Introduction to Multiparametric MR of the Prostate


KEY FACTS

Imaging

  • Multiparametric MR (mpMR)

    • Combination of anatomical and functional imaging

    • Anatomical imaging

      • T2WI

        • Lesion detection and characterization; gland volume and extraprostatic extension

      • T1WI

        • Rule out prostatic hemorrhage (tumor mimicker)

    • Functional imaging

      • Diffusion-weighted imaging (DWI)

      • Apparent diffusion coefficient map (ADC)

        • Interpretation of combined high b-value (≥ 1,400 s/mm²) DWI and ADC map

        • Lesion detection and characterization

      • Dynamic contrast-enhanced (DCE) study

        • Multiple T1WI obtained during and after IV injection of contrast

        • Lesion detection and characterization

        • Key sequence for assessment of tumor recurrence

      • MR spectroscopy (MRS)

        • Key metabolic compounds in prostate gland: Citrate [2.60 parts per million (ppm)]; creatine (3.04 ppm); choline (3.20 ppm)

    • Technical notes

      • Scanner: ≥ 1.5T

      • Coils: Surface multichannel phased array ± endorectal

      • At least 6 weeks after prostate biopsy

  • Normal prostate gland

    • Peripheral zone

      • 70% of gland volume

      • High and homogeneous signal intensity (SI) on T2WI

    • Transition zone

      • 5% of gland volume

      • In benign prostatic hyperplasia (BPH), volume increases and SI on T2WI is heterogeneous ("organized chaos")

    • Central zone: 25% of gland volume (↓ in BPH)

Medical illustration shows an axial view through the midprostate. The visualized key anatomical structures include peripheral zone
, transition zone
, neurovascular bundles
, and anterior fibromuscular stroma
.

Axial T2WI MR of the prostate through the midgland is shown. The peripheral zone
shows high signal intensity (SI) given the water content in the normal gland. The transition zone
shows heterogeneous SI in this subject with mild BPH. This image was obtained using an endorectal coil
.

Coronal T2WI MR shows the prostate in the same patient. Central zone appears as a triangular or V-shaped hypointense structure
in the posterosuperior portion of the gland. The seminal vesicles
appears as hyperintense tubular structures.

Composite figure shows axial DWI MR (at different b-value) and ADC map. The SI on DWI reflects the motility of water molecules. It is key for cancer detection. The ↑ cellularity of tumor restricts water diffusion, resulting in ↑ SI on high b-value DWI and ↓ SI on ADC map.

TERMINOLOGY

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