• Clinics in Shoulder and Elbow
• /
• 제25권3호
• /
• pp.182-187
• /
• 2022

Background: This study was designed to evaluate and compare the diagnostic value of magnetic resonance imaging (MRI) and indirect magnetic resonance arthrography (I-MRA) imaging with those of arthroscopy and each other. Methods: This descriptive-analytical study was conducted in 2020. All patients who tested positive for labrum lesions during that year were included in the study. The patients underwent conservative treatment for 6 weeks. In the event of no response to conservative treatment, MRI and I-MRA imaging were conducted, and the patients underwent arthroscopy to determine their ultimate diagnosis and treatment plan. Imaging results were assessed at a 1-week interval by an experienced musculoskeletal radiologist. Image interpretation results and arthroscopy were recorded in the data collection form. Results: Overall, 35 patients comprised the study. Based on the kappa coefficient, the results indicate that the results of both imaging methods are in agreement with the arthroscopic findings, but the I-MRA consensus rate is higher than that of MRI (0.612±0.157 and 0.749±0.101 vs. 0.449±0.160 and 0.603±0.113). The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of MRI in detecting labrum tears were 77.77%, 75.00%, 91.30%, 50.00%, and 77.14%, respectively, and those of I-MRA were 88.88%, 75.00%, 92.30%, 66.66%, and 85.71%. Conclusions: Here, I-MRA showed higher diagnostic value than MRI for labral tears. Therefore, it is recommended that I-MRA be used instead of MRI if there is an indication for potential labrum lesions.

• 치과방사선
• /
• 제29권1호
• /
• pp.7-20
• /
• 1999

Magnetic resonance imaging with its superior soft tissue contrast resolution and absence of beam hardening artifacts, combined with its ability to perform multiplanar imaging, is now effective tool in diagnostic imagings. Magnetic resonance is primarily a phenomenon that involves atomic nuclei. It provides totally new clinical informations with no known hazards through the use of very weak interactions with endogenous stable magnetic atomic nuclei. This article briefly summarizes the basic mechanism of generation and detection of the signals and general sorts of tissue properties which can influence the signals and thereby give rise to tissue contrast. It also describes how the machine-operating parameters can be used to manipulate the tissue contrast observed in the image.

• Korean Journal of Radiology
• /
• 제21권6호
• /
• pp.684-694
• /
• 2020

Objective: The purpose was to review the diagnostic performance of the length of tumor capsular contact (LCC) on magnetic resonance imaging (MRI) for detecting prostate cancer extraprostatic extension (EPE). Materials and Methods: PubMed and EMBASE databases were searched up to March 24, 2019. We included diagnostic accuracy studies that evaluated LCC on MRI for EPE detection using radical prostatectomy specimen histopathology as the reference standard. Quality of studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity were pooled and graphically presented using hierarchical summary receiver operating characteristic (HSROC) plots. Meta-regression and subgroup analyses were conducted to explore heterogeneity. Results: Thirteen articles with 2136 patients were included. Study quality was generally good. Summary sensitivity and specificity were 0.79 (95% confidence interval [CI] 0.73-0.83) and 0.67 (95% CI 0.60-0.74), respectively. Area under the HSROC was 0.81 (95% CI 0.77-0.84). Substantial heterogeneity was present among the included studies according to Cochran's Q-test (p < 0.01) and Higgins I² (62% and 86% for sensitivity and specificity, respectively). In terms of heterogeneity, measurement method (curvilinear vs. linear), prevalence of Gleason score ≥ 7, MRI readers' experience, and endorectal coils were significant factors (p ≤ 0.01), whereas method to determine the LCC threshold, cutoff value, magnet strength, and publication year were not (p = 0.14-0.93). Diagnostic test accuracy estimates were comparable across all assessed MRI sequences. Conclusion: Greater LCC on MRI is associated with a higher probability of prostate cancer EPE. Due to heterogeneity among the studies, further investigation is needed to establish the optimal cutoff value for each clinical setting.

• Investigative Magnetic Resonance Imaging
• /
• 제13권2호
• /
• pp.199-202
• /
• 2009

결합조직형성 섬유종은 골에 발생하는 종양중 매우 드문종양으로 조직학적으로 연부조직에서 발생하는 유건종과 유사하다. 이 양성 종양은 국소적으로 주위 조직에 침윤성으로 성장한다. 방사선학적으로 고립성 골낭종, 섬유성 골이 형성증, 거대세포종, 골육종과 감별이 쉽지 않다. 저자들은 방사선학적으로 골낭종과 비슷한 형태를 보이는 원위 대퇴골에 생긴 결합조직형성 섬유종을 경험하고 드문 골 종양임으로 참고문헌과 함께 보고하는 바이다.

• 한국자기공명학회논문지
• /
• 제1권1호
• /
• pp.7-20
• /
• 1997

The mapping of the spin-spin relaxation time T2 in pixed-by-pixel was suggested as a quantitative diagnostic tool in medicine. Although the CPMG pulse sequence has been known to be the best pulse sequence for T2 measurement in physics NMR, the supplied pulse sequence by the manufacture of MRI system was able to obtain the maximum of 4 CPMG images. Eight or more images with different echo time TEs are required to construct a reliable T2 map, so that two or more acquisitions were required, which easily took more than 10 minutes. 4-echo CPMG imaging pulse sequence was modified to generate the maximum of 8 MR images with evenly spaced echo time TEs. In human MR imaging, since patients tend to move at least several pixels between the different acquisitions, 8-echo CPMG imaging sequence reduces the acquisition time and may remove any misregistration of each pixel's signal for the fitting T2. The resultant T2 maps using the theoretically simulated images and using the MR images of the human brain suggested that 8 echo CPMG sequence with short echo spacing such as 17∼20 msec can give the reliable T2 map.

• Investigative Magnetic Resonance Imaging
• /
• 제12권1호
• /
• pp.55-59
• /
• 2008

37세 여자 환자의 하지에 연부 조직 악성 종양 형태로 발생한 Kimura 병을 보고 하고자 한다. 하지에 발생하는 경우는 매우 드물지만 피하 지방층에 경계가 안 좋은 고형 종괴가 임파선 형태를 유지하며 주위 조직으로 침윤이 있다면 Kimura 병을 감별진단에 포함시켜야 하며 말초 혈액검사와 혈청 IgE 수치 측정을 권유하여야 할 것으로 생각된다.

• 대한족부족관절학회지
• /
• 제7권1호
• /
• pp.131-134
• /
• 2003

Most interdigital neuroma can be diagnosed clinically. But, diagnostic local injection method, sonography and magnetic resonance image(MRI) have been used as secondary tests for clinical confirmation or surgery. Recently, there have been active discussions on the method of interdigital neuroma diagnosis for which sonography or MRI is used. For finding out the location or the number of interdigital neuroma particularly in non-typical clinical manifestation or surgery, MRIs, which are exellent in tissue contrast, may be quite helpful. This case had an interdigital neuroma showing non-typical manifestation. MRIs were used for clinical diagnostic confirmation and finding out the location and the number of interdigital neuroma. Thus, the validity along with literary consideration is being reported.

• 대한수의학회지
• /
• 제63권2호
• /
• pp.9.1-9.5
• /
• 2023

A 5-year-old Labrador Retriever presented with a subcutaneous mass on the right scapular region with localized calor. On magnetic resonance imaging (MRI), a heterogeneously hypointense mass was seen on T1-weighted images (WI) and hyperintense on T2WI and fat-suppressed T2WI with marginal contrast enhancement on postcontrast T1WI and invasion into the surrounding tissue. Histopathological examination of the mass confirmed subcutaneous mast cell tumor (MCT) infiltrating to the adjacent subcutaneous fat. This is the first report to describe the MRI findings of subcutaneous MCT in veterinary medicine. This study suggests that MRI may help evaluate the extent of invasion of subcutaneous MCT.

• Investigative Magnetic Resonance Imaging
• /
• 제7권2호
• /
• pp.100-107
• /
• 2003

목적 : 급성심근경색을 진단하는데 있어 심장자기공명영상의 유용성을 알아보고, 생존심근을 평가하는데 있어 Tl-201 심근관류 SPECT와 비교하고자 하였다. 대상 및 방법 : 흉통 및 호흡곤란이 있는 환자 중 심장자기공명영상과 Tl-201 SPECT를 시행한 17명을 후향적으로 조사하였다. 심장자기공명영상에서는 T2강조영상에서 심벽의 고신호 강도 유무, 영화영상에서 심벽 운동, Gd-DTPA 조영 증강 후 좌심실 벽의 관류 결손 및 주입 15분 후의 지연조영증강 유무를 평가하였다. T1-201 SPECT에서는 아데노신 부하 영상과 휴식기 영상을 얻어 관류 결손 유무와 관류 결손시 가역성 여부를 평가하였다. 결과 심장자기공명영상과 T1-201 SPECT 모두 급성심근경색을 진단하는데 통계적으로 의미가 있었고, T2강조영상, T1-201 SPECT, 지연조영증강 및 심벽운동 순으로 연관성이 있는 것으로 나타났고, 관류 결손은 통계적 유의성이 없었다. 생존심근 평가에 있어서는 두 검사간 유의한 차이가 없었으며, T2강조영상과 관류영상에서 T1-201 SPECT와 높은 일치율, 지연조영증강 및 심벽운동은 낮은 일치율을 보였다. 결론 : 심장자기공명영상은 급성심근경색을 진단하는데 매우 유의한 진단율을 보였고, 생존 심근여부의 판단에 있어 SPECT와 높은 일치율을 보였다. 그러나 각 검사별 판독 기준과 방법에서 많은 연구가 필요할 것으로 생각된다.

• 전기전자학회논문지
• /
• 제23권4호
• /
• pp.1157-1165
• /
• 2019

본 논문은 전류신호와 자속신호를 이용한 유도전동기 예방진단시스템을 개발하기 위한 머신러닝 알고리즘의 개발 및 적용 결과에 대하여 논하였다. 유도전동기의 결함 종류를 판별하기 위한 최적 특징추출단계를 통하여 총 29개의 특징을 도출하였다. 특히, 전류신호의 제7차 고조파 중심으로부터 사이드밴드까지의 주파수의 차이가 부하율 증가에 따라서 증가되는 경향을 이용하여 임의의 부하율 상태를 반영할 수 있는 알고리즘을 도출하였으며, KPCA 특징 축소 기법, k-NN 판단 알고리즘에 의한 분류 정확도를 조사한 결과, 약 84.6%의 분류 정확도를 보였다.