1.5t system

All MRI scans were conducted with patients in the prone position with a 1.5T system (Siemens, Erlangen, Germany) and a dedicated breast coil. Multiple contiguous axial and sagittal T1-weighted unenhanced and contrast-enhanced images (with and without fat suppression) and axial and sagittal images T2-weighted images were obtained. Reconstructed 3D maximum intensity and subtraction imaging were also performed. Residual tumors were defined based upon observed reductions in tumor enhancement and/or size when comparing MRI scans to those collected prior to NAC. Complete response (CR) was defined by total interval resolution of the previously detected lesion. MRI scans were evaluated by two radiologists based upon BI-RADS classification criteria, with any inconsistencies in their evaluations being resolved via discussion and consensus.

The lumbar spine was imaged using a 1.5 T System (Siemens, Germany) with a surface coil. Midsagittal T2-weighted MRIs were used for the evaluation of the discs. The signal intensity of the discs on the images was analysed by Vue PACS (Virtual Reading Profile, Carestream Health, Inc.). Multiplanar virtual reading (MPVR) was used to reconstruct three-dimensional (3D) colour MRI images.

Structural high-resolution 3D T1-weighted MR images of head were obtained on a 1.5 T system (Siemens Symphony, Erlangen, Germany) using magnetization-prepared rapid gradient echo (MPRAGE) sequence. Imaging parameters were as follows: 160 slices, 1 mm thick, with 1.0 × 1.0 mm in-plane resolution; pulse sequence parameters were as follows: TR = 1970 ms; TE = 4.38 ms; number of averages = 1; and scan time = 6.45 minutes. T2- and PD-weighted images were also obtained using dual-echo FSE sequence to assess hyperintense signal changes along corticospinal tract in ALS patients. Imaging parameters include the following: 40 contiguous slices; slice thickness = 4 mm; in-plane resolution = 0.9 × 0.9 mm; pulse sequence parameters were as follows: repetition time (TR) = 3900 ms; echo time (TE) = 26 ms and 104 ms; echo train length or turbo factor = 7; and number of averages = 1; total scan time = 3.5 minutes. Although this dataset was used in our previous VBM studies [9 (link)], we did not study brain parenchymal fraction and so applied it to this study.

The brain MRI was performed using a 1.5-T System (Siemens, Germany) with a head-sense-coil. Midsagittal T1-weighted MRIs were selected for the evaluation of brain sagging, which was defined as either cerebral aqueduct displacement ≥1.8 mm or cerebellar tonsil displacement ≥4.3 mm (Fig 1) [25 (link)]. The midportion of the dominant transverse sinus on sagittal T1-weighted MRIs was used for assessing the venous distension sign (VDS), as proposed by Farb et al. (Fig 2) [26 (link)]. Dural enhancement was evaluated on axial and coronal T1-weighted images with gadolinium enhancement (Fig 3).
CT myelography for detecting the sites of dural leakage was performed on a second-generation dual-source CT with tube voltages set at 100 kVp and 140 kVp (with tin filter). Leakage varied from a small amount of contrast tracking along a single nerve root to extensive bilateral collections of contrast within the paraspinal soft tissues (Fig 4) [7 (link)].
Two neuroradiologists (Q.Z. and D.W.) blinded to the study design reviewed all images to document the presence or absence of SDHs, and evaluated pachymeningeal enhancement, VDS, brain sagging, and the number of dural leaks. Inter-observer repeatability was calculated using the intra-class correlation coefficient, which ranged from 0.86 to 0.92 for the MRI evaluations and was 0.81 for the CT assessment, indicating good inter-observer reliability.

The T1-weighted MRI images of all subjects were acquired using a Siemens 1.5T system with the following scanning parameters: TR (Repetition Time)/TE (Echo Time) = 2000/3.1 ms, slice thickness = 1 mm, flip angle (FA) =8°, and field of view (FOV) =90.625. The ASL MRI images were obtained using the same scanner with the following parameters: TR/TE = 4600/15.9 ms, slice thickness = 3 mm, FA = 180°, and FOV = 100.

Conventional radiography was performed on the Luminos dRF MAX (Siemens, Erlangen, Germany). AP, lateral and Mortise view are the three standard images performed of the ankle. Additional axial image to visualize the hypertrophic tuberculum was performed. US images using EPIQ5G (Philips Health Systems, Bothell, WA 98021, USA) (Figure 3). Cone Beam CT (CBCT) imaging was performed on a Newtom 5G-system (QR, Verona, Italy), with a field of view of 8 × 8 cm, centered on the painful ankle region. MR examinations were performed on a 1.5T system (Siemens, Magnetom Aera, Erlangen, Germany). Our routine protocol consisted of sagittal, axial and coronal fat suppressed (FS) T2-Weighted Images (WI), coronal PD and axial T1-WI with a slice thickness of 3 mm. Only seven patients were examined by one imaging modality (MRI). The other patients had at least a combination of two imaging techniques of which the combination of MR and US was most frequent (6 patients or 26%).