Ultrasonographic Anatomy — MCQs
Which of the following is best assessed by FAST USG?
Which of the following is the best in-vivo screening choice for carotid artery stenosis?
In an ultrasound of the abdomen, which structure is best seen posterior to the stomach?
A patient has dyspareunia, and dysmenorrhea with adnexal tenderness. What is the first step of investigation?
A patient with infertility has an ultrasound (USG) suggestive of a uterine anomaly. Which of the following is the best method to confirm the diagnosis?
Investigation of choice to diagnose hypertrophic pyloric stenosis in infants is
Frequency of ultrasound waves in USG -
Which of the following statements about the umbilical cord is incorrect?
Which of the following anatomic boundary separates the true pelvis from the false pelvis?
Which of the following is a derivative of ventral mesogastrium ?
Ultrasonographic Anatomy Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is best assessed by FAST USG?
- A. Liver
- B. Pericardium (Correct Answer)
- C. Spleen
- D. Pleural cavity
Explanation: ***Pericardium*** - FAST USG is **most clinically significant** for detecting **pericardial effusions** and **cardiac tamponade** in trauma patients. - The **subxiphoid view** provides **excellent direct visualization** of the heart and pericardial space with minimal interference. - **Small volumes** of pericardial fluid (as little as 50-100 mL) are **clinically significant** and potentially life-threatening, requiring immediate intervention. - Cardiac tamponade is an **immediately reversible cause of shock** that demands urgent diagnosis and pericardiocentesis. - **Sensitivity >90%** for clinically significant pericardial effusions in the trauma setting. *Liver* - FAST assesses the **hepatorenal space (Morison's pouch)** for free fluid, not the liver parenchyma itself. - Requires **larger volumes of free fluid** (>200-500 mL) to be reliably detected in the peritoneal cavity. - Detailed assessment of actual liver injury requires **contrast-enhanced CT imaging**. *Spleen* - FAST evaluates the **splenorenal recess** for free fluid surrounding the spleen, not splenic parenchymal injury. - Detection depends on adequate volume of free fluid being present. - **CT scanning** is superior for defining splenic lacerations, hematomas, and grading injury severity. *Pleural cavity* - While Extended FAST (eFAST) can assess **pleural spaces** for effusion or pneumothorax, this is an **extension** of the standard 4-view FAST protocol. - Standard FAST focuses on the **four primary windows**: pericardial, perihepatic, perisplenic, and pelvic. - **Chest X-ray** and **CT** remain primary modalities for comprehensive thoracic assessment.
Question 2: Which of the following is the best in-vivo screening choice for carotid artery stenosis?
- A. Digital Subtraction Angiography (DSA)
- B. CT
- C. MRI
- D. USG (Correct Answer)
Explanation: ***USG*** - **Ultrasound** (USG), specifically **carotid duplex ultrasonography**, is the **safest**, most cost-effective, and readily available initial screening tool for carotid artery stenosis due to its non-invasive nature and ability to visualize blood flow and vessel morphology. - It combines **B-mode imaging** with **Doppler flow analysis** to provide real-time images and flow velocity measurements, allowing for assessment of the degree of **stenosis** and plaque characteristics without radiation or contrast agents. - Sensitivity and specificity exceed 85-90% for detecting significant stenosis, making it the preferred first-line screening modality. *Digital Subtraction Angiography (DSA)* - **DSA** is the **gold standard** for anatomical detail and remains the most accurate method for quantifying carotid stenosis, but it is **invasive** and requires arterial catheterization. - It involves **ionizing radiation** and **iodinated contrast agents**, carrying risks of stroke (0.5-1%), arterial dissection, nephrotoxicity, and contrast allergic reactions. - Due to its invasive nature and associated risks, DSA is reserved for **pre-surgical planning** or when non-invasive imaging is inconclusive, not for initial screening. *CT* - **Computed tomography angiography (CTA)** involves **ionizing radiation** and typically requires an **iodinated contrast agent**, which carries risks of allergy and nephrotoxicity. - Though CTA provides excellent anatomical detail and can visualize vessel wall calcification, it is generally reserved for confirmation or surgical planning rather than initial screening due to its higher cost, radiation exposure, and contrast-related risks. *MRI* - **Magnetic resonance angiography (MRA)** can visualize carotid arteries well but is more expensive, less accessible than ultrasound, and may require a **gadolinium-based contrast agent**, which can have adverse effects (nephrogenic systemic fibrosis in renal impairment). - It is often used when ultrasound findings are equivocal or in cases where CTA is contraindicated, but it's not the preferred initial screening method due to its complexity, cost, longer examination time, and contraindications (pacemakers, metallic implants).
Question 3: In an ultrasound of the abdomen, which structure is best seen posterior to the stomach?
- A. Pancreas (Correct Answer)
- B. Gallbladder
- C. Spleen
- D. Liver
Explanation: ***Pancreas*** - The **pancreas** is retroperitoneal and lies transversely across the posterior abdominal wall, making it located directly posterior to the stomach. - In ultrasound, the stomach, when filled with fluid, can act as an acoustic window to visualize the pancreas behind it. *Gallbladder* - The **gallbladder** is typically nestled in a fossa on the inferior surface of the liver, anterior to the duodenum and often anterior or inferior to the stomach [1]. - It is not positioned directly posterior to the stomach, but rather more to the right and inferior [1]. *Spleen* - The **spleen** is located in the left upper quadrant, superior and posterior to the stomach, but typically more lateral and posterior than directly behind it. - While it has a close relationship with the stomach, it is usually not considered "best seen posterior to the stomach" in the same straight-on fashion as the pancreas. *Liver* - The **liver** is primarily located in the right upper quadrant, largely anterior and superior to the stomach. - While a small portion of the left lobe of the liver can be anterior to the stomach, the bulk of the liver is not posterior to it.
Question 4: A patient has dyspareunia, and dysmenorrhea with adnexal tenderness. What is the first step of investigation?
- A. Colposcopy
- B. Diagnostic laparoscopy
- C. Transvaginal USG (Correct Answer)
- D. Transabdominal pelvic ultrasound
Explanation: ***Transvaginal USG*** - This is the **first-line investigation** for evaluating pelvic pain, dyspareunia, dysmenorrhea, and adnexal tenderness due to its ability to provide **high-resolution images** of the uterus, ovaries, and surrounding structures to identify potential pathology like **endometriomas** or other adnexal masses. - It allows for detailed assessment of **ovarian cysts**, fibroids, and other pelvic abnormalities, which can explain the patient's symptoms. *Colposcopy* - This procedure is primarily used to closely examine the **cervix, vagina, and vulva** for abnormal cells, often following an abnormal Pap test. - It is not the initial step for investigating generalized pelvic pain, dyspareunia, or adnexal tenderness. *Diagnostic laparoscopy* - While a **diagnostic laparoscopy** can provide a definitive diagnosis for conditions like **endometriosis**, it is an **invasive surgical procedure** and typically reserved for cases where non-invasive imaging, such as transvaginal ultrasound, has not yielded a clear diagnosis or when conservative management has failed. - It is not considered the first-step investigation due to its **invasive nature** and associated risks. *Transabdominal pelvic ultrasound* - A **transabdominal pelvic ultrasound** provides a broader view of the pelvic organs but often has **lower resolution** and is less accurate for detailed assessment of the uterus, ovaries, and adnexa compared to transvaginal ultrasound, especially in obese patients. - It is often used if a transvaginal ultrasound is not feasible or for assessing larger pelvic masses, but the **transvaginal approach** is superior for detailed evaluation of the female reproductive organs.
Question 5: A patient with infertility has an ultrasound (USG) suggestive of a uterine anomaly. Which of the following is the best method to confirm the diagnosis?
- A. Hysterosalpingography (HSG)
- B. Transvaginal Sonography (TVS)
- C. Hysteroscopy + Laparoscopy (Correct Answer)
- D. Laparoscopy
Explanation: ***Hysteroscopy + Laparoscopy*** - This combination allows for a comprehensive evaluation: **hysteroscopy** visualizes the uterine cavity to confirm the type of anomaly (e.g., septum), while **laparoscopy** assesses the external uterine contour and overall pelvic anatomy. - It is considered the **gold standard** for diagnosing complex uterine anomalies as it provides the most detailed information for both diagnosis and surgical planning. *Hysterosalpingography (HSG)* - HSG can delineate the **uterine cavity morphology** and patency of fallopian tubes. - However, it is an **X-ray based test** and does not provide information about the external contour of the uterus, which is crucial for differentiating anomalies like a bicornuate from a septate uterus. *Transvaginal Sonography (TVS)* - While TVS is an excellent initial screening tool and can suggest a uterine anomaly, it often **lacks the definitive resolution** to precisely classify the anomaly, especially differentiating between septate and bicornuate uteri. - Its accuracy can be **operator-dependent** and limited in visualizing the external uterine contour. *Laparoscopy* - Laparoscopy alone provides an excellent view of the **external uterine contour** and pelvic organs. - However, it **does not visualize the internal uterine cavity**, which is essential for identifying and classifying anomalies such as a uterine septum.
Question 6: Investigation of choice to diagnose hypertrophic pyloric stenosis in infants is
- A. Gastroscopy
- B. CT scan abdomen
- C. Ultrasound abdomen (Correct Answer)
- D. Contrast radiology
Explanation: ***Ultrasound abdomen*** - **Abdominal ultrasound** is the diagnostic procedure of choice due to its **non-invasive nature**, **lack of radiation exposure**, and high accuracy in visualizing the pylorus. - It allows for direct measurement of the **pyloric muscle wall thickness** (typically >3-4 mm) and **pyloric channel length** (typically >14-17 mm), which are characteristic findings of hypertrophic pyloric stenosis. *Gastroscopy* - While gastroscopy can visualize the gastric outlet, it is an **invasive procedure** and not the primary diagnostic tool due to the risk associated with endoscopy in infants. - It is often reserved for cases where the diagnosis is unclear or other upper gastrointestinal pathologies are suspected. *CT scan abdomen* - **CT scans** expose infants to **ionizing radiation**, making it an unsuitable primary diagnostic investigation, especially when a highly accurate non-irradiating alternative exists. - Although it can show pyloric thickening, its disadvantages outweigh its benefits for this diagnosis. *Contrast radiology* - **Barium studies** are less sensitive and specific than ultrasound for diagnosing pyloric stenosis, especially for distinguishing muscle thickening from spasm. - This method also involves **radiation exposure** and poses a risk of aspiration, making it a secondary choice.
Question 7: Frequency of ultrasound waves in USG -
- A. 2000 Hz
- B. 5000 Hz
- C. < 2 MHz
- D. >2 MHz (Correct Answer)
Explanation: ***>2 MHz*** - Medical diagnostic ultrasound typically uses frequencies in the **range of 2-15 MHz**, with some applications extending from 1-20 MHz. - Frequencies **above 2 MHz** are considered the standard for diagnostic ultrasonography, providing adequate **spatial resolution** and tissue penetration for imaging internal structures. - **Frequency selection** depends on the application: - **2-5 MHz**: Deep structures (abdominal, obstetric imaging) - better penetration - **5-10 MHz**: Vascular studies, cardiac imaging - **7-15 MHz**: Superficial structures (thyroid, breast, musculoskeletal) - better resolution - Higher frequencies provide better resolution but less penetration; the choice represents a trade-off based on clinical needs. *2000 Hz* - This frequency (2 kHz) falls within the **audible range** for humans (20 Hz to 20 kHz). - Such low frequencies would not provide the necessary **spatial resolution** for diagnostic imaging and lack the characteristics needed for medical ultrasound. *5000 Hz* - At 5 kHz, this is still within the **audible frequency range**. - These frequencies are far too low for medical ultrasound imaging, which requires **megahertz frequencies** to generate diagnostically useful images with adequate detail. *< 2 MHz* - Frequencies below 2 MHz, while technically ultrasound (>20 kHz), are generally **below the diagnostic range** for most clinical applications. - Although lower frequencies offer better tissue penetration, frequencies below 2 MHz provide **insufficient spatial resolution** for standard diagnostic medical imaging.
Question 8: Which of the following statements about the umbilical cord is incorrect?
- A. Two arteries and one vein
- B. Contains Wharton's jelly
- C. Typically 50 to 60 cm long
- D. Two veins and one artery (Correct Answer)
Explanation: ***Two veins and one artery*** - This statement is incorrect because the typical umbilical cord contains **two umbilical arteries** and **one umbilical vein**. - **Two veins and one artery** would represent a rare anomaly, often associated with other congenital malformations. *Two arteries and one vein* - This is the **normal anatomical configuration** of the umbilical cord, consisting of **two umbilical arteries** and **one umbilical vein**. - The arteries carry deoxygenated blood and waste products from the fetus to the placenta, while the vein carries oxygenated blood and nutrients from the placenta to the fetus. *Contains Wharton's jelly* - **Wharton's jelly** is a gelatinous substance found within the umbilical cord, surrounding the blood vessels. - Its primary function is to protect the umbilical vessels from compression and knotting, ensuring continuous blood flow. *Typically 50 to 60 cm long* - The average length of a term umbilical cord is indeed between **50 and 60 centimeters**. - Variations in length can occur, with excessively short or long cords potentially leading to obstetric complications.
Question 9: Which of the following anatomic boundary separates the true pelvis from the false pelvis?
- A. Linea terminalis (Correct Answer)
- B. Ischial spine
- C. Arcuate line
- D. Pectineal line
Explanation: ***Linea terminalis*** - The **linea terminalis** is the imaginary line forming the boundary between the **true (lesser) pelvis** and the **false (greater) pelvis** [1]. - It delineates the **pelvic inlet** and defines the space where the pelvic organs are located [1]. *Ischial spine* - The **ischial spine** is a bony prominence within the **true pelvis** that serves as an important landmark for assessing fetal station during labor. - It does not separate the true from the false pelvis but is entirely contained within the true pelvis [1]. *Arcuate line* - The **arcuate line** is a part of the **linea terminalis**, specifically located on the ilium. - It forms only a segment of the complete boundary that separates the true and false pelvis. *Pectineal line* - The **pectineal line** (pecten pubis) is another component of the **linea terminalis**, located on the superior ramus of the pubic bone. - Like the arcuate line, it is a part of the overall boundary and not the entire separating structure itself.
Question 10: Which of the following is a derivative of ventral mesogastrium ?
- A. Lesser omentum (Correct Answer)
- B. Splenorenal ligament
- C. Greater omentum
- D. Gastrosplenic ligament
Explanation: ***Lesser omentum*** - The **lesser omentum** is formed from the **ventral mesogastrium**, which connects the developing stomach to the anterior abdominal wall [1]. - It specifically derives from the part of the ventral mesogastrium that encloses the developing liver and extends to the lesser curvature of the stomach and the duodenum [1]. *Greater omentum* - The **greater omentum** develops from the **dorsal mesogastrium**, which means it is a derivative of the dorsal rather than the ventral mesentery [1]. - It arises from a rapid growth and fusion of the **dorsal mesogastrium**, hanging from the greater curvature of the stomach. *Splenorenal ligament* - The **splenorenal ligament** develops from the **dorsal mesogastrium**, specifically from the portion that connects the spleen to the posterior abdominal wall (near the kidney). - Its formation is a consequence of the rotation of the stomach and the development of the spleen within the dorsal mesentery. *Gastrosplenic ligament* - The **gastrosplenic ligament** is also derived from the **dorsal mesogastrium**, connecting the greater curvature of the stomach to the hilum of the spleen. - As the stomach rotates, the dorsal mesogastrium expands, eventually forming both the gastrosplenic and splenorenal ligaments.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free