BLADE Sequences Research Articles

Technical Application Of Denoising Kalman Filter For Artifact Reduction In Mri Anatomic Image Information

Fatsups and BLADE sequences are used to reduce artifacts and clarify anatomical images. Basedon theoretical studies, the STIR, BLADE sequences, the addition or subtraction of parameters, and theaddition of artificial intelligence used still have a weakness, namely increasing the scanning time to belonger. Another technique that can be used and sequences and parameters on MRI is the denoisingKalman filter technique in the Matlab (Matrix Laboratory) program. The denoising technique is appliedafter the scanning process. Denoising will not increase the MRI scanning time. This systematic reviewaims to know the technical application of denoising Kalman filter for reduction artifacts on MRIexamination. The search was done using google scholar, WILEY, IEE Explore, SPRINGER,PERPUSNAS, and Scopus in English with 2004-2020 articles period. The keywords are MRI artifact,reducing artifacts, and the Kalman filter algorithm. A review of 4 articles of filter Kalman intervention onMRI Brain, MRI Abdomen, and MR Cardiac shows that the Kalman filter is good enough to reduceartifacts and improve anatomical information. The Kallman filter could reduce flow artifacts, improveimage quality and clarify anatomical images on MRI.

Diagnostic Confidence and Feasibility of a Deep Learning Accelerated HASTE Sequence of the Abdomen in a Single Breath-Hold.

The aim of this study was to evaluate the feasibility of a single breath-hold fast half-Fourier single-shot turbo spin echo (HASTE) sequence using a deep learning reconstruction (HASTEDL) for T2-weighted magnetic resonance imaging of the abdomen as compared with 2 standard T2-weighted imaging sequences (HASTE and BLADE). Sixty-six patients who underwent 1.5-T liver magnetic resonance imaging were included in this monocentric, retrospective study. The following T2-weighted sequences in axial orientation and using spectral fat suppression were compared: a conventional respiratory-triggered BLADE sequence (time of acquisition [TA] = 4:00 minutes), a conventional multiple breath-hold HASTE sequence (HASTES) (TA = 1:30 minutes), as well as a single breath-hold HASTE with deep learning reconstruction (HASTEDL) (TA = 0:16 minutes). Two radiologists assessed the 3 sequences regarding overall image quality, noise, sharpness, diagnostic confidence, and lesion detectability as well as lesion characterization using a Likert scale ranging from 1 to 4 with 4 being the best. Comparative analyses were conducted to assess the differences between the 3 sequences. HASTEDL was successfully acquired in all patients. Overall image quality for HASTEDL was rated as good (median, 3; interquartile range, 3-4) and was significantly superior to HASTEs (P < 0.001) and inferior to BLADE (P = 0.001). Noise, sharpness, and artifacts for HASTEDL reached similar levels to BLADE (P ≤ 0.176) and were significantly superior to HASTEs (P < 0.001). Diagnostic confidence for HASTEDL was rated excellent by both readers and significantly superior to HASTEs (P < 0.001) and inferior to BLADE (P = 0.044). Lesion detectability and lesion characterization for HASTEDL reached similar levels to those of BLADE (P ≤ 0.523) and were significantly superior to HASTEs (P < 0.001). Concerning the number of detected lesions and the measured diameter of the largest lesion, no significant differences were found comparing BLADE, HASTES, and HASTEDL (P ≤ 0.912). The single breath-hold HASTEDL is feasible and yields comparable image quality and diagnostic confidence to standard T2-weighted TSE BLADE and may therefore allow for a remarkable time saving in abdominal imaging.

A blade tip-timing method without once-per-revolution sensor for blade vibration measurement in gas turbine engines

The blade vibration measurement is crucial for gas turbine engines to ensure safe operations. One of the techniques is blade tip-timing (BTT), which is under the assumption that rotor speed is constant and depends on a once-per-revolution (OPR) timing reference to calculate the blade tip displacement and to identify the blade sequence. However, this assumption is incorrect for transient conditions, and the installation of an OPR sensor sometimes is not allowable and reliable. These reasons greatly limit the application of the BTT technique. This paper proposes a self-correcting (SC)-BTT method to realize the blade vibration measurement under different operating conditions without the use of an OPR sensor. The proposed method is based on polynomial fitting, and a reference probe is used to correct high-order fitting coefficients. Numerical results show that the SC-BTT method can greatly reduce the fitting error caused by blade pitch and vibrational parameters. Experimental results demonstrate that the proposed method is capable of removing the limitation of the lack of an OPR sensor and overcoming the drawbacks of the OPR system, such as the failure of the OPR sensor or low-speed resolution. For three investigated cases, the relative errors of derived rotor speed are below 0.12%. The relative error of blade peak-to-peak amplitude (PPA) and initial phase angle are around 3% at the resonance region with engine order (EO) 2.

Magnetic Resonance Imaging of Osteochondral Lesions of the Talus: Comparison Between Small FOV Surface Coil with BLADE and Boot-Shape Coil Without BLADE

Background: It is common for osteochondral lesions of the talus (OLT) to be associated with ankle injury, residual ankle stiffness and pain after osteochondral injuries, and OLTs are most common in the dome of the talus. Before choosing the appropriate therapy based on diagnosis, it is necessary to determine if the OLT is a stabile lesion or not. More accurate diagnosis and classifications could be conducted to guide the clinical treatment. Objectives: To compare the accuracy rate and diagnostic indices of proton-density fat-saturation BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction in magnetic resonance systems from Siemens Healthcare) sequences from a small field of view (FOV) surface coil and proton-density fat-saturation sequences without BLADE in a routine FOV using a boot-shaped coil on the magnetic resonance imaging (MRI) of OLT. Patients and Methods: One hundred and one patients with ankle pain for greater than 6 weeks and normal X-ray participated in this study. They were ready for diagnosis by arthroscopy and treatment following MR examination. All patients were scanned by two different methods: (a) a coronal proton-density fat-saturated sequence with BLADE using a small FOV surface coil and (b) a coronal proton-density fat-saturated sequence without BLADE using a routine FOV boot coil. In this study, the arthroscopic results were regarded as the gold standard for assessing OLTs and were used to directly compare the ability of the two different scanning methods to produce accurate findings with regard to MR imaging of OLTs. Results: Of the 101 patients, 57 patients with cartilaginous injury were confirmed by the results of arthroscopy, and 44 patients were without cartilaginous injury. Forty-eight lesions had the same grade with the small FOV BLADE sequence MRI and arthroscopy, while 37 lesions had the same grade on routine FOV MRI and arthroscopy among 57 patients with cartilaginous injury. Among MR findings of 101 patients, the results of weighted Kappa, accuracy, sensitivity and specificity were 0.803, 90.10%, 84.21%, and 97.73%, respectively between small FOV and arthroscopy; 0.515, 75.25%, 64.91%, and 88.64%, respectively between routine FOV and arthroscopy. The accuracy rate, sensitivity and specificity of small FOV with BLADE were higher than routine FOV. Mc Nemar’s test confirmed that the accuracy, sensitivity and specificity of small FOV BLADE were significantly better than routine FOV (P < 0.001). Greater values of small FOV compared to routine FOV appeared in sensitivity of 0.94 vs. 0.81 (MR normal and grade I), 0.89 vs. 0.77 (MR normal and grade I - IIA), 0.90 vs. 0.74 (MR normal and grade I-IIB), 0.91 vs. 0.75 (MR normal and grade I - III) and specificity of 0.98 vs. 0.92 (MR normal and grade I), the same in specificity of 0.91 vs. 0.91 (MR normal and grade I - IIA), 0.80 vs. 0.80 (MR normal and grade I - III), only smaller in specificity of 0.60 vs. 0.80 (MR normal and grade I - IIB). Conclusion: Small FOV surface coil with BLADE sequence grading of OLT demonstrated a promising accuracy rate compared with arthroscopic diagnosis.

The values of pre-operative T staging of potentially resectable esophageal cancer: Blade combining with breath-free radial VIBE

Objective To analyze the value of conventional T2WI combining with breath-hold Cartesian VIBE sequence, and compared with Blade combining with breath-free radial VIBE sequences in pre-operative T staging of potentiallly resectable esophageal carcinoma. Methods Sixty-five cases of esophageal carcinoma were concluded prospectively. All patients had received pathological examination of gastroscope biopsy before MRI. Patients received MR examination, including T2WI, breath-hold VIBE, Blade, and breath-free radial VIBE sequences. Two radiologists with more than five years experiences in the diagnosis of chest, performed T staging in MRIby referring to the the 7th edition of UICC-AJCC TNM classification. The results of MRI T staging and the postoperative pathological T staging were analyzed by χ2 test. Results Sixty-five patients were included. Diagnostic coincidence rates of the preoperative T staging by using conventional T2WI combining with breath-hold Cartesian VIBE sequences and Blade combining with breath-free radial VIBE sequences were 51%(33/65) and 88%(57/65) ,with 32 and 8 cases overstaging or understaging respectively, and the statistical differences were significant(χ2=20.80, P<0.05). The former diagnostic accuracy of esophageal carcinoma in situ, muscularis violation and esophageal fiber membrane were 42%(8/19), 54%(14/26), 55%(11/20), and the latter were 89% (17/19), 88% (23/26), and 85% (17/20). Conclusions Diagnostic coincidence rate of the preoperative T staging by using Blade combining with breath-free radial VIBE sequences is much higher than conventional T2WI combining with breath-hold Cartesian VIBE sequences. Blade combining with breath-free radial VIBE sequences could be used as non-invasive imaging method in preoperative T staging of potentially resectable esophageal carcinoma. Key words: Esophageal neoplasms; Magnetic resonance imaging; Comparative study

Comparison of Cartesian and radial acquisition on short-tau inversion recovery (STIR) sequences in breast MRI.

ObjectiveThe purpose of this study was to compare two short-tau inversion recovery (STIR) sequences, Cartesian and radial (BLADE) acquisitions, for breast magnetic resonance imaging (MRI) examinations.Materials and MethodsNinety-six women underwent 1.5 T breast MRI exam (48 Cartesian and 48 BLADE). Qualitative analysis including image artifacts, image quality, fat-suppression, chest-wall depiction, lesion detection, lymph node depiction and overall impression were evaluated by three blinded readers. Signal to noise ratios (SNRs) were calculated. Cronbach's alpha test was used to assess inter-observer agreement. Subanalyses of image quality, chest-wall depiction and overall impression in 15 patients with implants and image quality in 31 patients with clips were correlated using Pearson test. Wilcoxon rank sum test and t-test were performed.ResultsMotion artifacts were present in 100% and in 0% of the Cartesian and the BLADE exams, respectively. Chemical-shift artifacts were present in 8% of the Cartesian exams. Flow artifacts were more frequent on BLADE. BLADE sequence was statistically superior to Cartesian for all qualitative features (p < 0.05) except for fat-suppression (p = 0.054). In the subanalysis, BLADE was superior for implants and clips (p < 0.05). SNR was statistically greater for BLADE (48.35 vs. 16.17). Cronbach ranged from 0.502 to 0.813.ConclusionBLADE appears to be superior to Cartesian acquisition of STIR imaging as measured by improved image quality, fewer artifacts, and improved chest wall and lymph node depiction.

Brain imaging: Comparison of T1W FLAIR BLADE with conventional T1W SE

IntroductionAlthough T1 weighted spin echo (T1W SE) images are widely used to study anatomical details and pathologic abnormalities of the brain, its role in delineation of lesions and reduction of artifacts has not been thoroughly investigated. BLADE is a fairly new technique that has been reported to reduce motion artifacts and improve image quality. ObjectiveThe primary objective of this study is to compare the quality of T1-weighted fluid attenuated inversion recovery (FLAIR) images with BLADE technique (T1W FLAIR BLADE) and the quality of T1W SE images in the MR imaging of the brain. The goal is to highlight the advantages of the two sequences as well as which one can better reduce flow and motion artifacts so that the imaging of the lesions will not be impaired. Materials and methodsBrain examinations with T1W FLAIR BLADE and T1W SE sequences were performed on 48 patients using a 1.5T scanner. These techniques were evaluated by two radiologists based on: a) a qualitative analysis i.e. overall image quality, presence of artifacts, CSF nulling; and b) a quantitative analysis of signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR) and Relative Contrast. The statistical analysis was performed using the Kruskal-Wallis non-parametric system. ResultsIn the qualitative analysis, BLADE sequences had a higher scoring than the conventional sequences in all the cases. The overall image quality was better on T1W FLAIR BLADE. Motion and flow-related artifacts were lower in T1W FLAIR BLADE. Regarding the SNR measurements, T1W SE appeared to have higher values in the majority of cases, whilst T1W-FLAIR BLADE had higher values in the CNR and Relative Contrast measurements. ConclusionT1W FLAIR BLADE sequence appears to be superior to T1W SE in overall image quality and reduction of motion and flow-pulsation artifacts as well as in nulling CSF and has been preferred by the clinicians. T1W FLAIR BLADE may be an alternative approach in brain MRI imaging.

Comparison of Quantitative Assessment of BLADE and Isotropic Three-Dimensional Fast Spin Echo Cube (3D T2 SPACE) Sequences with Conventional Protocols of wrist Joint at 3 Tesla Magnetic Resonance Imaging

Background: Magnetic resonance imaging (MRI) of the wrist joint is a useful method in the diagnosis of triangular fibrocartilage complex (TFCC), ligaments and tendons, peripheral nerves, cartilage and carpal tunnel syndrome. However, the evaluation of these small anatomical structures is a topic of investigation. In some instances, the diagnostic indices of MRI in tears and other lesions of cartilage and ligamentous structures are relatively low, so the protocols should be optimized. Objectives: In this study, we aim to compare new MRI protocols of 3D T2SPACE, PD BLADE and T2 BLADE with the conventional protocols, including T2 FSE, PD FSE, and T1 FSE in case of signal intensity. Patients and Methods: Twenty patients with a history of wrist trauma or suspected wrist lesions were referred by orthopedic hand surgeons and enrolled into the study. All the protocols were carried out on all patients and the images were assessed quantitatively by measurement of signal to noise ratio (SNR) and contrast to noise ratio (CNR). Then, these parameters were compared between different protocols. SPSS ver.18 was used for the statistical analyses. Results: SNR of the cartilage, TFCC on 3D T2SPACE and T1 FSE was better than other sequences (P < 0.001). SNR of the bone on PD BLADE was significantly higher (P < 0.001) than that of conventional protocols. PD BLADE images showed significantly higher bone- cartilage CNR and bone- TFCC CNR (P < 0.001 to P < 0.001). CNR of cartilage-TFCC on T1 FSE was better than other sequences, but no significant statistical differences were seen. Conclusion: High-resolution MR images of the wrist using 3D T2SPACE, PD BLADE and T2 BLADE were superior to those using conventional sequences quantitatively. High-SNR and CNR MR imaging with SPACE and BLADE would be a promising method to diagnose wrist lesions.

Diffusion weighted imaging in cystic fibrosis disease: beyond morphological imaging.

To explore the feasibility of diffusion-weighted imaging (DWI) to assess inflammatory lung changes in patients with Cystic Fibrosis (CF) METHODS: CF patients referred for their annual check-up had spirometry, chest-CT and MRI on the same day. MRI was performed in a 1.5T scanner with BLADE and EPI-DWI sequences (b = 0-600s/mm2). End-inspiratory and end-expiratory scans were acquired in multi-row scanners. DWI was scored with an established semi-quantitative scoring system. DWI score was correlated to CT sub-scores for bronchiectasis (CF-CTBE), mucus (CF-CTmucus), total score (CF-CTtotal-score), FEV1, and BMI. T-test was used to assess differences between patients with and without DWI-hotspots. Thirty-three CF patients were enrolled (mean 21years, range 6-51, 19 female). 4% (SD 2.6, range 1.5-12.9) of total CF-CT alterations presented DWI-hotspots. DWI-hotspots coincided with mucus plugging (60%), consolidation (30%) and bronchiectasis (10%). DWItotal-score correlated (all p < 0.0001) positively to CF-CTBE (r = 0.757), CF-CTmucus (r = 0.759) and CF-CTtotal-score (r = 0.79); and negatively to FEV1 (r = 0.688). FEV1 was significantly higher (p < 0.0001) in patients without DWI-hotspots. DWI-hotspots strongly correlated with radiological and clinical parameters of lung disease severity. Future validation studies are needed to establish the exact nature of DWI-hotspots in CF patients. • DWI hotspots only partly overlapped structural abnormalities on morphological imaging • DWI strongly correlated with radiological and clinical indicators of CF-disease severity • Patients with more DWI hotspots had lower lung function values • Mucus score best predicted the presence of DWI-hotspots with restricted diffusion.

Elimination of motion and pulsation artifacts using BLADE sequences in shoulder MR imaging.

To evaluate the ability of proton-density with fat-suppression BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction in MR systems from Siemens Healthcare, PDFS BLADE) and turbo inversion recovery magnitude-BLADE (TIRM BLADE) sequences to reduce motion and pulsation artifacts in shoulder magnetic resonance examinations. Forty-one consecutive patients who had been routinely scanned for shoulder examination participated in the study. The following pairs of sequences with and without BLADE were compared: (a) Oblique coronal proton-density sequence with fat saturation of 25 patients and (b) oblique sagittal T2 TIRM-weighed sequence of 20 patients. Qualitative analysis was performed by two experienced radiologists. Image motion and pulsation artifacts were also evaluated. In oblique coronal PDFS BLADE sequences, motion artifacts have been significantly eliminated, even in five cases of non-diagnostic value with conventional imaging. Similarly, in oblique sagittal T2 TIRM BLADE sequences, image quality has been improved, even in six cases of non-diagnostic value with conventional imaging. Furthermore, flow artifacts have been improved in more than 80% of all the cases. The use of BLADE sequences is recommended in shoulder imaging, especially in uncooperative patients because it effectively eliminates motion and pulsation artifacts.

SU-E-I-67: Arachnoid Cysts: The Role of the BLADE Technique

Purpose: The purpose of this study is first to show the extent by which BLADE sequences can reduce all the image artifacts and second to verify that the usefulness of this technique in certain pathological conditions is significant. Methods: In this study, fourteen consecutive patients (5 females, 9 males), who routinely underwent MRI brain examination, between 2010–2014, were selected. The applied routine protocols for brain MR examination included the following sequences: 1) T2-W FLAIR axial; 2) T2-W TSE axial; 3) T2*-W axial, 4) T1-W TSE sagittal; 5) DWI-W axial; 6) T1-W TSE axial; 7) T1-W TSE axial+contrast. In cases of cystic tumors, the T2-W FLAIR BLADE sequence was added to the protocol. All the images were evaluated independently at two separate settings with 3 weeks interval by two radiologists. The radiologists also evaluated the presence of image artifacts (motion, flow, chemical shift, Gibbs ringing). To evaluate the size of the cyst, the two radiologists compared the two techniques (conventional and BLADE) by assessing the extent of the divergence in the measurements of the cysts. Results: Regarding the extent of the cyst size, BLADE measurements were found to be more reliable than the conventional ones with the differences being statistically significantmore » (p<0.01). The qualitative measurements indicated that the T2 FLAIR BLADE sequences were superior to the conventional T2 FLAIR with statistically significant differences (p<0.001) in the following characteristics: 1) overall image quality, 2) CSF nulling; 3) contrast at the pathology and its surrounding; 4) limits of the pathology; 5) motion artifacts; 6) flow artifacts; 7) chemical shift artifacts and 8) Gibbs ringing artifacts. Conclusion: BLADE sequence was found to decrease both flow artifacts in the temporal lobes and motion artifacts from the orbits and it is proposed for clinical use.« less

Reduction of motion, truncation and flow artifacts using BLADE sequences in cervical spine MR imaging

PurposeTo assess the efficacy of the BLADE technique (MR imaging with ‘rotating blade-like k-space covering’) to significantly reduce motion, truncation, flow and other artifacts in cervical spine compared to the conventional technique. Materials and methodsIn eighty consecutive subjects, who had been routinely scanned for cervical spine examination, the following pairs of sequences were compared: a) T2 TSE SAG vs. T2 TSE SAG BLADE and b) T2 TIRM SAG vs. T2 TIRM SAG BLADE. A quantitative analysis was performed using the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measures. A qualitative analysis was also performed by two radiologists, who graded seven image characteristics on a 5-point scale (0: non-visualization; 1: poor; 2: average; 3: good; 4: excellent). The observers also evaluated the presence of image artifacts (motion, truncation, flow, indentation). ResultsIn quantitative analysis, the CNR values of the CSF/SC between TIRM SAG and TIRM SAG BLADE were found to present statistically significant differences (p<0.001). Regarding motion and truncation artifacts, the T2 TSE BLADE SAG was superior compared to the T2 TSE SAG, and the T2 TIRM BLADE SAG was superior compared to the T2 TIRM SAG. Regarding flow artifacts, T2 TIRM BLADE SAG eliminated more artifacts than T2 TIRM SAG. ConclusionsIn cervical spine MRI, BLADE sequences appear to significantly reduce motion, truncation and flow artifacts and improve image quality. BLADE sequences are proposed to be used for uncooperative subjects. Nevertheless, more research needs to be done by testing additional specific pathologies.

BLADE sequences in transverse T2-weighted MR imaging of the cervical spine. Cut-off for Artefacts?

The BLADE (PROPELLER) technique reduces artefacts in imaging of the cervical spine in sagittal orientation, but till now failed to do so in axial orientation, because here it increased through plane CSF-flow artefacts, which spoiled the benefit of BLADE artefact reduction "in plane". The aim of this study was to compare a BLADE sequence with optimised measurement parameters in axial orientation to T2-TSE. Both sequences were compared in 58 patients with 31 discal, 16 bony and 11 spinal cord lesions. Image sharpness, reliability of spinal cord depiction, CSF flow artefacts and lesion detection were evaluated by 3 independent observers. Additionally the observers were asked which sequence they would prefer for diagnostic workup. Statistical evaluations were performed using sign and χ2 test. BLADE was significantly superior concerning image sharpness, spinal cord depiction and overall lesion detection. BLADE was rated better for most pathologies, for bony lesions the differences compared with TSE were statistically significant. Regarding CSF-flow artefacts both sequences showed no difference. All readers preferred BLADE in side by side reading. An optimised axial T2 BLADE sequence decreases the problems of increased through plane CSF-flow artefacts in this orientation. By reducing various other artefacts it yields better image quality and has the potential to reduce the number of non-diagnostic examinations especially in uncooperative patients.

SU‐E‐I‐51: Use of Blade Sequences in Cervical Spine MR Imaging for Eliminating Motion, Truncation and Flow Artifacts

Purpose:To assess the efficacy of the BLADE technique to eliminate motion, truncation, flow and other artifacts in Cervical Spine MRI compared to the conventional technique. To study the ability of the examined sequences to reduce the indetention and wrap artifacts, which have been reported in BLADE sagittal sequences.Methods:Forty consecutive subjects, who had been routinely scanned for cervical spine examination using four different image acquisition techniques, were analyzed. More specifically, the following pairs of sequences were compared: a) T2 TSE SAG vs. T2 TSE SAG BLADE and b) T2 TIRM SAG vs. T2 TIRM SAG BLADE. A quantitative analysis was performed using the signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR) and relative contrast (ReCon) measures. A qualitative analysis was also performed by two radiologists, who graded seven image characteristics on a 5‐point scale (0:non‐visualization; 1:poor; 2:average; 3:good; 4:excellent). The observers also evaluated the presence of image artifacts (motion, truncation, flow, indentation).Results:Based on the findings of the quantitative analysis, the ReCON values of the CSF (cerebrospinal fluid)/SC (spinal cord) between TIRM SAG and TIRM SAG BLADE were found to present statistical significant differences (p&lt;0.001). Regarding motion and truncation artifacts, the T2 TSE SAG BLADE was superior compared to the T2 TSE SAG and the T2 TIRM SAG BLADE was superior compared to the T2 TIRM SAG. Regarding flow artifacts, T2 TIRM SAG BLADE eliminated more artifacts compared to the T2 TIRM SAG.Conclusion:The use of BLADE sequences in cervical spine MR examinations appears to be capable of potentially eliminating motion, pulsatile flow and trancation artifacts. Furthermore, BLADE sequences are proposed to be used in the standard examination protocols based on the fact that a significantly improved image quality could be achieved.

Diffusion-weighted imaging of the sellar region: A comparison study of BLADE and single-shot echo planar imaging sequences

PurposeThe purpose of this study is to compare BLADE diffusion-weighted imaging (DWI) with single-shot echo planar imaging (EPI) DWI on the aspects of feasibility of imaging the sellar region and image quality. MethodsA total of 3 healthy volunteers and 52 patients with suspected lesions in the sellar region were included in this prospective intra-individual study. All exams were performed at 3.0T with a BLADE DWI sequence and a standard single-shot EP-DWI sequence. Phantom measurements were performed to measure the objective signal-to-noise ratio (SNR). Two radiologists rated the image quality according to the visualisation of the internal carotid arteries, optic chiasm, pituitary stalk, pituitary gland and lesion, and the overall image quality. One radiologist measured lesion sizes for detecting their relationship with the image score. ResultsThe SNR in BLADE DWI sequence showed no significant difference from the single-shot EPI sequence (P>0.05). All of the assessed regions received higher scores in BLADE DWI images than single-shot EP-DWI.

BLADE Sequences in Sagittal T2-Weighted MR Imaging of the Cervical Spine and Spinal Cord – Lesion Detection and Clinical Value

Using the BLADE (PROPELLER) technique for T2-weighted MR imaging of the cervical spine has proven to be a reliable tool for reducing artifacts typically for this region. The aim of this study was to evaluate whether the application of BLADE sequences has an impact on the detection of small or low contrast spinal cord and epidural lesions. A standard TSE and a BLADE sequence were compared in 33 patients with 46 spinal cord and epidural lesions for T2-weighted sagittal imaging of the cervical spine. Image sharpness, visualization of the dura, reliability of spinal cord depiction as well as lesion contrast were evaluated by two independent readers. Additionally two experienced neuroradiologists selected in consensus the sequence they would prefer for diagnostic purposes. Statistical evaluations were performed using the sign and the χ2 test. BLADE was significantly superior to TSE regarding image sharpness, visualization of the dura and reliability of spinal cord depiction. Regarding lesion contrast there was a positive trend towards the BLADE sequence. In 17 of 46 lesions, BLADE was judged superior to TSE, while TSE was favored in 10 lesions. In consensus reading both neuroradiologists preferred BLADE for overall image quality in 27 of 33 patients and for lesion contrast in 10 and TSE in 14 of the 33 patients, but 3 TSE sequences were rated as non-diagnostic regarding this criterion. For the detection of even small and low-contrast spinal cord lesions, BLADE is at least equivalent to TSE, yielding better overall image quality and fewer non-diagnostic images.

Comparison of BLADE and conventional T2-TSE sequences for the sagittal visualization of the cervical spinal cord in multiple sclerosis patients — A case report

The purpose of this study is to report the significant differences found in the identification of lesions in cervical spinal cord of two patients with multiple sclerosis when using the BLADE T2-TSE and BLADE T2-TIRM sequences as opposed to the conventional T2-TSE and T2-TIRM sequences for sagittal acquisition at 1.5T. In both patients, one more lesion was identified with the BLADE sequences than with the conventional ones. Consequently, we suggest the use of BLADE T2-TSE and BLADE T2-TIRM sequences in place of conventional ones for sagittal examination of the cervical spinal cord of multiple sclerosis patients. The advantages of ΤΙRΜ to reveal the pathology of the cervical spinal cord and the advantage of BLADE sequences to improve image quality should be combined in a sequence that could be ideal for cervical spinal cord examinations.

Comparison of PD BLADE with fat saturation (FS), PD FS and T2 3D DESS with water excitation (WE) in detecting articular knee cartilage defects

The purpose of this study, is to compare the sequences: 1) proton density (PD) BLADE (BLADE is a PROPELLER-equivalent implementation of the Siemens Medical System) with fat saturation (FS) coronal (COR), 2) PD FS COR, 3) multi-planar reconstruction (MPR) with 3mm slice thickness and 4) multi-planar reconstruction (MPR) with 1.5mm slice thickness, both from the T2 3D-double-echo steady state (DESS) with water excitation (WE) sagittal (SAG), regarding their abilities to identify changes in the femorotibial condyle cartilage in knee MRI examinations. Thirty three consecutive patients with osteoarthritis (18 females, 15 males; mean age 56years, range 37–71years), who had been routinely scanned for knee examination using the previously mentioned image acquisition techniques, participated in the study. A quantitative analysis was performed based on the relative contrast (ReCON) measurements, which were taken both on normal tissues as well as on pathologies. Additionally, a qualitative analysis was performed by two radiologists. Motion and pulsatile flow artifacts were evaluated. The PD BLADE FS COR sequence produced images of higher contrast between Menisci and Cartilage, Fluid and Cartilage, Pathologies and Cartilage as well as of the Conspicuousness Superficial Cartilage and it was found to be superior to the other sequences (p<0.001). The sequences T2 3D DESS 1.5mm and T2 3D DESS 3mm were significantly superior to the PD BLADE FS COR and the PD FS COR sequences in the visualization of Bone and Cartilage and the Conspicuousness Deep Surface Cartilage. This pattern of results is also confirmed by the quantitative analysis. PD FS BLADE sequences are ideal for the depiction of the cartilage pathologies compared to the conventional PD FS and T2 3D DESS sequences.

SU‐E‐I‐70: Use of Blade Sequences to Eliminate Motion and Pulsation Artifacts in Knee MR Imaging

Purpose: The purpose of this study is to evaluate the ability of Proton Density (PD)‐BLADE sequences in reducing or even eliminating motion and pulsatile flow artifacts in knee MRI examinations. Methods: Eighty consecutive patients, who had been routinely scanned for knee examination, participated in the study. The following pairs of sequences with and without BLADE were compared: a) PD Turbo Spin Echo (TSE) Sagittal (SAG) Fat Saturation (FS) in thirty five patients, b) PD TSE Coronal (COR) FS in nineteen patients, c) T2 TSE AXIAL in thirteen patients and d) PD TSE SAG in thirteen patients. Both qualitative and quantitative analyses were performed based on the signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR), and relative contrast (ReCon) measures of normal anatomic structures. The qualitative analysis was performed by experienced radiologists. Also, the presence of image motion and pulsation artifacts was evaluated. Results: Based on the results of the SNR, CRN and ReCon for the different sequences and anatomical structures, the BLADE sequences were significantly superior in nineteen cases, whereas the corresponding conventional sequences were significantly superior in six only cases. The BLADE sequences eliminated motion artifacts in all the cases. However, motion artifacts were shown in: a) six PD TSE SAG FS, b) three PD TSE COR FS, c) three PD TSE SAG, and d) two T2 TSE AXIAL conventional sequences. In our results, it was found that in PD FS sequences (Sagittal and Coronal) the differences between the BLADE and conventional sequences regarding the elimination of motion and pulsatile flow artifacts were statistically significant. In all the comparisons, the PD FS BLADE sequences (coronal and sagittal) were significantly superior to the corresponding conventional sequences regarding the classification of their image quality. Conclusion: This technique appears to be capable to potentially eliminate motion and pulsatile flow artifacts in knee MR images.

SU‐E‐I‐69: Improving Image Quality in Brain MRI Using Blade Sequences

Purpose: The purpose of this study is to compare two types of sequences for brain MR examination of uncooperative and cooperative patients. For each group of patients, the pairs of sequences that were compared were two T2‐weighted (T2‐W) fluid attenuated inversion recovery (FLAIR) sequences with different k‐space trajectories (conventional Cartesian and BLADE) and two T2‐TSE weighted (T2‐W) with different k‐space trajectories (conventional Cartesian and BLADE). Methods: Twenty three consecutive unccoperative patients and forty four cooperative patients, who routinely underwent brain MRI examination, participated in the study. Both qualitative and quantitative analyses were performed based on the signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR), and relative contrast (ReCon) measures of normal anatomic structures. The qualitative analysis was performed by experienced radiologists. Also, the presence of motion artifacts, other artifacts (e.g. Gibbs, susceptibility artifacts, phase encoding from vessels) and pulsatile flow artifacts was evaluated. Results: In the uncooperative group of patients, BLADE sequences were superior to the corresponding conventional sequences in all the cases. Furthermore, the differences were found to be statistically significant in almost all the cases. In the cooperative group of patients, BLADE sequences were superior to the conventional sequences with the differences of the CNR and ReCon values in nine cases being statistically significant. Furthermore, the BLADE sequences eliminated motion and other artifacts and T2 Flair BLADE sequences eliminated pulsatile flow artifacts. Conclusion: BLADE sequences (T2 TSE and T2 Flair) should be used in brain MR examinations of uncooperative patients. In cooperative patients, T2 TSE BLADE sequences may be used as part of the routine protocol and orbital examinations. T2 Flair BLADE sequences may be used optionally in examinations of AVM, orbits, hemorrhages, ventricular lesions, lesions in the frontal lobe, periventricular lesions, lesions in regions close to artifacts and lesions in posterior fossa.