In this radiology lecture, the ultrasound appearance of complete molar pregnancy is revealed. Key points include: * AKA hydatiform mole = Most common form of gestational trophoblastic disease. * Gestational trophoblastic neoplasia (GTN) less common = Invasive mole and choriocarcinoma. * Approximately 1/1,000 pregnancies is a molar pregnancy. * Most common in females under age 20 and over age 35. * Two types of molar pregnancy: Complete (most common) and partial. * Complete: Diploid...

Quiz yourself with this week’s interactive video lecture as we present a total of 5 interesting musculoskeletal radiology cases followed by a diagnosis reveal and key teaching points after each case, all in just a few minutes! Click the YouTube Community tab or follow on social media for bonus teaching material posted throughout the week! Instagram: https://www.instagram.com/radiologistHQ/ Facebook: https://www.facebook.com/radiologistHeadQuarters/ Twitter: https://twitter.com/radiologistHQ

In this radiology lecture, we discuss the MRI appearance of septate uterus, and explain how to differentiate from other uterine anomalies. Key points include: * Most common müllerian duct anomaly (55%): Septal reabsorption abnormality. * Ultrasound and MRI provide assessment of external uterine contour and presence of renal anomalies. * Hysterosalpingogram of limited value, cannot reliably differentiate between subtypes. * On MRI, uterine fundus is typically convex or minimally...

In this radiology lecture, we discuss the ultrasound appearance of ovarian dermoid cyst, including the rarely seen but highly specific “floating sphere” sign! Key points include * AKA mature cystic teratoma. * Most common ovarian neoplasm. * Benign, mean age 30. * 10% bilateral. * Mature tissue from ≥2 embryonic germ cell layers: Sebaceous material, hair follicles, skin derivatives, fat, muscle, bone, and other tissues lined by squamous epithelium. * Specificity of US diagnosis...

In this radiology lecture, we discuss the ultrasound and CT appearance of retroperitoneal fibrosis. Key points include: * Most cases (70%) are idiopathic = Ormond disease. * Nonspecific symptoms depending on involved structures: Malaise, weight loss, low-grade fever. * Ureteral entrapment: Obstructive uropathy or renal failure, may see medial deviation of middle third of ureters with hydronephrosis. * Venous entrapment: Lower extremity edema, deep venous thrombosis. * CT: Soft tissue...

In this radiology lecture, we discuss the CT and MRI appearance of perihilar cholangiocarcinoma. Key points include: * Perihilar cholangiocarcinoma (AKA Klatskin tumor) occurs at bifurcation of the hepatic duct. * Cholangiocarcinoma (CC) is a primary malignant tumor of bile duct epithelium, usually adenocarcinoma. * CC is the most common primary hepatic malignancy after hepatocellular carcinoma (HCC), and most are extrahepatic (as opposed to intrahepatic). * Appearance of CC is based...

Join me in this radiology lecture revealing the ultrasound and CT appearance of medullary sponge kidney (MSK). Key points include: * MSK is a developmental ectasia with cystic dilatation of the collecting tubules in the pyramids leading to medullary nephrocalcinosis. * DDx medullary nephrocalcinosis: Hyperparathyroidism (most common cause in adults), renal tubular acidosis (type 1), MSK, hypervitaminosis D, other causes of hypercalcemia, sarcoidosis. * MSK associations:...

In this radiology lecture, we discuss the ultrasound and CT appearance of amebic liver abscess. Key points include: * Entamoeba histolytica infection. * Endemic in Africa, Southeast Asia, and Central & South America. * More common in males. * Presents as right upper quadrant pain, fever and hepatomegaly. * Both amebic and pyogenic (bacterial) abscesses can have a layered wall with the “double target” or “double rim” sign. * Amebic more likely to be unilocular (septations present...

In this radiology lecture, we discuss the chest x-ray and CT appearance of pulmonary infarction in the setting of acute pulmonary embolism. Key points include: * Uncommon complication of pulmonary embolism. * Most common in right lung. * Risk of infarction increases with large clot burden. * Typically wedge-shaped, peripheral consolidation with no air bronchograms (Hampton hump). * However, may not be wedge-shaped, and not all wedge-shaped opacities will be infarcts in the setting of...

In this radiology lecture, we discuss the ultrasound appearance of ruptured ectopic pregnancy. Key points include: * Most ectopic pregnancies occur in the fallopian tube: Ampulla most common, followed by isthmus and fimbria. * Risk factors: Prior ectopic pregnancy, prior surgery (fallopian tube), pelvic inflammatory disease, endometriosis, IVF. * “A single measurement of hCG, regardless of its level, does not reliably distinguish between ectopic and intrauterine pregnancy (viable or...

In this radiology lecture, we discuss the appearance of gallstone ileus on x-ray and CT. Key points include: * Gallstone ileus is a rare complication of chronic cholecystitis. * Actually not an ileus, but a small bowel obstruction. * Gallstone migrates through a fistula between gallbladder and small bowel (usually duodenum) and becomes impacted in the terminal ileum. * Stone can also impact in the proximal ileum, jejunum, even in the duodenum/distal stomach causing gastric outlet...

In this radiology lecture, we discuss the ultrasound appearance of testicular epidermoid cyst. Key points include: * Testicular epidermoid cyst is a rare, benign, intratesticular neoplasm. * Most common in 2nd-4th decades, typically presents as a painless mass. * Lamellated, onion-like, bull’s-eye appearance: Alternating hyperechoic and hypoechoic concentric rings. * Appearance secondary to cyst filled with layers of keratin and lined with keratinizing squamous epithelium. *...

In this radiology lecture, we discuss the imaging appearance of necrotizing pancreatitis on both CT and MRI. Key points include: * According to the revised Atlanta classification, there are two types of acute pancreatitis: Interstitial edematous pancreatitis (IEP) and necrotizing pancreatitis (NP). * For IEP, fluid collection in first 4 weeks = acute peripancreatic fluid collection, after 4 weeks = pseudocyst. * For NP, fluid collection in first 4 weeks = acute necrotic collection,...

In this radiology lecture, we discuss the imaging appearance of duplicated collecting system and ureterocele, with attention to US and VCUG. Key points include: * Weigert-Meyer rule: Remember the mnemonic “DUMI.” * With duplex kidneys and complete ureteral Duplication, ureter draining Upper pole inserts ectopically into bladder Medially and Inferiorly to ureter draining lower pole. * Lower pole moiety inserts orthotopically. * Upper pole moiety often ends as an ectopic ureterocele. *...

In this radiology lecture, we discuss the imaging appearance of large bowel lymphoma. Key points include: * Often isodense to skeletal muscle. * May have aneurysmal dilatation of involved bowel. * Less likely obstructive and longer segment involvement compared to colonic adenocarcinoma. * Located near ileocecal valve. * GI lymphoma: Most common in stomach, followed by small bowel (ileum, jejunum, duodenum), least common site colorectal. * Splenomegaly and severe lymphadenopathy favor...

In this case of the week radiology lecture, we discuss the ultrasound appearance of ovarian torsion. Key points include: * Rotation of ovarian vascular pedicle with obstruction to venous outflow and arterial inflow. * Enlarged, heterogenous ovary due to hemorrhage and edema. * Small peripheral cysts with “follicular ring” sign: Thick, hyperechoic rim surrounding follicles of torsed ovary. * Classically, absent vascular flow. * However, up to 60% of patients with torsion have normal...

In this inaugural case of the week radiology lecture, we discuss the imaging appearance of cecal volvulus! Key points include: * Cecal volvulus occurs when there is twisting of cecum around the mesentery with proximal large bowel obstruction. * Cecum normally 9 cm, rest of large bowel 6 cm. * Topogram (scout view) extremely helpful. * Vector typically points towards LUQ, but instead of worrying about vector direction, look for proximal dilated small bowel (as opposed to large bowel) to...

Check out my FREE webinar titled “Ultrasound of Ovarian Cystic Disease” on Wednesday, September 29, 2021 at 7-8 PM ET, hosted by the American Institute of Ultrasound in Medicine (AIUM). A Q&A session follows the presentation. In case you missed the lecture or would like to watch it again, click here: https://learn.aium.org/products/ultrasound-of-cystic-ovarian-disease-neoplastic-non-neoplastic Enjoy!

Quiz yourself with this week’s interactive video lecture as we present a total of 5 interesting head and neck radiology cases followed by a diagnosis reveal and key teaching points after each case, all in just a few minutes!

Quiz yourself with this week’s interactive video lecture as we present a total of 5 interesting musculoskeletal radiology cases followed by a diagnosis reveal and key teaching points after each case, all in just a few minutes!

Quiz yourself with this week’s interactive video lecture as we present a total of 5 interesting musculoskeletal radiology cases followed by a diagnosis reveal and key teaching points after each case, all in just a few minutes!