Procedures FINAL review

Name the parts of the small intestine from the end of the stomach to the beginning of the large intestine

Name the parts of the large intestine from the end of the small intestine to excretion

pyloric sphincter → duodenum → jejunum → ileum → ileocecal valve

→ cecum → ascending colon → transverse colon → descending colon → sigmoid colon → rectum → anus

what is the difference between an acute and chronic GI bleed

acute = perforation of intestines from foreign object

chronic = originating from a disease

what is the difference between hematochezia and melena

hematochezia comes from the lower GI tract, and is often bright right

melena is often dark red or black, and comes from the upper GI tract. People with melena can have low hemoglobin/hematocrit and orthostatic hypotension

what rph can you use for a GI bleed, and which one is preferred (what dose for the preferred one)

Tc99m RBCs (preferred) (15-30mCi pertechnetate)

Tc99m SC

what is the MOL of Tc99m RBCs to the GI bleed

extravasation into the intraluminal spaces

how should you position patient for a GI bleed scan

patient supine with xyphoid and pubic symphysis in FOV

where can you find unbound pertechnetate in a GI bleed

stomach, kidneys, gastric mucosa, bladder, small bowel, colon

what is the best method of tagging blood for a GI bleed

ultratag

what are contraindications of a GI bleed scan

• barium

• not actively bleeding

• chronic occult GI bleeding (rate of bleeding too low for detection)

what physiological factors can cause false positives or negatvies in GI bleed scans and interpretation

• full bladder block sigmoid/rectum (false -)

• urine in renal pelvis of transplanted kidney (false +)

• aneurysm (false +)

what will small bowel bleedings look like

rapid serpidimous movement

GI bleed studies can detect bleeding rates as low as _____ - _____ ml/min

0.04 - 1ml/min

what procedure has a >90% accuracy of making a diagnossi of an upper GI. bleed

endoscopy

name two therapeutic interventions for a GI bleed

coagulation via cautery, heat, laser

mechanical therapy via clips, bands

what is Meckel’s Diverticulum, when does it develop, and what does it develop from

a small sac that forms in the ileum, develops at Wk 5 from the vestigial remnant of yolk stalk of embryo

name all the “2s” in Meckels

• it’s 2in average

• 2ft from ileocecal valve

• in 2% of population

• complications in 2% of that 2% population

• symptomatic by age 2

what are the indications of Meckel’s study

• find ectopic gastric mucosa

• explain GI bleeding

• explain blood in feces

• explain abdominal pain

what rph do you use for Meckel’s and what dose (adult and ped)

8-12mCi Tc99m pertechnetate

0.05mCi/kg pediatric

what are the contraindications of a Meckel’s scan

• actively bleeding

• recently got potassium perchlorate

• bowel irritants within 24hr (false +)

• barium sulfate studies (false -)

• tagged RBCs 24hr prior

what is the patient prep for Meckel’s

• NPO 2-4hr

cimentidine dose and purpose

20mg/kg/day for 2 days prior to Meckel’s test

blocks release of pertechnetate

Pentagastric purpose and method of administration

increase mucosal uptake of pertechnetate

give 15min before test

Glucagon purpose and method of administration

lowers small bowel motility

give 10min post injection

how should you position a patient for a Meckel’s study

patient supine with xyphoid and pubic symphysis in FOV

when should ectopic gastric mucosa show up on a Meckel’s study

at the same time as normal gastric mucosa (30-60min)

what could cause a false - in a Meckels study

no gastric mucosa in the Meckel’s Diverticula

% esophageal reflux formula

(esophagus cts - esophagus bkg cts) / (max stomach cts) x 100%

Esophagus bkg cts formula

(bkg cts ROI / bkg cts pix) x esophagus cts pix

geometric mean formula

√ANT cts x POST cts

% gastric empty formula

(GM at T0 - GM at T) / (GM at T0)

% gastric remains at T formula

GM at T / GM at T0 x DF

primary perstalsis vs seconday peristalsis

primary peristalsis controls food from pharynx → esophagus → stomach

secondary peristalsis occurs in esophageal body in response to refluxed blood

what things can cause GERD

• chocolate

• smoking

• alcohol

• fatty foods

what are two tests besides NM that can evaluate for GERD

endoscopy

esophagram

what are the indications of esophageal reflux NM test

• determine presence/absence of GERD/pulmonary aspiration

• eval regurgitation/vomitting

• diagnose/eval reflux

• eval therapy

what are the contraindications of esophageal reflux NM test

• recent NM study

  • pregnant/breastfeeding

patient prep for esophageal reflux

• NPO 4hr or overnight

what rph and dose do you use for esophageal reflux study

0.5-2mCi Tc99m SC in 150-300mL orange juice, milk, formula, followed by 30mL water to wash it down

when do you image for esophageal reflux studies

15min after drinking

2-4hr/24hr is lung aspiration suspected

what % reflux for

normal

intermediate

abnormal

nornormal </=3%

intermediate 3-4%

abnormal >4%

what are the indications for a Milk scan

• eval children w/ asthma, chronic lung disease, aspiration, pneumonia, anatomic abnormalities

• negative barium swallow study

what is the rph and dose for a Milk Study

0.25-1mCi Tc99m SC or Tc99m/In111 DTPA (older children) given with liquid

when do you image for a milk scan

• immed

• 2hr

• 4hr

• 12-24hr for aspiration suspection

• must scan lungs @24hr

what are the 4 functions of the stomach

SARM

secretion

antibacterial barrier

reservoir

motility

name three advantages of a gastric empty study

gives % empty/retention

low RA dose

can measure solids/liquids

non-invasive

what main thing does the rate of emptying depend on (plus 2 or 3 more factors)

VOLUME

calories

concentration of nutrients

salinity

acidicty

what is the standard gastric empty meal

4oz egg whites, 120mL water, 2 slices white toast, 30mg jelly

what are the indications of a gastric empty test

• determine delayed/rapid gastric empty quauntitatevely

• eval obstructions

• eval symptoms

• eval weight loss

what are the contraindications of a gastric empty study

• allergy to any part of meal

• hypoglycemia (<40mg/dL)

• hyperglycemia (>275mg/dL

what is the patient prep for gastric empty study

• NPO 4-6hr

• stop prokinetic or delaying agent 2 days prior

• no smoking

• diabetic patients take small portion of insulin dose in morning with meal

what is the adult and pediatric dose for solid gastric empty test

0.5-2mCi Tc99m SC

0.25-0.5mCi Tc99m SC (ped)

what is the dose for a liquid study (liquid only and dual)

liquid only - 500uCi Tc99m DTPA

dual - 125uCi In111 DTPA

300mL water

what does a lack of GM correction cause?

a) rate overestimation

b) rate underestimation

c) anatomic innacuracy

b

what are the phases of gastric emptying

lag phase

prologned phase

slower phase

what are two possible cuases of both delayed and accelerated gastric empty

delayed

• surgery

• anorexia

accelerated

• vagotomy

• hyperthyroidism

whats the gold standard for evaluating size and shape of kidneys

US

where are the kidneys

between T12 and L3

name three functions of the kidney

• urine formation

• regulate BP

• waste excretion

what is the parenchyma of kidney made up of, and what do those elements contain

renal cortex - glomeruli

renal medulla - renal pyramids/renal columns

hilum - renal pelvis

what produces renin and where is it

juxtaglomerular apparatus, between the afferent and efferent arterioles

define ERPF and the normal range

effective renal plasma flow is the amount of plasma flowing to the parts of kidney that have a function in urine production (600mL/min)

define GFR and normal ranges

volume of water and solutes filtered out of plasma thru glomerular capillary walls per unit of time (120-125mL/min)

what % of cardiac output goes to the kidneys

20-25%

what are the 3 steps of urine production

1) filtration by glomerulus

2) tubular reabsorption

3) tubular secretion

what rph is a functional glomerular filtration agent

Tc99m DTPA

what rph is a functional tubular secretion agent and what is the dose

1-5mCi Tc99m MAG3

what is a morphological kidney rph and what is the dose

Tc99m DMSA

3-5mCi

0.05mCi/kg (ped)

what are the indications for a renography

• assess renal function

• eval acute/chronic renal failure

• determine % function of each kidney

• eval function of transplanted kidney

what are the contraindications of a renography

• recent NM study (48)

• renal arteriogram a few days before

• pregannt/breastfeeding

what is the most important patient prep for renographys

hydration day before, morning of, and 1hr-30min before test

how should you position a patient for a renography

• patient supine, find xiphoid, umbilicus, pubis symphysis, and sides in FOV

what four things should a tech evaluate during a renography

FASC

• function

• anatomy

• symmetry

• collecting system patency

% Lt kidney function formula

net cts in Lt. ROI (bkg corrected) / (net cts in Lt. ROI (bkg corrected) + net cts in Rt. ROI)

what % kidney function indicates abnormality

</=40%

what are the three phases of kidney imaging and how long are they

1) perfusion (30-60sec)

2) cortical/tubular concentration (1-5 min)

3) excretion (5-20min)

what are the indications for a diuretic renography

• obstructive vs nonobstructive hydronephrosis

• eval renal obstructive nephropathy

• monitor therapy effect

what are 4 nonobstructive causes of hydronephosis

PIVC

• previous obstruction

• infection (UTI)

• vesicouretal reflux

• congenital abnormalities

what is the diuretic renography pediatric dose with or without flow

with - 0.15mCi Tc99m MAG3

w/o - 0.10mCi Tc99m MAG3

when do you inject furosemide for a diuretic renography

when collecting systems are full (15-20min)

what could cause mechanical obstruction false positives

• dehydration

• full bladder

• reflux

• large renal pelvis

• infiltration

what is the purpose of a captopril renal scan

detect patients w/ RAS as the cause of hypertension and predict the curability of it

what are two common causes of RAS

atherosclerosis

fibromuscular dysplasia

why could RAS cause HTN?

decrease afferent arteriolar BP/perfusion pressure →

stimulate renin secretion by juxtaglomerular apparatus →

renin turns angiotensin → angiotensin I

ACE turns angiotensin I → angiotensin II

angiotensin II → vasoconstriction of efferent arteriole (balancing GFR)

angiotensin II → aldosterone secretion from adrenal glands

aldosterone → sodium/water retention, increased blood volume

INCREASED BLOOD PRESSURE

what could cause RVH false positives

hypotension induced during study induces oliguria/cortical retention

dehydration

bladder distension

patient prep for ACEI renography

• liquid only 4hr before

• no diuretics 3 days

• no ACEI 4-7 days

name two blood tests related to kidney function

BUN

creatinine (normal <1.2mg/dL)

what are the indications of morphological renal study

• acute vs chronic pyelonephritis

• eval renal cortex

• identify scarring

• eval/localize renal mass

what is the patient prep for morphological renal imaging

• hydrate night before/morning of/.5-1hr before test

• void before test

• no diuretics 24hr before

what is the procedure for morpholgical renal imaging

inj. Tc99m MAG3

wait 2-4hr

image POST using LEHR

or

patient prone, image POST using pinhole

name 3 pseudotumors

column of bertin

suprahilar hump

dromendary humps

what could acute polynephritis look like on morphological renal imaging

1) focal cortical defects

2) multifocal defects

3) diffusely decreaed actvity

where is a transplanted kidney located, and how does it get blood supply

anterior lilac fossa

hypogastric artery and external iliac vein

what is the indication for transplanted kidney imaging

eval kidney function and GU system in renal transplant patients

name three complications of renal transplant

1) acute tuberlar necrosis

2) acute/chronic rejection

3) urinomas

what is a radionuclide cystography for

eval and follow up of children w/ suspected vesicouretal reflux

what rph and dose do you use for radionuclide cystogragraphyphy

0.5-1mCi Tc99m pertechnetate, SC, or DTPA

what is the general proceuure for cystography

clamped IV bag of saline attatched to catheter

put tracer in catheter followed by saline

record filling volume when reflux is first observed

record pre-void statics

get dynamic images while patient pees in bed pan

get post-void statics

how to you calculate estimated bladder volume

(age in yr +2) x 30mL

define

horshoe kidney

polycystic kidney

ptotic kidney

hydronephrosis

horshoe kidney- bottoms of kidneys joined

polycystic kidney - multiple cysts on kidney

ptotic kidney - mobile kidney

hydronephrosis - dilation of reanl pelvis + ureters

what is the thyroid derived from

the ventral wall of the primitive pharynx