Abdominal Ultrasound

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Abdominal Ultrasound

• Peritoneum/Retroperitoneum
• Gastrointestinal Tract (1-5)

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Peritoneum

• Peritoneum
• Thin membrane consisting of two layers
• Parietal peritoneum
• Lines the abdominal cavity wall
• Visceral peritoneum
• Lines the organs

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Parietal Peritoneum
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Peritoneal Cavity

• Between the two layers is a potential space for
  fluid accumulation
• Both parietal and visceral peritoneum secrete a
  small amount of serous fluid which functions to
  lubricate the organ surfaces so that there is no
  friction
• Peritoneum allows for mobility of the organs to
  slip and slide
• The peritoneal cavity is divided into a greater
  and lessor sac

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Peritoneal Cavity

• The cavity is an enclosed sac in males
• The sac has an opening for the fallopian tubes in
  females
• The only communication between the lesser and
  greater peritoneal spaces is an opening a finger
  width in diameter, called the foramen of Winslow.
• The foramen of Winslow lies adjacent to the
  second portion of the duodenum.
• The lesser sac is usually empty, or nearly so,
  even when ascites is present in the greater sac

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Peritoneal Cavity

• Spaces in the peritoneal cavity for potential
  fluid collection include the
• Subhepatic region (morisons pouch)
• Right and left subphrenic areas (beneath the
  diaphragm)
• Lesser sac
• Paracolic gutters
• Cul-de-sac

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Subhepatic Space

• Morrison's pouch (hepatorenal pouch) - space
  formed beneath the right lobe of the liver the
  the right kidney
• It is the first location at which ascites
  collects in the right upper quadrant

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Subhepatic fluid collection
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Morisons Pouch
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Subphrenic Space

• Right left subphrenic space - folds in the
  peritoneum in the hepatic region, this space lies
  between the diaphragm the liver and the
  diaphragm and the spleen
• The falciform ligament divides the subphrenic
  space into right and left components.
• The bare area of the liver is delineated by the
  right superior and inferior coronary ligaments,
  which separate the posterior subphrenic space
  from the right superior subhepatic space(Morisons
  pouch)

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Ascites
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Morrisons Pouch
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Subphrenic Space
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Liver with Ascites
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Ascites with Spleen
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Lessor Sac

• Presence of lesser sac fluid indicates two forms
  of pathology.
• First, significant nearby disease, particularly
  pancreas or stomach.
• Second is peritoneal carcinomatosis, causing
  malignant ascites.
• Ordinary transudative ascites does not usually
  enter the lesser sac unless the quantity of
  ascites is massive.

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Lessor Sac
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Paracolic Gutters

• Extend downward
• Space between the abdominal wall and colon
• Lies along the lateral medial walls
• Communicates with the pelvis

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Ascites with Bowel
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Cul-de-Sacs
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Cul-de-Sacs
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Peritoneum

• Organs that are covered by peritoneum
• Liver
• Gallbladder
• Spleen
• Stomach
• Intestines
• Ovaries
• Except for the female pelvis, the peritoneum is
  essentially an empty sac

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Fluid Collections

• Sonographer must know where to look for the
  fluid.
• The most dependent part of the peritoneal space,
  with the patient supine, is the pelvic cavity.
• The next most likely location is along the
  lateral or anterior aspect of the liver.
• Dont forget to look anterior to the left and
  right lobes of the liver
• The next most common locations are Morisons
  pouch and the right paracolic gutter.

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Fluid Collections

• Important things to think about when a fluid
  collection is seen
• Where is the fluid collection?
• Peritoneal cavity, retroperitoneal,
  extraperitoneal space, or pleural cavity
• Is the fluid collection simple or complex?
• Septations, debris, or fluid levels
• Is there an explanation for the fluid collection?
• know patient history

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Ascites

• Free fluid in the peritoneal cavity
• Transudative ascites
• Accumulation of fluid resulting from insufficient
  osmotic pressure to keep fluid in blood vessels
• Benign, often observed in chronic cirrhosis and
  liver failure, renal failure or congestive heart
  disease
• Fluid containing little or no protein and is
  associated with heart, kidney, or liver failure
• Treatment is with a low sodium diet, diuretics
  and removal of fluid (therapeutic paracentesis)
• Transudative ascites is echo free

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Ascites/Jaundice
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Pleural Effusion
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Pleural Effusion
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Pleural Effusion
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Ascites
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Ascites
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Fetal Ascites
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Ascites

• Exudative ascites
• It is a reaction to an abnormality, associated
  with malignancy and inflammatory processes
• Causes include hemorrhage, infection and
  peritoneal malignancy (ovarian CA)
• Exudative ascites contains cells or proteinaceous
  debris, and may be echogenic
• May have septations and is not free flowing
• Paracentesis needle aspiration of ascites for
  diagnostic reasons

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Exudative Effusion
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Pseudomyxoma Peritonei

• Malignant ascites - it is a condition described
  as the filling of the peritoneal cavity with
  mucinous material and gelatinous ascites
• Adhesions are present which producing matting of
  the mesentery and bowel posteriorly in the
  abdominal cavity

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Pseudomyxoma Peritonei

• There are three causes of malignant ascites
• Metastasis
• Rupture of a mucinous cystadenocarcinoma of the
  ovary
• Rupture of an appendix

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Pleural Effusion w/ Mult. Loculations
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Pleural Effusion w/ Mult. Loculations
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Pseudomyxoma Peritoneidemonstrated by CT scan
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Retroperitoneum

• Only their anterior surfaces are covered with
  peritoneum
• Retroperitoneum structures include
• Pancreas
• Portions of the duodenum
• Kidneys ureters
• Ascending descending colon
• Adrenal glands
• IVC
• Aorta
• Prostate
• Lymph nodes
• Uterus
• Bladder

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Retroperitoneum
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Retroperitoneum

• Retroperitoneal spaces do not normally
  communicate with the peritoneal cavity
• Perinephric space
• Space formed around the kidney and adrenal gland
• Perirenal space
• Anterior pararenal space
• Posterior pararenal space
• Both Lymphoceles and Urinomas are found in the
  retroperitoneal space

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Retroperitoneal Fibrosis

• A dense fibrous tissue proliferation that
  generally is confined to the paravertebral and
  central abdominal region
• They may occur in association with aortic
  aneurysms
• They may encase the ureters causing secondary
  hydronephrosis
• Sonographically appears as a hypoechoic mass
  anterior to the lower lumbar or sacral region

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Lymphocele

• Collection of lymphatic fluid
• Typically are complecations of renal
  transplantation and gynecologic surgery
• The etiology is usually leakage of lymph from a
  renal transplant or by a surgical disruption of
  the lymphatic channels
• Loculated ascites, urinoma, hematoma or abscess
  may appear similar to lymphoceles
• The presence of internal echoes within the fluid
  collectin is more consistent with abscesses or
  hematomas than with lymphoceles

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Lymphocele

• Lymphocele adjacent to transplanted kidney

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Lymphocele

• Large septated lymphocele between lower pole of
  transplanted kidney and bladder.

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Urinoma

• Collection of urine
• They result form renal trauma, renal surgery or
  an obstructing lesion
• They are most commonly associated with renal
  transplantation and posterior urethral valve
  obstruction
• They sonographicly appear the same as lymphoceles

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Ultrasound Appearance

• Ultrasound can not tell you what the fluid is,
  however it can tell you if it is retroperitoneal,
  peritoneal or both
• It is not unusual for fluid to originate in the
  retroperitoneum and involve the peritoneal
  cavity, however the opposite is very unlikely

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Urinoma
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Urinoma
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Urinoma
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Urinoma
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Pleural Effusion

• Space formed surrounding the lung
• Pleural effusion's are a non-specific reaction to
  Another underlying problem, like
• Pulmonary disease, Cardiac disease
• Systemic disease, Cirrhosis
• End stage renal disease, Malignancy
• Infection, Trauma

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Ascites/Pleural Effusion
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Hemothorax
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Pleural Effusion
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Pleural Effusion
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Pleural Effusion
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Pleural Effusion
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CT of Pleural Effusion
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X-Ray of Pleural Effusion
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X-Ray of Pleural Effusion
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GI-Technique

• We typically evaluate these four areas of the GI
  tract with ultrasound
• Stomach-filling the stomach facilitates
  examination of the wall
• Appendix-examined with graded compression, the
  landmarks to identify are the terminal ileum,
  cecum and psoas
• Inguinal hernia-the transducer is placed in the
  groin sagittally. The Inferior epigastric artery
  is identified. Have the patient valsalva and see
  if the hernia will move into the inguinal canal
• Rectum-water enema can be used to evaluate the
  rectum, water is placed in the rectum and sigmoid
  colon to determine whether an apparent mass is
  actually normal gut

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Esophagus

• Sonoendoscopy can be used to evaluate the
  esophagus above the the diaphgram
• The esophagus is a muscular canal
• Extends from the pharynx to the stomach
• Sonographicly you can visualize the
  gastroesophageal junction (GEJ) in a sagittal
  cross section of the aorta, seen anterior to the
  aorta as a bulls eye structure

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Stomach

• Sonoendoscopy can be used to evaluate the stomach
• It has a target or bulls eye pattern
  sonographicly
• Hyperechoic mucosal layer (outer layer)
• Hypoechoic intramural layer
• Hyperechoic submucosa
• Hypoechoic muscularis
• Hyperechoic serosal layer (inner layer)
• The wall of the stomach should appear thin and
  uniform when distended and should not exceed 5.0
  mm
• Function is in the storage of food

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Small Intestine

• Extends from the pylorus to the ileocecal valve
• Surrounded superiorly and laterally by large
  bowel
• Duodenum, Jejunum, Ileum function is in the
  absorption of food
• Sonographic appearance
• Duodenum is usually gas filled, found to the
  right of the pancreas head, fluid may be seen
  within the second portion of the duodenum

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Colon

• Extends from the ileum to the anus
• Includes the cecum, aapendix, ascending colon,
  transverse colon, descending colon, sigmoid,
  rectum, anal canal
• The function is in the reabsorbtion of liquid and
  wastes formed into solid feces
• Sonographicly normal bowel wall should not
  exceed 4.0 mm and the rectum is best evaluated by
  endorectal ultrasound

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Hypertrophic Pyloric Stenosis

• HPS is characterized by hypertrophy and
  hyperplasia of the circular muscle which results
  in elongation of the pylorus and constriction of
  the canal
• It is familial and occurs more often in males
  (51)
• Symptoms include
• Projectile vomiting usually starting in the 2-3
  week of life
• Dehydration
• Weight loss
• Palpable abdominal mass

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Hypertrophic Pyloric Stenosis

• Sonographic appearance includes
• Target lesion seen medial to the gallbladder and
  lateral to the pancreas head
• Appears as a hypoechoic ring of hypertrophied
  pyloric muscle around an echogenic central mucosa
• Measurements
• Transverse abnormal muscle thickness is gt3-4
  mm, and a length gt13-15 mm
• Sagittal over 18 mm in length
• Obstructed fluid-filled stomach will be seen due
  to the stenosis

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Pyloric Stenosis
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Pyloric Stenosis
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Pyloric Stenosis
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Hypertrophic Pyloric Stenosis
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Pyloric Stenosis
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Pyloric Stenosis
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Pyloric Stenosis
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Pyloric Stenosis
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Pyloric Stenosis
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Appendicitis

• Population - acute appendicitis is more commonly
  seen in young adults
• Symptoms RLQ pain with rebound tenderness and
  elevated WBC
• Sonographic appearance includes
• Target lesion in the RLQ
• Inflamed appendix should measure more than 6 mm
  in diameter with the hypoechoic portion of the
  wall measuring more than 2 mm in thickness
• An inflamed appendix will have increased blood
  flow
• Appendiceal calculus (appendicolith) may be seen
  as an echogenic structure within an acoustic
  shadow, this finding alone is sufficient to
  diagnosis appendicitis even if the appendix is
  not enlarged
• Fluid may be seen around the appendix

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Acute appendicitis
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Acute appendicitis
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Appendicitis
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Appendicitis