Abstract
Objectives: Magnetic resonance imaging (MRI), particularly T2-weighted sequences, is increasingly used in the workup of cervical cancer. To improve image quality, we studied the feasibility of T2-weighted cervical cancer imaging on an ultra–high field MRI system. Central to our approach is the use of an endorectal antenna which should boost the signal-to-noise ratio (SNR), thus allowing higher resolutions. Here, we will assess patient discomfort and quantify its SNR increase.
Methods: We conducted a prospective feasibility study on 18 stage IB1 to IIB histology-proven cervical cancer patients who had a routine 1.5T MRI in their workup. All underwent an additional 7.0T MRI, which included transversal, sagittal, and oblique T2-weighted turbo spin echo sequences. Seven external transmit and receive dipole antennas were positioned around the pelvis, and combined with a single in-house built endorectal monopole antenna. Its signal receive optimum was placed 6 to 10 cm beyond the anodermal transition. Patients scored the level of discomfort related to the antenna from 0 (none whatsoever) to 10 (worst imaginable).
Results: Patients had a median age of 39.3 years (range, 25.3–66.5 years) and stage IB1 (n = 9), IB2 (n = 3), IIA (n = 1) or IIB (n = 5) cervical cancer. Discomfort of antenna placement and removal was low with a median score of 1 (range 0–5) and 0 (range 0–2), respectively. The endorectal antenna increased the SNR at the cervix by a mean factor of 1.8 and by 2.9 in a 30-mm radius from the antenna. No adverse events occurred related to the antenna. Although some artefacts remained, 7.0T MRI was found qualitatively superior to the clinical 1.5T MRI. In Fig. 1, the corresponding oblique (perpendicular to the cervical canal) T2-weighted slices of an exemplary stage IIB2 patient are shown.
Conclusions: We demonstrated the feasibility and qualitative increase of cervical cancer imaging with 7.0T MRI. The use of an endorectal antenna is well tolerated and enables optimal signal capture with a substantial increase in SNR.
Methods: We conducted a prospective feasibility study on 18 stage IB1 to IIB histology-proven cervical cancer patients who had a routine 1.5T MRI in their workup. All underwent an additional 7.0T MRI, which included transversal, sagittal, and oblique T2-weighted turbo spin echo sequences. Seven external transmit and receive dipole antennas were positioned around the pelvis, and combined with a single in-house built endorectal monopole antenna. Its signal receive optimum was placed 6 to 10 cm beyond the anodermal transition. Patients scored the level of discomfort related to the antenna from 0 (none whatsoever) to 10 (worst imaginable).
Results: Patients had a median age of 39.3 years (range, 25.3–66.5 years) and stage IB1 (n = 9), IB2 (n = 3), IIA (n = 1) or IIB (n = 5) cervical cancer. Discomfort of antenna placement and removal was low with a median score of 1 (range 0–5) and 0 (range 0–2), respectively. The endorectal antenna increased the SNR at the cervix by a mean factor of 1.8 and by 2.9 in a 30-mm radius from the antenna. No adverse events occurred related to the antenna. Although some artefacts remained, 7.0T MRI was found qualitatively superior to the clinical 1.5T MRI. In Fig. 1, the corresponding oblique (perpendicular to the cervical canal) T2-weighted slices of an exemplary stage IIB2 patient are shown.
Conclusions: We demonstrated the feasibility and qualitative increase of cervical cancer imaging with 7.0T MRI. The use of an endorectal antenna is well tolerated and enables optimal signal capture with a substantial increase in SNR.
| Original language | English |
|---|---|
| Article number | 205 |
| Journal | Gynecologic Oncology |
| Volume | 141 |
| DOIs | |
| Publication status | Published - 2016 |