imaging of gi system

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Imaging of Gastrointestinal System

義大醫院 影像醫學科 李浩銘醫師

Plain Photo

EUS

Fluoros copyNuclear Medicine

Ultrasound CT Scan MRI

Digestive system:

Digestive tracts:- Oral cavity- Pharynx- Esophagus- Stomach- Small bowel- Large bowel (Colon)- Rectum

Accessories organs:- Parotids- Liver- Billiary- Pancreas

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Plain abdominal x-ray

Technique :AP – Supine

AP – Erect

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LLD

Semi recumbent

CXR

Indication :Acute abdomen

What to Examine ??

- Air (bowel gas)

- Bone density

- Calcification (stone / foreign body)

- Soft tissue mass

Air

Sub diaphragm free airBowel perforation

Bowel obstruction

AP-semirecumbent

LLD, horizontal

AP-supine

-dilated bowel loops -thickening of bowel wall-multiple air-fluid levels

Ileo-cecal valveincompetentsmall and largebowel distention

Bowel obstruction

Mechanical large bowelobstruction

Colon dilatation

obstruction.

Barium enema

volvulus of sigmoid colon

Bone density

- Osteoporosis- Compression fracture

Calcifications, stones Soft tissue mass

Barium Enema (BE)

Plastic irigator :1. enema tip2. enema tube3. enema reservoir bag4. balloon with it inflator.

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Colon Radiology Anatomy

Technique & positioning

A.

Left lateral position :contrast filling rectum and rectosigmoid

B.

Left posterior oblique:contrast filling sigmoid

C.

Left lateral with 15o

Trendelenberg position :contrast flow to descendentcolon and splenic flexure

D.

Clockwise to prone position:contrast filling transversalcolon

E.

Clockwise to right lateralwith 15o Trendelenberg

position : contrast filling thehepatic flexure

F.

From E, turn left to supineposition : contrast fillinghepatic flexure andascendant colon

ContrastSingle DoubleBarium Barium + air

Contrast Single Double Motility study Mucosa study Simple & relative safe More difficult

IndicationDouble contrast BE

Melena / bloody stool

Cancer

Suspected colonic polyp

Family hx of colon ca / polyp

Chronic diarrhea / bowel habit change

IBD (inflamatory bowel disease)

Pain & abdominal discomfort

Diverticulosis

Intussusceptions

Hirschprungs disease

Fatique / very old patient /

serious illness

Suspected pelvic metastasi

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IndicationSingle contrast BE

Contraindication

Suspect bowel perforationToxic megacolonAfter colonic biopsyPregnant Patient

Complication

Gas pain

Colonic perforation/rupture

Intramural barium

Stool impaction

Bacterial contamination

Allergy / hypersensitivity

Patient preparation

Low residue dietIncreased fluid intakeRectal or oral laxativeAntispasmodic agent (if needed)

1. Glucagon: iv 0.5 – 1 mg2. Buscopan: iv or im 1 amp (20 mg/mL)

Record / filming

Plain abdominal photo

Spot photo

Overhead whole abdomen

Plain abdominal photo

Barium EnemaSingle

Contrast

Spot film : Single contrast

Rectum (left lateral)

Hepatic flexure

Sigmoid Splenic flexure

Cecum

Whole abdomen : single contrast

Whole colon :

overhead film

BariumEnemaDouble

Contrast

Spot film : double contrast

Rectum & sigmoid :

Lateral position Supine position Prone position

Spot film : double contrast

Sigmoid :

posterior oblique

Distal descendant colon Proximaldescendant colon

Spot film : double contrast

Splenic flexure(RPO)

Transverse colon

Erect position

Spot film : double contrastAscendant colon

Hepatic flexure

Erect position Erect position, LPO

Spot film : double contrast

Cecum & appendix Cecum & terminal ileum

Overhead film :

whole colon

Hirschsprung diseaseDilatation of proximal bowel with caliber change at rectumTransitional zone

Intussusception

Doughnut Sign

Polyp

Bubble

Filling defect

Pedunculated Polyp

Sessile Polyp

Mexican hat sign

Malignant polyp : villous type

Apple core sign

Colon cancer : annular type

Colonic diverticulitis

Colonic diverticulosis

Ulcerative colitis

Continuous lesion, lead pipe sign

Segmental colitis Pancolitis

Crohn’s diseaseDiscontinuous skip lesion

Fistula formation

Colitis TB

Rectal carcinomaOverhanging edges / shoulderingAnnular constrictionIrregularity border

Colonic polyp

Filling defect on single contrast Soft tissue mass on double contrast

Extraluminal tumor

ileocecal intussusceptions(Coiled spring appearance)

Digestive system:

Digestive tracts:- Oral cavity- Pharynx- Esophagus- Stomach- Small bowel- Large bowel (Colon)- Rectum

Accessories organs:- Parotids- Liver- Billiary- Pancreas

Diffuse esophageal spasm:corkscrew esophagus

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Foreign body

Mimicking tumor

Intraluminal filling defect

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Gastric wall filling defect

Gastric carcinoma

Linitis plastica

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Additional shadow

Duodenum diverticulosis

3. Small Intestines

Barium follow through (Single Contrast)

Enteroclysis (Double Contrast)

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Barium Follow Through

• Patient fasting

• Single contrast : 200 – 500 cc of bariumsuspension is given to drink

• Followed by fluoroscopic or conventional x- ray.

• Taken serial photo : 5‘ , 10’, 20’ etc.

• Examination must be stop when barium fillingthe cecum.

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Enteroclysis = small bowel enema

• Inserted the NG Tube (12F 135 cm long)

• Maneuver catheter tip to the antrum passing pylorus placed and fixationcatheter tip in duodenal 3rd parts.

• Contrast irrigation (+ methylcellulose) orair insufflating

• Filming

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Normal follow through

Enteroclysis - normal smallbowel mucosa

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ascariasis in small intestine24

Take home message

• ABCS in KUB

• Single v.s Double contrast

• Indication / Contraindication / Complication of barium enema

Learn to be better !