Urologic and Nephrological Imaging PDF

Urologic and Nephrological Imaging Morgan Davis, PA-C, MPAP Campbell PA 2015 UROLOGY V. NEPHROLOGY Urology - Surgical specialty - Structure - Surgical correction of diseases that affect function - Entire urinary tract Nephrology - Medical specialty - Function - Diseases that affect function UROLOGY...

Urologic and Nephrological Imaging Morgan Davis, PA-C, MPAP Campbell PA 2015 UROLOGY V. NEPHROLOGY Urology - Surgical specialty - Structure - Surgical correction of diseases that affect function - Entire urinary tract Nephrology - Medical specialty - Function - Diseases that affect function UROLOGY IS THE BEST! TOOLS OF THE TRADE X-RAY TECHNOLOGY KUB Intravenous Pyelogram (IVP) Voiding Cystourethrogram (VCUG) Retrograde Pyelogram (RGP) Renal Angiogram KUB (kidneys, ureters, bladder) KUB TECHNIQUE - Patient usually supine - 2-3 images PATIENT EXPECTATIONS - No prep work - Remain clothed, remove jewelry - Hold breath - Quick and painless INDICATIONS - Abdominal pain (outpt) - Kidney stones - Osseous abnormalities - Preliminary radiograph in series CONTRAINDICATIONS - Pregnancy PROS - Patient comfort - Minimal radiation CONS - vague, nonspecific - Constipation is a killer!! Bowel prep?? - No soft tissue evaluation Patient staghorn calculus Patient foreign body INTRAVENOUS PYELOGRAPHY (IVP) INTRAVENOUS PYELOGRAPHY TECHNIQUE - Patient supine, IV - KUB  IV contrast bolus  series of radiographs at timed intervals PATIENT EXPECTATIONS - Prep= +/- bowel prep - Warm feeling, flush, itch, nausea with IVc - Duration varies INDICATIONS - Hematuria - Recurrent UTI - Flank pain - Obstructive uropathy CONTRAINDICATIONS - Pregnancy - IVc allergy, iodine, shellfish - CKD, Cr > 2.0 PROS - Minimal radiation - Internal urinary tract CONS - BETTER IMAGING EXISTS INTRAVENOUS PYELOGRAPHY TECHNIQUE - Patient supine, IV - KUB  IV contrast bolus  series of radiographs at timed intervals PATIENT EXPECTATIONS - Prep= +/- bowel prep - Warm feeling, flush, itch, nausea with IVc - Duration varies INDICATIONS - Hematuria - Recurrent UTI - Flank pain - Obstructive uropathy CONTRAINDICATIONS - Pregnancy - IVc allergy, iodine, shellfish - CKD, AKI, Cr > 1.9 PROS - Minimal radiation - Internal urinary tract CONS - BETTER IMAGING EXISTS IVP with obstructing bladder tumor Obstructed IVP Bladder tumor filling defect VOIDING CYSTOURETHROGRAM (VCUG) VOIDING CYSTOURETHROGRAM (VCUG) TECHNIQUE - Pt supine; Urinary catheter in place - KUB contrast media instilled into bladder pt voids under fluoroscopy PATIENT EXPECTATIONS - Undressed, in gown - Females: frog leg position - Catheter placed per urethra - Remain still - Contrast media flows into bladder causing fullness - Urinate when instructed - 30 minutes VOIDING CYSTOURETHROGRAM (VCUG) INDICATIONS - Young child with recurrent UTIs - Known vesicoureteral reflux-monitoring or post surgical correction PROS - Minimal radiation exposure compared to CT - Detailed imaging of lower urinary tract - Best (only) test for reflux CONTRAINDICATIONS - Pregnancy - Shellfish, iodine or contrast medium allergy CONS - Radiation exposure - Catheter insertion can be uncomfortable - UTI post-procedure VOIDING CYSTOURETHROGRAM (VCUG) RETROGRADE PYELOGRAM (RGP) RETROGRADE PYELOGRAM (RGP) TECHNIQUE - Anesthesia required - Cystoscopy  ureteral catheters KUB directly into ureters during fluoroscopy contrast media instilled PATIENT EXPECTATIONS - Prep is similar to a surgery +/- bowel prep - Cystoscope will be placed per urethra and small catheters in ureters. All removed prior to recovery - Mild hematuria, dysuria after procedure is common RETROGRADE PYELOGRAM (RGP) INDICATIONS - Suspected or known ureteral obstruction - Known filling defect from prior CT imaging - Unable to perform CT urography CONTRAINDICTIONS - Recent barium enema or swallow - Pregnancy (sort of ☺) PROS - Less radiation than CT scan - Can be unilateral CONS - Anesthesia and an OR visit - Increased risks: - post-op UTI - If Bacteruria present, prior to procedure, can cause sepsis - Risk of bladder or ureteral tearing RGP on right side with extravasation of contrast– ureteral injury RENAL ANGIOGRAM RENAL ANGIOGRAM TECHNIQUE - Injection of dye directly into a renal artery - Peripheral access in groin aorta renal artery - Series of X-rays and fluoroscopy used to watch dye illuminate the renal artery. PATIENT EXPECTATIONS - NPO 6-8 hr prior - IV sedation - Access site will be numbed before catheter inserted. - Cannot feel catheter moving to artery - Pressure dressing applied to access site - Keep leg straight for 4-6 hours post procedure RENAL ANGIOGRAM INDICATIONS - Usually performed as a confirmatory test after CTA or renal Doppler shows an abnormality. - Look for: aneurysm, clot/blockage, AVM, site of active renal bleed, renal artery stenosis - Patient with unexplained high blood pressure, nonresponsive to multiple medications CONTRAINDICATIONS - Pregnancy - Therapeutic on anticoagulant or antiplatelet therapy - Bleeding disorders - IVc allergy - CKD, AKI or Cr > 1.9 RENAL ANGIOGRAM PROS - Very specific and detailed - Less radiation exposure compared to CTA - Can often perform treatment procedures at the same time CONS - Bruising and bleeding at insertion site - Perforation of an artery - Infection - Patient discomfort - IV contrast exposure higher than CTA - CTA and MRA are better initial tests. RENAL ANGIOGRAM IV (or arterial) CONTRAST Contrast medium is an iodine based compound used to illuminate vessels, organs, intraluminal spaces during X-ray and CT studies - Appears opaque (white) on images Processed/eliminated by the kidneys Can temporarily decrease renal function; Need Cr < 1.9 Risks: - Shellfish allergy patients - CKD or AKI (Creatinine needed prior to study) - Diabetics on metformin - CONTRAST INDUCED NEPHROPATHY CONTRAST INDUCED NEPHROPATHY (CIN) Impairment of kidney function after administration of IVc - >50% or 0.5 increase in Creatinine from baseline - Occurs within 48-72 hours - CKD or diabetic patients are at greatest risk - Patients with both at a 4x greater risk - Metformin needs to be held for 48h post contrast regardless of Creatinine - Build up of metformin= lactic acidosis - Other risk factors include osmolality and volume of contrast, patient age PATIENT DOES NOT NEED ANY RISK FACTORS TO HAVE A CONTRAST INDUCED NEPHROPATHY ULTRASOUND Renal Ultrasound Scrotal Ultrasound RENAL ULTRASOUND Normal renal US picture Doppler RENAL ULTRASOUND TECHNIQUE - Ultrasound transducer directly on skin - Transducer sends sound waves into body, measures the rebound (echogenicity) - Hyperechoic= stones, bones, solid tumors - Hypoechoic= fluid filled cysts - Color Doppler assesses blood flow PATIENT EXPECTATIONS - Mainly clothed, exposed area of interest - 30 minutes on average, painless - Arrive with full bladder, then void (in a restroom) for post-void residual RENAL ULTRASOUND PROS - Great at evaluation of: renal size, renal parenchyma, characterization of renal lesions, bladder volume, bladder mass or bladder stones - Easily evaluates renal cysts for size and character (fluid v. solid v. abscess) - Doppler= renal vessels, renal masses - Patient satisfaction: comfortable, quick, painless, no radiation exposure - Only option for pregnant patients CONS - Tech dependent - Body habitus - Cannot evaluate ureters or surrounding anatomy - If abnormality, will need CT scan RENAL ULTRASOUND INDICATIONS - Test of choice for evaluation of renal failure - Test of choice for unexplained AKI - Obstruction v. medical renal disease v. renal artery stenosis - Pregnant female!!! - Children: - Suspected renal stones, renal cysts or palpable abdominal mass (Wilm’s tumor) - Renal Masses: less specific than CT - Characterization: cyst v. solid - Screening test of choice for suspected PCKD - Renal transplant monitoring - Microhematuria - No risk factors for GU malignancy CONTRAINDICATIONS - No real contraindications - Caution with large body habitus - Caution with gross hematuria - Caution with nonspecific symptoms RENAL ULTRASOUND Renal ultrasound with renal mass SCROTAL ULTRASOUND SCROTAL ULTRASOUND TECHNIQUE - Similar to renal US PATIENT EXPECTATIONS - Scrotum will be exposed - 30 minute exam - If already having testicular pain, pressure of the transducer can cause pain INDICATIONS - Testicular pain - Palpable mass - Scrotal edema - Scrotal trauma - Scrotal abscess - TEST OF CHOICE FOR TESTICULAR CANCER AND TESTICULAR TORSION CONTRAINDICATIONS - none PROS - Best imaging study for this area of the body - Patient comfort - No radiation CONS - none SCROTAL ULTRASOUND SCROTAL ULTRASOUND COMPUTED TOMOGRAPHY STUDIES CT ABDOMEN AND PELVIS WITHOUT CONTRAST CT ABDOMEN AND PELVIS WITH CONTRAST CT UROGRAM- WITH AND WITHOUT CONTRAST (Hematuria protocol, Triphasic CT) CT ANGIOGRAM CT WITHOUT CONTRAST CT WITHOUT CONTRAST TECHINQUE - Beam of X-rays passed through the patient - Computers integrate data to reconstruct a cross sectional image PATIENT EXPECTATIONS - In gown, lying flat on table - Bed slides into open circular scanner - Must be very still - Quick, painless INDICATIONS - Kidney stones - Renal colic symptoms, known history - Nonspecific abdominal pain CONTRAINDICATIONS - Pregnancy - Caution in children - Obesity > 450lbs CT WITHOUT CONTRAST PROS - Wide field of view - Good detail of abdominal/pelvic organs - No IVc exposure CONS - Lack of contrast limits characterization of lesions - Cannot detect intraluminal pathology - Can lead to additional imaging - Radiation exposure - Implanted hardware causes artifact - Soft tissue resolution CT WITHOUT CONTRAST Kidney stones CT WITHOUT CONTRAST CT WITH IV CONTRAST CT WITH IV CONTRAST TECHNIQUE - Same as non-con - IV contrast administered as rapid bolus 1. Arterial phase: Renal artery opacification  2. Nephrogenic phase: renal parenchymal enhancement (60s)  3. Delayed phase: excretion of contrast into collecting system and bladder (3-5m) - Adrenal delay (10-15m) PATIENT EXPECTATIONS - Same as non-con - Peripheral IV access - Warm feeling with IV bolus - Creatinine drawn day of exam CT WITH IV CONTRAST INDICATIONS - Renal or adrenal masses - With and without for comparison of enhancement to determine character of lesion - Known malignancy, staging study - Abdominal pain- appendicitis, diverticulitis - Trauma CONTRAINDICATIONS - IVc allergy (iodine, shellfish) - Pregnancy - CKD or Cr > 1.9 - Prior CIN PROS - More detail of abdominal/pelvic organs - Better at detecting masses of visceral organs - Vessels, bones, visceral organs CONS - Radiation exposure - IVc administration/risk of CIN - No illumination of bowel - Poor soft tissue resolution - Hardware artifact CT WITH IV CONTRAST ABNORMAL IMAGING CT UROGRAM (ab/pel with and without) CT UROGRAM TECHNIQUE - Same as previous, pt expectations= same - IVc administered as rapid bolus 1. Arterial phase: Renal artery opacification  2. Nephrogenic phase: renal parenchymal enhancement (60s)  3. Delayed phase: excretion of contrast into collecting system and bladder (3-5m) PROS - DELAYED PHASE illuminates entire urinary tract - 3D reconstruction - Excellent specificity for renal, ureteral, bladder or adrenal malignancy - Non contrasted portion will find stones CONS - Same CT UROGRAM (ab/pel with and without) Three slide picture CT UROGRAM INDICATIONS - Gross hematuria - Asymptomatic hematuria + smoker - Suspected pyelonephritis Renal masses Renal pelvic tumors Bladder malignancy Recurrent UTIs EVERYTHING!! CONTRAINDICATIONS - Same as CT with IVc CT UROGRAM CT UROGRAM CT UROGRAM CT ANGIOGRAM TECHNIQUE - Similar to other CTs with IVc - IVc is administered more slowly to allow for illumination of arteries INDICATIONS - BEST method to detect renal artery stenosis or renal vein thrombus - Pt with unexplained progressive HTN PATIENT EXPECTATIONS - Similar to prior CONTRAINDICATIONS - Same as CT with IVc CT ANGIOGRAM UPTODATE: “CT angiography is the best imaging modality to evaluate the renal vasculature, specifically to diagnose renal artery stenosis (accuracy greater than 90 percent) thereby obviating the need for invasive angiography” MAGNETIC RESONANCE IMAGING MRI without Gadolinium MRI with Gadolinium MRI Urogram MRI WITHOUT GADOLINIUM MRI WITHOUT GADOLINIUM TECHNIQUE - Protons responding to magnetic field and radio wave pulses - Computers transform signals into crosssectional images PATIENT EXPECTATIONS - In gown, lying flat on table - Bed slides into narrow cylindrical tube. - Caution with claustrophic patients - Must be very still - Loud banging sound. Headphones will be provided for patient. - No ferrous metals on or in body - Pacemakers, implants, metalsmiths, machinists, shrapnel or BBs, IVDA MRI WITHOUT GADOLINIUM PROS - Great at soft tissue detail and fine detail - Vessels, tendons, muscles, deep tissue - Great for deep structures like prostate - Masses of intraabdominal organs - Easily narrow or widen focus of imaging by computer reconstruction - No radiation exposure - No CIN risk CONS - Claustrophobia - Only one body area at a time - Not all patients are candidates - Hardware causes artifact - Metal in body MRI WITHOUT GADOLINIUM INDICATIONS - Not many for uro/nephro world - Characterization of renal or adrenal masses - CKD patient with suspicious renal or adrenal mass - Renal vessels - Pregnancy and peds OK if absolutely necessary CONTRAINDICATIONS - Noncompatible implant - Metallic foreign body - Claustrophobia MRI WITHOUT GADOLINIUM MRI WITH GADOLINIUM TECHNIQUE - Same - Rapid IV bolus of gadolinium with rapid sequencing INDICATIONS - Renal mass, bladder mass with IVc allergy or CKD PATIENT EXPECTATIONS - Same just with an IV CONTRAINDICATIONS - GFR 1.9 MUST have AKI, CKD or ESRD SIGNS AND SYMPTOMS fatigue, peripheral edema, pruritus Cr increase >0.5 from baseline thick, tight skin, pruritus, papules No lab changes ONSET Occurs in 48-72 hours Occurs in 2-10 weeks (can happen years later) TREATMENT Treatment: IVF, monitoring, generally self limiting Treatment: No proven treatments, progressive MRI UROGRAM With and without Illuminate Urinary system only (no surrounding evaluation) Excretory phase Admin of Lasix Pregnancy and Peds Ok Cons: patient discomfort, cannot reliably detect calculi NUCLEAR MEDICINE IMAGING Renal Scintigraphy Adrenal Scintigraphy RENAL SCINTIGRAPHY TECHNIQUE - Used only for perfusion and function - Radiotracer injection emits tiny amount of radioactivity into patient - Travels to kidneys where it gives off gamma rays - Gamma ray camera used to measure rays; computer reconstruction into images PATIENT EXPECTATIONS - Radiotracer injection causes metallic taste - Lying flat or sitting - Bladder empty - 30 min to 2 hours - If cortical images are required, delay of 3 hours post injection necessary RENAL SCINTIGRAPHY RENAL SCINTIGRAPHY FOUR TYPES 1. Renal cortical imaging: detects amount of functioning renal parenchyma - 2-3 hour delay after admin of radiotracer 2. Renal perfusion and functional imaging: vascular evaluation and function 3. Diuretic renal images (MAG3, Lasix scan): detects obstructions by assessing images before and after administration of diuretic - Test of choice to determine obstructive v. nonobstructive hydronephrosis in children 4.Captopril renogram: helps determine if renovascular hypertension is present by comparing images before and after admin of Captopril (ACE-inhibitor). - Every 15 m x 1 hour RENAL SCINTIGRAPHY INDICATIONS - Captopril= renovascular HTN suspected - Lasix= ureteral obstruction suspected - Test of choice to determine obstructive v. nonobstructive hydronephrosis - Others are not commonly used CONTRAINDICATIONS - Breast feeding - Pregnancy PROS - Very minimal radiation exposure - Safe for kids - Allergic reaction to radiotracer extremely rare CONS - Time consuming - Cannot reliably evaluate for other pathology ADRENAL SCINTIGRAPHY Used solely for evaluation of function in the diagnosis of primary aldosteronism. - Per Up to Date: “While it has the potential advantage of correlating function with anatomic findings, it is not useful for evaluating small adrenal nodules, as tracer uptake is poor in APAs