Keywords:
Motility, Athletic injuries, Acute, Surgery, Imaging sequences, Diagnostic procedure, MR, Musculoskeletal system, Musculoskeletal joint, Extremities
Authors:
A. Paolicchi, V. Zampa, F. Ruschi, M. Barattini, F. Paolicchi, I. Castellini, L. Andreani, M. Lisanti, C. Bartolozzi; Pisa/IT
DOI:
10.1594/ecr2011/C-1439
Methods and Materials
Fifteen patients underwent MR examinations with both the dedicated MR scanner and the high field system between October and December 2010.
Inclusion criteria were: age between 18 and 60 years,
clinical suspicion of meniscal lesion,
no history of surgery on the affected knee.
Table 1: dedicated 0.31 T MR system: technical details
SMF Intensity
|
0,3 T ± 4 mT
|
Gantry opening
|
Height: 34 cm
Width: 18 cm
|
Dual-Phased Array receiving coils
|
Knee:[15*10*14]cm [W*D*H]
Ankle/Elbow:[28*15*19]cm
Hand/ Wrist: [20*7*12]cm
|
Patient seat: maximum weight
|
150 Kg
|
Overall dimension of installation site
|
[2.8*3.2]m
|
Power consumption (continous)
|
Lower than 1 kW
|
Sequences used with both systems were: SE T1,
FSE DP,
STIR in the sagittal plane; X BONE (0.31 T) and GE T2 fat sat (1.5 T) in the coronal plane.
Table 2: MR scanning protocols
1.5 T
|
THICKNESS
|
GAP
|
FOV
|
TE
|
TR
|
SE T1 SAG
|
4
|
0.8
|
150
|
12
|
450
|
STIR SAG
|
3.5
|
0.7
|
180
|
35
|
3830
|
FSE DP SAG
|
4
|
0.8
|
150
|
14
|
3080
|
GE T2 fat sat COR
|
4
|
0.4
|
190
|
23
|
1930
|
O.31 T
|
|
|
|
|
|
SE T1 SAG
|
4
|
0.4
|
140
|
20
|
720
|
STIR SAG
|
4
|
0.4
|
140
|
24
|
2000
|
FSE DP SAG
|
4
|
0.4
|
140
|
20
|
2000
|
X BONE T2 COR
|
4
|
0.4
|
140
|
11,
22
|
900
|
The exams performed with the dedicated MR system took about 16 minutes; when operating with the high-field MR system the examinations took about 13 minutes.
A few days after the MR exams,
all patients underwent arthroscopy,
that was taken as the gold standard concerning presence or absence of meniscal lesions.
Two expert radiologists performed a double-blind reading,
using the same monitor (Advantage Workstation GE,
Milwakee,
USA) in order to reduce bias related to monitor's resolution.
For each meniscus anterior and posterior horns were considered,
with the following scores: 0,
absence of lesion; 1,
uncertain interpretation; 2a,
degenerative lesion; 2b,
complete fracture and/or parameniscal cyst and/or bucket handle lesion.