Nick's Radiology Wiki

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====== Post-Traumatic Vascular Injury ======

===== CXR Signs =====
  * wide mediastinum
  * filling in of AP window
  * depressed L mainstem
  * rightward displacement of trachea or NG tube
  * L apical cap
  * L effusion
  * L upper rib fxs

===== Most Common Locations for TAI =====
  * Aortic root
  * Isthmus
  * Aortic hiatus

===== Classification of Dissections =====
| |{{db1.png}}|{{db2.png}}|{{db3.png}}|
| Percentage |  60%  |  10-15%  |  25-30%  |
| DeBakey |  I  |  II  |  III  |
| Stanford |  A  ||  B  |
| |  Proximal  ||  Distal  |
====== Aortic Aneurysms ======
  * CT signs of impending rupture
    * high attenuation crescent between intraluminal thrombus and the wall
====== Types of Endoleaks ======
  * Type 1 - bad seal @ prox/distal end
    * treatment is emergent
  * Type 2 - endoleak via IMA or lumbar collaterals
  * Type 3 - leak thru internal seal
  * Type 4 - porosity of graft
    * resolves spontaneously
  * Type 5 - endotension
    * sac not getting smaller, but no leak

====== Takayasu's ======
  * dilation or irregularity of the ascending aorta
  * narrowing of the descending artery
  * long stenoses or occlusions of arch vessels (especially the subclavian)
  * CT/MR show enhancement of the artery wall in the acute phase
  * angioplasty and stent should be delayed until the disease is inactive if possible
  * Type 1 -> stenoses of aortic arch and branch vessels
  * Type 2 -> descending thoracic and abdominal aorta + abdominal branches
  * Type 3 -> aortic arch plus abdominal aorta
  * Type 4 -> pulmonary artery and aorta

====== Giant Cell Artieritis ======
  * affects older women, and usually involves the temporal artery
  * involves the distal subclavian or axillary arteries, but not the brachiocephalic, common carotids or proximal subclavians
  * lesions are long and smooth

====== DDx Midaortic Stenosis ======
  * Midaortic stenosis
    * noninflammatory nonatheromatous vascular d/o
    * can cause renal artery stenosis
  * Takayasu's
  * Radiation induced
  * Neurofibromatosis
====== Aortic Occlusion ======
===== Collateral Pathways =====


===== Contraindications =====
  * recent surgery (intracranial, abdominal, or thoracic)
  * recent GI bleed
  * recent stroke or CNS neoplasm
  * recent major trauma
  * pregnancy
  * severe HTN
  * bleeding diathesis
  * infected thrombus
====== TIPS ======
===== Indications =====
  * variceal bleeding that cannot be treated medically (acute or chronic)
  * intractable ascites
===== Contraindications =====
==== Absolute ====
  * polycystic liver disease
  * severe R heart failure
  * severe hepatic failure
==== Relative ====
  * severe hepatic encephalopathy
  * hypervascular liver tumor
  * portal vein thrombosis
  * severe acute infection

===== Technique =====
  * Do u/s first to assess PV patency, flow direction, status of hepatic veins, degree of ascites, and eval for liver tumor
  * Check coags and correct w/ FFP
  * Broad spectrum antibiotics
  * 10Fr sheath RIJ and assess RA and IVC pressures
  * Measure wedged hepatic vein pressure which will equal PV pressure, subtract the IVC pressure to get gradient
  * Insert needle
  * Opacify the portal vein via a wedged contrast injection
  * Stick the needle anteromedially into the right portal vein
  * Needle is then withdrawn a bit until you get blood back
  * Inject contrast to check your position
  * Advance a guidewire into the PV and then to the splenic vein or SMV
  * Dilate the parenchymal track with a 10mm balloon
  * Place 10 or 12 mm Wallstent so that one end is within 3 cm of the portal bifurcation, and the other within 3cm of the IVC
  * Dilate tract with a 10mm balloon
  * If gradient remains (>12mm Hg), redilate w/ 12mm balloon
  * If gradient persists, can employ parallel stent or embolize varices

====== Paget-Schroetter Disease ======
  * Best seen w/ provocative maneuver such as hyperabduction
===== Causes =====
  * cervical rib
  * congenital fibromuscular bands
  * 1st rib anomalies
  * muscle hypertrophy
  * clavicle fxs

===== Management =====
  * If severe or pt has embolization, then correction of underlying abnormality is recommended

====== Colonic bleed ======
  * Causes of lower GI bleed:
    * diverticular dz
    * angiodysplasia (dilated submucosal veins and capillaries in the bowel wall)
    * post biopsy or polypectomy
    * tumors
    * polyps
    * IBD
    * ischemia
  * Patients with a positive Tc RBC or SC scan should undergo angio
  * Sensitivity:
    * angio - 0.5cc/min
    * Tc RBC - 0.1cc/min
  * Most likely vessel, based on nucs scan, should be injected 1st
  * Otherwise SMA then IMA, and if both negative, then celiac
  * In angidysplasia, a bleeding vessel is usually not seen
    * instead, you see early venous drainage from one portion of the bowel, or a tram track sign from simultaneous opacification of a feeding artery and draining vein
  * Treatment:
    * vasopressin - 0.2 units per minute
      * after 30 minutes a repeat angiogram is done, the infusion is continued at that rate with the pt in ICU
      * if persists, increase to 0.4u/min and repeat angio in 30 minutes
      * if still bleeding, need to pursue other methods
      * rebleeding is common
      * Contraindications: severe coronary artery dz, severe HTN, dysrhythmias, bleeding at sites with a dual blood supply, bleeding directly from a large artery (eg spl artery aneurysm) and after embolotherapy
      * Side effects: bowel ischemia, angina, arrythmia, HTN, bradycardia, and allergy
    * embo - performed with macrocoils or microcoils and gelfoam
      * embo usually does not work long term for angiodysplasia or AVM, these will require surgery
      * placed distally in the arcades proximal to the bleeding vasa recta to minimize intestinal ischemia
      * inject the proximal vessel to make sure there is no bleeding thru collaterals
      * complictions include bowel infarct <20%

====== Pulmonary Embolism ======
  * Primary finding - intraluminal filling defect at least partly surrounded by contrast
  * Secondary signs - vessel cutoff, regional hypoperfusion, pruning of vessels, slow flow, and filling of collaterals

===== Technique =====
  * check for LBBB & use pacer if present
  * also check u/s for groin clot
  * check PA pressures before injecting main PA; cut back on injection if pressures are elevated
====== Transhepatic Cholangiogram ======

===== Procedure =====
  * Start w/ antibiotics to include gram negative coverage - one hour prior to any biliary work
  * Right sided approach:
    * 22G Chiba needle is placed in the midaxiallry line below the 10th rib (to avoid the pleura)
    * fluoro is used to check the position of the pleura in full inspiration, so that it may be avoided
    * needle is passed over a rib, to avoid injury to the nerves and vessels which run on the undersurface
    * needle is directed toward a plane parallel to the table top aimed toward T11
    * remove the stylet and inject 0.1cc of 60% strength contrast while slowly retracting the needle
    * when contrast fills a tubular structure and stays there, you are likely in a bile duct, and you should remove 5-10 cc of bile and send for gram stain and culture
    * then inject an additional 5-10cc contrast to confirm and determine duct diameter and location relative to porta hepatis
  * Left sided access:
    * from a left subcostal approach in the epigastrium
    * US is used to access a bile duct while avoiding artery and portal vein
  * Treatment:
    * pass a 0.018 wire thru the chiba needle you used for the THC, then exchange for a .038 wire, and advance a catheter over that wire
    * a dominant proximal stricture can be angioplastied
    * stents can be used for malignancy b/c the pts life expectancy is short and the stent will likely last as long as the pt needs
    * for benign dz, stents should only be used for pts who are not operative candidates and who failed angioplasty
    * a wallstent is the stent of choice

====== IVC Filter ======
  * 

===== Contraindications =====
  * IVC thrombosed
  * pregnancy (clot may come from ovarian veins)
    * place suprarenal filter

====== Nephrostomy ======

===== Technique =====
  * check labs; stop anticoagulants
  * prophylactic antibiotics 1hr preprocedure (ancef 1g and gentamycin 80mg or specific to the organism)
  * place pt prone and select puncture site (4 fingers from midline, just below 11th rib)
  * start by puncturing collecting system with a 22G Chiba needle and opacifying collecting system
    * aspirate urine for culture and remove urine before injecting contrast to minimize sepsis risk
  * choose best entry site under fluoro:
    * for simple decomression, it is safest to puncture a lower pole calyx b/c that has the lowest risk for PTX
    * if ureteral stent placement is planned, then go for an interpolar calyx to get an easier angle to get the catheter down the ureter
    * puncture at least 12 cm lateral to midline in order to avoid going thru paraspinal muscles
  * puncture a posterior calyx (know posterior b/c seen en face in AP plane, or can inject air) with an 18G needle
    * posterolateral approach, with needle angled 40 degress from vertical is best (Brodel’s avascular line)
  * if infected, initially just decompress, do not manipulate more until infection is treated
  * place a stiff amplatz .035 down into ureter
  * the tract is dilated, and a 10 fr pigtail is placed over the .035 wire and locked into position by forming the pigtail
  * secure to skin with adhesive dressing or suture.

====== Signs of Leg Ischemia ======
  * hair loss
  * nail changes
  * purple toes
  * skin loss
  * ulcers

====== Sources of Hemoptysis ======
===== Bronchial Artery =====
  * Cystic Fibrosis
  * Infection
  * Bronchiectasis
  * Tumor
==== Technique ====
  * place the catheter deep into the abnormal bronchial artery
  * if you can not get deep with your initial catheter, place a coaxial microcath thru it to go out deeper
  * findings in pts with a bronchial artery bleed include eenlarged bronchial artery, hypervascularity, parenchymal stain, amd bronchial to pulmonary artery shunting
  * contrast extrav is not usually seen, and is not necessary for treating
  * look for the small branches to the anterior spinal artery which arise form the proximal portion of the vessel and take a hairpin turn going 1st superior and then inferior toward midline
  * if there is a spinal artery branch, some people wont embolize, but some will embo if they can get the catheter well beyond the branch
  * embo agent is PVA (medium sized particles) or gelfoam
  * if no bronchial or collateral bleeding source is found, then you have to inject the pulmonary arteries
===== Pulmonary Artery =====
  * Rasmussen Aneurysm
  * Pulmonary AVM
    * Unlike other AVM's, as there is no real nidus
    * Therefore, it is the only AVM where you embolize the feeding vessel
    * Use coils!
  * PA Pseudoaneurysm
====== TPA Thrombolysis ======
  * Dose = 0.5 mg/hr infusion
  * No bolus needed

===== Contraindications =====
  * Motor weakness in extremity
    * Do not want to perfuse dead tissue

====== Popliteal Artery Disease (ABCDE) ======
  * Atherosclerotic disease / Aneurysm
  * Buerger's disease
    * corkscrew vessels
  * Baker's cyst
  * Cystic adventitial disease
    * cysts in vessel wall on IVUS
  * Dissection
  * Entrapment
    * induced by plantarflexion or forced dorsiflexion of foot
    * caused by abnormal relationship with medial head of gastrocnemius
====== General Technique ======
===== Seldinger =====
  * 18G - .035 wire
  * 22G - .018 wire
===== Stenting =====
==== Good Locations for Covered Stents ====
  * SFA
  * TIPS
  * Lacerated vessel
===== Embolization =====
  * always use medium size particles
  * 500-700 microns
===== Vasopressin =====
  * Done from origin of vessel
  * Usually only if embo is not possible
===== TPA Infusion =====
  * place multisidehole catheter across occlusion
  * 2mg initial TPA bolus
  * then infuse 1mg/hour
  * f/u angiogram in 12hrs
    * treat residual stenosis w/ angioplasty
  * give heparin prior to thrombolysis
    * 5000U bolus then 1000U/hr infusion
====== Anatomy ======
===== Celiac =====
{{celiac.gif}}

===== SMA =====
{{sma.jpg}}

===== Adrenal =====
{{adrenalbs.jpg|Three blood supplies to the adrenal:
  * superior adrenal artery from the inferior phrenic artery
  * middle adrenal artery form the aorta above the renal artery
  * inferior adrenal artery from the proximal renal artery}}

Hover over image for info

===== Run-off =====
{{antro.gif|Anterior View}}{{postro.gif|Posterior View}}