IASO Thessalias Hospital

Lárisa, Greece

IASO Thessalias Hospital

Lárisa, Greece
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Mavroidis P.,University of Texas Health Science Center at San Antonio | Mavroidis P.,Karolinska Institutet | Lavdas E.,Techological Education Institute of Athens | Kostopoulos S.,Techological Education Institute of Athens | And 9 more authors.
Medical Physics | Year: 2013

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. © 2013, American Association of Physicists in Medicine. All rights reserved.


Lavdas E.,Techological Education Institute of Athens | Lavdas E.,Karolinska Institutet | Mavroidis P.,University of Texas Health Science Center at San Antonio | Mavroidis P.,Karolinska Institutet | And 5 more authors.
Medical Physics | Year: 2013

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. © 2013, American Association of Physicists in Medicine. All rights reserved.


Mavroidis P.,University of North Carolina at Chapel Hill | Mavroidis P.,Karolinska Institutet | Kostopoulos S.,Technological Educational Institute of Athens | Batsikas G.,IASO Thessalias Hospital | And 2 more authors.
Hippokratia | Year: 2016

Background: This study aims at demonstrating the ability of BLADE sequences to reduce or even eliminate all the image artifacts as well as verifying the significance of using this technique in certain pathological conditions. Material and Methods: This study involved fourteen consecutive patients (5 females, 9 males), who routinely underwent magnetic resonance imaging (MRI) brain examination, between 2010-2014. The applied routine protocol for brain MRI examination included the following sequences: i) T2-weighted (W) fluid-attenuated inversion recovery (FLAIR) axial; ii) T2-W turbo spin echo (TSE) axial; iii) T2*-W axial, iv) T1-W TSE sagittal; v) Diffusion-weighted (DWI) axial; vi) T1-W TSE axial; vii) T1-W TSE axial+contrast. Additionally, the T2-W FLAIR BLADE sequence was added to the protocol in cases of cystic tumors. Two radiologists independently evaluated all the images at two separate settings, which were performed 3 weeks apart. The presence of image artifacts such as motion, flow, chemical shift and Gibbs ringing artifacts, were also evaluated by the radiologists. In the measurements of the cysts, the extent of the divergence by the two MRI techniques (conventional and BLADE) was used by the two radiologists to evaluate the accuracy of the two techniques to determine the size of the cysts. Results: BLADE sequences were found to be more reliable than the conventional ones regarding the estimation of the cyst size. The qualitative analysis showed that the T2 FLAIR BLADE sequences were superior to the conventional T2 FLAIR with statistical significance (p <0.001) in the following fields: i) overall image quality, ii) cerebrospinal fluid (CSF) nulling; iii) contrast between pathology and its surrounding; iv) borders of the pathology; v) motion artifacts; vi) flow artifacts; vii) chemical shift artifacts and viii) Gibbs ringing artifacts. Conclusions: BLADE sequence was found to decrease both flow artifacts in the temporal lobes and motion artifacts from the orbits. Additionally, it was shown to improve flow artifacts and image quality in cystic pathologies such as arachnoid cysts. © 2016, Lithografia Antoniadis I - Psarras Th G.P. All rights reserved.


Lavdas E.,Institute of Technologists | Mavroidis P.,Karolinska Institutet | Hatzigeorgiou V.,IASO Thessalias Hospital | Arikidis N.,Sotiria General Hospital | And 3 more authors.
Magnetic Resonance Imaging | Year: 2012

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 magnetic resonance imaging examinations. 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 35 patients, (b) PD TSE coronal (COR) FS in 19 patients, (c) T2 TSE axial in 13 patients and (d) PD TSE SAG in 13 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. Based on the results of the SNR, CRN and ReCon for the different sequences and anatomical structures, the BLADE sequences were significantly superior in 19 cases, whereas the corresponding conventional sequences were significantly superior in only 6 cases. 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. In conclusion, this technique appears to be capable to potentially eliminate motion and pulsatile flow artifacts in MR images. © 2012 Elsevier Inc.


Lavdas E.,Institute of Technologists | Mavroidis P.,University of Texas Health Science Center at San Antonio | Mavroidis P.,Karolinska Institutet | Kostopoulos S.,Techological Education Institute of Athens | And 8 more authors.
Magnetic Resonance Imaging | Year: 2013

The purpose of this study is to compare two types of sequences in brain magnetic resonance (MR) examinations 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 sequences with different k-space trajectories (conventional Cartesian and BLADE) and two T2-TSE weighted with different k-space trajectories (conventional Cartesian and BLADE). Twenty-three consecutive uncooperative patients and 44 cooperative patients, who routinely underwent brain MR imaging examination, participated in the study. Both qualitative and quantitative analyses were performed based on the signal-to-noise ratio, 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, other (e.g., Gibbs, susceptibility artifacts, phase encoding from vessels) artifacts and pulsatile flow artifacts was evaluated. 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, BLADE sequences eliminated motion and other artifacts and T2 FLAIR BLADE sequences eliminated pulsatile flow artifacts. 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, haemorrhages, ventricular lesions, lesions in the frontal lobe, periventricular lesions, lesions in regions close to artifacts and lesions in posterior fossa. © 2013 Elsevier Inc.


Lavdas E.,Institute of Technologists | Mavroidis P.,University of Texas Health Science Center at San Antonio | Mavroidis P.,Karolinska Institutet | Kostopoulos S.,Technological Educational Institute of Athens | And 9 more authors.
Magnetic Resonance Imaging | Year: 2013

The purpose of this study is to evaluate the ability of T2 turbo spin echo (TSE) axial and sagittal BLADE sequences in reducing or even eliminating motion, pulsatile flow and cross-talk artifacts in lumbar spine MRI examinations. Forty four patients, who had routinely undergone a lumbar spine examination, participated in the study. The following pairs of sequences with and without BLADE were compared: a) T2 TSE Sagittal (SAG) in thirty two cases, and b) T2 TSE Axial (AX) also in thirty two cases. Both quantitative and qualitative analyses were performed based on measurements in different normal anatomical structures and examination of seven characteristics, respectively. The qualitative analysis was performed by experienced radiologists. Also, the presence of image motion, pulsatile flow and cross-talk artifacts was evaluated. Based on the results of the qualitative analysis for the different sequences and anatomical structures, the BLADE sequences were found to be significantly superior to the conventional ones in all the cases. The BLADE sequences eliminated the motion artifacts in all the cases. In our results, it was found that in the examined sequences (sagittal and axial) the differences between the BLADE and conventional sequences regarding the elimination of motion, pulsatile flow and cross-talk artifacts were statistically significant. In all the comparisons, the T2 TSE BLADE sequences were significantly superior to the corresponding conventional sequences regarding the classification of their image quality. In conclusion, this technique appears to be capable of potentially eliminating motion, pulsatile flow and cross-talk artifacts in lumbar spine MR images and producing high quality images in collaborative and non-collaborative patients. © 2013 Elsevier Inc.


Lavdas E.,Institute of Technologists | Mavroidis P.,University of Texas Health Science Center at San Antonio | Mavroidis P.,Karolinska Institutet | Topaltzikis T.,IASO Thessalias Hospital | And 6 more authors.
Magnetic Resonance Imaging | Year: 2013

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 1.5. T. 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. © 2013 Elsevier Inc.


PubMed | University of Texas at San Antonio, Technological Education Institute of Athens, IASO Thessalias Hospital, Center for Research and Technology of Thessaly and 3 more.
Type: Journal Article | Journal: Medical physics | Year: 2016

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.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).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<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.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.


PubMed | Institute of Technologists, Karolinska Institutet, IASO Thessalias Hospital, Technological Educational Institute of Athens and 3 more.
Type: Journal Article | Journal: Magnetic resonance imaging | Year: 2015

To 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.In 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).In 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.In 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.


PubMed | Institute of Technologists, University Hospital of Larissa, General Hospital Of Athens G Genimatas, IASO Thessalias Hospital and 2 more.
Type: | Journal: Magnetic resonance imaging | Year: 2016

Although 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.The 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.Brain 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.In 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.T1W 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.

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