Background: Comparison of three different sagittal sequences with fat suppression in the lumbar spine magnetic resonance imaging (MRI), evaluating several image characteristics and changing the phase direction. Materials and Methods: Forty-five subjects (20 males, 25 females, mean age 50 years old) participated in this retrospective study in an MRI machine of 1.5 Tesla (GE Signa Hdx). We compared three fat-saturated sequences {T2 Weighted (T2W) Fast Spin Echo (FSE) Fat Saturation (FS) with phase direction superior-inferior (S/I), T2W Short Tau Inversion Recovery (STIR) with phase direction superior-inferior (S/I) and T2W STIR with phase direction (A/P)}. A qualitative analysis was performed, while two experienced radiologists evaluated the images. The statistical analysis was determined by Kruskal-Wallis non-parametric test. Results: The T2W FSE FS was superior in almost all studied parameters {total image quality, presence of artifacts, artifacts in 4th lumbar vertebra (L4) - 1st Sacral vertebra (S1), depiction of lesions on vertebral bodies, depiction of lesions on L4-S1 region, sharpness} in comparison with T2W STIR sequences with statistically significant difference (p<0.001). The STIR sequences exceeded the T2W FSE FS in the fat saturation effectiveness with a statistically significant difference (p<0.001). Conclusion: The T2 Weighted (T2W) Fast Spin Echo (FSE) Fat Saturation (FS) was superior in the depiction of pathology and normal anatomy, eliminating many artifacts in comparison with T2 Short Tau Inversion Recovery (STIR) sequences, especially in the L4 vertebra- S1 vertebra anatomic region, between three under-study sequences. Choosing the appropriate sagittal fat-saturated sequence in each clinical question is useful to avoid misdiagnosis due to technical artifacts.

Background: The existence of air in hollow organs in the thoracic cavity constitutes a life-threatening situation most of the times. However, sometimes in thoracic Computed Tomography (CT) there are artifacts from different sources that could mimic air densities, disorientating the diagnosis. Materials and Methods: 100 patients (46 females and 54 males, mean age: 60 years, range: 20-90 years), who had been routinely scanned in the area of thorax using three different imaging protocols (follow up, aorta, pulmonary vessels) were retrospectively studied. In 67 cases, contrast agent was used during the examination. Every case was studied by two specialists. Results: Artifacts in pulmonary veins were observed in 38 of the cases. Of these artifacts 27 stemmed from contrast agent, calcifications in the vessels, metallic implants, movement of the patient, malfunction of a detector due to the size of field of view (FOV) or due to the existence of contrast agent on the examination table of the CT scanner. In 11 cases, small amounts of air had been inserted into blood circulation during contrast injection. Conclusions: This study characterized and classified many artifacts related to thorax CT in order to separate them from other serious thoracic pathologies (e.g. aortic dissection, ulcer of veins or arteries). The knowledge and identification of the different types of artifacts is very important in order to avoid the risk of misdiagnosis.

Objective. - To investigate the relationship between frequent episodic tension-type headache (FE-TTH) and 25-hydroxyvitamin-D (25(OH)D), folate, vitamin B12, and magnesium. Design-Methods. - A prospective case-control study involving adults with FETTH and age-sex matched healthy controls (HC) was performed. Individuals under the responsibility of the three provincial Health Centres of the prefecture of Trikala (Central Greece) were recruited during their regular check-up visits. The relationship between FETTH and serum levels of 25(OH)D, vitamin B12, folate, and magnesium was investigated (primary outcomes). Demographics, daily habits, somatometrics, psychometric and sleep quality measurements, laboratory indices, cardiovascular comorbidities and medications taken were also recorded and compared (secondary outcomes). Potential associations of the above-listed parameters with headache parameters (headache frequency, severity and analgesic consumption) were also examined (secondary outcomes). Results. - Between September and December 2020, 30 patients with FETTH and 30 HC were successfully recruited. Demographics, comorbidities, regular medications, smoking habits, alcohol and coffee consumption, body mass index measurements, markers of systemic inflammation, folate and vitamin B12 levels were similar between the two groups (P > 0.05). Lower serum 25(OH)D was both univariately (P < 0.001) and multivariately [OR= 0.72, 95%CI = (0.55, 0.94) per 1 ng/ml increase] associated with FETTH, while serum magnesium was found lower in FETTH only according to the univariate approach (P = 0.036). Higher levels of depression (P = 0.050) and anxiety (P = 0.020), as well as poor quality of sleep (P = 0.008), were univariately associated with FETTH. Only the effect of anxiety remained significant following the multivariate logistic regression [OR= 7.90, 95%CI = (1.00, 62.47)]. Headache parameters were not associated with any one of the assessed variables. Discussion. - Lower serum 25(OH)D was related to the presence of FETTH. This finding could imply a potential role for vitamin D in the pathophysiology of TTH. (C) 2021 Elsevier Masson SAS. All rights reserved.

PURPOSE:To visualize the meniscus of the knee joint in the axial plane and identify injuries that cannot be visualized using conventional sequences.METHODS:Two hundred and two subjects underwent an improvised 3-Dimensional Proton Density Fat Saturation (3D-PD FS) Magnetic Resonance (MR) sequence on their meniscus. The transverse images were reconstructed and examined. Fifty-three of the subjects had a healthy meniscus and their images were used as part of a qualitative evaluation to verify that all parts of the meniscus were properly visualized. The evaluation was based on a four-level scale indicating the visualization of meniscal parts. The same evaluation was also performed on the 149 subjects with meniscal pathologies. Another qualitative evaluation was performed on all subjects concerning five image characteristics based on a five-level scale. Finally, images from 20 patients with meniscal pathologies were compared with arthroscopic images visualizing meniscal tears.RESULTS:In all subjects, all parts of the meniscus were clearly visualized. The axial reformats provided ideal imaging of the meniscus, yielding high total image quality, satisfactory smoothing and sharpening, fewer artifacts, and successful fat saturation. The findings of the MR images from the 20 subjects with meniscal pathologies, concerning the topography of meniscal tears coincided at 100% with their arthroscopic findings.CONCLUSION:The use of the improvised 3D-PD FS sequence provides the possibility of axial reconstruction with a better depiction of the meniscus. These images can accurately illustrate the range of the meniscus and any meniscal tears along with their exact location with high image quality.

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. Hippokratia 2016, 20(3): 244-248.

Purpose: The aim of this present study is to increase bandwidth (BW) and echo train length (ETL) in Proton Density Turbo Spin Echo (PD TSE) sequences with and without fat saturation (FS) as well as in Turbo Inversion Recovery Magnitude sequences (TIRM) in order to assess whether these sequences are capable of reducing susceptibility artifacts. Methods: We compared 1) TIRM coronal (COR) with the same sequence with increased both BW and ETL 2) Conventional PD TSE sagittal (SAG) with FS with an increased BW 3) Conventional PD TSE SAG without FS with an increased BW 4) Conventional PD TSE SAG without FS with increased both BW and ETL. A quantitative analysis was performed to measure the extent of the susceptibility artifacts. Furthermore, a qualitative analysis was performed by two radiologists in order to evaluate the susceptibility artifacts, image distortion and fat suppression. The depiction of cartilage, menisci, muscles, tendons and bone marrow were also qualitatively analyzed. Results: The quantitative analysis found that the modified TIRM sequence is significantly superior to the conventional one regarding the extent of the susceptibility artifacts. In the qualitative analysis, the modified TIRM sequence was superior to the corresponding conventional one in eight characteristics out of ten that were analyzed. The modified PD TSE with FS was superior to the corresponding conventional one regarding the susceptibility artifacts, image distortion and depiction of bone marrow and cartilage while achieving effective fat saturation. The modified PD TSE sequence without FS with a high (H) BW was found to be superior corresponding to the conventional one in the case of cartilage. Conclusion: Consequently, TIRM sequence with an increased BW and ETL is proposed for producing images of high quality and modified PD TSE with H BW for smaller metals, especially when FS is used.

Purpose: The purpose of this study, is to compare the sequences: 1) proton density (PD) BLADE 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 derived from the T2 3D‐double‐echo steady state (DESS) with water excitation (WE) sagittal (SAG) sequence, regarding their abilities to identify changes in the femorotibial condyle cartilage in knee MRI examinations. Methods: Thirty three consecutive patients with osteoarthritis (18 females, 15 males; mean age 56 years, range 37‐71 years), 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. Results: 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, Cartilage and the Conspicuousness Deep Surface Cartilage. This pattern of results is also confirmed by the quantitative analysis. Also, in the PD BLADE FS COR sequence, the results of the Truncation Artifact, Pulsation Artifact, Edge Sharpness and Blurring Artifacts, were superior to the other sequences (p<0.001). Conclusion: PD FS BLADE sequences are ideal for the depiction of the cartilage pathologies compared to the conventional PD FS and T2 3D DESS sequences.

Purpose: The purpose of the present study is to investigate suggested means for the reduction or even elimination of errors that appear in enhancement kinetic curves in order to avoid pitfalls and increase the sensitivity and specificity of the method. Methods: This retrospective study included 115 women who underwent breast MRI in a magnetic resonance unit 3‐Tesla. In the MRI acquisition the following sequences were used: a) axial T2‐TSE, b) axial STIR and c) Vibrant (six phases) unenhanced and contrast‐enhanced axial T1‐weighted fat saturation. In the semi‐automated technique there was no consistency in the location of the selected region of interest — ROI in all the phases of the dynamic acquisition during the assessment of the kinetic curves. The measurements were repeated by positioning the ROIs manually from stable reference points in all the phases and the enhancement kinetic curves were subsequently plotted based on the signal intensity. Results: 115 patients were examined and 376 abnormalities were investigated. In 81 cases, a change of the enhancement kinetic curve type was found between the two methods. In large and dense breasts there was not any change in the type of the kinetic curves calculated between the two methods, whereas in the large but non‐dense breasts, 13 lesions were found to be of different type. In the case of the small and dense breasts only 4 lesions changed type, whereas in the case of the small and non‐dense breasts, 64 lesions changed type out of which 50 were observed in left breasts and 14 in right breasts. Conclusion: The derivation of enhancement kinetic curves should be performed by controlling and verifying that the ROIs lay at the same location of the lesion in all the phases of the dynamic study. In these cases, the use of stable reference points should be employed.

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.

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.

OBJECTIVE The purpose of this study was to investigate means for the elimination or reduction of errors that appear in enhancement kinetic curves in 3Telsa (3T) dynamic magnetic resonance (MRI) mammography from breathing or kinetic artifacts, in order to avoid pitfalls in the accurate determination of the curve type. METHOD A magnetic res onance unit 3-T (Signa, GE Healthcare) was used. Patients were imaged in the prone position with an eight-channel body phased array surface coil. The following sequences were used for MRI of both breasts: (a) axial.2-TSE, (b) axial STIR and (c) Vibrant (six phases) unenhanced and contrast-enhanced axial T1-weighted fat saturation with dynamic acquisition after intravenous injection of a bolus of 0.1 mmoL/kg of gadodiamide. During the assessment of the ki netic curves, it was observed that there was no consistency in the location of the selected region of interest (ROI) in all phases of dynamic acquisition. The ROIs were positioned manually, measuring distances from stable reference points (skin, sternum) in all the phases and the enhancement kinetic curves were plotted based on the signal inten sity. RESULTS In the 10 patients examined, 50 abnormalities were investigated for each of which an enhancement kinetic curve was derived (from the images of the multi-phasic sequence, Vibrant), both semi-automatically (using the calculation software of the system) and manually. In 31 (62%) of the cases of abnormality, a change of the en hancement kinetic curve type was found for both methods. In these cases, it was observed that with the semi-au tomated method 6 enhancement kinetic curves were of type III, whereas using the manual calculation they were of type I; with the semi-automated method 9 were of type III and using the manual calculation of type II, and with the semi-automated method 10 curves were of type II and using the manual calculation of type I. Of the cases for which no change of the enhancement kinetic curve type was found, 8 cases were curves of type I and 11 cases were curves of type II. CONCLUSIONS During the derivation of enhancement kinetic curves, it should be ensured that the ROI is at the same location of the lesion in all the phases of the dynamic study (enhancement). More attention should be given in the case of lesions that change size depending on the phase of enhancement. In these cases stable reference points should be noted (for example, the distance between the lesion and skin or sternum). In cases where there is no consistency of the ROI location in the different phases of the multi-phasic sequence, it should be placed manually using stable reference points and subsequently (based on the signal intensity values) the enhancement kinetic curves should be derived.

OBJECTIVE The purpose of this study was to record streak artifacts appearing in chest imaging examinations and also to evaluate the possibility of eliminating or minimizing them through spatial reconstruction, for better visualization of the thoracic aorta. Streak artifacts are very common as examinations are performed with the use of IV contrast medium injection in high concentrations (350-370 mgI/mL), at injection rates of higher than 4 mL/sec and a fast scan time of the area of interest. METHOD A spiral CT (Philips 5000 SR) was used, with a scan time of 1.5 seconds per rotation and 40 chest examinations were included in the study, which were selected randomly during the program, whenever the images contained artifacts that could simulate pathology. An experienced radiologist selected the cases, and an experienced radiographer applied the spatial resolution. Two experienced radiologists performed quality evaluation in a double-blind study and four different image categories were created, according to the improvement of image quality. RESULTS In the first category (no improvement) were classified 17.5% of the cases namely none of the processed images improved with the spatial reconstruction method (less than 10% compared to the initial images). In the second category (slight improvement) were classified 35% of the cases. The scoring rate was better by a percentage of 11-35% compared to the initial images. In the third category (substantial improvement) were classified 27.5% of the cases. The scoring rate was better by a percentage of 36-70% compared to the initial images. In the fourth category (significant improvement) were classified a 25% of the cases. The scoring rate was better by a percentage of 71-100% compared to the initial images. CONCLUSIONS Spatial reconstruction, when applied to chest CT examinations, improves the quality of the image and contributes to the derivation of more accurate conclusions. This process for the correction of streak artifacts is suggested not only for safety reasons but also because it is difficult for an examination to be repeated on the same day due to the maximum dose of the contrast medium received.