Hose pipe appearance of intestine is a feature of
Which CT view is best for visualizing paranasal polyps?
What is the investigation of choice for nasopharyngeal angiofibroma?
Tear drop sign is seen in?
What is the best imaging view for assessing the nasal bone in X-ray?
Radiological sign in case of Perthes disease?
In which condition is the 'Picture frame vertebra' seen?
Frequency of ultrasound waves in USG -
What is the standard radiation dose to point A in the cervix for brachytherapy in the treatment of cervical cancer?
What is an X-ray artifact?
NEET-PG 2013 - Radiology NEET-PG Practice Questions and MCQs
Question 11: Hose pipe appearance of intestine is a feature of
- A. Malabsorption syndrome
- B. Ulcerative colitis (Correct Answer)
- C. Crohn's disease
- D. Hirschsprung disease
Explanation: ***Crohns disease*** - The **hose pipe appearance** of the intestine on imaging is due to **transmural inflammation** and **strictures**, characteristic of Crohn's disease [1]. - This feature indicates a **narrowed lumen** due to fibrosis, often affecting the small intestine or colon [1]. *Malabsorption syndrome* - This condition is primarily associated with **nutrient absorption issues**, not structural changes in the intestine. - It typically presents with **diarrhea**, **weight loss**, and **malnutrition**, lacking the characteristic imaging findings. *Ulcerative colitis* - Usually presents with **continuous lesions** confined to the colonic mucosa, leading to ulcers and inflammation but not a **hose pipe appearance**. - Symptoms include **bloody diarrhea** and **abdominal pain**, distinctly different from Crohn's disease. *Hirsprung disease* - A congenital condition causing **intestinal obstruction** due to the absence of ganglion cells, leading to **dilated proximal bowel** rather than a hose pipe appearance. - Typically presents in infants with **severe constipation** and **abdominal distension**, unrelated to imaging features seen in Crohn's disease. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 366-367.
Question 12: Which CT view is best for visualizing paranasal polyps?
- A. Coronal view (Correct Answer)
- B. Axial view
- C. Sagittal view
- D. 3D view
Explanation: ***Coronal*** - The **coronal view** provides the best visualization of the **ostia of the paranasal sinuses**, which are crucial for assessing the extent and obstruction caused by polyps. - This orientation effectively demonstrates whether polyps are **protruding into the nasal cavity** or obstructing the drainage pathways. *Axial view* - The axial view is useful for evaluating **posterior structures** and **bony erosion** but is less optimal for assessing the vertical extent of polyps or ostial obstruction. - It can show the **anteroposterior dimensions** of polyps but does not offer the same clarity for sinus outflow tracts as the coronal view. *Sagittal view* - The sagittal view is good for showing the **craniocaudal extent** of lesions and differentiating between the nasal cavity and sphenoid sinus, but it is not ideal for comprehensive paranasal sinus polyp evaluation. - It can help in localizing some polyps but does not provide a clear overview of **sinus ostia** or lateral extension. *3D view* - A 3D reconstruction can be helpful for a general overview and surgical planning but does not offer the fine detail and specific orientation needed for primary polyp detection and ostial assessment as effectively as direct 2D views. - It is a derived image rather than a primary acquisition plane and might obscure smaller polyps or subtle anatomical relationships.
Question 13: What is the investigation of choice for nasopharyngeal angiofibroma?
- A. Contrast-enhanced CT (Correct Answer)
- B. Plain CT
- C. X-ray
- D. MRI
Explanation: ***Contrast-enhanced CT*** - A **contrast-enhanced CT** scan is the investigation of choice for **nasopharyngeal angiofibroma** due to its ability to clearly delineate the extent of the tumor, its vascularity, and its bony involvement. - The contrast highlights the **highly vascular nature** of the angiofibroma, which is crucial for surgical planning and embolization. *X-ray* - **X-rays** provide limited detail of soft tissue structures and mass lesions in the complex anatomy of the nasopharynx. - They are generally not sensitive enough to characterize a tumor like **angiofibroma** or determine its exact extent. *Plain CT* - A **plain CT** (non-contrast CT) can show soft tissue masses and bony erosion but lacks the ability to assess the **vascularity** of the tumor. - Without contrast, it's difficult to differentiate the tumor from surrounding tissues or identify its blood supply, which is critical for **angiofibroma** management. *MRI* - While **MRI** offers excellent soft tissue contrast and is valuable for assessing intracranial extension or perineural spread, **contrast-enhanced CT** is generally preferred as the primary imaging modality for angiofibroma. - **CT with contrast** is superior for demonstrating **bony erosion** and the characteristic **vascularity** of this tumor.
Question 14: Tear drop sign is seen in?
- A. Fracture zygomatic arch
- B. Fracture maxilla
- C. Fracture mandible
- D. Blow out fracture (Correct Answer)
Explanation: ***Blow out fracture*** - The **tear drop sign** on imaging (often CT scan) is characteristic of an **orbital blow-out fracture**, indicating herniation of orbital contents (fat, muscle) into the maxillary sinus. - This fracture typically involves the **orbital floor** or medial wall, often caused by a blunt force trauma to the eye. *Fracture zygomatic arch* - A fracture of the zygomatic arch is often associated with a **flattening of the malar prominence** rather than a "tear drop" sign. - It might lead to restricted jaw movement if the arch impinges on the coronoid process. *Fracture maxilla* - Maxillary fractures (e.g., Le Fort fractures) involve the midface bones and cause **facial deformity**, malocclusion, and mobility of the maxilla. - The tear drop sign is not a primary diagnostic feature of maxillary fractures. *Fracture mandible* - Mandibular fractures present with pain, swelling, and **malocclusion** of the teeth. - Imaging would reveal a break in the mandible, not a tear drop sign associated with orbital contents.
Question 15: What is the best imaging view for assessing the nasal bone in X-ray?
- A. Lateral (Correct Answer)
- B. Towne's
- C. Submentovertical
- D. Caldwell
Explanation: ***Lateral*** - The **lateral view** provides a clear profile of the nasal bones, allowing for the best assessment of fractures, displacement, and angulation. - It visualizes the nasal bone in relation to other facial structures, which is crucial for treatment planning. *Towne's* - The **Towne's view** is primarily used to visualize the **occipital bone** and the **foramen magnum**, not the nasal bones. - It projects the petrous pyramids inferiorly, which would obstruct the view of the nasal region. *Caldwell* - The **Caldwell view** is primarily used to assess the **frontal sinuses**, **ethmoid sinuses**, and **orbits**. - While it offers some visualization of the nasal region, it does not provide the detailed lateral projection needed for optimal nasal bone assessment. *Submentovertical* - The **submentovertical view** (also known as the **basal view**) is primarily used to visualize the **base of the skull**, **sphenoid sinuses**, and **zygomatic arches**. - This view does not offer a direct or clear projection of the nasal bones themselves.
Question 16: Radiological sign in case of Perthes disease?
- A. Flattening of femoral head (Correct Answer)
- B. Fragmentation of femoral head epiphysis
- C. Lateral femoral head displacement
- D. Limited hip abduction
Explanation: ***Flattening of femoral head*** - **Flattening** and **fragmentation** of the femoral head are characteristic radiological findings in **early-stage** Perthes disease. - This flattening is a direct consequence of the **avascular necrosis** and subsequent **remodeling** of the femoral epiphysis. *Fragmentation of femoral head epiphysis* - While **fragmentation** is a key feature of Perthes disease, it's typically observed **after** the initial flattening and sclerosis in the avascular stage. - It represents the process of **resorption** and **revascularization** as the bone attempts to heal. *Lateral femoral head displacement* - **Lateral displacement** of the femoral head is a more common finding in conditions like **slipped capital femoral epiphysis (SCFE)**, where the epiphysis slips from the metaphysis. - In Perthes disease, the primary issue is the **necrosis and collapse** of the femoral head itself, rather than displacement from the neck. *Limited hip abduction* - **Limited hip abduction** is a clinical sign, not a radiological sign, and it is a common symptom in Perthes disease due to pain, inflammation, and deformity of the femoral head. - Radiological signs are visual abnormalities observed on imaging studies like X-rays.
Question 17: In which condition is the 'Picture frame vertebra' seen?
- A. Paget disease (Correct Answer)
- B. Osteopetrosis (marble bone disease)
- C. Ankylosing spondylitis (AS)
- D. Osteoporosis
Explanation: ***Paget disease*** - The "picture frame vertebra" sign is a classic radiographic finding in **Paget disease**, characterized by **cortical thickening** and sclerosis around the vertebral body circumference, resembling a picture frame. - This appearance is due to the disordered bone remodeling processes (increased osteoclastic bone resorption followed by disorganized osteoblastic new bone formation) characteristic of Paget disease. *Osteopetrosis (marble bone disease)* - Osteopetrosis is characterized by **increased bone density** due to defective osteoclast function, leading to bones that are dense but brittle. - It does not typically present with the specific "picture frame" appearance of individual vertebrae, but rather with diffuse sclerosis of bones. *Ankylosing spondylitis (AS)* - Ankylosing spondylitis primarily affects the **axial skeleton**, causing inflammation and eventual fusion of the vertebrae (leading to a "bamboo spine" appearance). - While it involves the spine, it does not produce the "picture frame" vertebral sign seen in Paget disease. *Osteoporosis* - Osteoporosis is characterized by **reduced bone mass** and microstructural deterioration of bone tissue, leading to increased bone fragility and fracture risk. - Radiographically, it shows **decreased bone density** and possible vertebral compression fractures, which is the opposite of the increased bone density and cortical thickening seen in the "picture frame" sign.
Question 18: 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 19: What is the standard radiation dose to point A in the cervix for brachytherapy in the treatment of cervical cancer?
- A. 8000 rad (Correct Answer)
- B. 6000 rad
- C. 10000 rad
- D. 4000 rad
Explanation: ***8000 rad*** - The standard **total cumulative radiation dose** to **Point A** in the cervix for the treatment of cervical cancer is approximately **8000 rad (80 Gy)**. - This represents the **combined dose** from external beam radiation therapy (EBRT, typically 45-50 Gy) plus intracavitary brachytherapy (typically 30-40 Gy to Point A). - Point A is a classical reference point defined as **2 cm superior to the external cervical os and 2 cm lateral to the uterine canal**, representing the location where the uterine artery crosses the ureter. - This total dose aims to provide adequate tumor control while minimizing toxicity to surrounding organs like the bladder and rectum. *6000 rad* - A total dose of **6000 rad** is insufficient for definitive local control of cervical cancer. - This dose is below the therapeutic threshold and would result in significantly higher rates of local recurrence and treatment failure. - Adequate doses are essential for curative intent in cervical cancer management. *10000 rad* - A dose of **10000 rad** to Point A would be excessively high and significantly increase the risk of severe acute and late toxicities to surrounding tissues. - Such a high dose could lead to serious complications including **rectovaginal or vesicovaginal fistulas, proctitis, cystitis, bowel strictures, and tissue necrosis**. - The therapeutic window would be exceeded, causing more harm than benefit. *4000 rad* - A dose of **4000 rad** would be substantially lower than the standard therapeutic dose for cervical cancer. - This suboptimal dose would likely result in **inadequate tumor control and increased risk of local recurrence**. - It is far below the dose required for curative treatment of cervical cancer.
Question 20: What is an X-ray artifact?
- A. A radiographic finding that indicates disease pathology
- B. A normal anatomical structure visible on X-ray
- C. An image distortion produced when the patient moves during the X-ray procedure
- D. An unwanted image distortion that doesn't represent actual anatomy (Correct Answer)
Explanation: ***An unwanted image distortion that doesn't represent actual anatomy*** - An **X-ray artifact** is any feature or distortion on a radiographic image that is not present in the actual object being imaged. - These can arise from various sources such as patient movement, equipment malfunction, or improper technique, leading to **misinterpretation** of the image. - Artifacts are unwanted findings that can obscure true pathology or mimic disease. *A normal anatomical structure visible on X-ray* - This describes a **true anatomical finding**, which is the intended purpose of an X-ray. - Normal anatomical structures are expected and assist in diagnosis, unlike artifacts which obscure or mimic pathology. *An image distortion produced when the patient moves during the X-ray procedure* - While **patient motion** is a common cause of X-ray artifacts, this describes just one specific type (motion artifact), not a comprehensive definition of what an artifact is. - Other sources like metallic objects, scatter radiation, or detector issues can also cause artifacts. *A radiographic finding that indicates disease pathology* - This describes **true pathology** or disease findings, which is what radiologists aim to identify. - Artifacts are the opposite - they are false findings that do not represent actual anatomy or pathology.