Radiology Articles

Seen in a classic bimodal age distribution—the primary peak in children aged 5–15 years (most common pediatricnonglial suprasellar neoplasm) and a second peak in adults aged 50–70 years—presenting with visual field defects (bitemporal hemianopia), growth failure/short stature, diabetes insipidus, and obstructive hydroc

Seen in adults (peak age 30–60 years; accounts for 10–15% of all intracranial neoplasms and is the most common sellar/suprasellar mass in adults), presenting with bitemporal hemianopia (from superior compression of the optic chiasm), hypopituitarism, hyperprolactinaemia ('stalk effect' or prolactinoma), or acute thunde

Seen in older adults (peak age 50–70 years, strong male predominance, with >90% occurring in cigarette smokers; second most common benign parotid neoplasm), presenting with a painless, slow-growing, soft or fluctuant mass classically in the inferior pole (tail) of the parotid gland. Caused by heterotopic salivary ducta

Seen in middle-aged adults (peak age 30–60 years, 2:1 female predominance; accounts for 70–80% of all parotid gland tumours and is the most common salivary gland neoplasm overall), presenting with a painless, slow-growing, firm, mobile mass at the angle of the mandible or pre-auricular cheek. Caused by a benign biphasi

Seen in children and young adults (typically diagnosed at 1–15 years; incidence 1:3,000 live births, equal sex distribution) presenting with cafe-au-lait macules, axillary/inguinal freckling (Crowe sign), subcutaneous neurofibromas, progressive visual loss, proptosis, or macrocephaly. Caused by autosomal dominant mutat

Seen in children (peak age 3–8 years, male:female 1.5:1, the most common malignant pediatric brain tumor, accounting for 20% of all childhood CNS neoplasms; second smaller adult peak at 20–30 years). Presents with progressive morning headaches, recurrent non-bilious projectile vomiting, truncal ataxia, broad-based unst

Seen in young children (peak age 1–5 years, male:female 1.4:1; 70% of pediatric ependymomas arise within the posterior fossa; second peak in young adults at 30–40 years). Presents with subacute progressive morning headaches, vomiting, lethargy, torticollis, neck pain, and multiple cranial nerve palsies (CN VI, VII, IX,

Seen in older adults (55–75 years, male predominance) presenting subacutely with progressive headaches, cognitive decline, personality changes, new focal neurological deficits, or adult-onset seizures. Caused by WHO Grade 4 diffuse astrocytic glioma characterized by IDH-wildtype status, microvascular proliferation, and

Seen in young to middle-aged adults (peak age 30–50 years, female:male 2:1, strong association with underlying connective tissue disorders such as Marfan syndrome or Ehlers-Danlos syndrome) presenting with the pathognomonic clinical hallmark: severe, disabling Orthostatic (Postural) Headache. The headache develops or w

Seen in children and young adults (peak age 5–15 years, equal sex distribution, the most common primary pediatric brain tumor, accounting for >30% of all childhood CNS neoplasms). Most commonly located in the cerebellum (60%), followed by the optic pathway / hypothalamus (associated with Neurofibromatosis Type 1), brai

Seen across two major age groups—term/preterm neonates with perinatal asphyxia and adults (typically aged 40–80 years) experiencing severe systemic cardiorespiratory arrest, profound global cerebral hypoperfusion, asphyxiation, drowning, or carbon monoxide poisoning. Neonates present with Hypoxic-Ischemic Encephalopath

Seen in middle-aged and older adults (peak age 55–75 years, male:female 1.5:1, annual incidence 2:100,000). Presents with insidiously progressive, relentless muscle weakness characterized pathognomonically by the simultaneous presence of BOTH Upper Motor Neuron (UMN) and Lower Motor Neuron (LMN) signs across multiple a

Seen in adults (40–60 years, female predilection) presenting with hyperacute, catastrophic, explosive headache ('thunderclap headache', 'worst headache of my life'), neck stiffness, photophobia, altered mental status, or sudden collapse. Caused by rupture of an intracranial saccular (berry) aneurysm (85% of non-traumat

Seen in two distinct clinical age groups based on etiology (young males aged 18–45 years for direct traumatic Type A; postmenopausal females aged 50–70 years for indirect dural Types B–D): Direct (High-Flow) CCF: Young adult males presenting acutely following major blunt or penetrating skull base craniomaxillofacial tr

Seen in young adults (peak presentation age 20–40 years, equal sex distribution). Unruptured AVMs present with new-onset generalized or focal seizures (most common non-hemorrhagic symptom, 50%), progressive chronic pulsatile headache, or progressive focal neurological deficits from vascular steal. Ruptured AVMs present

Seen in adults (peak age 60–80 years, though also seen in younger adults aged 20–50 years with arterial dissection or cardioembolism) presenting with sudden-onset focal neurological deficits (unilateral hemiparesis, facial droop, hemisensory loss, acute aphasia, or hemineglect) within hours of onset (last seen well tim

Seen in middle-aged adults (40–60 years, equal sex distribution) presenting with insidious progressive unilateral sensorineural hearing loss (SNHL), high-pitched tinnitus, and dysequilibrium/imbalance. Caused by benign WHO Grade 1 nerve sheath tumor arising from the Schwann cells of the superior or inferior vestibular

Seen in two distinct clinical populations (immunocompetent older adults aged 60–75 years and immunocompromised patients aged 30–50 years): Immunocompetent Individuals: Older adults (peak age 60–80 years, male:female 1.5:1) presenting with subacute cognitive decline, personality changes, progressive lethargy, signs of e

Seen in severely immunocompromised adults (most commonly aged 30–60 years): HIV/AIDS patients (historically the most common cohort, typically CD4 count <100–200 cells/uL);

Seen in young adults (20–40 years, 3:1 female predilection) presenting with relapsing-remitting neurological episodes: optic neuritis (painful monocular vision loss), internuclear ophthalmoplegia (INO), transverse myelitis (Lhermitte sign), or sensory ataxia. Caused by chronic autoimmune inflammatory demyelinating dise

Seen in middle-aged to elderly adults (40–70 years, 2:1 female predilection) presenting with focal neurological deficits, new-onset seizures, chronic headaches, or detected incidentally on neuroimaging. Caused by extra-axial neoplasm arising from the arachnoid cap cells of the arachnoid villi; predominantly benign (WHO

Seen in patients of any age (bimodal peak: children <20 years and older adults >50 years, equal sex distribution) presenting acutely with the classic clinical triad: (1) acute high fever and severe headache, (2) rapidly progressive altered mental status, confusion, personality changes, or bizarre psychotic behavior, an

Seen in adults (prevalence 3–5% in the general population, female:male 1.5:1, peak rupture age 40–60 years, strong association with cigarette smoking, systemic hypertension, autosomal dominant polycystic kidney disease [ADPKD], and connective tissue disorders like Ehlers-Danlos Type IV). Unruptured aneurysms are discov

Seen in young adults (peak age 20–40 years, incidence 1:36,000 live births, equal sex distribution) presenting with cerebellar ataxia, gait instability, headache, and signs of elevated intracranial pressure (vomiting, papilledema) from posterior fossa mass effect. Associated symptoms include painless vision loss (retin

Seen in young to middle-aged adults (peak age 20–45 years; female:male 3:1, strong association with oral contraceptive use, pregnancy / puerperium, dehydration, systemic prothrombotic conditions [Factor V Leiden, antiphospholipid syndrome], COVID-19, and adjacent skull base / mastoid infections) presenting with severe,

Seen in elderly individuals (peak age >65–70 years, equal sex distribution) presenting with the classic clinical triad of Hakim and Adams (present in complete form in up to 50–60%): (1) Gait Disturbance: The earliest, most prominent, and most shunt-responsive symptom; characterized as a 'magnetic', slow, wide-based, sh

Seen in infants, children, and young adults (typically diagnosed at 0–10 years; incidence 1:6,000 live births, equal sex distribution) presenting with the classic Vogt Clinical Triad (present in <30%): intractable epilepsy / infantile spasms,