MR Imaging of the Spine at 3.0T with T2-Weighted IDEAL Fast Recovery Fast Spin-Echo Technique

Ai-Jun Ren,Yong Guo,Shu-Ping Tian,Li-Jing Shi,Min-Hua Huang 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.1

Objective: To compare the iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method with a fat-saturated T2-weighted (T2W) fast recovery fast spin-echo (FRFSE) imaging of the spine. Materials and Methods: Images acquired at 3.0 Tesla (T) in 35 patients with different spine lesions using fat-saturated T2W FRFSE imaging were compared with T2W IDEAL FRFSE images. Signal-to-noise ratio (SNR)-efficiencies measurements were made in the vertebral bodies and spinal cord in the mid-sagittal plane or nearest to the mid-sagittal plane. Images were scored with the consensus of two experienced radiologists on a four-point grading scale for fat suppression and overall image quality. Statistical analysis of SNR-efficiency, fat suppression and image quality scores was performed with a paired Student’s t test and Wilcoxon’s signed rank test. Results: Signal-to-noise ratio-efficiency for both vertebral body and spinal cord was higher with T2W IDEAL FRFSE imaging (p < 0.05) than with T2W FRFSE imaging. T2W IDEAL FRFSE demonstrated superior fat suppression (p < 0.01) and image quality (p < 0.01) compared to fat-saturated T2W FRFSE. Conclusion: As compared with fat-saturated T2W FRFSE, IDEAL can provide a higher image quality, higher SNR-efficiency, and consistent, robust and uniform fat suppression. T2W IDEAL FRFSE is a promising technique for MR imaging of the spine at 3.0T. Objective: To compare the iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method with a fat-saturated T2-weighted (T2W) fast recovery fast spin-echo (FRFSE) imaging of the spine. Materials and Methods: Images acquired at 3.0 Tesla (T) in 35 patients with different spine lesions using fat-saturated T2W FRFSE imaging were compared with T2W IDEAL FRFSE images. Signal-to-noise ratio (SNR)-efficiencies measurements were made in the vertebral bodies and spinal cord in the mid-sagittal plane or nearest to the mid-sagittal plane. Images were scored with the consensus of two experienced radiologists on a four-point grading scale for fat suppression and overall image quality. Statistical analysis of SNR-efficiency, fat suppression and image quality scores was performed with a paired Student’s t test and Wilcoxon’s signed rank test. Results: Signal-to-noise ratio-efficiency for both vertebral body and spinal cord was higher with T2W IDEAL FRFSE imaging (p < 0.05) than with T2W FRFSE imaging. T2W IDEAL FRFSE demonstrated superior fat suppression (p < 0.01) and image quality (p < 0.01) compared to fat-saturated T2W FRFSE. Conclusion: As compared with fat-saturated T2W FRFSE, IDEAL can provide a higher image quality, higher SNR-efficiency, and consistent, robust and uniform fat suppression. T2W IDEAL FRFSE is a promising technique for MR imaging of the spine at 3.0T.

A Comparative Quantitative Analysis of IDEAL (Iterative Decomposition of Water and Fat with Echo Asymmetry and Least Squares Estimation) and CHESS (Chemical Shift Selection Suppression) Technique in 3.0T Musculoskeletal MRI

Myoung-Hoon Kim,Jae-Hwan Cho,Seong-Gyu Shin,Kyung-Rae Dong,Woon-Kwan Chung,Tae-Hyun Park,Jae-Ouk Ahn,Cheol-Soo Park,Hyon-Chol Jang,Yoon-Shin Kim 한국자기학회 2012 Journal of Magnetics Vol.17 No.2

Patients who underwent hip arthroplasty using the conventional fat suppression technique (CHESS) and a new technique (IDEAL) were compared quantitatively to assess the effectiveness and usefulness of the IDEAL technique. In 20 patients who underwent hip arthroplasty from March 2009 to December 2010, fat suppression T2 and T1 weighted images were obtained on a 3.0T MR scanner using the CHESS and IDEAL techniques. The level of distortion in the area of interest, the level of the development of susceptibility artifacts, and homogeneous fat suppression were analyzed from the acquired images. Quantitative analysis revealed the IDEAL technique to produce a lower level of image distortion caused by the development of susceptibility artifacts due to metal on the acquired images compared to the CHESS technique. Qualitative analysis of the anterior area revealed the IDEAL technique to generate fewer susceptibility artifacts than the CHESS technique but with homogeneous fat suppression. In the middle area, the IDEAL technique generated fewer susceptibility artifacts than the CHESS technique but with homogeneous fat suppression. In the posterior area, the IDEAL technique generated fewer susceptibility artifacts than the CHESS technique. Fat suppression was not statistically different, and the two techniques achieved homogeneous fat suppression. In conclusion, the IDEAL technique generated fewer susceptibility artifacts caused by metals and less image distortion than the CHESS technique. In addition, homogeneous fat suppression was feasible. In conclusion, the IDEAL technique generates high quality images, and can provide good information for diagnosis.

T2 강조 복부자기공명영상에 대한 최적의 지방소거 기법의 정량적 평가

구은회(Goo, Eun-Hoe) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.10

본 실험의 목적은 TSE-SPIR 지방소거기법과 GE-PROSET 지방소거기법을 비교하여 복부자기공명영상에서 최적의 T2 강조 지방소거기법을 평가하고자 한다. 자기공명영상 검사는 16채널 다중채널을 사용하여 1.5 T(Philips, Medical System, Achieva)기기로 수행하였다. 모든 영상은 TSE-SPIR과 GE-PROSET을 이용하여 축면상(axial plane)을 얻었다. TSE-SPIR과 GE-PROSET에 대한 후복막 지방의 평균 SNRs는 31.50, 4.15 이었으며, 장간막 지방에 대한 SNRs는 32.39, 7.03이었다. TSE-SPIR과 GE-PROSET에서 장과 후복막 지방, 장간막 지방의 CNRs는 152.69, 74.54 와 26.12, 68.78이었다. 장벽에 대한 묘출도는 TSE-SPIR(2.4), GE-PROSET(1.8)로 TSE-SPIR가 높게 나타났으며, 췌장벽 (pancreas wall)에 대한 묘출도는 TSE-SPIR(1.90), GE-PROSET(2.80)로 GE-PROSET가 높게 나타났다. 결론적으로, T2 강조 지방소거 복부자기공명영상에서 GE-PROSET 지방소거기법 보다 TSE-SPIR 지방소거기법이 우위성 있은 평가를 얻었다. The purpose of this experiment is to evaluate of optimized FS techniques for T2 weighted abdominal MRI compared of TSE-SPIR fat suppression and GE-PROSET fat suppression. All MR examinations were performed on a 1.5 T(Philips, Medical System, Achieva) scanner using 16 channel mult-coils. All images were performed in the axial plane using TSE-SPIR and GE-PROSET. The mean SNRs of the retroperitoneal and mesenteric fat for TSE-SPIR and GE-PROSET were 31.50, 4.15 and 32.39, 7.03. The mean CNRs of the bowel and retroperitoneal, mesenteric fat for TSE-SPIR and GE-PROSET were 52.69, 74.54 and 26.12, 68.78). The delineation of bowel wall margins with TSE-SPIR(2.4) and GE-PROSET(1.8) were significantly improved using TSE-SPIR. The delineation of pancreas wall with TSE-SPIR(1.90), GE-PROSET(2.80) were significantly improved using GE-PROSET. In conclusion, TSE-SPIR fat suppression was superior to GE-PROSET fat suppression in T2 WI FS abdominal MRI.

A Comparative Quantitative Analysis of the IDEAL (Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-squares Estimation) and the CHESS (Chemical Shift Selection Suppression) Techniques in 3.0 T L-spine MRI

김응찬,조재환,김미혜,김기홍,최천웅,석종민,나길주,한만석 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.5

This study was conducted on 20 patients who had undergone pedicle screw fixation between March and December 2010 to quantitatively compare a conventional fat suppression technique, CHESS (chemical shift selection suppression), and a new technique, IDEAL (iterative decomposition of water and fat with echo asymmetry and least squares estimation). The general efficacy and usefulness of the IDEAL technique was also evaluated. Fat-suppressed transverse-relaxationweighed images and longitudinal-relaxation-weighted images were obtained before and after contrast injection by using these two techniques with a 1.5T MR (magnetic resonance) scanner. The obtained images were analyzed for image distortion, susceptibility artifacts and homogenous fat removal in the target region. The results showed that the image distortion due to the susceptibility artifacts caused by implanted metal was lower in the images obtained using the IDEAL technique compared to those obtained using the CHESS technique. The results of a qualitative analysis also showed that compared to the CHESS technique, fewer susceptibility artifacts and more homogenous fat removal were found in the images obtained using the IDEAL technique in a comparative image evaluation of the axial plane images before and after contrast injection. In summary, compared to the CHESS technique, the IDEAL technique showed a lower occurrence of susceptibility artifacts caused by metal and lower image distortion. In addition, more homogenous fat removal was shown in the IDEAL technique.

Quantitative Assessment and Ligament Traceability of Volume Isotropic Turbo Spin Echo Acquisition (VISTA) Ankle Magnetic Resonance Imaging: Fat Suppression versus without Fat Suppression

조경은,윤춘식,송호택,이영한,임대건,서진석,김성준 대한자기공명의과학회 2013 Investigative Magnetic Resonance Imaging Vol.17 No.2

Purpose : To compare the image quality and ligament traceability in ankle images obtained using Volume Isotropic Turbo Spin Echo Acquisition (VISTA) MRI with and without fat suppression. Materials and Methods: The signal-to-noise ratios (SNRs) in images from a phantom and from the ankle of a volunteer were compared. Ten ankles from 10 non-symptomatic volunteers were imaged for comparisons of contrast ratio (CR) and ligament traceability. All examinations were performed using VISTA sequences with and without fat suppression on a 3T MRI scanner. The SNRs were obtained from images with subjects and without subjects (noise-only). Contrast ratios from images of the 10 ankles were acquired between fluid and tendon (F-T), F-cartilage (C), F-ligament (L), fat (f)-T, f-C and f-L. Two musculoskeletal radiologists independently scored the traceability of 7 ligaments, in sagittal, axial and coronal images respectively, based on a 4-point scale (1 as not traceable through 4 as clearly traceable). The Wilcoxon signed-rank test was used to compare the CR. Fisher’s exact test and Pearson’s chi-squared test were used to compare the ligament traceability. Results: The SNRs did not differ significantly between the two sequences except in bone marrow. VISTA SPAIR showed the higher CR only in F-T (p = 0.04), whereas VISTA showed higher CR in f-T (p = 0.005), f-C (p = 0.005) and f-L (p =0.005). The calcaneofibular ligament traceability with VISTA was superior to that obtained with VISTA SPAIR (p < 0.05) in all planes. Conclusion: VISTA showed significant superiority to VISTA SPAIR in tracing CFL due to the superior CR between fat and ligament.

복부의 T2강조 영상에서 지방소거기법의최적의 평가

이다희,구은회,Lee, Da-Hee,Goo, Eun-Hoe 대한디지털의료영상학회 2012 대한디지털의료영상학회논문지 Vol.14 No.1

To test the real image quality of a spectral attenuated inversion-recovery (SPAIR) fat-suppression (FS) techniquein clinical abdominal MRI by comparison to turbo spin echo inversion-recovery (TSEIR) fat-suppression (FS) technique. 3.0T MRI studies of the abdomen were performed in 30 patients with liver lesions (hemangiomas n: 15; HCC n: 15). T2W sequences were acquired using SPAIR TSEIR. Measurements included retroperitoneal and mesenteric fat signal-to-noise (SNR) to evaluate FS; liver lesion contrast-to-noise (CNR) to evaluate bulk water signal recovery effects; and bowel wall delineation to evaluate susceptibility and physiological motion effects. SPAIR-TSEIR images produce significantly improved FS and liver lesion CNR. The mean SNR of the retroperitoneal and mesenteric fat for SPAIR were 20.5, 10.2 and TSEIR were 43.2, 24.1 (P<0.05). SPAIR-TSEIR images produced higher CNR for both hemangiomas CNR 164.88 vs 126.83 (P<0.05) and metastasis CNR 75.27 vs 53.19 (P<0.05). Bowel wall visualization was significantly improved using in both SPAIR-TSEIR (P< 0.05). The real image quality of SPAIR was better than over conventional TSEIR FS on clinical abdominal MRI scans.

Comparison of the SPIR and STIR MR Pulse Sequences in an Oil and Water Phantom

Song Yoon Lee,Jin Han,Dae Cheol Kweon 한국자기학회 2019 Journal of Magnetics Vol.24 No.2

The coexistence of fat and water in the human body causes difficulties in obtaining accurate images using magnetic resonance imaging (MRI). This study evaluated the usefulness of the spectral pre-saturation inversion recovery (SPIR) and short TI inversion recovery (STIR) pulse sequences in suppressing fat. MRI of a water-oil phantom was performed using an Ingenia 3.0-T scanner (Philips Medical Systems, Best, The Netherlands). For quantitative evaluation of the images, the plot profile, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured and compared using ImageJ program (NIH, Bethesda, MD, USA). The SNR for water was higher by 56.04 % on STIR (403.59) than on SPIR (258.64). The SNR for fat was higher by 52.10 % on STIR (17.34) than on SPIR (11.40). The CNR was higher by 24.87 % on STIR (308.75) than on SPIR (247.24). Compared to SPIR, the STIR pulse sequence showed a better fat clearing effect. Therefore, it is necessary to select the appropriate fat suppression method according to the clinical necessity.

퇴행성 슬관절염에서 대퇴골 내측과 관절연골 병변의 Fat-suppressed 3D SPGR 영상

김정만(Jung-Man Kim),지원희(Won-Hee Jee),정양국(Yang-Guk Chung),김양수(Yang-Soo Kim),라기항(Ki-Hang Ra),김동휘(Dong-Hui Kim) 대한정형외과학회 2005 대한정형외과학회지 Vol.40 No.6

목적: 퇴행성 슬관절염에서 대퇴내측과 관절연골의 국소적 결손의 범위와 정도를 알아보기 위해 자기공명영상의 시상면 fat-suppressed 3D SPGR의 유용성에 대해 평가하였다. 대상 및 방법: 정상 또는 퇴행성 관절염 등 총 112예의 내측 대퇴골과의 자기공명영상을 관절경 소견과 전향적으로 비교하였다. 관절경 소견은 Jackson (1992)의 등급 분류법을, 자기공명영상은 Disler (1996)의 등급 분류법을 사용하였다. 관절경 소견상 정상 10예, Ⅰ기 26예, Ⅱ기 36예, Ⅲ기 21예 그리고 Ⅳ기 19예였다. 결과: 관절경 소견상 정상으로 보인 10예에서 자기공명영상에서도 정상(0°)이었다. 관절경상 Ⅰ기인 26예 중 11예(42.3%)에서만 자기공명영상 소견상 관절연골 표면의 불규칙성을 보인 1°였고 나머지는 2°였다. 관절경 소견상 Ⅱ기는 자기공명 영상 2° 또는 3°를 보였으며, Ⅲ기는 3°를 보였다. Ⅳ기 19예 중 넓은 결손 13예(68.4%)만 자기공명영상 4°였다. 자기공명영상 기법을 이용한 선별 검사의 민감도(sensitivity)는 97%, 특이도(specificity)는 100%, 정확도(accuracy)는 97.3%였다. 가중 kappa 값은 0.7194, 표준 오차는 0,053으로 일치도가 높은 소견을 보였다. 결론: Fat-suppressed 3D SPGR영상은 퇴행성 관절염에서 초기와 아주 작은 병소를 제외하면 대퇴내측과 관절연골 병변의 정도, 깊이와 넓이를 예측하는데 유용한 방법이라 생각된다. Purpose: To evaluate the efficacy of sagittal fat-suppressed 3D SPGR MR imaging of the osteoarthritic medial femoral condyle in terms of extent and degree of a focal articular cartilage defect of the knee. Materials and Methods: The MRI findings (Disler scale) of normal and osteoarthritic medial femoral condyles from 112 knees were prospectively compared with the arthroscopic findings (Jackson staging). The arthroscopic findings were normal in 10 cases, stage Ⅰ in 26 cases, stage Ⅱ in 36 cases, stage Ⅲ in 21 cases and stage Ⅳ in 19 cases on arthroscopy. Results: All 10 cases arthroscopy findings were grade 0 in MRI. Among the 26 knees in arthroscopic stage Ⅰ, only 11 knees (42.3%) showed surface irregularities on MRI that were consistent with grade 1, otherwise grade 2. All cases of arthroscopic stage Ⅱ showed grade 2 or grade 3. Stage Ⅲ was grade 3 in all cases on MRI. Among the 19 knees in arthroscopic stage Ⅳ, 16 knees (84.2%) with a large defect showed grade 4 on MRI. The sensitivity, specificity and accuracy of the MRI compared with the arthroscopic findings was 97%, 100% and 97.3%, respectively. The weighted kappa index was 0.7194 and the SE (standard error) was 0.053, suggesting significant consistency. Conclusion: The sagittal fat-suppressed 3D SPGR MR imaging is valuable for determining the extent and degree of the articular cartilage lesion of the medial femoral condyle in an osteoarthritic knee.

Magnetic Susceptibility Artifacts by Air Space in Lumbar MRI Sagittal Fat Suppression

Hyun-Soo Jeon,Seong-Bong Cho,Dong-Kyoon Han,Young-Jin Lee,Eun-Bin Chung,Yeong-Cheol Heo 한국자기학회 2017 Journal of Magnetics Vol.22 No.4

The purpose of this study was to investigate whether the air space formed by the normal anatomical lordosis of the lumbar spine and the table affects magnetic susceptibility artifacts in sagittal MRI images using fat suppression. Thirteen patients complaining of simple low back pain were examined using a 3.0 Tesla MR system and 12-channels dS posterior coil. T2 fat-suppressed sagittal images were examined when the knee was extended and when it was supported by a 50° tilt support. The mean standard deviation of the images when the knee support was used was 131.00 ± 19.31, and it was 220.58 ± 26.86 when the knee was extended. In conclusion, it was confirmed that the air space formed between the table and the anatomical structures due to the curvature of the lumbar spine led to uniform images because of the magnetic susceptibility artifacts.

Three-Dimensional Fast Spin-Echo Imaging without Fat Suppression of the Knee: Diagnostic Accuracy Comparison to Fat-Suppressed Imaging on 1.5T MRI

조희우,서진석,박진오,김형식,정수윤,이영한,한석 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.6

Purpose: To evaluate the diagnostic performance of three-dimensional fast spin-echo (3D FSE-Cube) without fat suppression (NFS) for detecting knee lesions, using comparison to 3D FSE-Cube with fat suppression (FS). Materials and Methods: One hundred twenty-four patients who underwent 1.5T knee magnetic resonance imaging (MRI) scans and 25 subsequent arthroscopic surgeries were retrospectively reviewed. Using arthroscopic results and two-dimensional images as reference standards, diagnostic performances of 3D FSE-Cube-NFS and FS imaging about lesions of ligament, meniscus, subchondralbone marrow edema (BME), and cartilage were compared. Scan parameters of 3D FSE-Cube imaging were previously optimized by a porcine knee phantom. Results: No significant differences were observed between detection rates of NFS and FS imaging for detecting lesions of meniscusand cartilage (p>0.05). However, NFS imaging had lower sensitivity for detection of medial collateral ligament (MCL) tears, and lower sensitivity and specificity for detection of BME lesions, compared to FS imaging (p<0.05). Conclusion: 3D FSE-Cube-NFS imaging showed similar diagnostic performance for detecting lesions of meniscus or cartilage compared to FS imaging, unlike MCL or BME lesions.