UPSC-CMS 2025 - Radiology PYQs Practice Questions

Q: Which of the following are included in common causes of mediastinal masses in superior and anterior mediastinum? I. Goitre II. Thymic tumour III. Neurogenic tumour Select the correct answer using the code given below :

I and II only. ***I and II only*** - **Goitre** (retrosternal thyroid extension) is a common cause of superior mediastinal masses. - **Thymic tumors** (thymoma, thymic carcinoma) are characteristically found in the anterior mediastinum. *I, II and III* - While goitre and thymic tumors are common in the superior and anterior mediastinum respectively, **neurogenic tumors** are typically found in the posterior mediastinum. - This option incorrectly includes neurogenic tumors with masses of the superior and anterior mediastinum. *II and III only* - This option correctly identifies **thymic tumors** for the anterior mediastinum but incorrectly includes **neurogenic tumors**, which are found in the posterior mediastinum. - It also omits **goitre**, which is a significant cause of superior mediastinal masses. *I and III only* - This option correctly identifies **goitre** as a superior mediastinal mass but incorrectly includes **neurogenic tumors**, which are typically located in the posterior mediastinum. - It incorrectly omits **thymic tumors**, which are a primary cause of anterior mediastinal masses. [Practice more Radiology PYQs on OnCourse]

Q: A radiopaque density may be noticed in poisoning by which of the following agents?

Chloral hydrate. ***Chloral hydrate*** - Due to its halogenated structure, **chloral hydrate** can be radio-opaque on X-rays, making it one of the "CHIPES" substances. - This property allows for radiological detection of its presence in the **gastrointestinal tract** following ingestion, particularly in large overdoses. *Chloroquine* - **Chloroquine** is not significantly radio-opaque and is generally not detectable on plain radiographs following overdose. - Clinical diagnosis of chloroquine poisoning relies on symptoms such as **hypotension**, **cardiac arrhythmias**, and **hypokalemia**, not radiological findings. *Phenazopyridine* - **Phenazopyridine** is a urinary analgesic that does not possess properties that render it radiographically detectable. - Its metabolism and excretion do not produce **radio-opaque metabolites** or complexes. *Ethylene glycol* - **Ethylene glycol** itself is not radio-opaque on plain X-rays, and its presence is typically diagnosed through laboratory tests like anion gap metabolic acidosis. - While it can lead to the formation of **calcium oxalate crystals** in the kidneys, these are typically microscopic and not visible as general radiopacities in the GI tract. [Practice more Radiology PYQs on OnCourse]

Q: The first imaging modality of choice for a 35-year-old lady, presenting to surgical emergency with complaints of colicky pain in right lower quadrant of abdomen and vomiting since last 2 days is:

Ultrasound abdomen. ***Ultrasound abdomen*** - Ultrasound is the **first-line imaging modality** for evaluating acute right lower quadrant pain in women of reproductive age due to its **safety (no ionizing radiation)**, availability, and cost-effectiveness. - It effectively visualizes the **appendix**, ovaries, uterus, and can detect **appendicitis**, ovarian pathology (e.g., cysts, torsion, ectopic pregnancy), and other causes of acute abdominal pain. - Follows the **ALARA principle** (As Low As Reasonably Achievable) for radiation exposure in young women. *Plain X-ray abdomen erect view* - Plain X-ray has **limited utility** for acute right lower quadrant pain as it cannot visualize soft tissue structures like the appendix or ovaries. - Primarily useful for detecting **bowel obstruction** (air-fluid levels) or **pneumoperitoneum** (free air under diaphragm), which are not suggested by this clinical presentation. *Contrast CT abdomen* - While highly sensitive for appendicitis and intra-abdominal pathologies, contrast CT involves **ionizing radiation** and **IV contrast administration**. - Should be **minimized in women of reproductive age** due to radiation risks (including potential pregnancy). - Reserved for cases where ultrasound is **inconclusive** or when detailed anatomical assessment is required. *Non-contrast CT abdomen* - Non-contrast CT exposes the patient to **ionizing radiation** without the diagnostic advantage of contrast enhancement. - **Less effective** than contrast-enhanced CT for detecting inflammatory processes and appendiceal pathology. - Not preferred as first-line imaging when ultrasound is available and appropriate. [Practice more Radiology PYQs on OnCourse]

Q: On a chest radiograph, which of the following occupational diseases is most likely to be mistaken as a case of tuberculosis of lungs?

Silicosis. ***Silicosis*** - **Silicosis** manifests with radiographic findings such as **nodular opacities**, often in the upper lobes, and can progress to **progressive massive fibrosis**. These can be visually similar to granulomatous lesions seen in **tuberculosis**. - Additionally, patients with silicosis have an **increased susceptibility to tuberculosis** (silico-tuberculosis), making differentiation solely based on chest radiographs challenging. *Anthracosis* - **Anthracosis** (coal worker's pneumoconiosis) primarily causes diffuse, small, rounded opacities, which are generally less organized and prominent than the nodules seen in silicosis or tuberculosis. - While it can lead to **progressive massive fibrosis** in severe cases, the initial presentation is usually less likely to be confused with tuberculosis compared to silicosis. *Siderosis* - **Siderosis** is caused by the inhalation of iron dust and typically results in fine, diffuse, and irregular opacities on chest radiographs. - These opacities are generally benign and rarely lead to significant pulmonary fibrosis or mimic the discrete, nodular pattern of tuberculosis. *Byssinosis* - **Byssinosis** is an occupational lung disease associated with exposure to cotton dust. It is primarily characterized by **bronchial hyperreactivity** and **asthma-like symptoms**, particularly "Monday chest tightness." - It does not typically produce significant or distinctive radiographic changes that could be confused with tuberculosis, as it is a disease of the airways rather than parenchymal infiltrates. [Practice more Radiology PYQs on OnCourse]

Question 1

Which of the following are included in common causes of mediastinal masses in superior and anterior mediastinum?
I. Goitre
II. Thymic tumour
III. Neurogenic tumour

Select the correct answer using the code given below :

Accepted Answer

I and II only

Answer

I, II and III

Answer

II and III only

Answer

I and III only

Question 2

A radiopaque density may be noticed in poisoning by which of the following agents?

Accepted Answer

Chloral hydrate

Answer

Chloroquine

Answer

Phenazopyridine

Answer

Ethylene glycol

Question 3

The first imaging modality of choice for a 35-year-old lady, presenting to surgical emergency with complaints of colicky pain in right lower quadrant of abdomen and vomiting since last 2 days is:

Accepted Answer

Ultrasound abdomen

Answer

Plain X-ray abdomen erect view

Answer

Contrast CT abdomen

Answer

Non-contrast CT abdomen

Question 4

On a chest radiograph, which of the following occupational diseases is most likely to be mistaken as a case of tuberculosis of lungs?

Accepted Answer

Silicosis

Answer

Anthracosis

Answer

Siderosis

Answer

Byssinosis

UPSC-CMS 2025 — Radiology