Ultrasound Practice Questions

Q: Plethoric, non-collapsible IVC on echocardiography denotes?

Right heart failure. **Explanation:** The Inferior Vena Cava (IVC) serves as a reliable surrogate for measuring **Central Venous Pressure (CVP)** and right-sided heart function. In a healthy individual, the IVC diameter decreases by >50% during inspiration (the "sniff test") due to the negative intrathoracic pressure drawing blood into the right atrium. **Why Right Heart Failure is correct:** In **Right Heart Failure**, the heart cannot effectively pump blood forward, leading to a "backlog" of pressure in the venous system. This results in a **plethoric** (dilated, usually >2.1 cm) and **non-collapsible** IVC (collapse <50%). This lack of respiratory variation indicates high CVP and fluid overload. **Analysis of Incorrect Options:** * **Budd-Chiari Syndrome:** This involves obstruction of hepatic venous outflow. While it may cause IVC narrowing or membranes, it typically leads to hepatomegaly and ascites rather than generalized IVC plethora unless the obstruction is at the level of the suprahepatic IVC. * **Hepatic Venous Malformation:** These are localized vascular anomalies and do not typically cause systemic venous congestion or alter IVC respiratory dynamics. * **IVC Thrombosis:** While a thrombus can distend the vessel locally, it usually presents with intraluminal echoes (the clot itself) and distal venous engorgement, rather than the classic "plethoric" appearance associated with systemic heart failure. **High-Yield Clinical Pearls for NEET-PG:** * **IVC Index:** (Max diameter - Min diameter) / Max diameter. An index ** 10-15 mmHg). * **Shock Assessment:** A small, hyper-collapsible IVC ("kissing walls") is a hallmark of **hypovolemic shock**. * **Point-of-Care Ultrasound (POCUS):** The IVC is best visualized in the subxiphoid long-axis view.

Q: The TRIANGULAR CORD Sign is seen in which condition?

Biliary Atresia. **Explanation:** The **Triangular Cord Sign** is a pathognomonic ultrasonographic finding for **Biliary Atresia**. It represents a cone-shaped or triangular fibrotic mass of the cranial part of the extrahepatic biliary tree. On ultrasound, it appears as an echogenic (hyper-echoic) area located anterior to the bifurcation of the portal vein. A thickness of **>4 mm** is considered a positive sign and is highly specific for diagnosing biliary atresia in a neonate with conjugated jaundice. **Analysis of Options:** * **Biliary Atresia (Correct):** Characterized by the obliteration of the extrahepatic biliary tree. Other USG findings include a small/absent gallbladder (Ghost Gallbladder sign) and the absence of a common bile duct. * **Caroli’s Disease:** A congenital disorder characterized by multifocal segmental dilatation of large intrahepatic bile ducts. The classic radiological sign is the **"Central Dot Sign"** (portal vein branches surrounded by dilated bile ducts). * **Serous Cystadenoma:** A benign pancreatic neoplasm. On imaging, it typically shows a **"Sunburst" calcification** or a honeycomb appearance, not related to the biliary cord. * **Hydatid of Liver:** Caused by *Echinococcus granulosus*. Key USG findings include the **"Water Lily Sign"** (detached endocyst) or the presence of daughter cysts. **NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis:** Intraoperative Cholangiogram (IOC). * **Surgery of Choice:** Kasai Procedure (Hepatoportoenterostomy), ideally performed before 60 days of life. * **Most Common Cause:** Biliary atresia is the most common cause of neonatal cholestasis requiring surgery. * **Associated Sign:** The "Ghost Gallbladder" sign (length <19 mm, irregular contour).

Q: Color Doppler study can evaluate the following EXCEPT?

Intravascular pressure. **Explanation:** Color Doppler ultrasound is a non-invasive imaging technique based on the **Doppler Effect**, which detects the shift in frequency of sound waves reflected off moving red blood cells. **Why Option D is the Correct Answer:** Color Doppler **cannot directly measure intravascular pressure**. While Doppler can measure the velocity of blood flow, pressure is a hemodynamic parameter that usually requires invasive catheterization (manometry) or indirect calculation using the Bernoulli equation (commonly used in Echocardiography, but not a direct measurement of the Doppler signal itself). **Analysis of Incorrect Options:** * **A. Direction of blood flow:** This is the primary function of Color Doppler. By convention, flow toward the transducer is encoded in **Red**, and flow away from the transducer is encoded in **Blue** (BART: Blue Away, Red Toward). * **B. Velocity of blood flow:** Doppler measures the frequency shift, which is directly proportional to the velocity of the moving blood cells. Spectral Doppler provides precise quantitative velocity measurements. * **C. Impedance index:** Also known as the **Resistive Index (RI)** or Pulsatility Index (PI). These are calculated ratios derived from velocity waveforms (Systolic vs. Diastolic velocities) to assess the resistance to blood flow in a vessel. **High-Yield Clinical Pearls for NEET-PG:** * **Power Doppler:** More sensitive than Color Doppler for detecting slow flow (e.g., in torsion or inflammation) but does **not** show direction or velocity. * **Duplex Scanning:** Refers to the simultaneous use of B-mode (grayscale) imaging and Doppler ultrasound. * **Aliasing Artifact:** Occurs when the blood velocity exceeds the Nyquist limit (1/2 of the Pulse Repetition Frequency), causing the color to "wrap around" and appear as the opposite direction.

Q: What is the recommended frequency range for transvaginal ultrasound for obstetric purposes?

5 - 7.5 MHz. **Explanation:** The choice of ultrasound frequency involves a fundamental trade-off between **resolution** and **penetration**. Higher frequencies provide superior image resolution but have poor depth penetration, while lower frequencies penetrate deeper at the cost of image clarity. * **Option B (5 – 7.5 MHz) is Correct:** Transvaginal ultrasound (TVS) utilizes a probe placed in close proximity to the pelvic organs (uterus and ovaries). Because the distance to the target tissue is minimal, high penetration is not required. Therefore, a higher frequency range of **5 – 7.5 MHz** is used to achieve the high-resolution images necessary for early pregnancy detection, such as identifying a gestational sac or fetal cardiac activity. **Analysis of Incorrect Options:** * **Option A (3 – 5 MHz):** This is the standard frequency for **Transabdominal Ultrasound (TAS)**. It is lower because the sound waves must penetrate through the abdominal wall and a full bladder to reach the pelvic organs. * **Option C (7.5 – 20 MHz):** These very high frequencies are reserved for **superficial structures** with minimal depth, such as the thyroid, breast, testes, or musculoskeletal imaging. * **Option D (> 20 MHz):** These frequencies are used in specialized applications like **Intravascular Ultrasound (IVUS)** or high-resolution ophthalmic imaging. **High-Yield Clinical Pearls for NEET-PG:** * **Early Pregnancy:** TVS can detect a gestational sac as early as **4.5 to 5 weeks**, whereas TAS typically requires **5.5 to 6 weeks**. * **Discriminatory Zone:** The β-hCG level at which a gestational sac should be visible is **1,500–2,000 mIU/mL** for TVS and **>6,500 mIU/mL** for TAS. * **Yolk Sac:** The first structure to appear within the gestational sac; its presence confirms an intrauterine pregnancy.

Q: Which of the following statements about transvaginal ultrasound is incorrect?

The bladder should be full.. **Explanation:** In gynecological imaging, the state of the urinary bladder is a critical factor for image quality. For **Transabdominal Ultrasound (TAS)**, a **full bladder** is required because it acts as an acoustic window, pushing the gas-filled bowel loops out of the pelvis and providing a clear view of the uterus and ovaries. However, for **Transvaginal Ultrasound (TVS)**, the **bladder should be empty**. A full bladder during TVS is counterproductive as it pushes the pelvic organs away from the high-frequency vaginal probe, thereby decreasing the resolution and causing patient discomfort during probe manipulation. **Analysis of Options:** * **Option A (Correct):** This statement is **incorrect**. As established, TVS requires an empty bladder to bring the pelvic organs into the focal zone of the transducer. * **Option B:** This is a **correct** statement. Emptying the bladder improves the proximity of the probe to the target organs (uterus/adnexa). * **Option C:** This is a **correct** statement. Since TVS is an invasive procedure involving the insertion of a probe into the vaginal canal, obtaining informed consent (and often having a female chaperone present) is a mandatory medico-legal and ethical requirement. **High-Yield Clinical Pearls for NEET-PG:** * **TVS vs. TAS:** TVS uses higher frequency probes (5–9 MHz) compared to TAS (3–5 MHz), offering superior spatial resolution but less depth of penetration. * **Early Pregnancy:** TVS can detect a gestational sac as early as **4.5 to 5 weeks**, which is about 1 week earlier than TAS. * **Discriminatory Zone:** The β-hCG level at which a gestational sac should be visible on TVS is typically **1,500–2,000 mIU/mL**. * **Contraindication:** TVS is generally avoided in patients with an intact hymen (virgins) or if there is active heavy vaginal bleeding/premature rupture of membranes (relative).

Q: What is the characteristic radiological feature of pneumothorax on ultrasound?

Stratosphere sign. In ultrasound imaging of the lung, the diagnosis of pneumothorax relies on the absence of normal pleural movement. **Correct Answer: D. Stratosphere sign** In a normal lung, the visceral and parietal pleura slide against each other, creating a dynamic "shimmering" effect. In M-mode, this appears as the **Sea-shore sign** (motionless tissues above the pleura look like waves, while moving lung below looks like sand). In a **pneumothorax**, air separates the pleural layers, preventing the ultrasound beam from reaching the moving lung. This results in a series of static, horizontal parallel lines across the entire screen, resembling a barcode or the layers of the atmosphere. Hence, it is called the **Stratosphere sign** (or Barcode sign). **Explanation of Incorrect Options:** * **A. Lung sliding sign:** This is a normal finding. Its presence effectively rules out a pneumothorax at that specific location. * **B. Sea shore sign:** This is the normal M-mode appearance of a healthy, sliding lung. * **C. B lines:** Also known as "comet-tail artifacts," these are vertical hyperechoic lines originating from the pleural line. They indicate fluid in the interstitium. Their presence **rules out** pneumothorax because they require contact between the two pleural layers to form. **High-Yield Clinical Pearls for NEET-PG:** 1. **Lung Point Sign:** This is the most specific ultrasound sign for pneumothorax (100% specificity). It represents the physical transition point where the collapsed lung intermittently contacts the chest wall. 2. **E-FAST:** Ultrasound is more sensitive than a supine Chest X-ray for detecting a traumatic pneumothorax. 3. **Rule of Thumb:** If you see **Lung Sliding** or **B-lines**, you can 100% exclude a pneumothorax at that point.

Q: What is the investigation of choice for minimal ascites?

Ultrasound (USG). **Explanation:** **Ultrasound (USG)** is the investigation of choice for minimal ascites because of its high sensitivity and non-invasive nature. It can detect as little as **5–10 mL** of peritoneal fluid, typically first appearing in the **Pouch of Douglas** (in females) or the **rectovesical pouch** (in males). USG is preferred over other modalities due to its bedside availability, lack of ionizing radiation, and ability to guide diagnostic paracentesis. **Analysis of Options:** * **X-ray (A):** This is the least sensitive method. Ascites only becomes visible on a plain radiograph (as "ground-glass" opacification or bulging flanks) when the volume exceeds **500–1000 mL**. * **CT Scan (C):** While CT is highly sensitive and can detect small amounts of fluid (approx. 30 mL), it is not the *first-line* investigation due to high cost, radiation exposure, and the need for transport to a radiology suite. It is usually reserved for characterizing the cause of ascites (e.g., malignancy). * **MRI (D):** MRI is excellent for soft tissue characterization but is unnecessary, expensive, and time-consuming for the simple detection of fluid. **Clinical Pearls for NEET-PG:** * **Earliest site of fluid collection:** In a supine patient, fluid first collects in **Morison’s Pouch** (hepatorenal space). * **Physical Exam:** "Shifting dullness" requires at least **500 mL** of fluid, while "Fluid thrill" requires **1500–2000 mL**. * **FAST Scan:** Focused Assessment with Sonography for Trauma is used in emergencies to detect hemoperitoneum (blood in the peritoneal cavity).

Q: Gestational sac is seen on transvaginal sonography as early as:

35 days from LMP. **Explanation:** The visualization of pregnancy on ultrasound follows a predictable chronological sequence based on the **Last Menstrual Period (LMP)**. 1. **Why Option C is Correct:** The **Gestational Sac (GS)** is the first definitive sign of pregnancy seen on ultrasound. On **Transvaginal Sonography (TVS)**, it typically becomes visible at **4.5 to 5 weeks (32–35 days)** of gestation. At this stage, it appears as a small, eccentric fluid collection within the endometrium (the "intradecidual sign"). By 35 days, the mean sac diameter is approximately 2–5 mm. 2. **Why Other Options are Incorrect:** * **Options A & B (18 and 21 days):** These represent the 3rd week of gestation. At this point, implantation has only just occurred or is occurring. The blastocyst is microscopic and cannot be resolved by current ultrasound technology. * **Option D (42 days):** This corresponds to 6 weeks. While the GS is easily seen here, it is no longer the "earliest" finding. By 42 days, one should expect to see the **Yolk Sac** (appears at 5.5 weeks) and often the **Fetal Pole with cardiac activity** (appears by 6 weeks). **High-Yield NEET-PG Pearls:** * **TVS vs. TAS:** TVS can detect pregnancy landmarks approximately **1 week earlier** than Transabdominal Sonography (TAS). * **Discriminatory Zone:** This is the level of serum β-hCG at which a gestational sac should be visible. For TVS, it is generally **1,500–2,000 mIU/mL**. * **Order of Appearance (TVS):** 1. Gestational Sac (4.5–5 weeks) 2. Yolk Sac (5.5 weeks) – *First reliable sign of intrauterine pregnancy.* 3. Embryo/Cardiac activity (6 weeks). * **Double Decidual Sign:** Helps distinguish a true gestational sac from a pseudogestational sac (seen in ectopic pregnancy).

Q: Ultrasound is done in the 1st trimester for all except:

To know the position of the placenta. ### Explanation The primary goal of a first-trimester ultrasound (performed before 13 weeks 6 days) is to confirm viability, establish accurate dating, and determine chronicity in multiple gestations. **Why Option D is the Correct Answer:** In the first trimester, the placenta is not yet fully formed; instead, we see the **decidua capsularis and basalis**. More importantly, the lower uterine segment has not yet developed. As the uterus grows, the placenta appears to "move" away from the internal os—a phenomenon known as **placental migration**. Therefore, diagnosing the definitive position of the placenta (to rule out Placenta Previa) is only clinically reliable in the **second and third trimesters** (typically after 18–20 weeks). **Analysis of Incorrect Options:** * **A. Multiple pregnancy:** The first trimester is the "Gold Standard" time to determine **chorionicity** (e.g., identifying the T-sign or Lambda sign), which is crucial for managing twin pregnancies. * **B. Fetal anomalies:** While the detailed anatomy scan occurs at 18–20 weeks, major structural anomalies (like Anencephaly) and chromosomal markers (like **Nuchal Translucency**) are assessed between 11–13.6 weeks. * **C. To estimate gestational age:** The **Crown-Rump Length (CRL)** measured in the first trimester is the most accurate parameter for dating a pregnancy (error margin of ±3–5 days). **High-Yield Clinical Pearls for NEET-PG:** * **Most accurate measurement for dating:** CRL (1st Trimester). * **First sign of pregnancy on USG:** Gestational sac (at ~4.5–5 weeks). * **First sign of intrauterine pregnancy:** Yolk sac (at ~5–5.5 weeks). * **Placental Migration:** Occurs due to the differential growth of the lower uterine segment; 90% of "low-lying" placentas identified early will resolve by term.

Question 1

Plethoric, non-collapsible IVC on echocardiography denotes?

Accepted Answer

Right heart failure

Answer

Budd-Chiari syndrome

Answer

Hepatic venous malformation

Answer

IVC thrombosis

Question 2

The TRIANGULAR CORD Sign is seen in which condition?

Accepted Answer

Biliary Atresia

Answer

Caroli's Disease

Answer

Serous Cystadenoma

Answer

Hydatid of Liver

Question 3

Color Doppler study can evaluate the following EXCEPT?

Accepted Answer

Intravascular pressure

Answer

Direction of blood flow

Answer

Velocity of blood flow

Answer

Impedance index

Question 4

What is the recommended frequency range for transvaginal ultrasound for obstetric purposes?

Accepted Answer

5 - 7.5 MHz

Answer

3 - 5 MHz

Answer

7.5 - 20 MHz

Answer

> 20 MHz

Question 5

Which of the following statements about transvaginal ultrasound is incorrect?

Accepted Answer

The bladder should be full.

Answer

The bladder should be empty.

Answer

Informed consent is mandatory.

Answer

None of the above.

Question 6

What is the characteristic radiological feature of pneumothorax on ultrasound?

Accepted Answer

Stratosphere sign

Answer

Lung sliding sign

Answer

Sea shore sign

Answer

B lines

Question 7

What is the investigation of choice for minimal ascites?

Accepted Answer

Ultrasound (USG)

Answer

X-ray

Answer

CT scan

Answer

MRI scan

Question 8

Match the following ultrasound probe types with their typical frequency ranges (in MHz): 
1. Linear probe
2. Endoscopic probe
3. Curvilinear probe
4. Endocavitatory probe

A. 7-10 MHz
B. 3-5 MHz
C. 10-12 MHz
D. 20 MHz

Accepted Answer

1-D, 2-C, 3-A, 4-B

Answer

1-A, 2-D, 3-C, 4-B

Answer

1-C, 2-A, 3-B, 4-D

Answer

1-C, 2-B, 3-D, 4-A

Question 9

Gestational sac is seen on transvaginal sonography as early as:

Accepted Answer

35 days from LMP

Answer

18 days from LMP

Answer

21 days from LMP

Answer

42 days from LMP

Question 10

Ultrasound is done in the 1st trimester for all except:

Accepted Answer

To know the position of the placenta

Answer

Multiple pregnancy

Answer

Fetal anomalies

Answer

To estimate gestational age

Ultrasound — MCQs

Ultrasound — MCQs

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