Challenge

Challenge

ANSWERS – CASE 159

Hepatitis

1. Both views show increased echogenicity of the portal triads in the periphery of the liver.

2. This is referred to as the “starry sky” sign.

3. The starry sky sign is classically associated with hepatitis.

4. Usefulness of this sign is limited because (unlike this case) the abnormality is usually subtle, and it can be seen in patients who have no other clinical or laboratory evidence of hepatitis.

Reference

Kurtz AB, Rubin CS, Cooper HS, et al: Ultrasound findings in hepatitis. Radiology 1980;136:717–723.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 67–68.

Comment

Patients with right upper quadrant pain and abnormal liver function tests are often referred for sonographic evaluation. The main goal in this group of patients is to determine whether there are gallstones and whether there is any evidence of biliary obstruction. In the absence of either of these abnormalities, the next consideration is usually diffuse liver parenchymal disease.

Except for fatty infiltration and, to a lesser degree, cirrhosis, ultrasound is not a good way of evaluating or quantitating diffuse liver disease. Hepatitis is no exception. Nevertheless, there are some sonographic findings that are seen in patients with hepatitis. Perhaps the most common abnormality is thickening of the gallbladder wall (see Case 13). In fact, hepatitis can produce dramatic gallbladder wall thickening. It is also characteristic of patients with hepatitis for the gallbladder lumen to be contracted. Another finding seen commonly is mildly enlarged lymph nodes in the porta hepatis, around the celiac axis, and in the peripancreatic area. Unfortunately, mildly enlarged nodes are very common in these areas and can be associated with many other inflammatory or infectious conditions in the right upper quadrant. They are also common in liver diseases other than hepatitis, such as primary biliary cirrhosis and sclerosing cholangitis.

This case demonstrates the starry sky sign in the liver. Decreased echogenicity of the liver parenchyma around the portal triads and increased echogenicity of the fibrofatty tissues in the triads probably combine to produce this finding. Regardless of the cause, when the portal tracts are imaged in cross section in the periphery of the liver, the net result is small focal areas of increased echogenicity on a darker background, simulating stars in the night sky. Although this finding was described in association with hepatitis, it is not very helpful owing to poor sensitivity and a limited positive predictive value. In addition, when it is present, it is usually subtle enough that diagnostic confidence is limited. The changes seen in this case are considerably more striking than are usually seen.

ANSWERS – CASE 160

Splenic Sarcoid

1. Patchy hypoechoic areas in the spleen.

2. The differential diagnosis includes lymphoma, metastatic disease, sarcoidosis, infarction, and infection.

3. Sarcoidosis would be most likely, although lymphoma would also be a consideration.

4. Abdominal sarcoid also affects the liver and causes lymphadenopathy.

Reference

Warshaur DM, Molina PL, Hamman SM, et al: Nodular sarcoidosis of the liver and spleen: Analysis of 32 cases. Radiology 1995;195:757–762.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 214–217.

Comment

Sarcoidosis is a disease of unknown etiology that affects primarily the chest but can involve virtually any organ in the body. It is characterized by noncaseating granulomas in lymph nodes as well as in organs with a rich lymphatic supply. Approximately 50% of patients are asymptomatic at the time of diagnosis, so the disease can be detected as an incidental finding during abdominal sonography.

Sarcoidosis involves the abdominal lymph nodes in approximately 30% of cases. Lymph nodes are commonly seen in the region of the porta hepatis, celiac axis, pancreas, and retroperitoneum. Involvement of the liver and spleen is also seen in approximately 30% of cases. This is usually manifest as diffuse enlargement of the liver or spleen, but focal lesions can also be seen. It is extremely difficult to distinguish abdominal sarcoidosis from abdominal lymphoma purely on the basis of imaging findings.

ANSWERS – CASE 161

Hepatic Focal Nodular Hyperplasia

1. The first image shows a collection of vessels arranged in a spokewheel configuration. The underlying gray-scale appearance of the liver is barely distorted. The second image also shows a spokewheel configuration in three dimensions.

2. Focal nodular hyperplasia rarely causes clinical symptoms and has no malignant potential.

3. MRI and sulfur colloid scanning are both options.

4. Central calcification suggests the diagnosis of fibrolamellar hepatocellular carcinoma and would prompt a more aggressive approach.

Reference

Buetow PC, Pantograg-Brown L, Buck JL, et al: From the archives of the AFIP: Focal nodular hyperplasia of the liver: Radiologic–pathologic correlation. Radiographics 1996;16:369–388.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 57–58.

Comment

Focal nodular hyperplasia (FNH) is a benign tumor of the liver that is composed of Kupffer cells, hepatocytes, and biliary structures. It is hypothesized that it develops from a congenital vascular malformation that promotes hepatocellular hyperplasia. Pathologically, it often has a central, stellate scar. It is supplied by an internal arterial network that is arranged in a spokewheel pattern.

FNH is usually detected as an incidental mass on CT or on ultrasound. Like hepatic adenoma, FNH is more common in women. Unlike hepatic adenoma, it is not related to the use of birth control pills. The nodules seldom bleed or cause any clinical symptoms, although pain may be encountered when the lesions are large.

Although the appearance of FNH varies on sonography, most are isoechoic or nearly isoechoic to liver parenchyma. The central stellate scar, which is frequently seen on contrast-enhanced CT and MRI, is uncommonly seen on ultrasound. However, the spokewheel pattern of internal vascularity is better displayed on color or power Doppler than on CT or MRI.

When FNH is suspected based on ultrasound, sulfur colloid scans can be very useful. Due to the concentration of Kupffer cells, approximately 60% of FNHs are either more intense or isointense to adjacent liver. MRI can also show characteristics findings and is often very helpful. The typical features on ultrasound and either MRI or sulfur colloid scans are sufficient to make the diagnosis with a high degree of certainty. If the lesion is atypical on MRI or sulfur colloid scans, then FNH remains a possibility, but other lesions also need to be considered.

ANSWERS – CASE 162

Biceps Tendon Rupture

1. The transverse views show an empty groove on the right. The longitudinal views show lack of the normal fibrillar pattern in the tendon groove.

2. In most patients, the tendon and muscle belly retract and produce a bulge in the anterior arm that is easy to see and feel on physical examination.

3. The long head is involved.

4. The differential diagnosis for an empty biceps tendon groove includes tendon dislocation and anisotropic effects.

Reference

Middleton WD: Shoulder pain. In Bluth EI, Benson C, Arger P, et al (eds): The Practice of Ultrasonography. New York, Thieme, 1999.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 279–281.

Comment

Patients with impingement syndrome of the shoulder may have symptoms related to the rotator cuff, the biceps tendon, or both. The origin of these symptoms can be difficult to sort out clinically. For this reason, it is important to scan the biceps in patients suspected of having a rotator cuff tear.

Rupture of the biceps tendon is usually readily detected on physical examination because the retracted muscle belly forms a lump in the upper arm that becomes more prominent when the biceps is flexed. On sonography, biceps tendon rupture is one of the causes of an empty-appearing groove. Biceps tendon dislocation is the other cause. In addition, if the transducer is not oriented perpendicular to the tendon, the anisotropic properties of the tendon cause it to appear hypoechoic, resulting in an empty-appearing groove.

In some cases, a ruptured biceps tendon becomes scarred (autotenodesed) to the tendon groove or just below the tendon groove, resulting in minimal or no retraction of the muscle belly and a diagnosis that is not apparent on physical examination. Sonographically, the tendon appears attenuated at the level of the groove, but there are usually some detectable fibers, especially on longitudinal views. In most cases, the diagnosis is still possible because the intra-articular portion of the biceps is absent.

ANSWERS – CASE 163

Adrenal Masses

1. The first image shows a mass posterior to the liver. A portion of the normal adrenal gland is seen extending inferior to this mass. The second image shows a mass lateral to the aorta.

2. Adenomas, pheochromocytomas (second image), myelolipomas, adrenal cancer, metastases (first image), lymphoma, and hematomas.

3. Pheochromocytomas or functioning adenomas that secrete aldosterone (Conn’s disease).

4. Multiple endocrine neoplasia (MEN) type II. The adrenal mass would then be a pheochromocytoma.

Reference

Marchal G, Gelin J, Verbeken E, et al: High resolution real-time sonography of the adrenal glands, a routine examination. J Ultrasound Med 1986;5:65–68.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 238–241.

Comment

Ultrasonography is not a primary means of imaging the adrenal glands. Nevertheless, ultrasound frequently identifies masses in the right adrenal gland and infrequently identifies left adrenal gland masses. Right adrenal masses can be imaged from an intercostal or a subcostal approach. Masses appear immediately adjacent to the posterior surface of the liver and lateral to the inferior vena cava. Right adrenal masses are usually superior to the upper pole of the kidney. Left adrenal masses are located in a left paraaortic location at the level of the upper pole of the kidney. They are best identified from a left coronal intercostal approach, using the spleen or kidney as a window, or from an anterior subxiphoid approach.

The most common adrenal mass is the adenoma. Autopsy series identify adenomas in 3% of the population. Adenomas are usually asymptomatic but can produce Cushing’s syndrome (excessive glucocortisol) and Conn’s syndrome (hyperaldosteronism). They contain significant amounts of lipid and are typically low-attenuation lesions on CT. They are usually less than 3 cm in size and homogeneous. Despite their small size, the adrenals are the fourth most common site of metastases. Metastases are usually larger than adenomas and are heterogeneous. Pheochromocytomas produce symptoms of hypertension, headache, tachycardia, anxiety, and palpitations. They are referred to as “the 10% tumor” because 10% are malignant, 10% are extra-adrenal, 10% are bilateral, and 10% occur with MEN syndromes. Pheochromocytomas are typically large, vascular, heterogeneous tumors. Primary adrenal carcinomas are very rare tumors. They are typically very large masses that present with pain or symptoms due to the mass effect. Necrosis, hemorrhage, and calcification are common. Myelolipomas are benign tumors that contain hematopoietic and fatty elements. They rarely cause symptoms and can be small or large.

There is significant overlap in the sonographic appearance of various solid adrenal masses. In most cases, sonographic detection of an adrenal mass is followed by CT or MRI for further characterization. In some instances, laboratory studies are sufficient to determine the etiology of an adrenal mass. In this case, the lesion shown in the first image was a right adrenal metastasis in a patient with lung cancer. The lesion shown in the second image was a left adrenal pheochromocytoma in a hypertensive patient referred for a renal artery Doppler scan. Urinary catecholamine levels documented the diagnosis.

ANSWERS – CASE 164

Peyronie’s Disease

1. Calcification of the tunica albuginea.

2. Localized firmness and thickening.

3. Painful and/or curved erections.

4. This is most common on the dorsal side.

Reference

Balconi G, Angeli E, Nessi R, et al: Ultrasonographic evaluation of Peyronie’s disease. Urol Radiol 1988; 10:85–88.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 182–183.

Comment

Peyronie’s disease is fibrosis of the tunica albuginea of the corpora cavernosa. It is idiopathic and typically affects men older than 45 years of age. Since the tunica albuginea cannot stretch in the area of fibrosis, the penis bends toward the plaque during erection. Pain and penile curvature can make intercourse impossible.

On sonography, the plaques appear as localized areas of thickening of the tunica albuginea. They may be hypo- or hyperechoic. They are generally easier to palpate than visualize on sonography unless they are calcified. The typical location is along the dorsum of the penis near the base, but Peyronie’s disease can also involve the lateral margins and the septum.

ANSWERS – CASE 165

Full-Thickness Rotator Cuff Tear

1. Both patients have full-thickness rotator cuff tears.

2. The findings on sonography are diagnostic in both cases. No further imaging is required.

3. In the hands of experienced sonologists and experienced MRI readers, ultrasound and MRI are equivalent for detection of rotator cuff tears.

4. The patient with nonvisualization (second image) is likely to have superior migration of the humeral head detectable on shoulder radiographs.

Reference

Teefey SA, Rubin DA, Middleton WD, Hildeboldt CF, Leibold RA, Yamaguchi K: Detection and quantification of rotator cuff tears: Comparison of ultrasonographic, MRI, and arthroscopic findings in seventy one consecutive cases. J Bone Joint Surg 2004;86(A): 708–716.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 280–285.

Comment

Full-thickness rotator cuff tears are classified as wet or dry, depending on whether there is a significant amount of joint fluid surrounding the torn edges of the cuff. In the patients discussed here, the tears are dry. The appearance of dry tears is somewhat more difficult to understand than wet tears. When the defect created by the tear is not filled with fluid, it must be filled with something else. In most cases, the overlying subdeltoid bursa and peribursal fat drops into the defect. This produces a concavity in the reflections from the bursa and fat. In most cases, this concavity is readily visible at rest. If the torn ends of the tendon have not retracted from each other, a concavity may not be visible at rest. In such a case, compression of the shoulder with the transducer can push the bursa and peribursal fat into the defect at the same time that it produces some separation of the tendon ends. Compression can also exaggerate some tears that are otherwise subtle because they are filled with hypertrophied synovial tissue. This is due to the greater compressibility of the synovium compared to the rotator cuff. The normal rotator cuff does not compress at all.

When there is a massive tear with extensive retraction of the torn tendon, the humeral head becomes completely uncovered by cuff tissue. In such a situation, there is no sonographically visible cuff on standard images. This is referred to as nonvisualization of the cuff. In these cases, the subdeltoid bursa, peribursal fat, and deltoid muscle come into direct contact with the articular cartilage and humeral head.

ANSWERS – CASE 166

Transitional Cell Carcinoma

1. The first image shows a solid mass in the renal hilum. The second image shows the mass with minimal internal vascularity and multiple hilar vessels draped around its margins.

2. Both of the findings should suggest transitional cell carcinoma.

3. No. Most transitional cell cancers occur in the bladder.

4. Upper tract transitional cell cancer is treated with nephrectomy and ureterectomy.

Reference

Wong-You-Cheong JJ, Wagner BJ, Davis CJ Jr: From the archives of the AFIP: Transitional cell carcinoma of the urinary tract: Radiologic–pathologic correlation. Radiographics 1998;18:123–142.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 124–125.

Comment

Transitional cell cancer (TCC) is typically divided into tumors that involve the bladder and tumors that involve the upper urinary tract (ureter, renal pelvis, and intrarenal collecting system). Bladder tumors are much more common than upper tract tumors, and tumors of the renal pelvis are more common than tumors of the ureter. Approximately 90% of renal pelvis tumors and 99% of ureteral tumors are TCC.

Patients most often present with gross hematuria. Flank pain is uncommon and usually indicates obstruction and hydronephrosis. Colicky pain may develop during periods of clot passage. Patients with advanced disease may present with constitutional symptoms such as weight loss and anorexia.

Sonography is not a primary means of evaluating patients with TCC of the upper urinary tract. However, it may be the first test obtained in a patient with hematuria, and thus the initial identification of the tumor may be with ultrasound. TCC has a variety of sonographic appearances. It may appear as a solid mass within a dilated renal pelvis, as a solid mass distorting the renal sinus fat, or as an area of uroepithelial thickening. In general, the sonographic findings are nonspecific, and the differential diagnosis includes blood clots, sloughed papillae, and pyelonephritis. Detection of internal vascularity confirms that the lesion is viable soft tissue and almost always indicates a tumor of some sort. Further evaluation with intravenous urography, retrograde pyelography, or ureteroscopy is generally required.

ANSWERS – CASE 167

Liver Laceration and Hemoperitoneum

1. The first image shows peritoneal fluid around the liver. The second image shows mild distortion of the liver echotexture.

2. In the setting of trauma, any peritoneal fluid should be assumed to be a hemoperitoneum. The subtle changes in the liver indicate that the liver is the likely source as a result of a hepatic laceration.

3. Ultrasound is good at identifying hemoperitoneum. It is not very good at identifying an acute laceration of a parenchymal organ, such as the liver, spleen, or kidney.

4. The role of ultrasound in the setting of blunt abdominal trauma is controversial and in evolution. It is clear that ultrasound can substitute for the diagnostic peritoneal lavage. Given this, some believe that ultrasound should be used to identify patients with hemoperitoneum.

Reference

Richards JR, McGahan JP: Ultrasound for blunt abdominal trauma in the emergency department. Ultrasound Q 1999;15(2):60–72.

Cross-Reference

Ultrasound: THE REQUISITES, 2nd ed, pp 67, 225.

Comment

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Tags: General and Vascular Ultrasound Case Review Series

Dec 26, 2015 | Posted by admin in CARDIOVASCULAR IMAGING | Comments Off

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