Internal Medicine
1 questionsIn a patient with heart disease, which condition is most commonly associated with left atrial enlargement?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1181: In a patient with heart disease, which condition is most commonly associated with left atrial enlargement?
- A. Mitral stenosis (Correct Answer)
- B. Tricuspid regurgitation
- C. AR
- D. None of the options
Explanation: ***Mitral stenosis*** - **Mitral stenosis** leads to an obstruction of blood flow from the **left atrium to the left ventricle**, causing pressure buildup in the left atrium [1]. - This increased pressure over time results in **left atrial enlargement** as the chamber struggles to push blood through the narrowed valve [1]. *Tricuspid regurgitation* - **Tricuspid regurgitation** involves the backflow of blood from the **right ventricle to the right atrium**. - This condition primarily affects the **right side of the heart**, leading to **right atrial enlargement**, not left. *AR* - **Aortic regurgitation (AR)** is the backflow of blood from the **aorta into the left ventricle**. - While AR can cause **left ventricular enlargement** and eventually lead to left atrial dilation, it is not the most common direct cause of *primary* left atrial enlargement compared to mitral stenosis [2]. *None of the options* - **Mitral stenosis** is a well-established cause of significant left atrial enlargement due to the direct pressure overload it imposes on the left atrium [1].
Orthopaedics
1 questionsMost common site of osteochondritis dissecans?
NEET-PG 2013 - Orthopaedics NEET-PG Practice Questions and MCQs
Question 1181: Most common site of osteochondritis dissecans?
- A. Lateral part of the medial femoral condyle (Correct Answer)
- B. Medial part of the medial femoral condyle
- C. Lateral part of the lateral femoral condyle
- D. Medial part of the lateral femoral condyle
Explanation: ***Lateral part of the medial femoral condyle*** - This is the **most common site** for osteochondritis dissecans in the knee, accounting for about 85% of cases. - The condition involves a localized area of **osteonecrosis and subchondral bone separation** from the epiphysis, typically afflicting this specific load-bearing region. *Medial part of the medial femoral condyle* - This location is **less common** for osteochondritis dissecans compared to the lateral aspect of the medial femoral condyle. - While osteochondral lesions can occur on any part of the condyle, the specific biomechanical stresses make the lateral part more susceptible. *Lateral part of the lateral femoral condyle* - Osteochondritis dissecans is **rarely found** in this location. - The lateral femoral condyle is generally less involved in osteochondritis dissecans of the knee. *Medial part of the lateral femoral condyle* - This site is also an **uncommon location** for osteochondritis dissecans. - The disease has a strong predilection for the medial femoral condyle, particularly its lateral aspect.
Pathology
1 questionsCalcified pulmonary metastasis is seen in which carcinoma?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 1181: Calcified pulmonary metastasis is seen in which carcinoma?
- A. Pancreatic carcinoma
- B. Thyroid carcinoma (Correct Answer)
- C. Endometrial carcinoma
- D. None of the options
Explanation: ***Thyroid carcinoma*** - **Papillary** and **medullary thyroid carcinomas** can produce **calcified pulmonary metastases**. - In **papillary thyroid cancer**, calcification occurs due to **psammoma bodies** (concentrically laminated calcified structures). - In **medullary thyroid cancer**, calcification can occur through **dystrophic calcification** within the tumor tissue. - Other common causes of calcified lung metastases include **osteosarcoma** and **chondrosarcoma**. *Pancreatic carcinoma* - Pancreatic carcinoma rarely causes **calcified pulmonary metastases**; metastatic lesions are typically **non-calcified**. - Metastases are more commonly found in the **liver** and **peritoneum**. - Primary pancreatic tumors may show calcification, but metastases usually do not. *Endometrial carcinoma* - Endometrial carcinoma metastases to the lungs are usually **non-calcified** and appear as **soft tissue nodules**. - While it can metastasize to the lungs, **calcification** is not a typical feature of its pulmonary spread. *None of the options* - This option is incorrect because **thyroid carcinoma** (particularly papillary type) is a well-recognized cause of **calcified pulmonary metastases**. - Among epithelial malignancies, thyroid carcinoma is one of the classic causes of this finding.
Radiology
7 questionsWhich of the following conditions is the MOST COMMON cause of rib notching?
What is the most common feature of sarcoidosis on chest X-ray?
Which of the following is NOT a typical differential diagnosis for a solitary pulmonary nodule?
Air bronchogram on chest X-ray denotes -
In a patient with high clinical suspicion of pulmonary thromboembolism, best investigation would be?
Which view is best for visualizing the collapse of the middle lobe of the lung?
Which imaging modality delivers the highest dose of radiation?
NEET-PG 2013 - Radiology NEET-PG Practice Questions and MCQs
Question 1181: Which of the following conditions is the MOST COMMON cause of rib notching?
- A. Coarctation of aorta (Correct Answer)
- B. Atrial septal defect
- C. Chronic superior venacava obstruction
- D. Congenital interruption of aorta
Explanation: ***Coarctation of aorta*** - **Coarctation of the aorta** is the classic and **most common cause** of rib notching. - The notching is caused by the enlargement and tortuosity of the **intercostal arteries** as they provide collateral circulation to bypass the narrowed aorta. *Chronic superior venacava obstruction* - Chronic superior vena cava (SVC) obstruction may lead to the development of collateral circulation through the azygos and hemiazygos veins, but it does **not typically cause rib notching**. - Rib notching is specifically related to collateral flow bypassing an aortic obstruction, not a venous obstruction. *Atrial septal defect* - An **atrial septal defect (ASD)** is a communication between the atria that can lead to right heart volume overload and pulmonary hypertension. - While it's a congenital heart defect, an ASD does **not cause rib notching** as it does not involve an obstruction of systemic arterial flow requiring collateral circulation via the intercostal arteries. *Congenital interruption of aorta* - While **congenital interruption of the aorta** also involves an aortic obstruction, it is a **much rarer condition** than coarctation of the aorta. - Due to its rarity, it is not considered the most common cause of rib notching, even though it would theoretically lead to similar collateral vessel formation.
Question 1182: What is the most common feature of sarcoidosis on chest X-ray?
- A. Bilateral hilar lymphadenopathy (Correct Answer)
- B. Cavitation
- C. Pleural effusion
- D. Reticular opacities
Explanation: ***Bilateral hilar lymphadenopathy*** - **Bilateral hilar lymphadenopathy** is the hallmark radiological feature of sarcoidosis, seen in over 75% of cases. - This finding, often symmetrical, represents the accumulation of **non-caseating granulomas** in the lymph nodes. - Classic presentation in **Stage I and Stage II** sarcoidosis. *Pleural effusion* - **Pleural effusions** are uncommon in sarcoidosis, occurring in less than 5% of cases. - When present, they are usually small and unilateral, and their presence should prompt consideration of alternative diagnoses. *Cavitation* - **Cavitation** is a rare manifestation of sarcoidosis and is more characteristic of infectious processes like **tuberculosis** or certain fungal infections. - If seen, it usually suggests severe parenchymal involvement or superimposed infection. *Reticular opacities* - While **reticular opacities** (interstitial changes) can be seen in later stages of sarcoidosis, representing **pulmonary fibrosis**, they are not the *most common* initial finding. - These opacities indicate chronic disease progression (Stage III/IV) rather than the initial presentation.
Question 1183: Which of the following is NOT a typical differential diagnosis for a solitary pulmonary nodule?
- A. Tuberculoma
- B. Hamartoma
- C. Mycetoma (Correct Answer)
- D. Bronchogenic carcinoma
Explanation: ***Mycetoma*** - A mycetoma is a **fungal infection** that typically affects subcutaneous tissues, skin, and bone, forming granulomas and sinuses. It is not typically seen as a solitary pulmonary nodule. - While pulmonary fungal infections can occur, a mycetoma in the lung typically presents as a **fungus ball (aspergilloma)** within a pre-existing cavity, rather than a solitary, solid nodule. *Tuberculoma* - A tuberculoma is a **granuloma** caused by Mycobacterium tuberculosis, which can present as a well-defined, solitary pulmonary nodule or mass on imaging. - It represents a contained form of tuberculosis and is a common differential for a solitary pulmonary nodule, especially in endemic areas. *Hamartoma* - A hamartoma is a **benign tumor-like malformation** composed of normal tissues (like cartilage, fat, and muscle) that are disorganized. - It is one of the most common benign causes of a solitary pulmonary nodule. *Bronchogenic carcinoma* - Bronchogenic carcinoma, including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, is the most significant concern when evaluating a solitary pulmonary nodule. - It is a primary **malignant lung tumor** and represents a crucial differential diagnosis due to its poor prognosis if not detected and treated early.
Question 1184: Air bronchogram on chest X-ray denotes -
- A. Intrapulmonary lesion (Correct Answer)
- B. Extrapulmonary lesion
- C. Intrathoracic lesion
- D. Extrathoracic lesion
Explanation: ***Intrapulmonary lesion*** - An **air bronchogram** indicates that the air-filled bronchi are surrounded by consolidated or fluid-filled alveoli, making the bronchi visible against the opacified lung parenchyma. - This pattern is a strong sign of a process **within the lung tissue itself**, such as pneumonia, pulmonary edema, or malignancy. *Extrapulmonary lesion* - **Extrapulmonary lesions**, such as pleural effusions or masses originating from the chest wall, typically displace or compress the lung and bronchi, rather than filling the alveoli around them. - They usually do **not produce an air bronchogram** because the air in the bronchi is not juxtaposed against diseased lung parenchyma. *Intrathoracic lesion* - This is a broad term that includes all lesions within the thoracic cavity, both intrapulmonary and extrapulmonary. - While an air bronchogram is an intrathoracic finding, it specifically points to an **intrapulmonary process**, not just any intrathoracic lesion. *Extrathoracic lesion* - **Extrathoracic lesions** are located outside the chest cavity and would not manifest as an air bronchogram on a chest X-ray. - This option is **completely unrelated** to the interpretation of an air bronchogram.
Question 1185: In a patient with high clinical suspicion of pulmonary thromboembolism, best investigation would be?
- A. D-dimer
- B. CT angiography (Correct Answer)
- C. Catheter angiography
- D. Color Doppler
Explanation: ***CT angiography*** - In a patient with **high clinical suspicion** of pulmonary embolism (PE), CT angiography of the pulmonary arteries is the preferred and often definitive diagnostic test. - It allows for direct visualization of thrombi within the pulmonary arterial tree with high sensitivity and specificity. *D-dimer* - While useful for **ruling out PE** in patients with low or intermediate pre-test probability, a positive D-dimer is non-specific and requires further investigation in high-suspicion cases. - It has a high **negative predictive value** but a low positive predictive value, meaning a normal D-dimer makes PE unlikely, but an elevated one does not confirm it. *Catheter angiography* - This is an **invasive procedure** that is typically reserved for cases where CT angiography is inconclusive or contraindicated, or when interventional treatment is contemplated. - It carries risks such as **bleeding** and **contrast-induced nephropathy**, making it less appropriate as a first-line diagnostic in most situations. *Color Doppler* - Color Doppler ultrasound is primarily used to diagnose **deep vein thrombosis (DVT)** in the lower extremities, which is a common source of PE. - It is **not used to directly diagnose PE** in the pulmonary arteries; however, finding a DVT can support the diagnosis of PE indirectly.
Question 1186: Which view is best for visualizing the collapse of the middle lobe of the lung?
- A. Anteroposterior (AP)
- B. Oblique
- C. Lateral (Correct Answer)
- D. Lordotic
Explanation: ***Lateral*** - A **lateral chest X-ray** is crucial for localizing abnormalities to specific lung lobes because it allows for a clear visualization of the **fissures** which define the lung lobes. - Collapse of the right middle lobe is particularly well-visualized on a lateral view as a **triangular opacity** that points towards the hilum, often obliterating the right heart border. *Anteroposterior (AP)* - While an AP or PA view can show collapse, it often appears as a **non-specific wedge or triangular opacity** and struggles with precise lobar localization due to superimposed structures. - The **heart shadow and mediastinum** can obscure parts of the middle lobe, making definitive diagnosis challenging from this view alone. *Oblique* - Oblique views are typically used for specific purposes, such as evaluating the **pleura** or **ribs**, and are not a standard view for initial assessment of lobar collapse. - They introduce **distortion and superimposition** that can make the identification and characterization of lobar collapse more difficult than a standard lateral projection. *Lordotic* - A lordotic view is primarily used to visualize the **lung apices** and to differentiate apical lesions from superimposed clavicular shadows. - It is not effective for visualizing the middle lobe, which is located more inferiorly, and would introduce significant distortion, making assessment of its collapse unreliable.
Question 1187: Which imaging modality delivers the highest dose of radiation?
- A. Cardiac perfusion scan (Correct Answer)
- B. CT scan of the chest
- C. Mammogram
- D. CT scan of the brain
Explanation: ***Cardiac perfusion scan*** - A **cardiac perfusion scan (nuclear cardiology)** involves the administration of a radioactive tracer, and the radiation dose can be significant due to the nature and energy of the isotopes used. - While varying, the effective dose for these scans can range from **10 to 30 mSv**, placing it among some of the highest radiation exposures from medical imaging. *CT scan of the chest* - A **CT scan of the chest** provides a relatively high radiation dose compared to plain X-rays, typically ranging from **5 to 7 mSv**. - This is generally lower than some nuclear medicine studies, particularly complex or prolonged cardiac perfusion scans. *Mammogram* - A **mammogram** involves a relatively low dose of radiation, typically in the range of **0.2 to 0.7 mSv**. - Its objective is to image the breast tissue with minimal exposure, making it one of the lower-dose imaging modalities available. *CT scan of the brain* - A **CT scan of the brain** usually delivers a moderate radiation dose, estimated to be around **1 to 2 mSv**. - This is often less than a chest CT due to the smaller volume and different shielding considerations, and significantly less than a cardiac perfusion scan.