Table 2 Detailed semantic descriptors for prostate cancer a) broad categories b) feature description

Features

Description

1

16

Shape, border, lymphadenopathy

(F1:shape, F2:border,

F3:T2 intensity, F4:ADC intensity,

F5:homogeneity, F6:enhacement degree, F7:early enhancement,

F8:enhanced homogenicity,

F9:capsule, F10:cyst,

F11:extraprostatic extension,

F12:seminal vesicles, F13:distal sphincter, F14:bladder neck,

F15:lymph adenopathy, F16:BPH)

2

1

Over-all

Characteristics

Definition

Scoring definition

lesion

Location

section

central location: nodule located in the central zone or transitional zone

peripheral location: tumor located in the peripheral zone

1 = central gland

2 = peripheral zone

3 = both

Lateral

The prostate is divided into right/left on axial sections by a vertical line drawn through the center

1 = L

2 = R

3 = Both

Size

maximum transverse diameter

longest nodule width measured on axial images

maximum longitudinal diameter

Longest nodule length measured on sagittal images

maximum AP diameter

Longest nodule anterior-posterior diameter measuring on axial images

the overall shape of roundness

1 = round/ oval

2 = irregular

3 = amorphous

Margin

Border definition

well or ill-defined border

1 = well defined

2 = everything else between 1 and 3

3 = poorly defined

Capsule

Whether capsule could be found for the nodule

0 = absence

1 = presence

intensity

rT2

The intensity of nodule on T2WI compared with the intensity of normal peripheral zone

T₂WI _nodule/T₂WI _peri

rADC

The ADC value of nodule compared with that of normal peripheral zone

ADC _nodule /ADC _peri

T2 intensity

T2 signal intensity of the lesion was compared to surrounding tissues and defined as “marked hypointensity” if the lesion expressed similar signal intensity than back muscles, “hypointensity” if the lesion was brighter than back muscles but darker than adjacent prostate tissue, “iso” if the lesion was similar to adjacent prostate tissue, and “hyperintensity” if the lesion was brighter than the adjacent prostate tissue.

1 = hyperintensity

2 = iso-intensity

3 = hypointensity

4 = marked hypointensity

Homogeneity on T2WI

0 = no

1 = yes

Cyst

The presence or absence of cyst in the nodule

0 = absence

1 = presence

ADC intensity

1 = hyperintensity

2 = iso-intensity

3 = hypointensity

4 = marked hypointensity

Enhancement degree

1 = no enhancement

2 = slight enhancement

3 = moderate enhancement

4 = obvious enhancement

Early enhancement

0 = absence

1 = presence

Enhancement homogeneity

Nodule homogeneity after enhancement

0 = absence

1 = presence

Extraprostatic extension

Extracapsular extension

0 = No signs of ECE

1 = Capsular abutment

3 = Capsular irregularity, retraction or thickening

4 = Neurovascular bundle thickening

4 = Bulge or loss of capsule

5 = Measurable extracapsular disease

Seminal vesicle

Whether seminal vesicle is invaded by prostate tumor or not

0 = No signs of invasion

1 = Expansion

2 = Low T2 signal

3 = Filling in of angle

4 = Enhancement and impeded diffusion

Bladder neck

Whether bladder neck is invaded by prostate tumor or not

2 = Adjacent tumor

3 = Loss of low T2 signal in bladder muscle

4 = Abnormal enhancement extending into bladder neck

Distal sphincter

Whether distal sphincter is invaded by prostate tumor or not

2 = Adjacent tumor

3 = effacement of low signal sphincter muscle

4 = Abnormal enhancement extending into sphincter

prostate

(maximum AP diameter) × (maximum transverse diameter) × (maximum longitudinal diameter) × 0.52

The AP/transverse/ longitudinal diameter of prostate larger than 5 cm

0 = absence

1 = presence

other

The short axis of lymph node larger than 8 mm

0 = absence

1 = presence