:S59-S71. Wile et al. CT and MR Imaging after Imaging-guided Thermal Ablation of Renal Neoplasms. RadioGraphics 2007 27:325-339. Kawamoto et al. Sequential Changes after Radiofrequency Ablation and Cryoablation of Renal Neoplasms: Role of CT and MR Imaging, RadioGraphics 2007 27:343-355.5) Lung Interventions Gupta et al. Imaging-guided Percutaneous Biopsy of Mediastinal Lesions: Different Approaches and Anatomic Considerations. RadioGraphics 2005 25:763-786. Dupuy et al. Clinical Applications of Radio-Frequency Tumor Ablation in the Thorax. RadioGraphics 2002 22 :S259-S2696) Drains: Maher et al. The Inaccessible or Undrainable Abscess: How to Drain It. RadioGraphics 2004 24:717-735 Harisinghani et al. CT-guided Transgluteal Drainage of Deep Pelvic Abscesses: Indications, Technique, Procedure-related Complications, and Clinical Outcome. RadioGraphics 2002 22:1353-13677) Biopsies: Gupta et al. Various Approaches for CT-guided Percutaneous Biopsy of Deep Pelvic Lesions: Anatomic and Technical Considerations. RadioGraphics 2004 24:175-189Thanks to Sophie Chheang, MD; Amy Asandra, MD; and Mailan Cao, MD for their contributions to this guide.