Podcast
Radiology Lectures | Radquarters
Hosted by Daniel J. Kowal, MD · EN
Radiology education. Simplified.
13episodes
Episodes
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Contrast-Enhanced Ultrasound of Hemangioma
Aug 15, 202400:10:03Tap to summarizeIn this radiology lecture, we review the contrast-enhanced ultrasound appearance of hepatic hemangioma! Key teaching points include: Microbubble contrast agents are gas-filled microspheres with a lipid or protein shell Sulfur hexafluoride lipid-type A microspheres: Inert gas of six fluoride atoms bound to one sulfur atom, surrounded by a phospholipid shell Similar in size to red blood cells, unique when compared to the molecular sizes of CT and MR imaging contrast agents. Small enough to cross capillary beds, too large to enter interstitial space = Pure intravascular agents, ideal for assessing vascularity and perfusion After IV injection, US contrast agents half-life is about 10 minutes (eliminated via lungs). Multiple injections possible in a single session Contrast-enhanced US (CEUS) has high contrast resolution: Can visualize individual microbubbles and depict a minute amount of flow = Differentiate avascular debris from small solid nodules in complex cysts. Negative predictive value of CEUS in excluding the presence of flow in a lesion is close to 100% CEUS also has high temporal resolution: Effectively eliminates motion artifact, a major source of artifact on CT and especially MRI scans. In elderly or debilitated patients, or when there is any other cause of motion, CEUS may be the contrast-enhanced modality of choice Accuracy and specificity of CEUS for the diagnosis of hepatic hemangioma approaches 100% Mechanical index (MI) = Measure of acoustic power output. At high MI, microbubbles burst. At low MI, microbubbles are preserved and have a nonlinear response to US, unlike other tissues which have a linear response. Allows for creation of a vascular-only image Hemangioma has peripheral discontinuous globular enhancement in arterial phase. Progressive centripetal contrast filling and iso- or hyperenhancement in portal venous and late phase Non-hepatocellular malignancy typically demonstrates early (less than 1 minute) and/or marked washout Hemangioma filling may be partial or complete depending on lesion size To learn more about the Samsung RS85 Prestige ultrasound system, please visit: https://www.bostonimaging.com/rs85-prestige-ultrasound-system-4 See more impressive visuals by filmmaker and freelance motion graphics artist Nick Shaheen: https://www.instagram.com/nickhshaheen Click the YouTube Community tab or follow on social media for bonus teaching material posted throughout the week! Spotify: https://spoti.fi/462r0F2 Instagram: https://www.instagram.com/Radquarters/ Facebook: https://www.facebook.com/Radquarters/ X (Twitter): https://twitter.com/Radquarters Reddit: https://www.reddit.com/user/radiologistHQ/ The post Contrast-Enhanced Ultrasound of Hemangioma appeared first on Radquarters.
Transcribe →Ultrasound of Tennis Leg
Jul 14, 202400:09:20Tap to summarizeIn this radiology lecture, we review the ultrasound appearance of tennis leg, including medial gastrocnemius and plantaris injury! Key teaching points include: Tennis leg = Injury to muscles of the calf. Tear of myotendinous junction of medial head of gastrocnemius, rupture of plantaris tendon (less common), in isolation or together Classically described in tennis players, but can occur in various athletic activities (running, skiing) with extension of knee and forced dorsiflexion of ankle. Typically seen in middle-aged, active individuals Clinical: Sudden sharp calf pain with associated popping/snapping sensation followed by tenderness and swelling Gastrocnemius & soleus are pennate muscles. Fascicles attach obliquely to a tendon = Aponeuroses with long length of musculotendinous junction. Feathers converging on a single point Triceps surae muscle = Two headed gastrocnemius, soleus and plantaris. Distal continuation of the gastrocnemius and soleus forms the Achilles tendon Distal medial head of gastrocnemius where tapers over soleus = One of most commonly injured calf structures Medial gastrocnemius tear appears as disrupted tendon fibers at aponeurosis with anechoic/hypoechoic fluid or hemorrhage +/- muscle retraction May see retracted muscle fascicles. Hematoma can dissect between and extends into medial gastrocnemius and soleus muscles Tx: Conservative (self-limiting). Surgical fasciotomy if compartment syndrome Plantaris muscle arises from the posterosuperior aspect of lateral femoral condyle near lateral head origin of gastrocnemius muscle. Medially crosses posterior knee joint in oblique fashion Plantaris continues into calf as a long, thin tendon traveling between medial head of gastrocnemius and soleus muscles. Courses distally at medial aspect of Achilles tendon, usually inserts onto calcaneus. Plantaris is absent in up to 20% Plantaris injury/rupture less common than medial head gastrocnemius tear and typically more proximal in calf (at myotendinous junction) To learn more about the Samsung RS85 Prestige ultrasound system, please visit: https://www.bostonimaging.com/rs85-prestige-ultrasound-system-4 Click the YouTube Community tab or follow on social media for bonus teaching material posted throughout the week! Spotify: https://spoti.fi/462r0F2 Instagram: https://www.instagram.com/Radquarters/ Facebook: https://www.facebook.com/Radquarters/ X (Twitter): https://twitter.com/Radquarters Reddit: https://www.reddit.com/user/radiologistHQ/ The post Ultrasound of Tennis Leg appeared first on Radquarters.
Transcribe →Ultrasound of Interstitial Ectopic Pregnancy
Jun 6, 202400:07:50Tap to summarizeIn this radiology lecture, we review the ultrasound appearance of interstitial ectopic pregnancy! Key teaching points include: Interstitial ectopic pregnancies are rare, occurring in proximal (interstitial) portion of fallopian tube within muscle wall of uterus Much less common than tubal ectopic pregnancy occurring in the more distal ampullary and isthmic portions of fallopian tube Interstitial ectopic pregnancies are important because higher morbidity and mortality due to later presentation and risk of life-threatening hemorrhage Abnormally eccentric gestational sac with thin surrounding myometrium: less than 5 mm myometrial thickness highly suspicious “Interstitial line” sign: Thin echogenic line extending from endometrial cavity to ectopic gestational sac. Thought to represent interstitial portion of tube separating the ectopic pregnancy from the endometrium Medical: Systemic MTX, may also be injected into gestational sac Surgery: Cornual wedge resection when ruptured versus hysterectomy Can be confused with angular pregnancy: Rare, intrauterine pregnancy with implantation eccentrically high at the lateral angle of uterine cavity. More medial than interstitial ectopic pregnancies. No interstitial line sign, and greater than 5 mm thickness of overlying myometrial mantle Angular pregnancy can result in normal pregnancy, but increased risk of miscarriage and uterine rupture. Should be followed closely to ensure growth towards endometrial cavity Angular pregnancy is sometimes referred to as a “cornual pregnancy,” but controversial as earliest use of term cornual pregnancy refers to intrauterine implantations in anomalous unicornuate, bicornuate or septate uteri. To avoid confusion, best to specifically describe whether the gestational sac is intrauterine or ectopic To learn more about the Samsung RS85 Prestige ultrasound system, please visit: https://www.bostonimaging.com/rs85-prestige-ultrasound-system-4 Click the YouTube Community tab or follow on social media for bonus teaching material posted throughout the week! Spotify: https://spoti.fi/462r0F2 Instagram: https://www.instagram.com/Radquarters/ Facebook: https://www.facebook.com/Radquarters/ X (Twitter): https://twitter.com/Radquarters Reddit: https://www.reddit.com/user/radiologistHQ/ The post Ultrasound of Interstitial Ectopic Pregnancy appeared first on Radquarters.
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