Hyperechoic foci

Contraindications include coagulation disorders, superficial hyperechoic foci (e. g. haemangioma), vascular aneurysm, portal hypertension, obstructive jaundice and hydatid cysts. Care should also be taken not to damage any unknown structures along the path of the biopsy needle. 

Fig. 5.34a-g. Calcium pyrophosphate deposition disease, a-c Transverse 12-5 MHz US images obtained over a the femoral trochlea, b the posterior aspect of the medial condyle and c the lateral meniscus in a patient with bilateral degenerative osteoarthritis of the knee reveal scattered hyperechoic foci (arrowheads) due to crystal deposition within the hyaline cartilage, the medial meniscus and the joint capsule (arrows). F, femur T, tibia. Note that crystals tend to be deposited in the middle layer of the cartilage, parallel to the subchondral bone, d-f Radiographic correlation, g Schematic drawing illustrates the typical deposition pattern of pyrophosphate crystals within the cartilage... 

At US, rotator cuff calcifications appear as intra-tendinous hyperechoic foci. Three main types of calcium deposits can be identified with US depending on the amount of calcium contained in the deposit. Type I calcifications appear as hyperechoic foci with well-defined acoustic shadowing, similar to gallstones (Fig. 6.101a). These calcifica-... 

O Reilly et al. 2003). If the retinaculum appears normal, its medial insertion into the border of the patella should be carefully examined to rule out cortical avulsions (O Reilly et al. 2003). These have the appearance of subtle hyperechoic foci located in close proximity to the insertion of the retinaculum and are painful when local pressure is applied over them. Differentiation of retinacular tears from a surgical access during arthroscopy is based on demonstration of a more focal discontinuity and on clinical correlation (Fig. 14.53). Tears of the lateral retinaculum are almost always iatrogenic and result from surgical release in patients affected by lateral patellar instability. In these cases, US reveals a sharp discontinuity of both ligament and adjacent tissues. 

EHE usually presents as multiple peripheral hy-poechoic masses. Hyperechoic and mixed hypo-hyperechoic appearances, however, have also been described. The hyperechoic masses may have a peripheral hypoechoic rim. There is no correlation between sonographic pattern and the size of the lesions. In diffuse lesions hyperechoic foci correspond to calcification (Miller et al. 1992). 

With unclarified abdominal pain, sonography is usually the diagnostic procedure of choice. An aneurysm appears as a round or oval focus either intrahepatically or extrahepatically between the portal hilum and the pancreas. The hypoechoic, cystic focus may contain hyperechoic, thrombotic material. Occasionally, there is a connection to an afferent vessel. (128) A suspected aneurysm can be confirmed by colour Doppler sonography, with the possibility of distinguishing blood flow and arterial blood. An echo-free aneurysm provides a typical arterial sphygmogram. 

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