RAD 250RAD 250: GASTROINTESTINAL RADIOLOGY

RAD 250 [8]: RadiologyLec 05: Gastrointestinal Radiology (X-ray Imaging)T. Benedicto, MD1October 16, 2014TOPIC OUTLINEI. Plain FilmsA. Gas PatternB. Extraluminal AirC. Calcification and Foreign BodiesD. Masses/Densities and fluid collectionsII.Contrast StudiesA. EsophagusB. StomachC. Small IntestineIII. CholangiogramIV. Barium Enema

We only included the slides that were discussed by Dr. Benedicto. She skipped quite a lot of slides. I. Plain films

What to Examine:Gas patternExtraluminal airSoft tissue masses/densities & fluid collections (e.g. psoas)CalcificationsForeign bodies

Plain abdominal start at diaphragmKUB must include the inferior border

Important feature of abdominal radiographs: presence of gas

A. gas patternThe abdomen is unique in such as a sense that you can do triple contrast (air, IV contrast, barium contrast)

large vs. small bowel

Large bowelPeripheralHaustral marking dont extend from wall to wall

Small bowelCentralValvulae extend across the lumen

Location will tell you (large bowel is outer box)

Normal bowel gas patternAir is normal within intestine.Ask the patient to fast and not to talk or cry (baby), so as not to introduce solids or liquid or gas into the bowelAir produced is from: Swallowed air and bacterial production

StomachAlways with gas

Small bowel2-3 loops of non-distended bowelNormal diameter is < 2.5-3.0cm (diameter of 1 peso coin)

Large bowelAlmost always with gas in rectum and sigmoid

The bowels should be clean (no fecal material, gas, etc.). Preparation is key! If the bowels were badly prepared, you may mistake opacities or lucencies as tumors.

normal air-fluid levels (Afl)

StomachAlways (except in supine film)

Small bowelTwo to three levels possible

Large bowelNone normally

From 2016 trans:Differential: obstructive (AFL are not aligned)Non-differential: ileus or paralytic ileus

complete abdominal seriesIf chest has series like AP, and lateral views, abdomen also has.SupineUpright or Left lateral decubitus Left lateral decubitus if the patient cannot stand (e.g. trauma, unconscious) Why left? Because the liver is in the R (air can be delineated by the liver border if patient is asked to lie on L)Chest upright or supineProne or lateral rectum (useful if suspecting obstruction) Why prone or lateral? Because rectum is at posterior (positioning the patient at prone or lateral places the gas to the rectum)

abdominal gas patterns: ileus and obstructionIleus is more benign. It means the bowels move slowly versus obstruction wherein nothing passes.

Sentinel loops: loops surrounding areas of pathology. The pathology causes edema of adjacent bowel which causes gas accumulation in the bowel, as seen in the sentinel loops.

The area where dilated loops clump is the area of pathology. Example: if the impression is a gallbladder pathology, expect sentinel loops at that area. Therefore, this technique is confirmatory! Another usual indication is in cases of appendicitis. But this technique is not anymore used nowadays.

Key features: 1-2 persistently dilated loops Gas in rectum or sigmoid

Pitfalls: May resemble mechanical small bowel obstruction Clinical course Follow-up 6 hours to 8 hours

postoperative: adynamic ileusYou expect dilated loops and air-fluid levels in post-op patients though this may resemble ileus. Therefore, do a sequential study (It is important to know how many hours post-op). You expect gas to decrease thru time. Left image: dilated loops; Right image: air-fluid level

mechanical obstruction: causesTumorVolvulusHerniaDiverticulitisIntussusception

Mechanical Small Bowel Obstruction: Key Features and Pitfalls 3-5 hours gas/fluid accumulate Dilated small bowel with air-fluid level Early SBObstruction may resemble localized ileus and should get follow-up

This is an SBO because of the valvulae conniventes.

If obstruction is incomplete/early see some gas in the colonIf complete and prolonged obstruction no gas in large bowel

Fluid accumulates string of beads (see R side of the patient on the image taken upright)Proximal jejunal obstruction entirely filled with fluid

gallstone ileusAerobilia It happened so fast haha. Sorry. Wala din yung slide na yun sa copy naming ng ppt.

large bowel obstruction

B. EXTraluminal air

free air: causes(not presented or skipped but in the powerpoint)

Rupture of hollow viscus Perforated ulcer Perforated diverticulitis Perforated carcinoma Trauma or instrumentationPost-op: 5-7 daysNot usually seen in perforated appendix

pneumoperitoneum(Left image: fluid collection at the R side of patient; look at CP angle)

Air beneath the diaphragmLeft lateral decubitus view- air outlines liver

Riglers SignAir inside and outside bowel lumen outlines See the R side of patient, yung tatlong rows of intestine

(Image below) In pediatric patients, youll see the falciform ligament when there is gas in the peritoneum. This is called the football sign.

Left image: There is delineation of the liver border under the diaphragm.Right image: There are horns at the side of the bladder.

For pneumoperitoneum: If few air is present ok lang (Im assuming this means no need for Rx)If progressively increasing this is a problem

c. calcification and foreign bodies

The location of the calcification tells you which organ is involved.Also, TB must always be ruled out if you see calcifications.

Hepatic calcification

Urolothiases are are usually benign unless there are too much.

Mercury Ingestion: There are flecks of irregular calcification. Management is antidote Coin ingestion: management is monitoring for signs of obstruction.

D. masses/densities & fluid collections

soft tissue masses/densities(skipped)

Hepatosplenomegaly Plain films poor for judging liver sizeTumor or cyst Bowel displacement Paucity of gas Pad sign extrinsic compression of the bowelFluid collections Abscesses/Hematomas Ascites/Loculated fluid collections

(Image above: Hepatosplenomegaly)

Pharyngeal space usually 2-3mm in X-ray. If bulging, then it is edematousII. CONTRAST STUDIES

A. ESOPHagus

Esophagogram study of esophagus using 2 cups of Barium, using fluoroscopyUpper GI series uses double contrast (air + fluid, ie. Barium with carbonated drinks Plate #. Shows the normal barium swallow findings

ACHAlasiaHypertonic distal lower esophageal sphincter (LES)Loss of peristalsisBirds beak appearance esophagus tapers at the level below thoracic inlet Etiology: loss of ganglion cells of esophageal myenteric plexus (controls esophageal peristalsis Plate #. Arrows point to the Birds Beak appearance of LES

zenkers diverticulum Also called Pharyngoesophageal diverticulumExcessive pressure within the lower pharynx causing the weakest portion of the pharynx to balloon out forming a diverticulmPulsion type due to motility disorder, mechanical obstruction, chronic wear and tearCauses: Obstruction, bleeding, perforation, infection, CANotice retention of dye in esophagogramFor better visualization, it is important to have a lateral film with contrast also. Lateral on plate #, also shows the stricture caused by diverticulum Frontal and Lateral Esophagogram of Zenkers Diverticulum

Hiatal hernias [READING ASSIGNMENT]An abnormal protrusion of the esophagus and/or stomach through the esophageal hiatus. These hernias occur at the GEJ.

A-line = ampulla B-line = GEJ (junction between squamous esophageal mucosa and gastric columnar mucosa)

SLIDING / AXIALThe gastroesophageal junction (GEJ) or B-line herniates >2cm above the diagphragm Associated with GERD Comprises 99% of all hiatal hernias

PARAESOPHAGEAL / ROLLINGHave a normal GEJ but the gastric fundus extends through the esophageal hiatus into the mediastinum Comprises 1% of all hiatal herniasLife-threatening due to risk of volvulus and incarceration

Red arrows: Schatzkis ring which represents the GEJ associated with sliding hernias; White arrow: herniated stomach; Green arrow: distorted tertiary waves of contraction

foreign body Barium or barium-soaked cotton delineates level of radio-opaque FB

Red arrow: Shape of the superior edge of balut delineated

small esophageal ulcers Candidiasis, Herpes, and CMV can lead to small esophageal ulcers These ulcers appear as grooves and lines on upper GI series Plaque-like vertically oriented lesionsDiffuse/long segment filling defectsRagged appearance with poor peristalsis

caustic esophageal stricturelong segment involvedby 2-4 weeks get healing with fibrosisprogressive luminal narrowing

esophageal carcinomaasymptomatic until causes obstruction irregular /nodulareccentric narrowing shelf-like marginsApple-core deformity: mass surrounds the wall forming a stricture

B. stomach

Upper GI Series. D1: duodenal bulb, D2: descending aortaD3: transwerse colon; D4: descending colon

gastric ulcerulcer crater project outside wallsign of undermining - Hamptons line, smooth rim or collar of edema

chemical gastritis strong alkali & acids affect both esophagus & stomachalkalis cause coagulation necrosis3-10 weeks cicatrization atonic stomach, small capacity (+) pyloric spasm will spare duodenum

C. small intestinesWall thickness: approximately 1.0 2.0 mmJejunum luminal diameter: 3.5 cm Ileal luminal diameter: 3.0 cmJejunal folds do not disappear with distention while ileal folds will

Green line: Division of jejunum and ileum

duodenal ulcer

ascariasisSeen on contrast filmAlive: takes in contrast, radioopaqueDead: cannot take in contrast, radiolucent

foreign bodyContrast will delineate foreign bodies

duodenal diverticula1 mucosa prolapse thru muscularis (2nd & 3rd portions)2 inflammation (1st portion) Causes: obstruction ,bleeding, perforation, infection.

bockdalek hernia Congenital diaphragmatic hernia at the left side

Bockdalek Hernia. Back Door at the LEFTIII. CHOLANGIOGRAM T-TUBE, PTC, ERCP: BILIARY TREEectopic gallbladder

Red arrows: Gallbladder. Right plate shows gallbladder above liver

gallstones

Gallstones with radioopaque borders

T-Tube cholangiogramLeft by surgeons in order to visualize stones after a monthEstablishes patency of biliary tree

choledocholithiasesNote the presence of lucencies with well-defined borders inside the biliary tree

biliary ascariasis

Lucent ascaris with opaque body walls

IV. barium enema

4 positions:

Position 1, Right Lateral Decubitus

Position 2, Left Lateral Decubitus

Position 3, Anteroposterior

Position 4, Post-evac

intussusceptionChildren - common ileo-colic 2 inflammed lymphoid tissue Adults look for leading lesion or post-op coil spring appearanceProcedure can also be therapeutic, barium enema will push the intussusceptum (telescoping segment) out

Intussuscipiens: white, with barium enema

hirschprungs diseaseAbsence of myenteric ganglia at distal colon commonly rectosigmoid Look for transitional zone

Red arrow: Transitional zone. Fuzzy bowel since it is feces-filled.

END OF TRANSCRIPTION

Andrew: Hello blockmates! Libre ko kayo after ng Radio exam!

Karen: Yeay! Super long trans! Hahaha. But mostly photos. Last week of Radio na! More block food outing please!

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