ULTRASOUND OF THE ABDOMEN PART II LECTURE 12

ULTRASOUND OF THE ABDOMEN PART II LECTURE 12: RETROPERITONEUM PART B HHHOLDORF

OUTLINE The Abdomen - Overview Abscess Biloma Ascites Lymphocele Urinoma Pseudomyxoma Peritonei Hematoma Lymphoma Thorax (non-Cardiac Chest) Baker’s cyst Rectus Sheath Hematoma Abdominal Wall neoplasm Hernias/Inguinal Hernia

BOUNDARIES OF THE ABDOMINAL CAVITY Superiorly…. Diaphragm Inferiorly…. Pelvis Anteriorly…Abdominal Wall muscle Posteriorly…Vertebral column, ribs, Iliac fossa.

SURFACE LANDMARKS OF THE ANTERIOR ABDOMINAL WALL Xiphoid process Palpated where the costal margins meet at the infra-sternal angle Costal margins Curved lower margin of the thoracic wall Iliac crest Palpated and ends in front at the anterior iliac spine and behind at the posterior iliac spine Pubic symphysis Cartilaginous joint that lies in the midline between bodies of the pubic bones Linea albea (white Line) Midline fibrous band that extends from the pubic symphysis to the Xiphoid process Umbilicus Remnant of the fetal umbilical cord

ANATOMY OF ANTERIOR ABDOMINAL WALL From outermost layer working in: Skin- epidermis is highly echogenic Superficial fascia Subcutaneous fat- relatively anechoic. Muscle layers Transversalis fascia Extraperitoneal fat

IMAGES OF THE ANTERIOR ABDOMINAL WALL

ANTERIOR ABDOMINAL MUSCLES CONT. Rectus sheath- Fibrotic band which extends from the Xiphoid process to the symphysis pubis. Linea Alba- The rectus sheath joins in the midline to form linea alba, separating the rectus muscles in the midline. Linea semilunaris- A curved tendinous line placed one on either side of the rectus Abdominis. Arcuate line- Located midway between the umbilicus and symphysis pubis. At this level the post caudal portion of the rectus sheath ends and the joining of all three muscles pass in front of the rectus muscle.

LINEA ALBA

ARCUATE LINE

POSTERIOR ABDOMINAL WALL MUSCLES Psoas Muscle Medial and posterior to kidneys Lateral to spine Quadratus Lumborum Adjacent to the iliac crest Depending on the level; posterior to kidneys, colon, psoas m. Tapers cephalically (Sag. ) Iliacus Muscle- within the iliac space iliopsoas Muscle- A convergence of the iliacus and psoas muscle.

POSTERIOR ABDOMINAL WALL MUSCLES

DIAPHRAGM A large muscle Forms partition between thoracic and abdominal cavities Dome shaped Moves with respiration- Due to large effusion or bronchial Cancer the diaphragm might not move with respiration and become flatten or Convex Normal US- concave, echogenic Appearance can change due to hernia, pleural effusion, COPD (Chronic obstructive pulmonary disease)

DIAPHRAGM CONT. The Aorta, IVC, esophagus pass through individual openings called Hiatuses in the diaphragm. Crura: Are elongated muscular bands that arise from the lumbar vertebrae and insert into the diaphragm and connect the diaphragm and the spinal column. On the Us Crus appears as low level echoes. The right crus- Post. to IVC The left crus- Ant. to Aorta, proximal to the celiac trunk Attachments: Attached to Xiphoid process in front Attached to costal margins at sides Rt. & Lt. parts insert into the central tendon.

HOW DOES THE DIAPHRAGM MOVE WITH RESPIRATION? HOW DOES THIS AFFECT LOWER EXTREMITY VENOUS RETURN?

ABSCESS The sonographic appearance of an abscess is quite variable. Typically, an abscess is a complex mass (solid or cystic). Debris, septations and gas can be seen within the abscess. The boarders of an abscess are typically irregular. Gas within the abscess may produce a reverberation (comet-tail) artifact. Abscesses typically demonstrate posterior enhancement depending on the cystic component of the abscess. The most reliable findings in patients with abscesses are: Presence of fever Increased white blood cell count

ABSCESS: Variable appearance on US: Generally hypo to anechoic some may contain internal debris. Usually has acoustic enhancement. Presence of gas produces bright echogenic reflections and dirty shadow

INTRA-ABDOMINAL ABSCESS

INTRA-ABDOMINAL ABSCESS CT

BILOMA Bilomas are extrahepatic collections of extravasated bile. They are caused by abdominal trauma, gallbladder disease, or biliary surgery. Bilomas are predominantly cystic masses located in the right upper quadrant.

BILOMA: Extrahepatic collection of extravagated bile. Causes: trauma, GB disease, biliary surgery. Ultrasound appearance: Anechoic mass with sharp borders & good through transmission. May contain some debris. Located in RUQ or mid abdomen.

BILOMA ON ULTRASOUND

BILOMA ON CT

ASCITES Ascites is the excessive accumulation of serous fluid in the peritoneal cavity. The mechanisms that produce Ascites are complex and incompletely understood. Two mechanisms that produce Ascites are: Low serum osmotic pressure (protein Loss) High portal venous pressure Causes of Ascites include: Cirrhosis (most common cause) Hypoalbuminemia (decreased protein) Budd-Chiari Syndrome Heart failure Cancer Nephrotic syndrome (protein loss)

Hypoalbuminemia (low protein) can be the result of liver failure, nephritic syndrome or malnutrition. Transjugular intrahepatic portal systemic shunting (TIPS) can successfully treat Ascites by lowering portal pressure. Ascites is commonly found at the Inferior aspect of the right lobe of the liver Morison’s pouch Pelvic cul de sac Paracolic gutters

Gallbladder wall thickening is frequently seen with Ascites Benign Ascites is indicated by freely floating bowel. With malignant Ascites, the bowel loops are tethered or matted to the posterior abdominal wall surrounded by complex or loculated fluid collections.

Pleural effusion- fluid collection superior to the diaphragm Ascites- Excessive accumulation of serous free fluid surrounding or interposed between organs. Collects Inferior to the diaphragm. Over 90% are due to Cirrhosis, Neoplasm, or CHF. Other causes: Hypoalbuminemia, endocrine disease. Pancreatic Ascites may develop due to chronic pancreatitis or Pancreatic pseudocyst.

ASCITES: TRANSUDATIVE VS. EXUDATIVE Transudative ascites is defined as having less than 3 g of protein per 100 ml of fluid. It is, as its name would suggest, a transudate* - a result of raised hydrostatic pressure forcing fluid out of blood vessels. Causes include: cardiac failure. *A filtrate of blood

Exudate ascites is defined as ascites with a protein content of greater than 3 g protein per 100 ml of fluid. Possible causes of exudate ascites include: malignant disease. pyogenic infection. tuberculosis.

ASCITES CONT. Transudative US: Anechoic region in peritoneal cavity. Collects in the most dependent area of the abdomen First seen in the Morrison’s pouch or pouch of Douglas. then seen in Paracolic gutters. Freely mobile, bowel loop can be seen floating within ascites.

ASCITES CONT. Exudative Due to inflammation and malignancy. US: May have Septations, Echogenic debris, loculation of fluid, matted bowel loops. Loculated ascites: is no compressible, does not move with change of position. Differential Diagnosis: Abscess, cystic Neoplasm, hematoma, lymphocele.

ASCITES Urine ascites: results from renal transplant, pt. on chronic hemodialysis. Bloody Ascites: caused by ruptured Aorta, ruptured ectopic pregnancy, etc.

ASCITES IN SEVERAL ABDOMINAL COMPARTMENTS

IMAGE OF BENIGN ASCITES

MALIGNANT ASCITES

LYMPHOCELE Lymphoceles are complications of Renal transplantation Gynecologic surgery Vascular Surgery Urological Surgery Caused by leakage of lymph from a renal allograft (transplant) or by a surgical disruption of the lymphatic channels. Differential diagnosis includes any fluid collection such as loculated Ascites, Urinoma, hematoma, or abscess. The presence of internal echoes within the collection is more consistent with an abscess or hematoma than with a Lymphocele.

LYMPHOCELE A lymph–filled cystic mass with no epithelial lining. Causes: Complication of surgery ( involving-vascular, urological, gynecological, renal. ) Leak by surgical disruption of the lymph. US: round, /elliptical, anechoic, septations seen frequently, w/ good through transmission

LYMPHOCELE.

URINOMA An Urinoma is a collection of urine which is located outside of the kidney or bladder. Urinomas are caused by renal trauma, renal surgery, or from an obstructing lesion. Most commonly associated with Renal transplantation. Posterior urethral valve obstruction May accumulate directly after a renal transplant due to an anastomotic leak of the ureter. sonographic appearance is similar to a Lymphocele.

URINOMA: A collection of urine, located outside the kidney or bladder due to an obstructing lesion. Causes : Renal trauma, renal surgery, renal transplant. US: elliptical anechoic mass located in perinephric space. Differential Diagnosis: Lymphocele.

A URINOMA

PSEUDOMYXOMA PERITONEI The filling of the peritoneal cavity with mucinous material and gelatinous Ascites. Tumor implants are found on the peritoneal surfaces. Bowel loops will be matted to the posterior abdominal wall. Caused by metastasis or rupture of a mucinous cystadenocarcinoma of the ovary or mucinous tumor of the appendix. This is referred to as malignant Ascites.

AN ULTRASOUND IMAGE OF A PSEUDOMYXOMA PERITONEI

A CT SCAN OF A PSEUDOMYXOMA PERITONEI.

HEMATOMAS A hematoma is a collection of blood which is usually confined to an organ, tissue or space. The ultrasound appearance of hematomas is variable and depends on the age of the collection. Fibrin invasion causes hematomas to appear hyperechoic. Gradual hemolysis eventually creates an anechoic appearance. Organization of clot or fragmentation of the clot will produce irregular echoes. Calcifications are often associated with longstanding hematomas. A decrease in the hematocrit level indicates the presence of a hematoma. Hematocrit is the volume of red blood cells fond in 100 ml of blood. Blood spillage outside the circulatory system will result in a decreased hematocrit

AN NEW HEMATOMA – TENNIS LEG

AN OLD HEMATOMA- TRANSPLANTED KIDNEY HEAMTOMA- ECHOFILLED

LYMPHOMA Lymphoma encompasses two groups of neoplasms: Non-Hodgkin Lymphoma (NHL) Hodgkin disease Both Hodgkin’s lymphoma and non-Hodgkin’s lymphoma are a type of cancer that begins in a subset of WBCs called lymphocytes, which are an important part of the immune system. The main difference between Hodgkin’s and non-Hodgkin’s is in the specific lymphocyte each one involves. If a Reed-Sternberg cell is detected, the lymphoma is classified as Hodgkin’s. If the RS cell is not seen, then it is Non-Hodgkin’s, and the treatment and outcome for each type can be quite different.

Lymph nodes sonographically appear as an anechoic/hypoechoic mass containing a central echogenic foci. Lymph tissue is not associated with acoustic enhancement. The SANDWICH or MANTLE sign is the presence of peri-vessel lymphoma. Lymphomatous nodules typically cluster anterior and posterior to linear structures such as the aorta or the Superior Mesenteric Artery. This finding can be clinically important as it is found more frequently with non-Hodgkin lymphoma than with Hodgkin’s lymphoma.

Findings associated with non-Hodgkin lymphoma include: Peripheral lymphadenopathy Splenomegaly Hepatomegaly Cytopenia – A reduction in the number of blood cells. Abdominal mass causing bowel obstruction Hydronephrosis due to retroperitoneal nodes.

NORMAL LYMPH NODES

THE SANDWICH (MANTLE) SIGN

THORAX (NON-CARDIAC CHEST) Ultrasound imaging is utilized in the thorax for: Identifying a pleural effusion Identifying solid pleural masses Identifying a pneumothorax Localization for Thoracentesis

Localization of pleural fluid is performed with the patient in a sitting position. A dorsal intercostals space is marked so that a puncture can easily access the fluid away from the diaphragm Solid pleural masses and loculated thoracic fluid are typically seen fixed away from the diaphragm, opposed to free fluid that accumulated in the recesses of the diaphragm. A pneumothorax is identified with the absence of gliding of the parietal and visceral pleura and the presence of a comet tail artifact between these layers. This exam is typically performed with a trauma patient. With the patient in a supine position, air can be located on the anterior medial location of the thorax.

PLEURAL EFFUSION

BAKER’S CYST A Baker’s cyst is a collection of synovial fluid in the popliteal fossa. It is commonly located in the medial aspect of the popliteal fossa. They may also extend downward into the calf muscles. Causes include Rheumatoid arthritis Osteoarthritis Overuse of the knees Symptoms may be mistaken for deep venous thrombosis due to pain and swelling behind the knee and the upper calf.

AN IMAGE OF A BAKER’S CYST

RECTUS SHEATH HEMATOMA The rectus Abdominis muscles are two longitudinally oriented muscles extending from the Xiphoid process to the pubic bone. They are encased in a sheath anteriorly and posteriorly. These sheaths join at the midline to form the LINEA ALBA. The Anterior and posterior rectus sheath extend from the costal margin to the arcuate line (Semi-circular line), which is located midway between the umbilicus and the symphysis pubis, where the posterior wall of the sheath ends.

RECTUS SHEATH HEMATOMA Posttraumatic Direct trauma; surgery Sudden vigorous abdominal contraction- seizure, coughing, sneezing Spontaneous Anticoagulants therapy is the most common cause of rectus sheath hematoma Bleeding disorders pregnancy

RECTUS SHEATH HEMATOMA CONT. US Appearance: Depends on the relation to Arcuate line, Age and the transducer. Above Arcuate line hematoma is ovoid, does not cross midline. Below Arcuate line can spread across and even to pelvis, forming large mass, compressing the urinary bladder.

HEMATOMA: Collection of blood , usually confined to an organ, tissue, space. Causes: Trauma or surgery- most common in pt. on anticoagulant. Hemophiliacs, leukemic. US- variable depending on the age of the bleed: Subcapsular Hematomas retain the shape of the organ they surround. Peritoneal Hematomas can be ovoid or crescent. Lab. -There is a drop in patients hematocrit level.

A rectus sheath hematoma is a result of a tear in the epigastric vessels or the muscle fibers of the rectus abdomens. A rectus muscle hematoma superior to the arcuate line is confined between the anterior and posterior sheaths and should not move across eth midline due to the linea alba. A rectus muscle hematoma inferior to the arcuate line will extend into the pelvis mimicking pelvic pathology causing external compression on the urinary bladder. As with all hematomas, the sonographic appearance is variable depending on the age of the bleed.

Rectus Sheath hematomas occur in a variety of conditions such as: Trauma Pregnancy Surgical Injury Anticoagulation therapy Long term steroid therapy Heavy physical actively Violent coughing

CT IMAGE OF A RECTUS SHEATH HEMATOMA

CLINICAL ASSESSMENT OF A RECTUS SHEATH HEMATOMA

RSH- ULTRASOUND

ABDOMINAL WALL NEOPLASMS Uncommon Desmoid tumor: Most common benign tumor. Arises from fascia or aponeurosis* of muscle. Seen commonly in people with history of previous abd. surgery. 70% seen between age of 20 -40 years. 3: 1 female preponderance Other Benign tumors are; Neuroma, Lipoma, Neurofibroma *A sheet of pearly-white fibrous tissue that takes the place of a tendon in sheet-like muscles having a wide area of attachment.

ABDOMINAL WALL NEOPLASMS CONT. Metastatic Melanoma: Is the most common malignant subcutaneous nodule. Other malignancies may locally invade from pleura, peritoneum, diaphragm (mesothelioma, rhabdomyosarcoma, fibrosarcoma), or intra-abdominal organs like colon. Mets from: lymphoma, CAs of lung, breast, ovary and colon are less common

HERNIAS Inguinal Ventral Spigelian Lumbar Incisional Femoral

TYPES OF HERNIAS

WHAT IS AN INGUINAL HERNIA? An inguinal hernia occurs when tissue pushes through a weak spot in your groin muscle. This causes a bulge in the groin or scrotum. The bulge may hurt or burn.

INGUINAL HERNIA Occurs in the inguinal canal which extend from the deep inguinal ring (a defect in the transversalis m. fascia ant. To the femoral vessels and above the inguinal ring) to the superficial Inguinal ring (an opening in the aponeurosis of the ext. oblique m. ) Inguinal hernias can be direct or indirect and US can not distinguish them, but it can distinguish them from other inguinal canal pathologies. ex. undescended testicles, varicoceles. Both direct and indirect inguinal hernias can extend into the scrotum.

SYMPTOMS The main symptom of an inguinal hernia is a bulge in the groin or scrotum. It often feels like a round lump. The bulge may form over a period of weeks or months. Or it may appear all of a sudden after you have been lifting heavy weights, coughing, bending, straining, or laughing. The hernia may be painful, but some hernias cause a bulge without pain

Most inguinal hernias occur because an opening in the muscle wall does not close as it should before birth. That leaves a weak area in the belly muscle. Pressure on that area can cause tissue to push through and bulge out. A hernia can occur soon after birth or much later in life

The diagnosis of inguinal hernia is usually based on the patient’s medical history and a physical exam. Tests such as ultrasound and CT scans are not usually needed to diagnose an inguinal hernia. In most cases, a doctor can identify an inguinal hernia during a physical exam.

THE INFERIOR EPIGASTRIC ARTERY

INDIRECT INGUINAL HERNIA Exits through the deep inguinal ligament ring and is lateral to the Inferior Epigastric Artery and courses through the inguinal canal.

INDIRECT

DIRECT INGUINAL HERNIA Protrudes through a weakened inguinal canal floor medial to the Inferior epigastric artery.

DIRECT

DIRECT VS. INDIRECT

INGUINAL HERNIA CONT. Direct Protrudes through a weakened inguinal canal floor medial to the IEA (Inferior epigastric artery). Indirect Exits via deep inguinal ligament ring(lat to IEA) & courses through the inguinal canal.

PROTOCOL Ultrasound examination of the inguinal region with the patient in the supine and upright positions and with the Valsalva maneuver has been reported to have a diagnostic sensitivity and specificity of greater than 90 percent. The ultrasound examination may also be helpful in differentiating an incarcerated hernia from a pathologic lymph node or other cause of a firm, palpable mass.

WHAT IS AN INGUINAL HERNIA? An inguinal hernia occurs when tissue pushes through a weak spot in your groin muscle. This causes a bulge in the groin or scrotum. The bulge may hurt or burn.

WHAT ARE THE SYMPTOMS? The main symptom of an inguinal hernia is a bulge in the groin or scrotum. It often feels like a round lump. The bulge may form over a period of weeks or months. Or it may appear all of a sudden after you have been lifting heavy weights, coughing, bending, straining, or laughing. The hernia may be painful, but some hernias cause a bulge without pain

WHAT CAUSES AN INGUINAL HERNIA? Most inguinal hernias happen because an opening in the muscle wall does not close as it should before birth. That leaves a weak area in the belly muscle. Pressure on that area can cause tissue to push through and bulge out. A hernia can occur soon after birth or much later in life

EXAMS & TESTS The diagnosis of inguinal hernia is usually based on the patient’s medical history and a physical exam. Tests such as ultrasound and CT scans are not usually needed to diagnose an inguinal hernia. In most cases, a doctor can identify an inguinal hernia during a physical exam.

INDIRECT INGUINAL HERNIA exits through the deep inguinal ligament ring and is lateral to the inferior epigastric artery and courses through the inguinal canal. DIRECT INGUINAL HERNIA protrudes through a weakened inguinal canal floor medial to the Inferior epigastric artery. Difference between direct and indirect cannot be seen. INDIRECT & DIRECT INGUINAL HERNIA

HERNIAS

WITH RELATION TO ULTRASOUND Ultrasound may be ordered to diagnose a hernia or to characterize the contents of a hernia and determine its reducibility. The ultrasound examination is dynamic because it is performed in real time, showing motion live, and because it can be performed while the patient is lying on his/her back or standing upright. It can also be performed when the patient is breathing quietly or straining vigorously. Ultrasound can be performed while the hernia is being compressed with the ultrasound transducer.

CT and MR scans, on the other hand, can only be done with the patient lying on his/her back and generally without straining. Because of the ability of ultrasound to show motion during dynamic maneuvers, ultrasound has several advantages over more expensive CT and MR scans in evaluating for groin and anterior abdominal wall hernias.

• Ultrasound, like CT and MR, can show larger nonreducible hernias, but can also smaller show reducible hernias that CT and MR cannot show. • Because ultrasound images show real time motion, we can see reducible hernias moving in and out during dynamic maneuvers.

• During the ultrasound examination, any hernia that is found can be compressed with the ultrasound probe to determine if the hernia is reducible or tender. CT and MR, on the other hand, even when they show a hernia, cannot determine whether the hernia is tender. Tenderness is important, because hernias are so common, that we often find “incidental” small hernias that are not the cause of the patient’s pain. If a hernia is tender when compressed by the ultrasound probe, it is far more likely that the hernia is, indeed, the cause of pain, and not merely a common incidental finding.

LONG Distal inguinal canal Epididymal head Testicle-Medial, Mid, Lateral Epididymal tail Measure length pole to pole PROTOCOL TRANS Epididymal head Testicle- Upper, Mid, Lower Epididymal tail Measure transverse and AP

PROTOCOL Color Doppler each testicle in longitudinal Make sure to use same color gain throughout study Measure all masses and cysts and large hydroceles in 3 dimensions Suspected Inguinal Hernia- Scan up into inguinal canal. Look for loops of bowl or herniate knuckles of mesenteric fat Undescended Testicles- Scan both hemiscrotum. If testicles are absent, scan inguinal canals up into pelvis. Valsalva may show hernia Annotate ALL images

ULTRASOUND Ultrasound examination of the inguinal region with the patient in the supine and upright positions and with the Valsalva maneuver has been reported to have a diagnostic sensitivity and specificity of greater than 90 percent. The ultrasound examination may also be helpful in differentiating an incarcerated hernia from a pathologic lymph node or other cause of a firm, palpable mass.

PATIENT PREP FOR INGUINAL HERNIA REPAIR Patients will have standard preoperative blood and urine tests, an electrocardiogram and a chest x ray to make sure that the heart, lungs, and major organ systems are functioning well. A week or so before surgery, medications may be discontinued, especially aspirin or anticoagulant drugs. Starting the night before surgery, patients must not eat or drink anything. Once in the hospital, an IV may be placed into a vein in the arm to deliver fluid and medication during surgery. A sedative may be given to relax the patient

VENTRAL HERNIA Acquired Obese, elderly, previous trauma, surgery Congenital Gastroschisis isolated, Rt side of the umbilical cord Omphalocele Three times more common Mid Line at the site of umbilical cord insertion Covered with a membrane Associated with other organ malformations

Gastroschisis- Umbilical cord inserts normally into the fetal abdomen (short arrow), adjacent to non-dilated exteriorized bowel (long arrow).

Gastroschisis- Exteriorized bowel loops (arrow), partly separated by fluid and not covered by a membrane.

Omphaloceles occur in approximately 1: 4, 000 live births, and include a spectrum of midline defects that range from large (usually containing liver and bowel) to small (which may contain only 1 or 2 bowel loops). The exteriorized viscera are contained by an amnio-peritoneal membrane, and the umbilical cord inserts midline into the sac. Features most predictive of prognosis are other serious malformations (expected in 50% to 75% of affected fetuses, including cardiac malformations in 30% to 35%) and chromosomal abnormalities (approximately 10% to 20%), mainly Trisomies 18 and 13. Although "bowel-only" omphaloceles are generally smaller, less conspicuous sonographically, and often easier to repair postnatally, the rate of chromosomal abnormalities (perhaps 70% to 80%) is 8 to 10 times higher than that found in fetuses in whom the omphaloceles contain liver within herniated sac. Be aware that small bowel-only omphaloceles may contain only one or two loops of bowel that have migrated into the cord so that the abnormality may not be recognized solely by examination of the cord insertion into the fetal abdomen. Thus, examination of the umbilical cord beyond the fetal abdomen for several centimeters is prudent.

ULTRASOUND IMAGE DEMONSTRATING OMPHALOCELE CONTAINING LIVER(L)

THE SPIGELIAN LINE

SPIGELIAN HERNIA The only spontaneous hernia of the lateral abdominal wall. Due to a defect in the layers of flat broad tendons of transversus abdominis muscle lateral to the rectus sheath.

FEMORAL HERNIA Patients have groin pain and no palpable mass. The mass is demonstrated medial to the femoral vein. Differential Diagnosis: Hematoma, Pseudoaneurysm, AV fistula, Lipoma, Lymph -node, saphenous varices.