Diagnostic ultrasound ( PDFDrive )

358 PART II Abdominal and Pelvic Sonography
A B C
D
E
F
G H I
FIG. 9.68 Complex Renal Cysts. (A) Tiny renal cyst (arrow) in the anterior cortex is not resolved. A bright echogenic focus with ring-down
artifact is the only visible abnormality. (B) Discernible cyst shows a bright echogenic focus with ring-down artifact. This echogenicity does not
represent calciication. (C) Complex benign cyst with a few thin septations. Ring-down artifact originates from the septations and the cyst wall.
(D) Complex cyst containing several thin septations. Septation was imperceptible at follow-up MRI. Septation is accentuated at ultrasound, and
Bosniak classiication is ultimately made based on features at MRI or CT. (E) Cyst shows numerous internal thick and thin septations. (F) Complex
cyst shows thick nodular septations. (G) Cyst containing thick, nodular septations. Lack of enhancement of septations at CT suggested a Bosniak
category 3 lesion, although a decrease in size of the mass at short follow-up imaging conirmed a hemorrhagic cyst. (H) Cyst with large solid
component post trauma. Real-time color Doppler examination conirmed that the solid component was mobile and avascular. Intracystic clot resolved
at follow-up sonography. (I) Large hemorrhagic cyst shows extensive internal debris within an otherwise simple-appearing cyst.
at the wall attachment, should be viewed with concern (Fig.
9.68E-G). Cyst aspiration is not indicated in these multiseptated
cystic lesions. 236 Ultrasound is oten better than CT in deining
the internal characteristics of a cystic lesion.
Calciication of renal cysts may be ine and linear or amorphous
and thick. hin wall or septal calciication suggests a
complicated cyst rather than malignancy, if all other features of
a benign cyst are shown at ultrasound, with no associated sot
tissue mass enhancement at CT. 237 hick, irregular, amorphous
calciication is more worrisome, however, and should prompt
additional assessment with CT. 237 On the other hand, layering
milk of calcium within a cyst is a benign inding. Mimicking
cyst wall calciication, the bright, echogenic foci with ring-down
artifact are frequently seen in septa and cyst walls at ultrasound
(Fig. 9.68A-C). hese foci are of no consequence, and no corresponding
calciication is shown at CT. hickened walls or mural
nodularity typically excludes a diagnosis of a benign cyst (Fig.
9.68E-H) although ultimate management is based on corresponding
features at CT/MRI and, in the appropriate clinical context
(e.g., fever, leukocytosis or trauma), imaging follow-up.