Chest Radiology Practice Questions

Q: What is the most helpful radiological investigation in a patient suspected of left pleural effusion?

Left lateral decubitus. **Explanation:** The diagnosis of pleural effusion relies on the movement of free fluid within the pleural space due to gravity. **Why Left Lateral Decubitus is correct:** In a **lateral decubitus view**, the patient lies on their side. Gravity causes free pleural fluid to accumulate along the dependent (downward) chest wall. This creates a linear opacity between the lung and the ribs, making it much easier to detect small amounts of fluid compared to a standard erect film. For a suspected **left-sided** effusion, the patient must lie on their **left side** (Left Lateral Decubitus) so that the fluid layers out along the left costal margin. This view can detect as little as **5–10 mL** of fluid. **Why the other options are incorrect:** * **Right lateral decubitus:** This would be used to detect a *right-sided* effusion. If a patient with a left effusion lies on their right side, the fluid shifts toward the mediastinum, making it difficult to visualize. * **Left/Right lateral erect:** While a lateral erect film can show blunting of the posterior costophrenic angle, it requires at least **50–75 mL** of fluid to be visible. It is less sensitive than the decubitus view for small effusions. **High-Yield Clinical Pearls for NEET-PG:** * **Sensitivity Hierarchy:** USG Chest > Lateral Decubitus View > Lateral Erect > PA View (Erect). * **PA View:** Requires **~150–200 mL** of fluid to cause blunting of the lateral costophrenic angle (the "Meniscus sign"). * **Subpulmonic Effusion:** Suspect this if there is an apparent elevation of the hemidiaphragm with the apex shifted laterally. * **Loculated Effusion:** If fluid does *not* shift on a decubitus film, it suggests the effusion is loculated (common in empyema).

Q: The "sandstorm" appearance on a chest radiograph is characteristic of which condition?

Pulmonary alveolar microlithiasis. **Explanation:** The "sandstorm" appearance is a classic radiological sign pathognomonic for **Pulmonary Alveolar Microlithiasis (PAM)**. This rare genetic condition (mutation in the *SLC34A2* gene) results in the accumulation of tiny calcium phosphate crystals (microliths) within the alveoli. On a chest X-ray, these thousands of microliths appear as diffuse, fine, sand-like calcifications that often obscure the heart borders and diaphragm, creating the characteristic "sandstorm" effect. **Analysis of Options:** * **Pulmonary Alveolar Microlithiasis (Correct):** The dense, calcific micronodules (1–3 mm) are most concentrated in the lower zones, leading to the "sandstorm" appearance and the "black pleura" sign (a lucent line between the calcified lung and the ribs). * **Pulmonary Edema:** Typically presents with "Bat-wing" opacities, Kerley B lines, and cardiomegaly, representing fluid rather than calcification. * **Pulmonary Alveolar Proteinosis (PAP):** Characterized by a "Crazy Paving" pattern on HRCT (ground-glass opacities with superimposed interlobular septal thickening), not sand-like calcifications. * **Pulmonary Thromboembolism:** Classic X-ray signs include Westermark sign (focal oligemia) and Hampton’s hump (wedge-shaped opacity), which are vascular/infarct-related findings. **NEET-PG High-Yield Pearls:** * **Black Pleura Sign:** Seen in PAM due to the contrast between dense calcified lung and the pleura. * **Clinical-Radiological Dissociation:** Patients with PAM often remain asymptomatic for a long time despite the dramatic "sandstorm" appearance on imaging. * **Gene Mutation:** *SLC34A2* gene (encodes a sodium-dependent phosphate cotransporter).

Q: High-resolution CT of the lung is a specialized CT technique that utilizes what to provide greater detail of lung parenchyma?

Bone algorithm for image reconstruction. **Explanation:** High-resolution CT (HRCT) is a specialized technique designed to visualize the lung parenchyma with maximum clarity, specifically targeting the secondary pulmonary lobule. **Why the correct answer is right:** The use of a **high-spatial-frequency reconstruction algorithm (Bone algorithm)** is fundamental to HRCT. Unlike standard soft tissue algorithms that smooth images to reduce noise, the bone algorithm sharpens the edges of structures. This enhances the interface between air and the delicate pulmonary interstitium, allowing for the detection of fine details like subtle ground-glass opacities, reticulation, and early bronchiectasis. **Analysis of incorrect options:** * **A. Special lung filters:** While "filters" is a term sometimes used interchangeably with "kernels" or "algorithms" in older literature, the technical requirement is specifically the mathematical reconstruction algorithm (Bone/Sharp kernel). * **B. Thick collimation:** This is the opposite of HRCT technique. HRCT requires **thin collimation** (typically 0.625 mm to 1.5 mm) to minimize volume averaging and improve spatial resolution. * **D. Large field of view:** HRCT utilizes a **targeted (small) field of view (FOV)**. By reconstructing only the area of the lungs rather than the entire chest circumference, the pixel size is reduced, further increasing spatial resolution. **High-Yield Clinical Pearls for NEET-PG:** * **The HRCT Triad:** 1. Thin sections (≤1.5 mm), 2. High-spatial-frequency (Bone) algorithm, 3. Small/Targeted FOV. * **Inspiratory vs. Expiratory HRCT:** Expiratory scans are specifically used to detect **air trapping** (seen in obliterative bronchiolitis or asthma). * **Prone HRCT:** Used to differentiate dependent atelectasis (which clears in prone position) from early interstitial lung disease/asbestosis (which persists).

Q: The 'Comet Tail Sign' is most characteristically seen in which of the following conditions?

Round atelectasis. **Explanation:** The **Comet Tail Sign** is the pathognomonic radiological feature of **Round Atelectasis** (also known as Blesovsky’s syndrome). **Why it is correct:** Round atelectasis occurs when a portion of the lung collapses in a rounded shape, usually adjacent to pleural thickening (often due to asbestos exposure). As the lung collapses and "curls" inward, the associated bronchovascular bundles (bronchi and pulmonary vessels) are pulled toward the mass-like area. On a CT scan, these converging vessels and bronchi create a curvilinear opacity extending from the hilum to the mass, resembling the tail of a comet. **Why the other options are incorrect:** * **A & C (Lobe Collapse):** While round atelectasis is a form of collapse, typical lobar collapses present with characteristic signs like the *Golden S-sign* (RUL collapse with a mass) or shifting of fissures, rather than a focal "comet tail" appearance. * **D (Consolidation):** Consolidation typically presents with *air bronchograms* and ill-defined margins. It does not cause the architectural distortion or the curvilinear pulling of vessels seen in round atelectasis. **High-Yield Pearls for NEET-PG:** * **Triad of Round Atelectasis:** (1) Pleural-based rounded opacity, (2) Associated pleural thickening, and (3) The Comet Tail Sign. * **Common Association:** Asbestos-related pleural disease is the most common cause. * **Clinical Significance:** It is a benign condition but is frequently mistaken for a peripheral lung carcinoma (bronchogenic carcinoma). * **Crow’s Feet Sign:** Another term sometimes used to describe the radiating bands seen in this condition.

Q: Which of the following is a cause of a unilateral hyperlucent lung on chest radiography?

Poland syndrome. **Explanation:** The correct answer is **Poland syndrome**. A unilateral hyperlucent lung on a chest X-ray occurs when one lung field appears darker (more radiolucent) than the other. This can be due to either increased air in the lung (obstructive) or a decrease in the thickness of the overlying soft tissues (extrapulmonary). **1. Why Poland Syndrome is correct:** Poland syndrome is a congenital anomaly characterized by the **unilateral absence of the pectoralis major muscle** (and sometimes the pectoralis minor). Because there is less soft tissue to attenuate the X-ray beam on the affected side, more radiation reaches the film, resulting in a **false hyperlucency** of the lung on that side, despite the lung parenchyma itself being normal. **2. Why the other options are incorrect:** * **Asthma & Acute Bronchiolitis:** These typically present with **bilateral** hyperlucency due to generalized air trapping and hyperinflation. While focal air trapping can occur, they are not classic causes of a persistent unilateral hyperlucent lung. * **Pleural Effusion:** This causes **increased radiopacity** (whiteness) on the affected side, not hyperlucency. **3. NEET-PG High-Yield Pearls:** * **Differential Diagnosis of Unilateral Hyperlucent Lung:** * *Technical:* Rotation of the patient. * *Extrapulmonary:* Poland syndrome, Mastectomy. * *Pulmonary:* **Swyer-James-MacLeod Syndrome** (post-infectious obliterative bronchiolitis), Pneumothorax, Large Bullae, or Obstructive Emphysema (e.g., foreign body acting as a check-valve). * **Poland Syndrome triad:** Unilateral absence of pectoralis major, chest wall depression, and **ipsilateral syndactyly** (brachysyndactyly). * **Swyer-James-MacLeod Syndrome:** Look for a small, hyperlucent lung with reduced vascular markings and air trapping on expiration.

Q: Egg shell calcification is seen in which of the following conditions?

Silicosis. **Explanation:** **Eggshell calcification** refers to a characteristic radiological pattern where calcium deposits form in the periphery of hilar or mediastinal lymph nodes. This occurs due to the peripheral rim-like calcification of the lymph node capsule. **1. Why Silicosis is Correct:** Silicosis is the most classic and common association for eggshell calcification. Inhalation of silica particles leads to a chronic inflammatory response in the pulmonary lymphatics. The resulting fibrosis and dystrophic calcification occur predominantly at the periphery of the enlarged hilar lymph nodes, creating the "eggshell" appearance on a chest X-ray or CT scan. **2. Analysis of Incorrect Options:** * **Bronchiolitis (A):** This is an inflammatory condition of the small airways (bronchioles), typically presenting with "tree-in-bud" patterns or air trapping, not lymph node calcification. * **Carcinoma of Bronchus (C):** While lung cancer can cause lymphadenopathy, the nodes are usually bulky and necrotic. Calcification is rare unless it is a mucinous adenocarcinoma or occurs after radiotherapy. * **Sarcoidosis (D):** While Sarcoidosis is a major differential for eggshell calcification, **Silicosis remains the primary and most classic association** for this specific pattern. In Sarcoidosis, lymph nodes more commonly show "potato-like" bilateral hilar lymphadenopathy or "popcorn" calcification. **3. NEET-PG High-Yield Pearls:** * **Differential Diagnosis for Eggshell Calcification:** Silicosis (Most common), Coal Worker’s Pneumoconiosis (CWP), Sarcoidosis (5% of cases), treated Lymphoma, and occasionally Blastomycosis. * **Silicosis Key Features:** Upper lobe predominant nodules, "progressive massive fibrosis" (PMF), and an increased risk of Tuberculosis (Silicotuberculosis). * **Snowstorm Appearance:** Seen on X-ray in acute silicosis (miliary pattern).

Q: Which of the following radiological findings does NOT indicate increased pulmonary blood flow?

Kerley B lines. This question tests the ability to distinguish between **Pulmonary Hyperemia** (increased blood flow, e.g., Left-to-Right shunts) and **Pulmonary Venous Hypertension** (congestion, e.g., Mitral Stenosis or Heart Failure). ### **Why Kerley B lines is the correct answer:** **Kerley B lines** are a hallmark of **Pulmonary Venous Hypertension/Congestion** and interstitial pulmonary edema. They represent thickened interlobular septa caused by fluid accumulation or lymphatic engorgement. They do not indicate increased arterial flow (hyperemia), but rather a backup of pressure from the left heart or pulmonary veins. ### **Analysis of Incorrect Options (Findings of Increased Flow):** * **A. Descending pulmonary artery >16 mm:** In adults, the normal diameter of the right descending pulmonary artery is 1:** Normally, a peripheral pulmonary artery is roughly the same size as its accompanying bronchus. If the diameter of two or more arteries exceeds their bronchi, it signifies increased flow (hyperemia). * **D. >6 peripheral vessels in the outer 1/3rd:** In a normal chest X-ray, the outer third of the lung field is relatively "vessel-free." Visualizing more than six vessels in this zone is a classic sign of increased pulmonary blood flow. ### **High-Yield Clinical Pearls for NEET-PG:** * **Kerley A lines:** Longer (2–6 cm) lines radiating from the hila (peribronchovascular thickening). * **Kerley B lines:** Short (1–2 cm), horizontal lines at the lung bases, perpendicular to the pleura. * **Cephalization (Antler Sign):** Redirection of blood flow to the upper lobes; the earliest sign of pulmonary venous hypertension (PCWP 12–18 mmHg). * **Shunt Vascularity:** Increased flow seen in ASD, VSD, and PDA.

Q: What is the cause of an opaque hemithorax?

Foreign body. **Explanation:** An **opaque hemithorax** (white-out of one lung) occurs when the lung becomes airless or is replaced by fluid/mass, causing it to appear radio-opaque on a chest X-ray. **1. Why Foreign Body is correct:** In pediatric cases, a long-standing inhaled **foreign body** can cause complete bronchial obstruction. This leads to **resorptive atelectasis** (collapse) of the entire lung. As the air is absorbed and the lung collapses, the hemithorax becomes opaque, typically accompanied by an **ipsilateral mediastinal shift** (pulling the heart and trachea toward the side of the opacity). **2. Analysis of Incorrect Options:** * **Poland’s Syndrome:** Characterized by the congenital absence of the pectoralis major muscle. On X-ray, this results in a **hyperlucent** (darker) hemithorax due to the lack of overlying soft tissue, not opacity. * **McLeod’s Syndrome (Swyer-James Syndrome):** A post-infectious sequela of childhood bronchiolitis obliterans resulting in a small, **hyperlucent** lung with decreased vascularity. * **Congenital Lobar Emphysema:** This involves over-distension of a lung lobe (usually the left upper lobe). On X-ray, it presents as a **hyperlucent** area that causes a contralateral mediastinal shift (pushing the heart away). **Clinical Pearls for NEET-PG:** * **Differential Diagnosis of Opaque Hemithorax:** 1. **Large Pleural Effusion:** Mediastinal shift to the **opposite** side (Push). 2. **Total Lung Collapse (e.g., Foreign body, Mucus plug):** Mediastinal shift to the **same** side (Pull). 3. **Pneumonectomy:** Surgical removal; shift to the **same** side with rib crowding. 4. **Diaphragmatic Hernia:** Bowel loops may mimic opacity or lucency depending on content. * **Key Rule:** If the mediastinum is central in an opaque hemithorax, suspect a consolidation or a combination of collapse and effusion.

Q: An expiratory chest radiograph is particularly useful to detect which of the following conditions?

Pneumothorax. **Explanation:** In a standard inspiratory chest X-ray, the lungs are fully expanded, which can sometimes mask a small or apical pneumothorax. An **expiratory film** is a high-yield diagnostic maneuver for this condition due to two physiological reasons: 1. **Volume Reduction:** During expiration, the lung volume decreases while the volume of the intrapleural air remains constant. This makes the pneumothorax occupy a larger relative proportion of the hemithorax. 2. **Increased Lung Density:** As air is exhaled, the lung parenchyma becomes more radiopaque (whiter). This provides a sharper contrast against the radiolucent (black) pleural air, making the visceral pleural line much easier to visualize. **Analysis of Incorrect Options:** * **A. Pleural effusion:** Best detected on an **Inspiratory Erect** film (for blunting of costophrenic angles) or a **Lateral Decubitus** view (to detect small amounts of fluid or determine if it is free-flowing). * **C. Pulmonary edema:** Characterized by Kerley B lines, cephalization, and perihilar haze; these are best evaluated on a standard inspiratory film to assess heart size and vascular markings accurately. * **D. Pulmonary infarct:** Presents as "Hampton’s Hump" (wedge-shaped opacity); it does not require expiratory films for identification. **NEET-PG High-Yield Pearls:** * **Indications for Expiratory X-ray:** Small pneumothorax, foreign body aspiration (demonstrates air trapping/obstructive emphysema), and evaluating diaphragmatic excursion. * **Gold Standard:** While expiratory films are useful, **NCCT Chest** is the most sensitive investigation for detecting a pneumothorax. * **Tension Pneumothorax:** This is a **clinical diagnosis**. Do not wait for an X-ray; immediate needle decompression is required.

Q: The CT chest of a patient shows the presence of what abnormality?

Bronchiectasis. ***Bronchiectasis*** - CT chest shows **signet ring sign** (dilated bronchi with adjacent pulmonary arteries) and **broncho-arterial ratio > 1**. - Characteristic **tram-tracking** appearance with **dilated, thick-walled bronchi** that don't taper normally toward the periphery. *Pneumatoceles* - Appear as **thin-walled, air-filled cysts** within the lung parenchyma, typically following **pneumonia** or **trauma**. - Show **smooth, thin walls** without the bronchial dilatation and wall thickening seen in bronchiectasis. *Normal scan* - Would demonstrate **normal broncho-arterial ratios** (< 1) with **tapering bronchi** toward the periphery. - Absence of **airway wall thickening**, **signet ring signs**, or **tram-tracking** patterns. *Loculated empyema* - Presents as **pleural-based fluid collection** with **enhancing pleural surfaces** and possible **air-fluid levels**. - Shows **pleural thickening** and **loculations** within the pleural space, not involving bronchial structures.

Question 1

What is the most helpful radiological investigation in a patient suspected of left pleural effusion?

Accepted Answer

Left lateral decubitus

Answer

Right lateral decubitus

Answer

Left lateral erect

Answer

Right lateral erect

Question 2

The "sandstorm" appearance on a chest radiograph is characteristic of which condition?

Accepted Answer

Pulmonary alveolar microlithiasis

Answer

Pulmonary edema

Answer

Pulmonary alveolar proteinosis

Answer

Pulmonary thromboembolism

Question 3

High-resolution CT of the lung is a specialized CT technique that utilizes what to provide greater detail of lung parenchyma?

Accepted Answer

Bone algorithm for image reconstruction

Answer

Special lung filters

Answer

Thick collimation

Answer

Large field of view

Question 4

The 'Comet Tail Sign' is most characteristically seen in which of the following conditions?

Accepted Answer

Round atelectasis

Answer

Lower lobe collapse

Answer

Right upper lobe collapse

Answer

Left lower lobe consolidation

Question 5

Which of the following is a cause of a unilateral hyperlucent lung on chest radiography?

Accepted Answer

Poland syndrome

Answer

Asthma

Answer

Acute bronchiolitis

Answer

Pleural effusion

Question 6

Egg shell calcification is seen in which of the following conditions?

Accepted Answer

Silicosis

Answer

Bronchiolitis

Answer

Carcinoma of bronchus

Answer

Sarcoidosis

Question 7

Which of the following radiological findings does NOT indicate increased pulmonary blood flow?

Accepted Answer

Kerley B lines

Answer

Descending pulmonary artery diameter greater than 16 mm

Answer

Diameter of two peripheral pulmonary arteries greater than their accompanying bronchus

Answer

More than six peripheral pulmonary arteries in the outer one-third of the lung field

Question 8

What is the cause of an opaque hemithorax?

Accepted Answer

Foreign body

Answer

Poland's syndrome

Answer

Mcleod's syndrome

Answer

Congenital lobar emphysema

Question 9

An expiratory chest radiograph is particularly useful to detect which of the following conditions?

Accepted Answer

Pneumothorax

Answer

Pleural effusion

Answer

Pulmonary edema

Answer

Pulmonary infarct

Question 10

The CT chest of a patient shows the presence of what abnormality?

Accepted Answer

Bronchiectasis

Answer

Pneumatoceles

Answer

Normal scan

Answer

Loculated empyema

Chest Radiology — MCQs

Chest Radiology — MCQs

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