Radiology Lectures | Radquarters

Daniel J. Kowal, MD
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  • MEDICINE
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Radiology Lectures | Radquarters

High-yield, educational radiology lectures utilizing a multimodality imaging approach including MRI, CT, ultrasound, radiography, and nuclear medicine. Lectures are presented in both didactic and quiz formats. These video podcasts are designed for radiology residents, fellows, and radiologists, as well as any student or practitioner interested in optimizing patient care through radiology. Visit www.radiologistHQ.com for more info and reference material.

  1. FEB 6 · VIDEO

    Ultrasound of Submandibular Sialolithiasis (Salivary Stones)

    In this radiology lecture, we review the ultrasound and CT appearance of submandibular stone disease, together with floor of mouth anatomy! Key teaching points include: * Submandibular glands are paired salivary glands located inferior to body of mandible * Submandibular glands are intermediate in size compared to the larger parotid and smaller sublingual glands, and they do not contain lymph nodes * The submandibular duct (= Wharton’s duct) extends from gland hilum and travels superiorly to open at floor of mouth on either side of base of frenulum of tongue. The duct is not typically seen unless abnormally dilated * On ultrasound, normal submandibular glands appear as encapsulated structures with homogeneous echotexture similar to the parotid. Fine linear echodensities may be present representing intraglandular ductules. Physiologic intravascular flow is typically evident. Superficial portion of the gland is almond-shaped, deep portion triangular * Sialolithiasis = Salivary calculous disease. Most common in submandibular gland because gland secretes a more alkaline, viscous saliva, and the long submandibular duct drains uphill = Increased salivary stasis * With acute obstruction, gland becomes enlarged (= sialadenitis) and duct proximal to stone dilated. Presents with colicky pain most pronounced around times of eating * US can detect even radiolucent stones, but small stones may not shadow * At the floor of mouth, the submandibular space (SMS) and sublingual space (SLS) are divided by mylohyoid musculature = Inferior sling of mouth. SMS is below (inferolateral to) mylohyoid, and SLS is above (superomedial to) mylohyoid * SMS contains: Submandibular glands, lymph nodes, anterior belly of digastric muscle * SLS contains: Sublingual glands, submandibular duct, and anterior aspect of hyoglossus muscle * Remember that while the submandibular glands are in the submandibular space, the submandibular duct is located in the sublingual space! * The submandibular duct travels between the hyoglossus and mylohyoid muscles, which are both useful sonographic landmarks aiding in duct location References: * Ching AS, Ahuja AT. High-resolution sonography of the submandibular space: anatomy and abnormalities. AJR Am J Roentgenol. 2002 Sep;179(3):703-8. * Grewal JS, Jamal Z, Ryan J. Anatomy, Head and Neck, Submandibular Gland. [Updated 2022 Dec 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. 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/

    10 min

  2. JAN 16 · VIDEO

    Ultrasound of Trigger Finger (Stenosing Tenosynovitis)

    In this radiology lecture, we review the ultrasound appearance of trigger finger! Key teaching points include: * Pulleys are fibrous retinacula on ventral finger that secure flexor tendons to phalanges preventing tendon displacement and bowstringing with finger flexion * Finger has 5 annular pulleys. Odd-numbered at joints, even-numbered at phalanges: A1, A3, A5 are located about the MCP, PIP, DIP joints, respectively. A2 is located at the proximal phalanx, and A4 at the middle phalanx * Cruciform pulleys lie between annular pulleys, but are not usually well-seen on ultrasound * Trigger finger, also known as stenosing tenosynovitis, is characterized by impaired flexor tendon movement due to thickened pulley leading to tendon constriction * Most common at A1 pulley, but can also occur at A2/A3 pulleys, palmar aponeurosis (A0) and wrist * Symptoms: Triggering/locking when flexed, painful snapping when extended, pain, joint stiffness * Most common in female patients, history of diabetes mellitus, and rheumatoid arthritis * Often idiopathic, can occur with repetitive microinjury (flexion-extension). Can also be post-traumatic or due to compressive mass/cyst * Tx: Splinting, NSAIDs, US-guided corticosteroid injection, surgical release * A1 pulley thickness cutoff = 0.62 mm*. Mean normal thickness = 0.5 mm, range with trigger finger 1.1-2.9 mm**. Comparison with asymptomatic side helpful * Additional findings: Pulley hyperemia, nodular tendon thickening (tendinosis) or tear, buckling of flexor tendon on dynamic imaging, “dark tendon” sign (anisotropic hypoechogenicity due to tendon constriction), synovial sheath effusion (acute), and peri-pulley cyst/cystic degeneration References: * *Spirig A, Juon B, Banz Y, Rieben R, Vogelin E. Correlation between sonographic and in vivo measurement of A1 pulleys in trigger fingers. Ultrasound Med Biol 2016; 42:1482–1490. * **Guerini H, Pessis E, Theumann N, Le Quintrec JS, Campagna R, Chevrot A, Feydy A, Drapé JL. Sonographic appearance of trigger fingers. J Ultrasound Med. 2008 Oct;27(10):1407-13. * Bianchi S, Gitto S, Draghi F. Ultrasound Features of Trigger Finger: Review of the Literature. J Ultrasound Med. 2019 Dec;38(12):3141-3154. * Shohda E, Sheta RA. Misconceptions about trigger finger: a scoping review. Definition, pathophysiology, site of lesion, etiology. Trigger finger solving a maze. Adv Rheumatol. 2024 Jul 11;64(1):53. 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! Website: https://Radquarters.com/ Spotify Video Podcast: https://spoti.fi/462r0F2 Apple Video Podcast: https://apple.co/3ZhHuGu 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/

    12 min

  3. 12/12/2024 · VIDEO

    Ultrasound of Hydrosalpinx, Pyosalpinx & Tubo-ovarian Abscess

    Ultrasound of Hydrosalpinx, Pyosalpinx & Tubo-ovarian Abscess In this radiology lecture, we review the ultrasound appearance of hydrosalpinx, pyosalpinx and tubo-ovarian abscess! Key teaching points include: * Hydrosalpinx = Fluid-filled, blocked fallopian tube * Hydrosalpinx causes: Pelvic inflammatory disease (most common), endometriosis, prior surgery, adhesions * Hydrosalpinx US: Thin-walled, tubular structure filled with anechoic simple fluid. Dilated tube may fold upon itself forming tubular C-shaped or S-shaped cystic mass. Incomplete septations common * With chronic hydrosalpinx, may see “beads-on-a-string” sign: Short, round, 2-3 mm projections seen along inner tubal walls in cross section = Flattened, fibrotic remnants of endosalpingeal folds. Don’t confuse with solid mural nodules * O-RADS US v2022 management of hydrosalpinx = Imaging: None. Clinical: Gynecologist * Pyosalpinx: Inflamed, blocked fallopian tube filled with purulent debris. Indicates pelvic inflammatory disease * Pyosalpinx US: Thick-walled tubal structure filled with complex fluid. Like hydrosalpinx, typically conforms to a C or S-shape * “Cogwheel” sign of pyosalpinx: Thickened endosalpingeal folds with surrounding tubal wall thickening. Typical of acute tubal inflammation * Tubal wall hyperemia more common with pyosalpinx than hydrosalpinx * Tubo-ovarian complex (TOC): With severe salpingo-oophoritis, ovary and tube adhere to each other. Can distinctly identify ovary from tube but cannot separate the two with transducer pressure. Tx: Antibiotics * Tubo-ovarian abscess (TOA): As pelvic inflammatory disease progresses, complete or near-complete loss of adnexal architecture with pockets of purulent fluid develop. Multiloculated mass with septations, irregular margins, may be bilateral. Tx: Antibiotics, percutaneous drainage, surgery 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/

    11 min

  4. 10/17/2024 · VIDEO

    Ultrasound of Gallbladder Adenomyomatosis

    In this radiology lecture, we review the ultrasound appearance of adenomyomatosis of the gallbladder! Key teaching points include: * Common cause of benign gallbladder wall thickening seen in up to 9% of patients * Incidence increases with age * Usually asymptomatic, but may be associated with sporadic RUQ pain * Hyperplastic changes of gallbladder wall with mucosal overgrowth. Mucosal herniations protrude into muscular layer forming tiny, bile-filled cystic spaces = Rokitansky-Aschoff sinuses * If large, sinuses may appear as discrete cystic spaces in gallbladder wall * Cholesterol crystals in sinuses cause comet-tail reverberation artifact: Most common finding and highly specific for adenomyomatosis. Can exaggerate comet-tail with addition of color Doppler * Three types: Focal/fundal, segmental/annular and diffuse. Regardless of type, comet-tail artifacts and/or cystic spaces are key to diagnosis * Focal/fundal type: Most common. Often exhibits an “ovary on the gallbladder” appearance. Can be confused with a gallbladder mass. High-frequency linear transducer may be helpful to identify morphology * Segmental/annular type: Narrows waist of gallbladder yielding a figure 8 or hourglass configuration. Gallstones and/or sludge often form in proximal lumen due to increased stasis * If necessary, MRI helpful for problem solving: T2 hyperintense pearl necklace/string of beads appearance sensitive and specific 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/

    8 min

  5. 09/12/2024 · VIDEO

    Ultrasound of de Quervain’s Tenosynovitis

    In this radiology lecture, we review the ultrasound appearance of de Quervain’s Tenosynovitis! Key teaching points include: * Stenosing tenosynovitis of first extensor compartment tendons = Extensor pollicis brevis (EPB) and abductor pollicis longus (APL) * Second most common hand entrapment tendinopathy after trigger finger * Most common in middle-aged females * Associations include repetitive hand motions, pregnancy, arthritis, and trauma * Clinical presentation: Pain with thumb and wrist movement, tenderness and swelling at radial styloid * Positive Finkelstein maneuver may be present: Grasp thumb, ulnar deviate hand = Pain over distal radius * Ultrasound findings: Increased fluid in EPB/APL tendon sheath (tenosynovitis), hypoechoic, edematous tendon thickening (tendinosis), and thickening of extensor retinaculum (comparison scanning of contralateral thumb helpful) * Advanced findings: Impaired tendon movement, tendon tear (anechoic clefts), retinacular and peritendinous hyperemia * Don’t confuse normal APL slips with longitudinal tear (“lotus root” sign) * Important to identify variant intertendinous septa: Helps to properly guide steroid injection, increased incidence of asymmetric EPB involvement * If conservative therapy fails, surgical decompression may be required. More likely when septum present 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/

    9 min

  6. 08/15/2024 · VIDEO

    Contrast-Enhanced Ultrasound of Hemangioma

    In 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/

    10 min

  7. 07/14/2024 · VIDEO

    Ultrasound of Tennis Leg

    In 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/

    9 min

  8. 06/06/2024 · VIDEO

    Ultrasound of Interstitial Ectopic Pregnancy

    In 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/

    8 min
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    About

    High-yield, educational radiology lectures utilizing a multimodality imaging approach including MRI, CT, ultrasound, radiography, and nuclear medicine. Lectures are presented in both didactic and quiz formats. These video podcasts are designed for radiology residents, fellows, and radiologists, as well as any student or practitioner interested in optimizing patient care through radiology. Visit www.radiologistHQ.com for more info and reference material.

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