Xray KUB KUB xray is a plain AP

Xray KUB

• KUB x-ray is a plain AP supine radiograph of the abdomen to assess the organs and structures of the urinary and/or gastrointestinal (GI) system • K = Kidneys, U = Ureters, B = Bladder

INDICATION • Diagnosis of suspected stone disease • To be a control film in anticipation of contrast administration • To assess the presence of residual contrast from a previous imaging procedure • After treatment of stone disease. • To assess the position of stents and drains • Adjunct to investigation of blunt or penetrating trauma to urinary tract

PROCEDURE Bowel Preparation for the procedure: Time honored technique of being empty stomach overnight accompanied by either dulcolax or purging in form of enema. However recently it has been shown that bowel prep is not needed. Before examination: • 1) Identify the correct patient • 2) Bowel preparation. Yes/No? • 3) Ask pt to remove any jewelry or metal objects, and put on an x-ray gown • 4 ) Female patient : pregnant or not • 5 ) Empty the bladder

During examination: • 1) Pt lie down supine on x-ray table • 2) Pillow under head, hands on side, use knee support • 3) Centre x-ray tube and the cassette • 4) Centre the region of interest (CR for KUB: perpendicular and directed at mid sagittal line, level of illiac crest) • 5) Collimation (upper border = level of T 11, lower border = symphysis pubis, lateral collimated) • 6) Put on gonad shield, put on marker • 7) Give instruction (expiration) • 8) Make exposure at the end of expiration After Examination • 1) Pt can change to his/her clothes • 2) Process the film

Exposure • 70 – 80 k. Vp , 20 – 30 m. As • • Good penetration – visualize bony trabecular patterns & cortical outlines of lumbar vertebra & pelvis • . • Good contrast & density – can demonstrate psoas muscle , kidneys and other soft tissues.

Projection & Position • PROJECTION: true AP ( no rotation ) • POSITION: • spinous process aligned with midline of vertebra column • distance : pedicles to spinous process same ( both side ). • sacrum center

HOW TO READ? • #1 = Name and Date!! • Quality, exposure (too dark is over exposed) • Penetration • pt position, orientation

Reading a KUB • Spine and bony pelvis abnormalities • Organ outline : kidneys, bladder • Soft tissues : • Psoas muscle • Soft tissue masses • Radio-opaque shadow (calculus /phleboliths / calcifications) • Bowel

Kidneys on abdominal X-ray • what to find -Size , shape , position , axis and orientation. • Natural contrast between the kidneys and the low density retroperitoneal fat that surrounds them means they are often visible on an X-ray of the abdomen. • They lie at the level of T 12 -L 3 and lateral to the psoas muscles. The right kidney is usually slightly lower than the left due to the position of the liver. • The size of the kidneys varies with the size and sex of the patient; • an average renal length equal to three to four vertebral bodies is norma. L The average length of the left kidney is approximately 0. 5 em greater than that of the right kidney

Position of Kidneys Normal : T 12 -L 3 RK : L 1 -L 3 LK : T 12 -L 2/L 3

• size discrepancies are likely to represent abnormalities if the right kidney is more than 1. 5 cm longer than the left or if the left kidney is more than 2 cm longer than the right or if left kidney is 0. 5 cm smaller than right kidney.

Ureter • In searching for a ureteric stone on a plain radiograph of the abdomen, one must imagine the course of the ureter in relation to the bony skeleton. • It lies along the tips of the transverse processes, crosses in front of the sacroiliac joint, swings out to the ischial spine and then passes medially to the bladder. • An opaque shadow along this line is suspicious of calculus. • This course of the ureter is readily studied by examining a radiograph showing a radio-opaque ureteric catheter in situ.

Ureter

the ureter is divided into three sections • upper third: from renal pelvis to the top edge of the sacrum • middle third: from the top edge to the lower edge of the sacrum • distal third: lower edge of the sacrum to the urinary bladder

Bladder • Bladder abdominal X-ray • The bladder has variable appearance depending on how full it is. It has the same density as other soft tissue structures, due to its water content

Urethra

Psoas muscle • It is obliterated in Enlarged kidney Psoas abscess Splenic injury

Positive finding • Calculi in kidneys and ureters • Calcification of kidneys and ureters • Vesical calculi or calcification • Urethral calculi • Prostatic calcification • Calcification of spermatic tract • Foreign bodies in urinary tract • Lesions invoving the lumbar vertebrae and bony pelvis

extra urinary shadows • Calcification of blood vessels(phlebolith)- focal calcifications, often with radiolucenters (if present, a helpful sign to distinguish them from urolithiasis), round, either side of pelvis, in the distribution of pelvic veins, 2 -6 mm in diameter • Two signs are helpful in distinguishing a ureteric calculus from a phlebolith: • comet-tail sign: favours a phlebolith. The sign refers to a tail of soft tissue extending from a calcification, representing the collapsed/scarred/thrombosed parent vein. When well seen it is said to have a positive predictive value of 100% 1. • soft-tissue rim sign: favours a ureteric calculus

• Calcification of intraabdominal organs • Calcification of costal cartilages and transverse process of lumbar vertebra • Calcified mesentric and retroperitoneal lymph nodes • Foreign bodies (surgical clips, IUDs, IVC filters) • Female genital tract • Pessaries, Tampoons • Carcinoma of ovary • Dermoid cysts of ovary

Source of error • Errors in technique • Overexposed film • Motion artifact of the patient • Unclean cassette • Fecal material , Gas in the GI tract

Limitations • Loaded colon may obscure small stones • Calcifications in pelvic veins or vascular structures may be confused with ureteric calculi • Radiolucent stones not visualized