Tigriod pattern on MRI is seen in –
Now, in MRI, different tissues have different signal intensities. A tigriod pattern is often associated with certain pathologies. Let me think about conditions that cause such a pattern. I think of the adrenal glands. Adrenal hemorrhage or certain tumors might show a tigriod appearance. Wait, there's also a condition called adrenoleukodystrophy, which affects the adrenal glands and the brain. In adrenoleukodystrophy, the adrenal cortex might show a tigriod pattern on T2-weighted MRI images due to the infiltration of myelinated fibers from the spinal cord into the adrenal cortex. That's a key point.
So, the correct answer is adrenoleukodystrophy. Now, why are the other options incorrect? Let's consider possible distractors. For example, adrenal adenoma might show a homogeneous appearance, not tigriod. Adrenal metastasis could have a different imaging pattern, maybe heterogeneous but not the specific tigriod. Cushing's syndrome might involve adrenal hyperplasia, but again, not the tigriod pattern.
The clinical pearl here is that tigriod pattern on MRI is a hallmark of adrenoleukodystrophy, especially in the adrenal glands. Students should remember that this imaging finding is associated with this genetic disorder, which also affects the nervous system. So, the correct answer is adrenoleukodystrophy, and the explanation revolves around the infiltration of myelinated fibers causing the alternating signal intensity.
**Core Concept**
The *tigriod pattern* on MRI is a radiological sign characterized by alternating bands of high and low signal intensity, resembling tiger stripes. It occurs due to infiltration of myelinated nerve fibers into the adrenal cortex, a hallmark of **adrenoleukodystrophy (ALD)**.
**Why the Correct Answer is Right**
Adrenoleukodystrophy is an X-linked recessive peroxisomal disorder causing accumulation of very long-chain fatty acids (VLCFAs). In ALD, myelinated Schwann cell fibers infiltrate the adrenal cortex, replacing normal adrenal tissue. On T2-weighted MRI, this creates a "tigriod" pattern due to alternating zones of myelinated fiber (high signal) and fibrotic/adipose tissue (low signal). This is most commonly observed in **Addison’s disease** associated with ALD.
**Why Each Wrong Option is Incorrect**
**Option A:** Adrenal adenoma typically presents as a homogeneous, well-circumscribed mass without tigriod bands.
**Option B:** Adrenal metastasis may show heterogeneous enhancement but lacks the characteristic striped appearance.
**Option C:** Cushing’s syndrome involves adrenal hyperplasia or adenoma, not tigriod pattern.
**Clinical Pearl / High-Yield Fact**
Tigriod pattern on adrenal MRI is pathognomonic for **adrenoleukod