How do you tell a malignant node from a reactive one on MRI?

A reactive node keeps its fatty hilum and normal shape; a malignant node loses the hilum, rounds up, brightens on T2 fat-sat and restricts diffusion on DWI (bright DWI, dark ADC). No single sign is definitive, so they are read together.

Why is the axial angled to the airway?

Angling perpendicular to the trachea and cervical spine gives clean, comparable cross-sections of the nodal levels and the relationship of any mass to the airway and great vessels.

What coverage does a neck study need?

From the hard palate down to the aortic arch — high enough to include Waldeyer's ring (tonsils and adenoids) and low enough for the supraclavicular nodes, which are common metastatic sites.

Resources/Protocols

Neck mass / lymphadenopathy

The crossroads of airway, vessels and nerves — where a single swallow can ruin a sequence. You are separating reactive nodes from malignant ones, and mapping a mass against the carotid and airway.

Protocols/Soft-tissue neck

When this study is used

Neck mass or lymphadenopathy — reactive versus malignant.
Head-and-neck squamous cell carcinoma staging.
Thyroid or salivary-gland mass.

Patient & coil positioning

Head-first supine in a head–neck array coil; neck neutral — hyperextension adds platysmal motion, flexion collapses the airway.
Coil close to the skin but not touching the Adam's apple, which triggers swallowing.
Anterior saturation band over the oral cavity/tongue; coach the patient to swallow only in the quiet gaps.
Centre on the thyroid cartilage.

Localizer

Three-plane localizer; the sagittal must span the hard palate to the sternal notch.

Sequence planning

Each sequence below lists how the slice group is positioned — the reference line it follows, its coverage, and why it earns its place in the protocol. Plan against the localizer, not by eye.

Axial T1

Axial

Planning — Perpendicular to the trachea/cervical spine (the airway axis). Hard palate to aortic arch, covering Waldeyer's ring and the supraclavicular nodes.

Why — Anatomy map — nodes grey, fat white; separates a node from surrounding fat.

Axial T2 fat-sat

Axial

Planning — Matched airway-axis coverage.

Why — Pathology detector — a malignant node loses its fatty hilum and brightens.

Axial DWI (b≈800)

Axial

Planning — Same coverage.

Why — Densely cellular malignant tissue restricts diffusion.

T1 fat-sat + contrast (axial + coronal)

Axial / coronal

Planning — Coronal parallel to the anterior cervical spine (vertebral-body axis).

Why — Mass enhancement, perineural spread and brachial-plexus/gland symmetry.

Representative parameters

Ranges, not commandments — field strength, coil and vendor move the numbers. What must not move is understanding why each sits where it does.

Sequence	Plane	Notes
T1	Axial	Anatomy; node vs. fat
T2 fat-sat	Axial	Malignant node brightens
DWI (b≈800)	Axial	Restricted diffusion
T1 +C fat-sat	Axial + coronal	Enhancement, perineural spread

Artifacts & how to fix them

Artifact	Typical cause	Mitigation
Swallowing ghost	Involuntary swallow during scan	Oral-cavity sat band; scan in quiet gaps; phase A–P
Carotid pulsation	Flow across the jugular nodes	Flow compensation (gradient moment nulling)
Platysmal motion	Hyperextended neck	Keep the neck neutral
Cropped coverage	Missed Waldeyer's ring / low nodes	Hard palate to aortic arch

What am I looking at?

You are not reporting the study, but recognising pathology helps you keep it in the field of view and know when to add a sequence or contrast. How the common findings read on the console:

Finding	Sequence to check	How it reads
Malignant node	T2 FS + DWI	Lost fatty hilum, bright on T2, restricts on DWI
Perineural spread	T1 +C fat-sat	Enhancement tracking along a nerve toward the skull base
Salivary tumour	T1 non-FS + T1+C	Dark mass against the bright fatty gland; enhances with contrast

Review checklist

Neck neutral; no swallow artefact across the nodal stations.
Coverage hard palate to aortic arch.
DWI acquired for nodal characterisation.
Carotid pulsation steered off the jugular chain.

Mistakes that cost repeats

A swallow mid-acquisition wiping out a sequence.
Hyperextension adding motion; flexion collapsing the airway.
Carotid ghosts over the jugular nodes with no flow compensation.
Too little superior or inferior coverage.

Common questions

How do you tell a malignant node from a reactive one on MRI?: A reactive node keeps its fatty hilum and normal shape; a malignant node loses the hilum, rounds up, brightens on T2 fat-sat and restricts diffusion on DWI (bright DWI, dark ADC). No single sign is definitive, so they are read together.
Why is the axial angled to the airway?: Angling perpendicular to the trachea and cervical spine gives clean, comparable cross-sections of the nodal levels and the relationship of any mass to the airway and great vessels.
What coverage does a neck study need?: From the hard palate down to the aortic arch — high enough to include Waldeyer's ring (tonsils and adenoids) and low enough for the supraclavicular nodes, which are common metastatic sites.

Try it in ScanFlo: Scan a nodal level while the patient swallows, then holding still with an oral-cavity sat band in place. The difference between a blurred, non-diagnostic node and a crisp one is the whole reason for swallow suppression.

← All soft-tissue neck studies