X-RAY KUB (KIDNEY, URETER, BLADDER)
ANATOMY OF URINARY SYSTEM
In medicine, KUB refers to a diagnostic medical imaging technique of the abdomen and stands for Kidneys, Ureters, and Bladder. A KUB is a plain frontal supine radiograph of the abdomen. A kidney, ureter, and bladder (KUB) X-ray may be performed to assess the abdominal area for causes of abdominal pain, or to assess the organs and structures of the urinary and/or gastrointestinal (GI) system. A KUB X-ray may be the first diagnostic procedure used to assess the urinary system.
KUB is typically a single x-ray procedure and also used to investigate gastrointestinal conditions such as a bowel obstruction and gallstones, and can detect the presence of kidney stones. The KUB is often used to diagnose constipation, to assess positioning of indwelling devices such as ureteric stents and nasogastric tubes. The KUB does not necessarily include the diaphragm. The projection includes the entire urinary system, from the pubic symphysis to the superior aspects of the kidneys. The anteroposterior (AP) abdomen projection, in contrast, does include the bilateral diaphragm.
X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body tissues onto specially treated plates (similar to camera film) and a "negative" type picture is made (the more solid a structure is, the whiter it appears on the film) .
KUB radiography is often used as a first step in diagnosing problems of the urinary system, and is usually done in conjunction with intravenous pyelography/urography. Other related procedures that may be used to diagnose problems of the urinary organs of the abdomen include computed tomography (CT scan) of the kidney, kidney ultrasound, kidney scan, cystography, cystometry, cystoscopy, intravenous pyelogram, kidney biopsy, magnetic resonance imaging (MRI), prostate ultrasound, retrograde cystography, retrograde pyelogram, uroflowmetry, and renal venogram.
INDICATIONS:- Pain in abdomen Unexplained nausea suspected problems in urinary system e.g kidney stones, renal cell tumor etc identify blockage in the intestine to locate the swallowed object fluid in the abdominal cavity foreign bodies in the stomach. Sometimes gall stones
CONTRAINDICATIONS:- Pregnancy- birth defects. Presence of IUCD, recent barium x-rays of the abdomen, presence of gas, bismuth containing medication(should stop 4 days before KUB), faeces or foreign body in the intestine, uterine or ovarian masses all of these conditions may interefere with the accuracy of a x-ray KUB. Generally no prior preparation such as fasting or sedation is required. KUB usually done as an outpatient procedure. In males, external genitalia should be covered with lead apron. A radiologist or a qualified technician should perform KUB.
Before the procedure:- Your doctor will explain the procedure to you. Generally, no prior preparation, such as fasting or sedation, is required, but its better to avoid to eat and drink anything 4 hrs prior to the test. Notify the radiologic technologist if you are pregnant or have an IUCD. Notify your doctor and radiologic technologist if you have taken a medication that contains bismuth, such as Pepto-Bismol, in the past four days. Remove any jewellery or metal objects. Put on an X-Ray gown.
During the procedure A KUB X-ray may be performed on an outpatient basis or as part of your stay in a hospital. Generally, a KUB X-ray follows this process: Remove any clothing, jewelry, or other metal objects that might interfere with the procedure and wear hospital gown. You will be positioned carefully the part of the abdomen that is to be X-rayed between the X-ray machine and a cassette. You may be asked to stand erect, to lie flat on a table, or to lie on your side on a table, depending on the Xray view your doctor has requested. You may have X-rays taken from more than one position. Body parts not being imaged may be covered with a lead apron (shield). Once you are positioned, the radiologic technologist will ask you to hold still for a few moments while the X-ray exposure is made.
It is extremely important to remain completely still while the exposure is made, as any movement may distort the image and even require another X-ray to be done to obtain a clear image. The X-ray beam will be focused on the area to be photographed. The radiologic technologist will step behind a protective window while the image is taken. While the X-ray procedure itself causes no pain, the manipulation of the body part being examined may cause some discomfort or pain, particularly in the case of a recent injury or invasive procedure, such as surgery. The radiologic technologist will use all possible comfort measures and complete the procedure as quickly as possible to minimize any discomfort or pain.
After the procedure Generally, there is no special type of care following a KUB X-ray. Risks and Complications of KUB Radiography X-ray exams involve minimal exposure to radiation. After the KUB Radiography You may return home and resume your usual activities. Results of KUB Radiography X-ray films are usually ready shortly after the test is completed. A radiologist will examine the images for abnormalities. A definitive diagnosis can rarely be made based on a KUB study alone. In most cases, additional tests—such as USG or intravenous pyelography—are required in order to establish a diagnosis and determine the extent of the problem.
uUreteric cal
FINDINGS OF KUB:- Results of a KUB study may show injuries to the stomach or intestines, fluid in the abdominal cavity, or a blockage of the intestines. In addition, results may show the presence of kidney stones or gallstones. Abnormal findings include:- Abdominal masses, fluid in the abdomen, Certain types of gallstones, Foreign object in the intestines, Hole in the stomach/intestines, Injury to the abdominal tissue, Intestinal blockage, Kidney stones
The test may be performed for:- Abdominal aortic aneurysm, Acute appendicitis, Acute cholecystitis, Acute kidney failure, Addison disease, Adenomyosis, Annular pancreas, Ascariasis, Atheroembolic renal disease, Biliary atresia, Blind loop syndrome, Cholangitis, Chronic renal failure, Cirrhosis,
Echinococcus, Encopresis, Hirschsprung disease, Idiopathic aplastic anemia, Injury of the kidney and ureter, Intussusception (children), Necrotizing enterocolitis, Nephrocalcinosis, Peritonitis, Primary or idiopathic intestinal pseudo-obstruction, Renal artery stenosis, Renal cell carcinoma, Secondary aplastic anemia, Toxic megacolon, Wilms tumor
Constipation in a young child as seen by KUB X-ray. Circles represent areas of faecal matter.
PLAIN X-RAY ABDOMEN ERECT POSTURE - AP VIEW
diagrammatic representation of the radiological anatomy of the abdomen
It is often used for urgent investigation - for example, of acute abdominal pain. Investigations are normally undertaken after history and examination. Other imaging techniques should be considered, including ultrasound, CT scans and MRI scans Erect abdominal X-rays are employed to look for fluid levels in obstruction or ileus. Air may be seen under the diaphragm in an erect film if the bowel has been perforated, although a CXR is more usual to look for that sign. Abdominal X-ray is of no value in haematemesis.
Indications:- Renal colic. Intestinal obstruction. Perforation of the intestine. Appendicitis. Intussusception. Detection of swallowed foreign bodies
Intestinal obstruction: Erect and supine films are used to confirm the diagnosis. Obstruction of the small bowel shows a ladder-like series of small bowel loops but this also occurs with an obstruction of the proximal colon. Fluid levels in the bowel can be seen in upright views. Distended loops may be absent if obstruction is at the upper jejunum. Obstruction of the large bowel is more gradual in onset than small bowel obstruction and distension may be very marked. Fluid levels will also be seen in paralytic ileus when bowel sounds will be reduced or absent rather than loud and tinkling as in obstruction. In an erect film, a fluid level in the stomach is normal as may be a level in the caecum. Multiple fluid levels and distension of the bowel are abnormal.
Perforation of the intestine: If the bowel has been perforated and a significant amount of gas has been released it will show as a translucency under the diaphragm on an erect film. Gas will also be found under the diaphragm for some time after laparotomy or laparoscopy. Appendicitis: An appendicolith may be apparent in an inflamed appendix in 15% of cases but as a diagnostic point in the management of appendicitis, the plain X-ray is of very limited value. It may be of value in infants.
Intussusception: Intussusception occurs in adults and children. A plain abdominal X-ray may show some characteristic gas patterns. Detection of swallowed foreign bodies: Plain X-ray will detect the presence of radiopaque foreign bodies. A plain abdominal X-ray will show 90% of cases of 'body packing' (internal concealment of drugs to avoid detection) but there will be false positives in 3%.
Suggested approach to viewing films Identify the name and date on the film. If there are previous films, use them for comparison. Identify the projection of the film (most are anteroposterior (AP)). Identify the view taken ('supine' , 'erect' or 'lateral decubitus'). Confirm that an adequate area has been covered. An abdominal film should include the lower anterior ribs. Check exposure. Artefacts may be immediately obvious. Piercing of the umbilicus is very popular, especially in young women but genital piercing is not infrequent. Metallic objects are obvious. There may be clips or materials from previous surgery. Occasionally a retained surgical instrument is seen. Swabs contain a radio-opaque band.
Solid organs, hollow organs and bones can be classified as: Visible or not visible. Normal in size, enlarged, or too small. Distorted or displaced. Abnormally calcified. Containing abnormal gas, fluid, or discrete calculi. Bones Identify: Lower rib cage Lumbar spine, Sacrum, Pelvis, Hip joints Check for: Cortical outline, Joint and disc space, Trabecular pattern, General bone density, Lysis, fracture, sclerosis, Epiphyseal lines
Solid organs Liver: There is soft tissue density in the right upper quadrant that displaces any bowel from this area. Spleen: Soft tissue mass in the left upper quadrant about the size of a fist (usually is not visible). Kidneys: A shadow may be visible. The left kidney is higher than the right. The upper poles tilt medially. They should be about three vertebrae in size. Psoas muscles: Form straight lines extending inferolaterally from the lumbar spine to the lesser trochanter of the femur.
Bladder: If the bladder is full, it will appear as a soft tissue density in the pelvis. Uterus: Sits on top of and may indent the bladder. It is often not seen on plain films. Prostate: Sits deep in the pelvis. Usually only seen if calcified.
Hollow organs Stomach: When supine, air in the stomach will rise anteriorly and fluid will pool posteriorly. Small bowel: Gas will be seen in polygonal shapes, due to peristalsis. Normal small bowel is 2.5 to 3.0 cm in diameter. Valvulae may be seen crossing the entire lumen. Appendix: Occasionally, an appendicolith is seen. Less commonly, barium from an old study, or ingested foreign bodies will appear in the appendix. Colon: Start in the right iliac fossa with the caecum that may show fluid levels.Follow it up to the hepatic flexure, over to the splenic flexure, and down into the pelvis. It may be filled with air or faeces.
Normal calcification:- Costal cartilage Mesenteric lymph nodes Pelvic vein phleboliths Prostate gland Abnormal calcification:- Calcium indicates pathology in: Pancreas. Renal parenchymal tissue. Blood vessels and vascular aneurysms. Calcium can make the following pathology visible: Biliary calculi Renal calculi Appendicolith Bladder calculi Teratoma
Other calcification Costal cartilages Mesenteric lymph nodes may calcify and be confused with ureteric calculi. Phleboliths from calcified pelvic veins may appear like bladder stones. Calcification may appear in the ageing prostate,in the pelvic brim. Prostate calcification may also occur in malignancy. Calcification occurs in chronic pancreatitis and may show the whole outline of the gland. Calcification of the renal parenchyma indicates hyperparathyroidism, renal tubular acidosis, and medullary sponge kidney.
Calcification of blood vessels. Extensive calcification may indicate widespread atheroma, especially in diabetes. Calcification of Abdominal aortic aneurysms are usually below the 2nd lumbar vertebra. Uterine fibroids can become calcified. Gallstones are visible in only 10-20% of cases. Renal calculi especially at the pelvi-ureteric junction, brim of the pelvis, and vesico-ureteric junctions. In the pelvic region, bladder calculi may occasionally be seen. Calcification of a bladder tumour may also occur. Sometimes, ovarian teratoma may show a tooth.