Carotids

• < 50% => gray scale estimate

• >50% => hemodynamic parameters

• Distal stenosis => high resistive waveforms

Thyroid

• Benign follicular adenoma

• Papillary cancer

  • Lymphatic dissemination

  • 90-95% 20 year survival

  • Multifocal in 20%

  • Variants: mixed (papillary/follicular), microcarcinoma

  • Hypoechoic, solid

  • Ca++ in psammoma bodies

• Follicular cancer

  • Hematogenous spread

  • No Ca++

• Medullary cancer

  • MEN Type II

  • Microcalcifications are common

• Anaplastic cancer

  • Large, solid, hypoechoic mass

• Parenchymal disease

  • Hashimoto's thyroiditis

    • Enlarged, hypoechoic gland

    • Atrophic at end stages

  • Grave's

  • Subacute granulomatous (deQuervain's)

    • Poorly marginated area or areas of decreased echogenicity

Parathyroid

• Parathyroid adenomas

  • Hypoechoic homogenous solid mass

  • May be confused with posterior thyroid septations

Pancreas

• Pancreatitis

  • Enlargement

  • Hypoechoic

  • Heterogenous echogenicity

• Focal pancreatitis can mimick mass

• Pancreatic carcinoma

• Islet cell tumors

  • Insulinomas (90% - 95% benign)

  • Gastrinomas (most are malignant)

• Lymphoma

• Metastases

• Cystic pancreatic neoplasms

  • Microcystic adenoma = Serous cystadenoma = Glycogen rich cystadenoma

  • Macrocystic adenoma = Mucinous cystadenoma = Cystadenocarcinoma (premalignant or malignant)

• Intraductal papillary mucinous tumor

Gallbladder

Liver

• Echogenic ducts - periductal fibrosis (can be seen in PSC)

Bile ducts

• Bile duct is usually slightly more prominent in its midportion. If distal and proximal bile duct is not dilated, it is probably not obstructed

Spleen

• Cysts

  • Most are from trauma (hematomas which evolve into seromas)

  • Epidermoid (true) cysts are rare Þ Squamous cells in the walls

  • Parasitic cysts

  • Hydatid

  • Pseudoaneurysms, AVMs

  • Perisplenic cysts

• Tumors

  • Hemangiomas

  • Hamartomas

  • Lymphangiomas

  • Lymphoma

  • Hemangiosarcomas

  • Metastases

• Infection

  • Splenic abscesses are uncommon

  • Fungal abscesses

  • Granulomas

    • TB

    • Histoplasmosis

    • Sarcoid

• Trauma

• Infarction

  • Coarsened echotexture

Kidney

Scrotum

• Extratesticular masses

  • Spermatocele

  • Hydroceles - potential space of tunica vaginalis

  • Varicoceles - veins

  • If unilateral on the right - retroperitoneal mass or situs inversus should be considered

  • Scars

  • Sperm cell granulomas

  • Chronic hematomas

  • Hernias

  • Scrotoliths

  • Adenomatoid tumor

  • Lipomas, liposarcomas, leiomyoma, leiomyosarcomas

• Intratesticular

  • Simple testicular cysts

  • Tunica albuginea cysts

  • Tubular ectasia of rete testes

  • Germ cell tumors

    • Seminomas (homeogenous and hypoechoic)

  • Non-germ cell tumors (more likely to contain cystic regions and calcify)

    • Leydig cell tumors

    • Sertoli cell tumors

  • Mixed germ cell tumor

    • Combination of seminoma, teratoma, embryonal cell carcinoma, choriocarcinoma

  • Epidermoid cysts

  • Metastasis

  • Lymphoma

  • Leukemia

  • Testicular atrophy or fibrosis also produce hypoechoic regions

  • Testicular microlithiasis

    • Classic - 5 or more microliths on an image

    • Limited - less than 5 microliths on all images

Bladder

• Primary neoplasms

  • TCC (90% of bladder tumors)

    • Smoking, analgesic abuse, industrial carcinogens

    • Posterior wall - trigone region

  • SCC (5%)

  • Adenocarcinoma (2%)

    • Usually in urachal remnants and in bladder extrophy

  • Pheochromocytoma

• Invasion from adjacent structures and adjacent inflammation

• Blood clots

• Stones

• Fungus balls

• Bladder diverticula

• Urachal diverticulum or cyst

• Ureteroceles

Penis

• Erectile dysfunction

  • Papaverine or prostaglandin E

  • Systolic velocities > 35 cm/sec considered normal < 25 cm/sec abnormal

• Priapism

  • High-flow => AV fistula

  • Low-flow => thrombosis of the dorsal penile vein

• Peyronie's disease

  • Lack of expansion of tunica albuginea in the area of fibrosis (plaque)

Prostate

• Four zones

  • Peripheral

  • Central

  • Transitional

  • Fibromuscular stroma => anterior non-glandular tissue

• 70% of prostate cancers are hypoechoic with respect to the peripheral zone

• Benign prostatic hypertrophy => transitional zone

• Prostatic cysts

  • Midline

    • Utricle cysts

    • Mullerian duct cysts

    • Ejaculatory duct cysts

Transplant

• Draining vein thrombosis => reversal of diastolic flow

• Thrombosis of feeding artery => decreased resistive indices and tardus et parvus waveform