Emergency Radiology Practice Questions

Q: A man presents to the emergency department with a head injury following a vehicular accident. What is the investigation of choice?

NCCT. ***NCCT*** - **Non-contrast Computed Tomography (NCCT)** of the head is the **investigation of choice** for acute head trauma due to its rapid acquisition, wide availability, and excellent sensitivity for detecting acute hemorrhage, fractures, and mass effects. - It rapidly identifies life-threatening conditions such as **epidural, subdural, and intracerebral hemorrhages**, which require immediate intervention. *MRI* - **MRI** is superior for detecting subtle brain tissue injuries, diffuse axonal injury, and non-hemorrhagic lesions but is generally **not the first-line investigation** in acute trauma due to longer scan times, limited availability in the emergency setting, and inability to detect acute hemorrhage as clearly as CT. - Its use is typically reserved for follow-up studies or when CT findings are inconclusive or specific soft tissue detail is required. *CECT* - **Contrast-enhanced CT (CECT)** of the head is reserved for specific indications like evaluating vascular lesions (e.g., aneurysms, arteriovenous malformations) or tumors, which are generally **not the primary concern** in the initial assessment of acute head trauma. - Administering contrast agents can delay imaging, may pose risks to patients with renal impairment or allergies, and does not significantly improve the detection of acute traumatic hemorrhage compared to NCCT. *X-ray* - **X-rays** of the skull are useful for detecting **skull fractures**, but they provide **limited information** regarding intracranial injuries or soft tissue damage, which are critical in head trauma. - They have largely been superseded by CT scans, which offer a more comprehensive view of both bony structures and intracranial contents.

Q: A 43-year-old man presents to the emergency department after falling down a flight of stairs and landing on his head. He did not lose consciousness. He complains of severe headache, marked decreased acuity in hearing in the left ear, and a "runny nose" since the fall. On physical examination, he is found to have a left-sided Battle's sign (an ecchymosis in the area of the left mastoid process) and hemotympanum. He has a constant dripping of a clear, watery fluid through his nose. Findings on his neurologic examination, other than the hearing loss, are completely normal. X-ray studies will reveal which of the following?

A temporal bone fracture with CSF rhinorrhea. ***A temporal bone fracture with CSF rhinorrhea*** - The combination of **Battle's sign**, **hemotympanum**, unilateral hearing loss, and clear nasal discharge after head trauma strongly indicates a **temporal bone fracture**. - **CSF rhinorrhea** refers to cerebrospinal fluid leaking from the nose due to a skull base fracture involving the temporal bone, typically affecting the petrous part. - The CSF can reach the nasal cavity via the **eustachian tube** or through fracture lines extending to the middle ear and mastoid air cells. *Occipital bone fracture* - While occipital fractures are possible with head trauma, they do not directly explain the specific findings of **hemotympanum** or unilateral hearing loss. - An occipital fracture would typically cause symptoms related to damage to the **brainstem** or **cerebellum**, depending on the extent. *A skull-base fracture with a mucocele* - A **mucocele** is a cyst filled with mucus, usually resulting from obstruction of a sinus ostium, and is not an acute traumatic finding. - While a skull-base fracture is present, the presence of a mucocele does not fit the acute injury presentation. *A fracture of the cribriform plate with a CSF leak into the paranasal sinuses* - A **cribriform plate fracture** would result in CSF rhinorrhea, but it typically causes CSF to leak directly from the anterior cranial fossa into the nasal cavity. - It would not explain the **hemotympanum**, Battle's sign, or unilateral hearing loss, which are characteristic of **temporal bone injury**.

Q: FAST can detect free blood if it is a minimum of

100ml. ***100ml*** - A **Focused Assessment with Sonography for Trauma (FAST)** exam is capable of detecting a minimum of **100ml** of free fluid (blood) in the abdomen or pericardium. - This threshold makes it a useful, but not a universally sensitive, tool for identifying significant internal hemorrhage. *200ml* - While 200ml of free fluid would certainly be detectable, this volume is above the established minimum detection threshold for a FAST exam. - The FAST exam is designed to pick up smaller, though still clinically significant, amounts of fluid. *400ml* - Detecting 400ml of free fluid is well within the capabilities of a FAST exam, but this option represents a much larger volume than the minimum often cited. - If 400ml is present, it's a clear indication of substantial bleeding. *10 ml* - A FAST exam typically **cannot reliably detect** as little as 10ml of free fluid in body cavities. - Detecting such a small amount would require higher resolution imaging like CT scans.

Q: FAST (Focused Assessment with Sonography for Trauma) is used to detect free fluid in which of the following areas?

All of the options. ***All of the options*** - The **FAST (Focused Assessment with Sonography for Trauma)** exam is a rapid ultrasound done at the bedside in trauma patients to look for **free fluid** (blood) in several key areas. - The standard FAST views include the **pericardial sac**, **right subcostal (hepatorenal)**, **left subcostal (splenorenal)**, and **pelvic (suprapubic)** regions. *Hepatic* - The **hepatorenal recess (Morison's pouch)** is one of the primary areas assessed in a FAST exam to detect free fluid adjacent to the liver. - Free fluid in this area can indicate significant intra-abdominal bleeding, often associated with **hepatic trauma**. *Splenic* - The **splenorenal recess** is another critical view in the FAST exam, looking for free fluid around the spleen. - This area is frequently checked for bleeding associated with **splenic injury**, which is common in blunt abdominal trauma. *Pericardial* - The **pericardial sac** is evaluated in the FAST exam to detect the presence of **pericardial effusion**, particularly **hemopericardium**. - Hemopericardium can lead to **cardiac tamponade**, a life-threatening condition requiring urgent intervention in trauma settings.

Q: The imaging modality primarily used in FAST (Focused Assessment with Sonography for Trauma) exam is:

USG. **USG** - **Focused Assessment with Sonography for Trauma (FAST)** exam specifically uses **ultrasound (USG)** to rapidly detect free fluid (blood) in pericardial, perihepatic, perisplenic, and pelvic spaces. - Its quick, non-invasive nature and portability make it ideal for **point-of-care assessment** in trauma settings. *X-ray* - While X-rays are useful in trauma for detecting **fractures** and some pneumothoraces, they are not the primary modality for detecting free fluid in the peritoneal or pericardial cavities during a FAST exam. - X-rays do not provide real-time, dynamic imaging of soft tissues and fluid accumulation as effectively as ultrasound. *CT* - **Computed Tomography (CT)** is a highly detailed imaging modality used in trauma for comprehensive assessment of injuries to organs, bones, and vessels. - However, it involves **radiation exposure**, takes longer to perform, and is typically reserved for hemodynamically stable patients after initial resuscitation and FAST exam. *MRI* - **Magnetic Resonance Imaging (MRI)** provides excellent soft tissue contrast, but its use in acute trauma is very limited due to its **long scan times**, high cost, and incompatibility with many metallic medical devices. - MRI is not suitable for rapid assessment of free fluid in hemodynamically unstable trauma patients.

Q: A patient of RTA with injury over chest and limbs has low SpO2. M-mode ultrasound of right upper chest shows stratosphere sign. What is the diagnosis?

Pneumothorax. ***Pneumothorax*** - A **stratosphere sign** (also known as a barcode sign) on M-mode ultrasound indicates the absence of lung sliding, which is a key diagnostic feature of **pneumothorax**. - In a patient with chest injury and low SpO2, the presence of a **collapsed lung** due to air in the pleural space explains respiratory distress. *Cardiac tamponade* - Characterized by **fluid accumulation in the pericardial sac**, leading to impaired cardiac filling and shock. - While it can cause low SpO2 and be associated with chest trauma, the **stratosphere sign** is not a diagnostic feature of cardiac tamponade. *Hemothorax* - Involves the **accumulation of blood in the pleural space**, often following trauma, leading to respiratory compromise. - Ultrasound in hemothorax would show **anechoic or complex fluid collections** but not the stratosphere sign. *Pulmonary embolism* - A condition where a **blood clot blocks blood flow to the lungs**, causing sudden onset dyspnea and hypoxemia. - Although it causes low SpO2, pulmonary embolism is not diagnosed by chest ultrasound revealing a **stratosphere sign**.

Q: Investigation of choice in an unstable patient with suspected intra-abdominal injury is -

USG (FAST). ***USG*** - **Focused assessment with sonography for trauma (FAST) exam** is the investigation of choice in an **unstable patient** due to its rapid, non-invasive nature and ability to detect free fluid (blood) in the peritoneal, pericardial, and pleural spaces. - It can be performed at the **bedside** without moving the patient, making it ideal for hemodynamically unstable individuals with suspected intra-abdominal injury. *CT scan* - While a **CT scan** provides detailed anatomical information, it requires the patient to be stable enough for transport to a radiology suite and prolonged scanning time. - It is often difficult to obtain in **unstable patients** who may require continuous resuscitation and monitoring. *X-ray abdomen* - An **X-ray abdomen** has limited utility for detecting intra-abdominal injuries and primarily identifies issues like free air under the diaphragm (suggesting hollow organ perforation) or foreign bodies. - It is **not sensitive** for detecting free fluid (hemoperitoneum) or solid organ injuries, which are critical in trauma. *DPL* - **Diagnostic peritoneal lavage (DPL)** is an invasive procedure that involves inserting a catheter into the peritoneal cavity to detect blood or other fluid. - While sensitive, it is **invasive**, can complicate subsequent imaging, and has largely been replaced by the FAST exam due to the latter's non-invasive nature and comparable diagnostic accuracy for free fluid.

Q: Investigation of choice for diagnosis of splenic rupture –

CT scan. **CT scan** - A **CT scan** with intravenous contrast is the investigation of choice for splenic rupture due to its high sensitivity and specificity in detecting **splenic injury**, **hematomas**, and **free intraperitoneal fluid**. - It provides detailed anatomical information, crucial for grading the injury and guiding management decisions, especially in hemodynamically stable patients. *MRI* - **MRI** offers excellent soft tissue contrast, but it is **time-consuming** and often **not readily available** in emergency settings for acute trauma. - It is typically reserved for more chronic or complex cases where detailed soft tissue characterization is not immediately needed in acute trauma. *Peritoneal lavage* - **Diagnostic peritoneal lavage (DPL)** is an **invasive procedure** that is less specific than imaging for diagnosing splenic rupture. - It detects the presence of **intraperitoneal bleeding** but does not localize the injury or provide information about the extent of organ damage. *Ultrasound* - **Ultrasound (FAST exam)** is a rapid, non-invasive tool for detecting **free fluid** in the abdomen but has limited sensitivity for directly visualizing the spleen or accurately grading splenic injuries. - While useful for rapid assessment of **hemodynamically unstable** patients, a **negative FAST exam does not rule out splenic injury**, especially in stable patients.

Q: Gas shadow in the heart and great vessels is characteristically seen in:

Air embolism. ***Air embolism*** - An **air embolism** occurs when air or gas enters the bloodstream and travels to the heart or great vessels, appearing as a gas shadow on imaging. - This can be due to medical procedures, trauma, or certain deep-sea diving injuries, where gas forms within the vascular system. *Gas-forming infection* - While gas-forming infections can produce gas, they typically result in gas within tissues or organs, not directly as a prominent gas shadow within the **heart chambers** or **great vessels** themselves. - Examples include **clostridial myonecrosis** or abscesses, which are localized and distinct from an intravascular gas collection. *Traumatic injury* - Traumatic injury can lead to **pneumothorax**, **pneumomediastinum**, or gas in soft tissues, but usually not directly within the heart and great vessels to the extent seen with an air embolism. - While gas might be seen if a vessel or heart chamber is perforated, it is typically a secondary effect and not the primary cause of intravascular gas shadow. *Septic thrombophlebitis* - **Septic thrombophlebitis** involves infected blood clots in veins and can lead to inflammation and systemic infection. - It does not typically generate gas or gas shadows within the heart and great vessels; rather, it involves the presence of pus and infected thrombi.

Q: A 25-year-old patient presents in emergency with abdominal trauma. Why is FAST done?

Detection of free fluid in the abdomen (hemoperitoneum). ***Detection of free fluid in the abdomen (hemoperitoneum)*** - **FAST (Focused Assessment with Sonography for Trauma)** is primarily used to rapidly identify the presence of **free fluid**, typically blood, within the peritoneal, pericardial, or pleural spaces. - In abdominal trauma, the detection of **hemoperitoneum** guides immediate management decisions, such as the need for surgical intervention. *Detection of aortic injury* - While FAST can sometimes identify large pericardial effusions or mediastinal hematomas which might suggest aortic injury, it is **not sensitive or specific enough** to definitively diagnose an aortic injury. - **CT angiography** is the gold standard for diagnosing aortic injuries. *Detection of mesenteric injury* - **Mesenteric injuries** involve damage to the blood supply of the intestines and are difficult to detect with FAST. - These injuries might cause **intraperitoneal bleeding** detectable by FAST, but FAST cannot directly visualize the mesenteric damage itself. *Detection of bowel perforation* - **Bowel perforations** release air and contents into the peritoneal cavity, but FAST is generally **poor at detecting free air**. - While it might indirectly show some free fluid as a result of inflammation, it is not the primary diagnostic tool for perforation; **plain radiographs** or **CT scans** are more effective.

Question 1

A man presents to the emergency department with a head injury following a vehicular accident. What is the investigation of choice?

Accepted Answer

NCCT

Answer

MRI

Answer

CECT

Answer

X-ray

Question 2

A 43-year-old man presents to the emergency department after falling down a flight of stairs and landing on his head. He did not lose consciousness. He complains of severe headache, marked decreased acuity in hearing in the left ear, and a "runny nose" since the fall. On physical examination, he is found to have a left-sided Battle's sign (an ecchymosis in the area of the left mastoid process) and hemotympanum. He has a constant dripping of a clear, watery fluid through his nose. Findings on his neurologic examination, other than the hearing loss, are completely normal. X-ray studies will reveal which of the following?

Accepted Answer

A temporal bone fracture with CSF rhinorrhea

Answer

Occipital bone fracture

Answer

A skull-base fracture with a mucocele

Answer

A fracture of the cribriform plate with a CSF leak into the paranasal sinuses

Question 3

FAST can detect free blood if it is a minimum of

Accepted Answer

100ml

Answer

200ml

Answer

400ml

Answer

10 ml

Question 4

FAST (Focused Assessment with Sonography for Trauma) is used to detect free fluid in which of the following areas?

Accepted Answer

All of the options

Answer

Hepatic

Answer

Splenic

Answer

Pericardial

Question 5

The imaging modality primarily used in FAST (Focused Assessment with Sonography for Trauma) exam is:

Accepted Answer

USG

Answer

X-ray

Answer

CT

Answer

MRI

Question 6

A patient of RTA with injury over chest and limbs has low SpO2. M-mode ultrasound of right upper chest shows stratosphere sign. What is the diagnosis?

Accepted Answer

Pneumothorax

Answer

Cardiac tamponade

Answer

Hemothorax

Answer

Pulmonary embolism

Question 7

Investigation of choice in an unstable patient with suspected intra-abdominal injury is -

Accepted Answer

USG (FAST)

Answer

CT scan

Answer

X-ray abdomen

Answer

DPL

Question 8

Investigation of choice for diagnosis of splenic rupture –

Accepted Answer

CT scan

Answer

MRI

Answer

Peritoneal lavage

Answer

Ultrasound

Question 9

Gas shadow in the heart and great vessels is characteristically seen in:

Accepted Answer

Air embolism

Answer

Gas-forming infection

Answer

Traumatic injury

Answer

Septic thrombophlebitis

Question 10

A 25-year-old patient presents in emergency with abdominal trauma. Why is FAST done?

Accepted Answer

Detection of free fluid in the abdomen (hemoperitoneum)

Answer

Detection of aortic injury

Answer

Detection of mesenteric injury

Answer

Detection of bowel perforation

Emergency Radiology — MCQs

Emergency Radiology — MCQs

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