Saudi Board Diagnostic Radiology Final Written Exam (SCFHS)

During a pelvic CT examination, which of the following parameter changes would reduce the CTDIvol (Volume Computed Tomography Dose Index) while maintaining the pitch?

• AIncreasing the tube voltage (kVp).
• BDecreasing the tube current-exposure time product (mAs).
• CDecreasing the pitch.
• DIncreasing the active detector collimation width.

A patient with a cardiac pacemaker requires an MRI. What does the term 'MR Conditional' imply regarding the safety of this implant in the MR environment?

• AThe implant is safe for MR scanning under any magnetic field strength up to 3.0 Tesla.
• BThe implant can be safely scanned only under specific, strictly defined conditions of use…
• CThe implant poses no safety hazards in any MR environment but may cause severe image arti…
• DThe implant is safe to scan only if the pacemaker is programmed to an asynchronous pacing…

Regarding the biological effects of ionizing radiation, which of the following is classified as a deterministic (tissue reaction) effect?

• AThyroid carcinoma.
• BLeukemia.
• CHereditary genetic mutations.
• DRadiation-induced cataracts.

In magnetic resonance imaging, how does doubling the static magnetic field strength (from 1.5T to 3.0T) affect the Specific Absorption Rate (SAR)?

• ASAR increases by a factor of 4.
• BSAR doubles.
• CSAR remains unchanged.
• DSAR decreases by half.

Which of the following ultrasound parameters is the primary determinant of the Mechanical Index (MI), which monitors the potential for non-thermal bioeffects like cavitation?

• ASpatial-peak temporal-average intensity (ISPTA).
• BCenter frequency of the transducer.
• CPeak negative (rarefactional) pressure.
• DPulse repetition frequency (PRF).

What is the primary physical mechanism responsible for 'beam hardening' artifacts in clinical CT imaging?

• A Compton scattering of high-energy photons causing them to lose energy and change directi…
• BPhoton starvation at highly attenuating regions, resulting in streak artifacts.
• CPreferential absorption of lower-energy photons from a polychromatic X-ray beam as it pas…
• DNon-linear amplification of signal at the detector level due to high-density materials.

In digital radiography, what does the Exposure Indicator (EI) signify?

• AAn estimate of the average incident radiation exposure reaching the digital detector.
• BThe exact patient entrance skin dose (ESD) received during the exposure.
• CThe signal-to-noise ratio (SNR) of the final processed image.
• DThe spatial resolution limit of the detector system in line pairs per millimeter.

During fluoroscopically guided interventions, which of the following actions will result in the greatest reduction in radiation exposure to the performing radiologist?

• AIncreasing the distance between the patient and the image receptor.
• BUsing continuous fluoroscopy at 30 frames per second instead of pulsed fluoroscopy.
• CStanding on the detector side of the C-arm rather than the X-ray tube side during lateral…
• DRemoving the grid from the image receptor.

What is the purpose of the 'anti-aliasing filter' used in CT and MRI reconstruction pipelines?

• ATo eliminate frequencies higher than the Nyquist limit from the raw data prior to samplin…
• BTo reduce statistical noise in low-dose CT acquisitions using iterative loop smoothing.
• CTo correct for magnetic field inhomogeneities along the phase-encoding axis.
• DTo minimize the partial volume averaging effect by sharpening voxel borders.

A 10-year-old child requires a chest CT. Which of the following adjustments is most appropriate to optimize radiation protection in this pediatric patient?

• AIncreasing the tube current (mAs) to compensate for the smaller body size.
• BUsing a grid with a higher grid ratio to reduce scatter.
• CIncreasing the scan coverage to include the upper abdomen routinely.
• DLowering the tube voltage (kVp) to 80-100 kVp based on patient weight.

In a gamma camera, what is the primary function of the collimator?

• ATo multiply the incoming gamma-ray photons into visible light photons.
• BTo convert gamma-ray energy into an electrical signal using a photomultiplier tube.
• CTo restrict incoming gamma rays to only those traveling parallel to the holes, thereby al…
• DTo filter out scatter radiation by absorbing low-energy beta particles.

Which of the following factors determines the 'Half-Value Layer' (HVL) of a diagnostic X-ray beam?

• AThe filtration material and the peak kilovoltage (kVp) of the tube.
• BThe tube current (mA) and the exposure time (seconds).
• CThe distance from the X-ray tube source to the detector (SID).
• DThe focal spot size of the cathode filament.

What is the principal hazard associated with a rapid loss of cryogenic liquids (helium) in an MRI scanner room, also known as a quench?

• ASevere electrical shock due to collapse of the superconducting magnetic field.
• BProjectile injuries from objects drawn into the scanner bore.
• CAsphyxiation due to displacement of oxygen by gaseous helium in the room.
• DExposure to dangerous ionizing radiation generated by the collapsing field.

Regarding the ALARA (As Low As Reasonably Achievable) principle, what are the three basic protective measures used to limit radiation exposure?

• ACollimation, Grid use, and Kilovoltage.
• BDosimetry, Badges, and Calibration.
• CTime, Distance, and Shielding.
• DAperture, Focal spot, and Filtration.

Which type of artifact in MRI is characterized by bands of alternating high and low signal intensity along the borders of high-contrast interfaces, such as the skull-brain interface, and is caused by truncating the Fourier series?

• AChemical shift artifact.
• BSusceptibility artifact.
• CGibbs (truncation) artifact.
• DMagic angle artifact.

In CT imaging, which dose metric accounts for both the X-ray beam output and the total scan length along the z-axis?

• AVolume CT Dose Index (CTDIvol).
• BDose Length Product (DLP).
• CWeighted CT Dose Index (CTDIw).
• DSize-Specific Dose Estimate (SSDE).

How does increasing the transducer frequency in diagnostic ultrasound affect axial resolution and penetration depth?

• AAxial resolution degrades, but penetration depth increases.
• BAxial resolution improves (finer detail), but penetration depth decreases.
• CBoth axial resolution and penetration depth increase.
• DBoth axial resolution and penetration depth decrease.

Which of the following contrast agents carries the highest risk of causing Nephrogenic Systemic Fibrosis (NSF) in patients with severe renal impairment (GFR < 30 mL/min/1.73m²)?

• AMacrocyclic ionic gadolinium-based contrast agents (e.g., Gadoterate meglumine).
• BHigh-osmolar iodinated contrast agents (e.g., Diatrizoate).
• CSuperparamagnetic iron oxide nanoparticles (SPIO).
• DLinear non-ionic gadolinium-based contrast agents (e.g., Gadodiamide).

What is the annual occupational effective dose limit recommended by the International Commission on Radiological Protection (ICRP) for radiation workers?

• A5 mSv per year.
• B100 mSv per year.
• C1 mSv per year.
• D20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding…

In magnetic resonance imaging, the spatial distortion artifact caused by the presence of metallic implants (e.g., orthopedic hardware) can be minimized by which of the following technique modifications?

• ADecreasing the receiver bandwidth to improve SNR.
• BIncreasing the receiver bandwidth and using view angle tilting (VAT) sequences.
• CSwitching from a Spin Echo (SE) to a Gradient Recalled Echo (GRE) sequence.
• DScanning at 3.0 Tesla instead of 1.5 Tesla.

A 65-year-old male presents with acute onset right-sided weakness. A non-contrast head CT performed 2 hours after symptom onset is normal. What is the most sensitive MRI sequence for detecting hyperacute ischemic stroke at this stage?

• AFluid-Attenuated Inversion Recovery (FLAIR).
• BDiffusion-Weighted Imaging (DWI).
• CT2-weighted Fast Spin Echo.
• DGradient Recalled Echo (GRE) T2*.

An MRI of the brain in a 45-year-old patient reveals a well-circumscribed, extra-axial mass along the cerebral convexity. The mass is dural-based, intensely and homogeneously enhances after gadolinium administration, and displays a 'dural tail' sign. What is the most likely diagnosis?

• AMeningioma.
• BGlioblastoma.
• CBrain metastasis.
• DVestibular schwannoma.

A 30-year-old female presents with optic neuritis and paresthesias. Brain MRI reveals multiple ovoid T2/FLAIR hyperintense lesions oriented perpendicular to the lateral ventricles. What is this classic imaging sign called?

• ASteeple sign.
• BDawson's fingers.
• CMount Fuji sign.
• DEmpty delta sign.

Following a high-speed motor vehicle accident, a head CT reveals a biconvex (lentiform), high-density extra-axial fluid collection that does not cross cranial sutures. What vascular structure is most commonly injured in this condition?

• ABridging cortical veins.
• BSuperficial temporal artery.
• CBasilar artery.
• DMiddle meningeal artery.

A CT scan of the cervical spine in a trauma patient reveals a fracture of the anterior and posterior arches of the C1 vertebra. What is the specific name of this fracture?

• AHangman's fracture.
• BClay-shoveler's fracture.
• CChance fracture.
• DJefferson fracture.

A 52-year-old female presents to the emergency department with the 'worst headache of her life.' A non-contrast head CT confirms acute subarachnoid hemorrhage. What is the most common location for intracranial aneurysms responsible for non-traumatic subarachnoid hemorrhage?

• ABasilar artery bifurcation.
• BAnterior communicating artery.
• CMiddle cerebral artery bifurcation.
• DPosterior inferior cerebellar artery (PICA).

During a contrast-enhanced CT venogram of the brain, a filling defect is noted within the posterior aspect of the superior sagittal sinus. On coronal images, this appears as a central dark area surrounded by enhancing dural margins. What is this sign called?

• ACord sign.
• BPanda sign.
• CHot nose sign.
• DEmpty delta sign.

An MRI of a 6-year-old child with a history of occipital headache reveals cerebellar tonsils herniating 7 mm below the level of the foramen magnum. The third and fourth ventricles are normal, and there is no evidence of myelomeningocele. What is the most likely diagnosis?

• AChiari II malformation.
• BChiari I malformation.
• CDandy-Walker malformation.
• DJoubert syndrome.

A 40-year-old male presents with progressive right-sided sensorineural hearing loss and tinnitus. Contrast-enhanced MRI of the internal auditory canals reveals an enhancing mass in the right cerebellopontine angle. The mass extends into the internal auditory canal, widening it, and displays an 'ice cream cone' configuration. What is the most likely diagnosis?

• AMeningioma.
• BEpidermoid cyst.
• CAneurysm of the anterior inferior cerebellar artery (AICA).
• DVestibular schwannoma.

A head and neck MRI in a patient with a pulsatile neck mass reveals a tumor at the carotid bifurcation that spreads the internal and external carotid arteries apart. On T2-weighted images, the tumor shows multiple punctate foci of signal void and hyperintensity, giving it a 'salt and pepper' appearance. What is the most likely diagnosis?

• AVagal schwannoma.
• BCarotid body paraganglioma (carotid body tumor).
• CCarotid artery aneurysm.
• DCervical lymph node metastasis.

A 15-year-old male presents with a painless, midline neck mass located just infrahyoid. The mass is cystic on ultrasound and moves upward when the patient protrudes his tongue. What is the embryological origin of this lesion?

• AIncomplete obliteration of the thyroglossal duct.
• BFailure of closure of the second branchial cleft.
• CEctopic lymphatic tissue rests (lymphangioma).
• DAbnormal development of the thyroid lobes.

A 35-year-old male presents with nasal obstruction and epistaxis. A CT and MRI of the paranasal sinuses demonstrate a dumbbell-shaped mass centered in the cribriform plate, extending superiorly into the anterior cranial fossa and inferiorly into the nasal cavity. What is the most likely diagnosis?

• AJuvenile nasopharyngeal angiofibroma (JNA).
• BEsthesioneuroblastoma (Olfactory neuroblastoma).
• CInverting papilloma.
• DSquamous cell carcinoma.

A 58-year-old female presents with progressive visual field deficits. MRI shows a sellar and suprasellar mass that is hyperintense to gray matter on T2-weighted images. The mass displays a 'snowman' configuration due to constriction by the diaphragmatic sellae, and normal pituitary tissue is not separately identified. What is the most likely diagnosis?

• ACraniopharyngioma.
• BRathke's cleft cyst.
• CPituitary macroadenoma.
• DOptic chiasm glioma.

An MRI of the spine in a 30-year-old patient with progressive myelopathy reveals an intramural, cystic spinal cord tumor in the cervical region. The tumor is centrally located, shows focal nodular enhancement, and has associated hemorrhage at its margins ('hemosiderin cap' sign). What is the most likely diagnosis?

• ASpinal cord astrocytoma.
• BHemangioblastoma.
• CSpinal cord ependymoma.
• DSpinal meningioma.

A 34-year-old male from a rural area presents with new-onset seizures. A contrast-enhanced head CT reveals multiple parenchymal brain lesions. Some lesions are small, non-enhancing calcified nodules. Others are cystic lesions containing a small, hyperdense eccentric nodule ('scolex'). What is the most likely diagnosis?

• ATuberculosis (tuberculomas).
• BToxoplasmosis.
• CNeurocysticercosis.
• DCerebral metastases.

Which MRI sequence is most sensitive for detecting subarachnoid hemorrhage within the first 12-24 hours?

• AT1-weighted Spin Echo.
• BFluid-Attenuated Inversion Recovery (FLAIR).
• CT2-weighted Fast Spin Echo.
• DDiffusion-Weighted Imaging (DWI).

A 70-year-old male presents with progressive dementia, gait ataxia, and urinary incontinence. An MRI of the brain demonstrates ventricular enlargement disproportionate to the degree of cerebral sulcal atrophy, with prominent transependymal CSF flow (interstitial edema) around the frontal horns. What is the most likely diagnosis?

• AAlzheimer's disease.
• BEx-vacuo ventriculomegaly.
• CObstructive non-communicating hydrocephalus.
• DNormal Pressure Hydrocephalus (NPH).

During temporal bone CT evaluation for conductive hearing loss, a dehiscence of the bone overlying the superior semicircular canal is suspected. What is the clinical syndrome associated with this finding?

• AGradenigo's syndrome.
• BMénière's disease.
• CMinor's syndrome (Superior semicircular canal dehiscence).
• DRamsay Hunt syndrome.

An axial T2-weighted MRI of the brain in a 25-year-old female shows bilateral, symmetric hyperintensities in the putamen and globus pallidus. There is a characteristic outer hyperintense ring and a central hypointense core in the midbrain, known as the 'face of the giant panda' sign. What is the diagnosis?

• AHuntington's disease.
• BCarbon monoxide poisoning.
• CParkinson's disease.
• DWilson's disease.

Which of the following spaces in the neck contains the sympathetic trunk, lymph nodes, and the internal carotid artery and internal jugular vein?

• ACarotid space.
• BMasticator space.
• CRetropharyngeal space.
• DDanger space.

A chest CT of a 62-year-old male smoker with progressive dyspnea shows subpleural, basal-predominant reticular opacities, traction bronchiectasis, and honeycombing. There are no features suggesting an alternative diagnosis. What is the classification of this pattern according to current guidelines?

• ANon-Specific Interstitial Pneumonia (NSIP) pattern.
• BUsual Interstitial Pneumonia (UIP) pattern.
• CCryptogenic Organizing Pneumonia (COP) pattern.
• DDesquamative Interstitial Pneumonia (DIP) pattern.

A 45-year-old male presents with sudden, tearing chest pain radiating to the back. A contrast-enhanced chest CT demonstrates a tear in the intima of the ascending aorta, extending into the descending aorta. What is the Stanford classification for this dissection?

• AStanford Type A.
• BStanford Type B.
• CStanford Type C.
• DStanford Type I.

A CT pulmonary angiogram (CTPA) demonstrates a filling defect in the right main pulmonary artery. Which of the following secondary signs of pulmonary embolism represents a wedge-shaped pulmonary consolidation distal to the occlusion, indicating pulmonary infarction?

• AWestermark sign.
• BHampton's hump.
• CFleischner sign.
• DKnuckle sign.

According to the Fleischner Society guidelines, what is the recommended management for a single, solid, non-suspicious lung nodule measuring 5 mm in a high-risk patient (e.g., heavy smoker)?

• ARepeat chest CT in 12 months.
• BNo routine follow-up CT required.
• CPerform FDG-PET/CT.
• DRefer for percutaneous needle biopsy.

A 55-year-old patient with hepatitis C cirrhosis undergoes a multiphase liver CT. A 2.5 cm hepatic mass shows intense arterial phase hyperenhancement followed by portal venous phase washout and the development of an enhancing capsule. According to the LI-RADS classification, what category should this mass be assigned?

• ALR-5 (Definitely Hepatocellular Carcinoma).
• BLR-4 (Probably Hepatocellular Carcinoma).
• CLR-M (Malignant, but not HCC-specific).
• DLR-3 (Intermediate probability of HCC).

A 30-year-old female presents with an incidental liver mass. MRI demonstrates a lesion that is iso-to-hypointense on T1 and hyperintense on T2. It has a central scar that enhances on delayed phases. The mass demonstrates uptake and retention of contrast on hepatobiliary phase images after Eovist (Gadoxetate disodium) injection. What is the most likely diagnosis?

• AHepatic adenoma.
• BHemangioma.
• CFocal Nodular Hyperplasia (FNH).
• DFibrolamellar hepatocellular carcinoma.