Ultrasound of the knee

Ultrasound of the knee is best suited for the evaluation of tendons, fluid collections and effusion, synovitis, periarticular soft tissue masses, muscles, and the collateral ligaments. Advantages of sonographic evaluation include the lack of ionizing radiation, the noninvasive nature of the examination, focused evaluation correlated with the specific site of pain, multiplanar capability, and utility in patients for whom magnetic resonance imaging (MRI) is contraindicated. The ability to visualize the microanatomy of tendons, ligaments, nerves, and muscles is also an advantage over MRI. Moreover, ultrasound is generally readily accessible and of lower cost than MRI. Ultrasound is less suited for the evaluation of internal derangement. Certain structures that are exquisitely evaluated by MRI, including the menisci, cruciate ligaments, bone marrow, and articular cartilage, are suboptimally evaluated by sonography. This article reviews the structures and pathological processes for which ultrasound has been shown useful, emphasizing appropriate technique and normal anatomy, appearance of pathological processes, and advantages and limitations of sonographic evaluation.     

Sonography of renal inflammatory disease

The sonographic findings and differential diagnoses of a wide spectrum of acute and chronic renal inflammatory processes are reviewed. These include focal and diffuse forms of bacterial nepbritis, pyonephrosis, intra- and extrarenal abscess, renal tuberculosis and fungal infection, xanthogranulomatous pyelonephritis, and renal parenchymal malakoplakia. The role of ultrasound in the diagnostic and therapeutic management of patients with these diseases is discussed.     

The role of ultrasound in breast imaging

Sonography has become an important tool for evaluating breast abnormalities, including inflammatory processes, hematomas, ductal ectasia, cysts and solid lesions. This article describes protocols for ultrasound imaging of the breast and the sonographic appearance of common breast conditions, with particular attention to differentiating benign from malignant lesions. Ultrasound's role in interventional breast procedures and radiation therapy planning also are discussed.     

Sonography of renal inflammatory disease

The sonographic findings and differential diagnoses of a wide spectrum of acute and chronic renal inflammatory processes are reviewed. These include focal and diffuse forms of bacterial nephritis, pyonephrosis, intra- and extrarenal abscess, renal tuberculosis and fungal infection, xanthogranulomatous pyelonephritis, and renal parenchymal malakoplakia. The role of ultrasound in the diagnostic and therapeutic management of patients with these diseases is discussed.     

Papillary process of the caudate lobe of the liver: sonographic appearance

The papillary process of the caudate lobe of the liver may appear separate from the liver and thus mimic lymph nodes or a pancreatic mass. In order to evaluate the sonographic appearance of this anatomic structure, 400 male and female patients with a mean age of 50 years were studied prospectively by means of ultrasound. The papillary process appeared to be separate from the liver on transverse sonograms in 62 patients (15.5%) and had an egg shape with a maximal transverse diameter of 8-39 mm. In all 62 patients, the papillary process appeared above and in front of the common hepatic artery close to the portal vein and pancreatic isthmus. Enlarged papillary processes were more frequently seen in patients with chronic liver disease. Knowledge of the anatomy, sonographic pattern, and vascular relationships of the papillary process enable its correct identification.     

Fetal gastrointestinal abnormalities

A wide range of abnormalities of the fetal gastrointestinal tract is currently detectable by antenatal sonography, but the sonographic appearance of normal fetal bowel is variable, with considerable overlap between normal and abnormal patterns. In examining the major gastrointestinal disorders that may be recognized by in utero sonography, this article emphasizes potential pitfalls due to confusion with normal anatomic variants and pathologic processes arising elsewhere in the fetus.     

Abdominelle Magnetresonanztomographie beim Kind

MRI provides diagnostic information in multiple abdominal diseases in childhood. Additional information to sonographic findings can be achieved in the diagnosis of abdominal malformation as well as in several inflammatory processes. In childhood cancer imaging MRI is essential at the beginning as well as during therapy to assess response to therapy. Because of radiation protection MRI has to replace CT in abdominal imaging in children. Some technical details have to be considered when children are examined.     

CT scanning in cystic liver changes (author's transl)]

Computer tomography is outstandingly suitable for detecting cystic processes in the liver. The genesis of such cysts can vary widely, so that there are bound to be differences in the clinical relevance of the findings. This is discussed on the basis of 20 case histories of cystic changes of the liver observed during one and a half years. For the purpose of discussion of the value of CT scanning, comparisons with sonographic and angiographic examinations were carried out.     

Solid extratesticular masses in children: radiographic and pathologic correlation

OBJECTIVE: The purpose of this pictorial essay is to review the sonographic and pathologic appearances of the most common solid and complex extratesticular masses in children. CONCLUSION: Solid or complex extratesticular masses, especially those that are rapidly growing and are painless, raise concerns regarding malignant rhabdomyosarcoma. Mimickers of rhabdomyosarcoma include inflammatory processes such as pseudotumor, chronic epididymitis, or meconium periorchitis. Because sonography cannot distinguish benign from malignant, worrisome extratesticular masses should be biopsied or removed.     

Sonography of diffuse benign liver disease: accuracy of pattern recognition and grading

Sonograms of 110 patients were compared to recently performed liver biopsies for evaluation of the accuracy of sonography in predicting the type (pattern) of pathology and its grade of severity (mild, moderate, or severe) in a wide variety of diffuse liver processes. There are two distinct, abnormal sonographic patterns: the fatty-fibrotic pattern seen primarily with cirrhosis, chronic hepatitis, and/or fatty infiltration, and the centrilobular pattern seen primarily with acute hepatitis. Sonography was 88% accurate in assigning the correct pattern to the corresponding pathology (sensitivity 89%, specificity 86%, p less than 0.001). The degree of accuracy was dependent on the grade of pathologic severity, with mild disease offering the greatest difficulty; moderate and severe diseases were accurately detected and placed in the correct pattern in all cases. Sonographic grading of the severity of disease was far less precise (63% overall). This study showed that sonography can distinguish between two abnormal sonographic patterns of diffuse benign liver disease as well as between normal and abnormal patterns.     

Differential diagnosis of pelvic masses by gray scale sonography.

An approach to the sonographic differential diagnosis of pelvic masses based on their size, location, internal consistency, and definition of borders is presented. Diagnostic schemes were derived from correlating the sonographic features with histomorphology in 170 surgically proven pelvic masses. Besides separating pelvic masses into the conventional categories of cystic, complex, and solid, gray scale sonographic features of a pelvic mass can be used to subcategorize these masses into a more useful differential diagnoses. Although the features seen on a sonographic image were specific in only two types of pelvic masses (pattern specificity greater than 85%), the sonographic information can be effectively utilized for establishing differential diagnoses of pelvic masses. Among the various sonographic patterns observed, homogenously cystic adnexal masses were the least specific pattern, whereas a predominantly cystic, extrauterine mass with internal septation was highly specific for a pseudomucinous cystadenoma. Several pelvic masses such as dermoid cysts demonstrated more than one sonographic appearance and, therefore, had to be considered in more than one diagnostic category.     

Sonographic pitfalls in the diagnosis of enteric duplication cysts

OBJECTIVE: The sonographic double wall sign has been well described in the literature and is often the cornerstone in suggesting the diagnosis of an enteric duplication cyst. We report two cases with this sign that were erroneously diagnosed as enteric cysts and a third case without this sonographic feature that proved to be a duplication cyst. Histologic analysis of the specimens helps explain the cause of the sonographic pitfalls. CONCLUSION: The potential sonographic visualization of the split hypoechoic muscularis propria layer or identification of all five layers will increase the specificity in making the sonographic diagnosis of duplication cyst.     

Spectrum of sonographic findings in 125 renal masses other than benign simple cyst

The sonographic findings of 125 renal masses that did not meet the sonographic criteria of benign simple cyst were retrospectively reviewed and correlated with the pathologic diagnosis. Of the 125 masses, 102 were renal cell carcinoma. These carcinomas, two of nine angiomyolipomas, and the 14 other renal masses of various histologic types exhibited a broad spectrum of sonographic findings. Seven of nine angiomyolipomas and the one multiloculated cystic nephroma had a rather characteristic sonographic appearance. With the knowledge of this spectrum of sonographic findings and strict attention to scanning techniques and sonographic criteria, the radiologist should be able to define the characteristics of a variety of renal masses and suggest the correct diagnosis. It should be possible to make the diagnosis of angiomyolipoma confidently if the characteristic sonographic and computed tomographic appearance of these tumors can be demonstrated. In some cases, the correct histologic diagnosis of a renal mass can be made only with biopsy or surgery.     

Sonographic patterns in trophoblastic diseases.

A range of sonographic patterns in patients with hydatidiform moles can be appreciated with gray scale ultrasonography, which more readily reveals areas of internal hemorrhagic degeneration and fetal growth within a molar mass. Sonography may be used to evaluate patients suspected of having recurrent or invasive trophoblastic disease; a focus of invasive trophoblastic tumor can be identified as a cluster of high-amplitude echoes within the myometrium, which is frequently associated with echo-free areas of hemorrhage. The enlargement or regression of theca lutein cysts associated with these disease processes can also be monitored.     

An assessment of sonography in the diagnosis and management of neonatal renal candidiasis

The renal sonographic findings in six cases of neonatal candidiasis and 13 cases previously reported in the literature are reviewed. Focal and diffuse parenchymal changes and obstruction due to mycetoma formation were frequent features. In the current series the sonographic changes were found to bear an inconstant relationship to the probable time of onset of the infection. In addition, apparent sonographic deterioration occurred in neonates well after adequate antifungal treatment was initiated. In view of the potential toxicity of systemic antifungal therapy, sonographic renal parenchymal changes are not considered an adequate indication for either its initiation or its continuation.     

Palpable prostatic nodules: comparison of US and digital guidance for fine-needle aspiration biopsy

This study was undertaken to evaluate the use of transrectal sonographically guided fine-needle aspiration biopsy and to compare sonographic with digital guidance for biopsy. In 62 patients in whom prostatic carcinoma was suspected at digital rectal examination, fine-needle aspiration biopsies were performed transperineally under sonographic guidance and transrectally under digital guidance. These patients had 89 nodules, 73 of which were sampled with both techniques. Malignant cells were obtained under digital guidance in 17 of 73 nodules (23%) and under sonographic guidance in 16 (22%). An additional seven nodules, which were not seen sonographically, were sampled under digital guidance and proved to be negative. In nine other nodules that were nonpalpable and evident only with sonography, malignant cells were obtained under sonographic guidance in three. These findings indicate that sonographic guidance for fine-needle aspiration biopsy is as good as digital guidance for palpable lesions.     

Ultrasound evaluation of renal parenchymal disease and hydronephrosis

The ultrasonic findings in renal disease are reviewed and a differential diagnosis is formulated for each sonographic abnormality. Lesions can be characterized by their location and sonographic texture. The sonographic findings combined with the clinical history may lead to a specific diagnosis or be useful in determining the next imaging study that should be obtained.     

Changes in the epididymis after vasectomy: sonographic findings

Scrotal sonograms were obtained in 31 men before vasectomy and at 2 and 12 months after vasectomy to determine the effect of the surgery on the sonographic appearance of the testis and epididymis. The sonographic appearance of the testis was unchanged after vasectomy. However, in 14 men (45%), there were persistent changes in the epididymis. These consisted of enlargement (14 patients), development of cysts (11 patients), and an inhomogeneous echo pattern (five patients). The presence of these sonographic changes was unrelated to symptoms. The history of vasectomy in men referred for scrotal sonography should be noted so that the altered sonographic appearance of the epididymis may be interpreted properly.     

Sparing of fatty infiltration around focal hepatic lesions in patients with hepatic steatosis: sonographic appearance with CT and MRI correlation

OBJECTIVE: The purposes of this study were to illustrate the sonographic features of focal hepatic lesions with peritumoral sparing of fatty infiltration in patients with hepatic steatosis, to correlate the sonographic findings with CT and MRI findings, and to discuss the possible mechanisms. CONCLUSION: Various focal hepatic lesions can accompany peritumoral sparing of fatty infiltration in patients with hepatic steatosis, and they can manifest with an atypical sonographic appearance.     

Saline microbubbles monitoring sonography-assisted abscess drainage

The objective of this study was to assess the use of saline microbubbles as a sonographic contrast medium in monitoring abscess drainage. Seven abscesses were localized and drained with sonographic guidance. Four were in the brain and three were small abscesses in the liver, the subhepatic region, and the pancreas. After aspiration of the purulent material, irrigation with saline produced a highly echogenic sonographic pattern that was free of artifacts and distinctly different from the abscess contents and capsule, and the surrounding parenchyma. In one case, previously unsuspected loculation was detected, requiring repositioning of the needle for complete drainage. All abscesses were resolved and no untoward effects, such as sepsis, were encountered. In one additional patient, microbubble sonographic evaluation was used to monitor the progress of an abscess in which a percutaneous catheter was placed. Saline microbubbles may be used as a sonographic contrast medium to monitor sonography-assisted abscess drainage.