Magnetic resonance imaging (MRI) is an essential modality for the diagnosis of musculoskeletal system defects because of its higher soft-tissue contrast and spatial resolution. With the recent development of MRI-related technology, faster imaging and various image plane reconstructions are possible, enabling better assessment of three-dimensional musculoskeletal anatomy and lesions. Furthermore, the image quality, diagnostic accuracy, and acquisition time depend on the MRI protocol used. Moreover, the protocol affects the efficiency of the MRI scanner. Therefore, it is important for a radiologist to optimize the MRI protocol. In this review, we will provide guidance on patient positioning; selection of the radiofrequency coil, pulse sequences, and imaging planes; and control of MRI parameters to help optimize the MRI protocol for the six major joints of the musculoskeletal system.

OBJECTIVE: To evaluate the feasibility of synthetic magnetic resonance imaging (MRI) compared to conventional MRI for the diagnosis of internal derangements of the knee at 3T. MATERIALS AND METHODS: Following Institutional Review Board approval, image sets of conventional and synthetic MRI in 39 patients were included. Two musculoskeletal radiologists compared the image sets and qualitatively analyzed the images. Subjective image quality was assessed using a four-grade scale. Interobserver agreement and intersequence agreement between conventional and synthetic images for cartilage lesions, tears of the cruciate ligament, and tears of the meniscus were independently assessed using Kappa statistics. In patients who underwent arthroscopy (n = 8), the sensitivity, specificity, and accuracy for evaluated internal structures were calculated using arthroscopic findings as the gold standard. RESULTS: There was no statistically significant difference in image quality (p = 0.90). Interobserver agreement (κ = 0.649– 0.981) and intersequence agreement (κ = 0.794–0.938) were nearly perfect for all evaluated structures. The sensitivity, specificity, and accuracy for detecting cartilage lesions (sensitivity, 63.6% vs. 54.6–63.6%; specificity, 91.9% vs. 91.9%; accuracy, 83.3–85.4% vs. 83.3–85.4%) and tears of the cruciate ligament (sensitivity, specificity, accuracy, 100% vs. 100%) and meniscus (sensitivity, 50.0–62.5% vs. 62.5%; specificity, 100% vs. 87.5–100%; accuracy, 83.3–85.4% vs. 83.3–85.4%) were similar between the two MRI methods. CONCLUSION: Conventional and synthetic MRI showed substantial to almost perfect degree of agreement for the assessment of internal derangement of knee joints. Synthetic MRI may be feasible in the diagnosis of internal derangements of the knee.
Arthroscopy ; Cartilage ; Diagnosis* ; Ethics Committees, Research ; Humans ; Knee Joint ; Knee* ; Ligaments ; Magnetic Resonance Imaging* ; Sensitivity and Specificity ; Tears

BACKGROUND: Folliculotropic mycosis fungoides (FMF) is a variant of mycosis fungoides (MF) that is characterized clinically by variable types of skin eruptions, including plaques, acneiform lesions, and alopecic patches. Histopathologically, FMF is characterized by folliculotropic infiltrates. OBJECTIVE: This study was conducted to scrutinize the clinical and histopathologic features of FMF in Koreans and the responses to phototherapy. METHODS: Twenty Koreans diagnosed with MF who had histopathologic evidence of folliculotropism were enrolled. RESULTS: Eighteen patients had head-and-neck-region infiltration, while five had solitary lesion. In all patients, the atypical lymphocytic infiltrate had a perifollicular distribution. Twelve patients were treated with ultraviolet A (UVA)-1. Eleven of these 12 patients with early-stage FMF experienced >80% improvement (8: complete remission; 3: partial remission). Four patients, including 2 who relapsed after UVA-1, were treated with photodynamic therapy (PDT), reaching complete remission after PDT. CONCLUSION: As FMF has variable clinical presentations, skin biopsy is required to confirm the diagnosis. And both UVA-1 and methyl aminolevulinate-PDT are clinically effective in treatment of early-stage FMF.
Biopsy ; Diagnosis ; Humans ; Mycosis Fungoides* ; Photochemotherapy* ; Phototherapy ; Skin

In the originally published version of this article, complete anonymity was not achieved.

PURPOSE: We aimed to investigate the effectiveness of ferritin as a contrast agent and a potential reporter gene for tracking tumor cells or macrophages in mouse cancer models. MATERIALS AND METHODS: Adenoviral human ferritin heavy chain (Ad-hFTH) was administrated to orthotopic glioma models and subcutaneous colon cancer mouse models using U87MG and HCT116 cells, respectively. Brain MR images were acquired before and daily for up to 6 days after the intracranial injection of Ad-hFTH. In the HCT116 tumor model, MR examinations were performed before and at 6, 24, and 48 h after intratumoral injection of Ad-hFTH, as well as before and every two days after intravenous injection of ferritin-labeled macrophages. The contrast effect of ferritin in vitro was measured by MR imaging of cell pellets. MRI examinations using a 7T MR scanner comprised a T1-weighted (T1w) spin-echo sequence, T2-weighted (T2w) relaxation enhancement sequence, and T2*-weighted (T2*w) fast low angle shot sequence. RESULTS: Cell pellet imaging of Ad-hFTH in vitro showed a strong negatively enhanced contrast in T2w and T2*w images, presenting with darker signal intensity in high concentrations of Fe. T2w images of glioma and subcutaneous HCT116 tumor models showed a dark signal intensity around or within the Ad-hFTH tumor, which was distinct with time and apparent in T2*w images. After injection of ferritin-labeled macrophages, negative contrast enhancement was identified within the tumor. CONCLUSION: Ferritin could be a good candidate as an endogenous MR contrast agent and a potential reporter gene that is capable of maintaining cell labeling stability and cellular safety.
Animals ; Brain Neoplasms/*diagnostic imaging/pathology ; Cell Line, Tumor ; Cell Tracking/*methods ; Colonic Neoplasms/*diagnostic imaging/pathology ; *Contrast Media/administration & dosage ; Disease Models, Animal ; Female ; *Ferritins/administration & dosage ; Genes, Reporter ; Glioma/*diagnostic imaging/pathology ; Humans ; Injections, Intravenous ; Macrophages ; Magnetic Resonance Imaging/*methods ; Male ; Mice ; Neoplasm Transplantation ; Skin Neoplasms/*diagnostic imaging/pathology ; Time Factors

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, subchondral bone 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 meniscus and 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.
Arthroscopy ; Bone Marrow ; Cartilage ; Collateral Ligaments ; Edema ; Humans ; Imaging, Three-Dimensional ; Knee* ; Ligaments ; Magnetic Resonance Imaging* ; Retrospective Studies ; Sensitivity and Specificity ; Tears

Esophageal perforation is a rare but potentially fatal complication of robot-assisted thyroidectomy (RAT). Herein, we report the long-term outcome of an esophageal reconstruction with a jejunal free flap for esophageal rupture after RAT. A 33-year-old woman developed subcutaneous emphysema and hoarseness on postoperative day1 following RAT. Esophageal rupture was diagnosed by computed tomography and endoscopy, and immediate surgical exploration confirmed esophageal rupture, as well as recurrent laryngeal nerve injury. We performed a jejunal free flap repair of the 8-cm defect in the esophagus. End-to-side microvascular anastomoses were created between the right external carotid artery and the jejunal branches of the superior mesenteric artery, and end-to-end anastomosis was performed between the external jugular vein and the jejunal vein. The right recurrent laryngeal nerve injury was repaired with a 4-cm nerve graft from the right ansa cervicalis. Esophagography at 1 year after surgery confirmed that there were no leaks or structures, endoscopy at 1 year confirmed the resolution of vocal cord paralysis, and there were no residual problems with swallowing or speech at a 5-year follow-up examination. RAT requires experienced surgeons with a thorough knowledge of anatomy, as well as adequate resources to quickly and competently address potentially severe complications such as esophageal rupture.
Adult ; Animals ; Carotid Artery, External ; Deglutition ; Endoscopy ; Esophageal Perforation ; Esophagus ; Female ; Follow-Up Studies ; Free Tissue Flaps* ; Hoarseness ; Humans ; Jejunum ; Jugular Veins ; Mesenteric Artery, Superior ; Microsurgery ; Rats ; Recurrent Laryngeal Nerve Injuries ; Rupture* ; Subcutaneous Emphysema ; Surgeons ; Thyroidectomy* ; Transplants ; Veins ; Vocal Cord Paralysis

OBJECTIVE: To investigate the interobserver and test-retest reproducibility of T1ρ and T2 measurements of lumbar intervertebral discs using 3T magnetic resonance imaging (MRI). MATERIALS AND METHODS: This study included a total of 51 volunteers (female, 26; male, 25; mean age, 54 ± 16.3 years) who underwent lumbar spine MRI with a 3.0 T scanner. Amongst these subjects, 40 underwent repeat T1ρ and T2 measurement acquisitions with identical image protocol. Two observers independently performed the region of interest measurements in the nuclei pulposi of the discs from L1–2 through L5–S1 levels. Statistical analysis was performed using intraclass correlation coefficient (ICC) with a two-way random model of absolute agreement. Comparison of the ICC values was done after acquisition of ICC values using Z test. Statistical significance was defined as p value < 0.05. RESULTS: The ICCs of interobserver reproducibility were 0.951 and 0.672 for T1ρ and T2 mapping, respectively. The ICCs of test-retest reproducibility (40 subjects) for T1ρ and T2 measurements were 0.922 and 0.617 for observer A and 0.914 and 0.628 for observer B, respectively. In the comparison of the aforementioned ICCs, ICCs of interobserver and test-retest reproducibility for T1ρ mapping were significantly higher than T2 mapping (p < 0.001). CONCLUSION: The interobserver and test-retest reproducibility of T1ρ mapping were significantly higher than those of T2 mapping for the quantitative assessment of nuclei pulposi of lumbar intervertebral discs.
Humans ; Intervertebral Disc Degeneration ; Intervertebral Disc* ; Magnetic Resonance Imaging* ; Male ; Spine ; Volunteers

PURPOSE: To determine whether we should recommend ultrasonography (US) for an incidental thyroid nodule identified by additional cervicothoracic sagittal T2-weighted image (C-T sag T2WI) of lumbar spine magnetic resonance imaging (MRI). MATERIALS AND METHODS: A retrospective study of 61 patients who underwent both lumbar spine MRI and thyroid US between December 2011 and April 2015 was conducted. For all US-found thyroid nodules > 1 cm, investigators evaluated whether there was any correlation between thyroid nodule detectability by C-T sag T2WI and US features such as echogenicity, composition, or suspicion of malignancy. RESULTS: Solid hypoechoic (2/4; 50%) or mixed echoic nodules (4/8; 50%) appeared to be found relatively more easily by C-T sag T2WI than more benign-looking solid isoechoic (1/4; 25%) or spongiform nodules (0/6; 0%). Among six nodules with ultrasonographic suspicion for malignancy, only one nodule was detected by C-T sag T2WI. CONCLUSION: If an incidental thyroid nodule is seen by C-T sag T2WI, it would be better to recommend thyroid US for identifying malignancy.
Humans ; Magnetic Resonance Imaging* ; Research Personnel ; Retrospective Studies ; Spine* ; Thyroid Gland* ; Thyroid Nodule* ; Ultrasonography*