Differentiation of salivary gland tumours using diffusion-weighted image-based virtual MR elastography: a pilot study.

OBJECTIVES: Differentiation among benign salivary gland tumours, Warthin tumours (WTs), and malignant salivary gland tumours is crucial to treatment planning and predicting patient prognosis. However, differentiation of those tumours using imaging findings remains difficult. This study evaluated the usefulness of elasticity determined from diffusion-weighted image (DWI)-based virtual MR elastography (MRE) compared with conventional magnetic resonance imaging (MRI) findings in differentiating the tumours. METHODS: This study included 17 benign salivary gland tumours, 6 WTs, and 11 malignant salivary gland tumours scanned on neck MRI. The long and short diameters, T1 and T2 signal intensities, tumour margins, apparent diffusion coefficient (ADC) values, and elasticity from DWI-based virtual MRE of the tumours were evaluated. The interobserver agreement in measuring tumour elasticity and the receiver operating characteristic (ROC) curves were also assessed. RESULTS: The long and short diameters and the T1 and T2 signal intensities showed no significant difference among the 3 tumour groups. Tumour margins and the mean ADC values showed significant differences among some tumour groups. The elasticity from virtual MRE showed significant differences among all 3 tumour groups and the interobserver agreement was excellent. The area under the ROC curves of the elasticity were higher than those of tumour margins and mean ADC values. CONCLUSION: Elasticity values based on DWI-based virtual MRE of benign salivary gland tumours, WTs, and malignant salivary gland tumours were significantly different. The elasticity of WTs was the highest and that of benign tumours was the lowest. The elasticity from DWI-based virtual MRE may aid in the differential diagnosis of salivary gland tumours.

Bright diffusion sign: A sensitive and specific radiologic biomarker for multinodular and vacuolating neuronal tumor.

BACKGROUND AND PURPOSE: Accurate differentiation between multinodular and vacuolating neuronal tumor (MVNT) and dysembryoplastic neuroepithelial tumor (DNET) is important for treatment decision-making. We aimed to develop an accurate radiologic diagnostic model for differentiating MVNT from DNET using T2WI and diffusion-weighted imaging (DWI). MATERIALS AND METHODS: A total of 56 patients (mean age, 47.48±17.78 years; 31 women) diagnosed with MVNT (n = 37) or DNET (n = 19) who underwent brain MRI, including T2WI and DWI, were included. Two board-certified neuroradiologists performed qualitative (bubble appearance, cortical involvement, bright diffusion sign, and bright apparent diffusion coefficient [ADC] sign) and quantitative (nDWI and nADC) assessments. A diagnostic tree model was developed with significant and reliable imaging findings using an exhaustive chi-squared Automatic Interaction Detector (CHAID) algorithm. RESULTS: In visual assessment, the imaging features that showed high diagnostic accuracy and interobserver reliability were the bright diffusion sign and absence of cortical involvement (bright diffusion sign: accuracy, 94.64 %; sensitivity, 91.89 %; specificity, 100.00 %; interobserver agreement, 1.00; absence of cortical involvement: accuracy, 92.86 %; sensitivity, 89.19 %; specificity, 100.00 %; interobserver agreement, 1.00). In quantitative analysis, nDWI was significantly higher in MVNT than in DENT (1.52 ± 0.34 vs. 0.91 ± 0.27, p < 0.001), but the interobserver agreement was fair (intraclass correlation coefficient = 0.321). The overall diagnostic accuracy of the tree model with visual assessment parameters was 98.21 % (55/56). CONCLUSION: The bright diffusion sign and absence of cortical involvement are accurate and reliable imaging findings for differentiating MVNT from DNET. By using simple, intuitive, and reliable imaging findings, such as the bright diffusion sign, MVNT can be accurately differentiated from DNET.

Comparison of tissue tracking assessment by cardiovascular magnetic resonance for cardiac amyloidosis and hypertrophic cardiomyopathy.

BACKGROUND: Administration of gadolinium-contrast can cause problems in cardiac amyloidosis (CA) patients with impaired renal function. PURPOSE: To compare patterns of cardiovascular magnetic resonance tissue tracking (CMR-TT) for CA and hypertrophic cardiomyopathy (HCM) and to assess the feasibility of CMR-TT to distinguish between these diseases without administration of gadolinium-contrast. MATERIAL AND METHODS: Included were 54 patients with biopsy-proven CA, 40 patients with HCM, and 30 healthy people. We calculated strain ratio of apex to base (SRAB) in the left ventricle (LV) using radial (R), circumferential (C), and longitudinal (L) strain from CMR-TT. The LV ejection fraction (LVEF) and the ratio of septal to posterior wall at basal level were also calculated. Late gadolinium enhancement (LGE) image analysis was performed for differential diagnosis. Area under the receiver operating characteristic curve (AUC) comparisons were used. RESULTS: All SRAB values were significantly different between CA and HCM (all P < 0.001). AUC values for parameters were 0.806 for LVEF, 0.815 for ratio of wall thickness, 0.944 for the LGE pattern, 0.898 for SRABR, 0.880 for SRABC, and 0.805 for SRABL. AUCs for the LGE pattern were significantly higher than for LVEF, ratio of wall thickness and SRABL (all P < 0.008). No significant differences were seen between AUCs for the LGE pattern, SRABR, and SRABC (all P > 0.109). CONCLUSION: SRABR and SRABC were reliable parameters for distinguishing between CA and HCM.

MR Findings of Fungus Ball: Significance of High Signal Intensity on T1-Weighted Images.

BACKGROUND: Central dark-signal intensity with high-signal, hypertrophic mucosal wall of paranasal sinuses on T2-weighted images (T2WI) is a characteristic magnetic resonance imaging (MRI) feature of sinonasal fungus ball. However, this finding is usually interpreted as non-fungal chronic sinusitis with central normal sinus air. In addition, T1-weighted images (T1WI) and T2WI are basic sequences of all magnetic resonance (MR) examinations. Therefore, we evaluated the usefulness of T1WI for detecting fungus balls comparing with computed tomography (CT) findings and T2-weighted MRI findings. METHODS: This retrospective study was approved by the Institutional Review Board of Korea University Guro Hospital. Two reviewers assessed preoperative CT and MR images of 55 patients with pathologically confirmed fungus balls. Reviewers evaluated the presence and patterns of calcifications on CT. Overall signals and the presence and extent of certain signals of fungus balls on MRI were also assessed. The relationship between calcifications and MRI signals was also evaluated. RESULTS: Of the patients, 89.1% had calcifications on CT. All had dark signal portions with high signal, hypertrophic mucosal walls on T2WI. Most (92.7%) patients showed iso- to hyper-intense overall signals on T1WI and 89.1% had T1-weighted high signal portions on MRI. The presence, patterns, and location of calcifications had no significant correlation with T1-weighted high-signal intensity portion. CONCLUSION: Fungus ball can be suggested by the presence of the hyper-signal intensity portions in the fungal mass on T1WI in conjunction with dark-signal lesions surrounded by high-signal, hypertrophic mucosal walls in paranasal sinuses on T2WI.

Sarcopenia is a predictor for Alzheimer's continuum and related clinical outcomes.

Low body mass index is closely related to a high risk of Alzheimer's disease (AD) and related biomarkers including amyloid-ß (Aß) deposition. However, the association between sarcopenia and Aß-confirmed AD remains controversial. Therefore, we investigated the relationship between sarcopenia and the AD continuum. We explored sarcopenia's association with clinical implications of participants on the AD continuum. We prospectively enrolled 142 participants on the AD continuum (19 with preclinical AD, 96 with mild cognitive impairment due to AD, and 28 with AD dementia) and 58 Aß-negative cognitively unimpaired participants. Sarcopenia, assessed using dual-energy X-ray absorptiometry and hand grip measurements, was considered a predictor. AD continuum, defined by Aß deposition on positron emission tomography served as an outcome. Clinical severity in participants on the AD continuum assessed using hippocampal volume, Mini-Mental State Examination (MMSE), Seoul Verbal Learning Test (SVLT), and Clinical Dementia Rating Scale Sum of Boxes Scores (CDR-SOB) were also considered an outcome. Sarcopenia (odds ratio = 4.99, p = 0.004) was associated independently with the AD continuum after controlling for potential confounders. Moreover, sarcopenia was associated with poor downstream imaging markers (decreased hippocampal volume, ß = - 0.206, p = 0.020) and clinical outcomes (low MMSE, ß = - 1.364, p = 0.025; low SVLT, ß = - 1.077, p = 0.025; and high CDR-SOB scores, ß = 0.783, p = 0.022) in participants on the AD continuum. Sarcopenia was associated with the AD continuum and poor clinical outcome in individuals with AD continuum. Therefore, our results provide evidence for future studies to confirm whether proper management of sarcopenia can effective strategies are required for sarcopenia management to prevent the AD continuum and its clinical implications.

Evaluating the Elasticity of Metastatic Cervical Lymph Nodes in Head and Neck Squamous Cell Carcinoma Patients Using DWI-based Virtual MR Elastography.

PURPOSE: The assessment of metastatic cervical lymph nodes in head and neck squamous cell carcinoma patients is crucial; as such, many studies focusing on non-invasive imaging techniques to evaluate metastatic cervical lymph nodes have been performed. The aim of our study was to assess the usefulness of elasticity values on diffusion weighted imaging (DWI)-based virtual MR elastography in the evaluation of metastatic cervical lymph nodes from head and neck squamous cell carcinoma. METHODS: Two head and neck radiologists measured the elasticity values of 16 metastatic cervical lymph nodes from head and neck squamous cell carcinoma and 13 benign cervical lymph nodes on DWI-based virtual MR elastography maps. Mean, minimum, maximum, and median elasticity values were evaluated for lymph nodes between the two groups and interobserver agreement in measuring the elasticity was also evaluated. RESULTS: The mean, maximum, and median elasticity values of metastatic cervical lymph nodes were significantly higher than those of benign cervical lymph nodes (P = 0.001, 0.01, and 0.002, respectively). Diagnostic accuracy, sensitivity, and specificity of the mean elasticity were 82.8%, 93.8%, and 69.2%, respectively. Interobserver agreement was excellent for the mean and median elasticity (intraclass correlation coefficients were 0.98 for both). CONCLUSION: Estimated elasticity values based on DWI-based virtual MR elastography show significant difference between benign and metastatic cervical lymph nodes from head and neck squamous cell carcinoma. While precise modulation of MR sequences and calibration parameters still needs to be established, elasticity values can be useful in differentiating between these lymph nodes.

Uterine artery embolization for emergent management of postpartum hemorrhage associated with placenta accreta.

BACKGROUND: Although uterine artery embolization (UAE) is a well-recognized alternative treatment for postpartum hemorrhage (PPH) with a high clinical efficacy, the reported success rate of UAE for PPH associated with placenta accreta (PA) is lower. Recently, with advances in techniques and expertise, a few studies have reported favorable results of UAE in controlling PPH in the setting of PA. PURPOSE: To evaluate the efficacy of UAE in the emergent management of intractable PPH associated with PA. MATERIAL AND METHODS: Seventeen consecutive patients who underwent emergent UAE for the management of PPH associated with PA were included in this retrospective study. Medical records were reviewed regarding the delivery and UAE procedure. Follow-up gynecologic outcomes after UAE were obtained by telephone interview. RESULTS: UAE successfully controlled PPH in 14 patients (82.4%). Three patients underwent hysterectomy after UAE failed to stop the bleeding. All hysterectomy cases were accompanied by uterine atony or total placenta previa. Relevant gynecologic findings were obtained from 10 patients; three patients were breastfeeding and seven patients resumed normal menstruation, including one pregnancy. CONCLUSION: UAE appears to be a safe and effective means by which to control PPH associated with PA. PA complicated by uterine atony or placenta previa may be at increased risk of UAE failure.

Usefulness of 3D High-resolution Vessel Wall MRI in Diffuse Nonaneurysmal SAH Patients.

PURPOSE: In 15-20% of patients with nontraumatic diffuse subarachnoid hemorrhage (SAH), the initial conventional angiography does not reveal a causative vascular abnormality, such as intracranial aneurysm. In this study, we evaluated clinical utility of 3D high-resolution vessel wall magnetic resonance imaging (HR-VWI) in patients with diffuse nonaneurysmal SAH. METHODS: A total of 17 patients with diffuse nonaneurysmal SAH were included in this retrospective study. We characterized demographics and HR-VWI findings and reviewed the clinical management and outcomes. RESULTS: Of the patients 14 (14/17; 82.4%,) showed abnormal findings on HR-VWI, including 5 with intracranial dissections (29.4%), 3 with blood blister-like aneurysm (17.6%), 1 with ruptured fusiform aneurysm (5.9%), and 5 with focal nodular wall enhancement without unclassified pathology (29.4%). Of these patients were treated with endovascular management. Most patients (16/17) had a favorable modified Rankin scale scores of 0-2 on discharge. CONCLUSION: The 3D HR-VWI revealed various hidden pathologies, such as intracranial arterial dissection, blood blister-like aneurysm, and fusiform aneurysm in patients with diffuse nonaneurysmal SAH. In addition, 3D HR-VWI had an impact on the management of SAH. The 3D HR-VWI can be a complementary diagnostic method for patients with diffuse nonaneurysmal SAH in a research or clinical setting.

Pulmonary mycobacterial disease: diagnostic performance of low-dose digital tomosynthesis as compared with chest radiography.

PURPOSE: To compare the diagnostic performance of a low-radiation-dose digital tomosynthesis (DTS) technique with that of conventional radiography in the detection of lung lesions in patients with pulmonary mycobacterial disease. MATERIALS AND METHODS: The institutional review board approved this study, and all patients provided informed consent. In this study, 100 patients (65 study patients, 35 control patients) underwent multidetector computed tomography (CT), chest radiography, and low-dose DTS (effective doses: 3.4, 0.02, and 0.05 mSv, respectively). Two radiologists evaluated radiographs and DTS images for the presence of parenchymal lesions and the number of cavities in each patient; CT served as the reference standard. Wilcoxon signed rank and McNemar tests and κ statistics were used. RESULTS: The accuracies of DTS and radiography in depicting mycobacterial disease were 97% and 89%, respectively, for observer 1 (P = .039) and 99% and 93%, respectively, for observer 2 (P = .031). The accuracies of DTS and radiography in depicting each lesion type were, respectively, 95% and 77% for bronchiolitis, 92% and 76% for nodules, 86% and 79% for consolidation, and 93% and 70% for cavities. Interobserver agreement with DTS (κ = 0.62-0.94) was superior to that with radiography (κ = 0.46-0.62). Of a total of 141 cavities found with CT, means of 27 (19%) cavities at chest radiography and 108 (77%) cavities at DTS (P < .01) were detected by the two observers. CONCLUSION: DTS performed with a low-dose technique is superior to radiography for the detection of lung lesions in patients with pulmonary mycobacterial disease.

Rathke Cleft Cysts with Apoplexy-Like Symptoms: Clinicoradiologic Comparisons with Pituitary Adenomas with Apoplexy.

BACKGROUND: Rathke cleft cyst (RCC) can cause acute symptoms mimicking pituitary adenoma (PA) apoplexy. We evaluated the clinicoradiologic features for distinguishing RCC from PA apoplexy. METHODS: We retrospectively evaluated 22 patients with RCC and 24 patients with PA with apoplexy-like symptoms who underwent surgery via a transsphenoidal approach between November 1999 and December 2016. We compared the clinical data and magnetic resonance (MR) images between the 2 groups. RESULTS: The RCC group was younger and had smaller tumors compared with the PA group (P = 0.02 and 0.001, respectively). The incidences of visual deficits and cranial nerve palsy were lower in the RCCs than in the PAs (P ≤ 0.02 for all). MR images showed more frequent intracystic nodules in the RCCs (P < 0.001), whereas nodular enhancement and lateral deviation of the pituitary stalk were more commonly seen in the PAs (P ≤ 0.003 for both). However, the presence of endocrine dysfunction or decreased consciousness, and the recurrence ratio, were not significantly different between the groups (P ≥ 0.48 for all). In the multivariable logistic regression analysis, patients without nodular enhancement had a 15.84-fold greater risk of RCC than did those with nodular enhancement (P = 0.031). The probability of RCC decreased 0.59-fold with each 1-cm3 increase in tumor volume. CONCLUSIONS: RCC with apoplexy-like symptoms has different clinicoradiologic features compared with PA apoplexy. Patients with RCC present with milder ocular symptoms and smaller tumor volumes compared with those with PA apoplexy. The absence of nodular enhancement on MR images could suggest RCC.

Performance of deep learning to detect mastoiditis using multiple conventional radiographs of mastoid.

OBJECTIVES: This study aimed to compare the diagnostic performance of deep learning algorithm trained by single view (anterior-posterior (AP) or lateral view) with that trained by multiple views (both views together) in diagnosis of mastoiditis on mastoid series and compare the diagnostic performance between the algorithm and radiologists. METHODS: Total 9,988 mastoid series (AP and lateral views) were classified as normal or abnormal (mastoiditis) based on radiographic findings. Among them 792 image sets with temporal bone CT were classified as the gold standard test set and remaining sets were randomly divided into training (n = 8,276) and validation (n = 920) sets by 9:1 for developing a deep learning algorithm. Temporal (n = 294) and geographic (n = 308) external test sets were also collected. Diagnostic performance of deep learning algorithm trained by single view was compared with that trained by multiple views. Diagnostic performance of the algorithm and two radiologists was assessed. Inter-observer agreement between the algorithm and radiologists and between two radiologists was calculated. RESULTS: Area under the receiver operating characteristic curves of algorithm using multiple views (0.971, 0.978, and 0.965 for gold standard, temporal, and geographic external test sets, respectively) showed higher values than those using single view (0.964/0.953, 0.952/0.961, and 0.961/0.942 for AP view/lateral view of gold standard, temporal external, and geographic external test sets, respectively) in all test sets. The algorithm showed statistically significant higher specificity compared with radiologists (p = 0.018 and 0.012). There was substantial agreement between the algorithm and two radiologists and between two radiologists (κ = 0.79, 0.8, and 0.76). CONCLUSION: The deep learning algorithm trained by multiple views showed better performance than that trained by single view. The diagnostic performance of the algorithm for detecting mastoiditis on mastoid series was similar to or higher than that of radiologists.

Differentiating cervical metastatic lymphadenopathy and lymphoma by shear wave elastography.

Shear wave elastography (SWE) is a recent technological advance of ultrasonography (US) to assess tissue stiffness. The purpose of this study is to assess tissue stiffness of malignant cervical lymph nodes (LN) with SWE, to reveal diagnostic performance of SWE in differentiating metastatic LN from lymphoma, and to assess inter-observer agreement of SWE. We assessed 62 malignant LN (24 lymphomas and 38 metastatic LN) and their median speed was 6.34 m/s and median elasticity was 69.7 kPa. Add of SWE with conventional US improved diagnostic accuracy of differentiating metastasis from lymphoma (16.13, 8.07 and 11.3% for three radiologists). Kendall's Coefficient of Concordance of three readers for analyzing SWE patterns was 0.86. SWE can be a useful tool to discriminate metastatic cervical LN from lymphoma with improvement of diagnostic accuracy when using with conventional US.

Early Prediction of Periventricular Leukomalacia Using Quantitative Texture Analysis of Serial Cranial Ultrasound Scans in Very Preterm Infants.

We compared texture parameters of serial cranial ultrasound (cUS) images of periventricular leukomalacia (PVL) and normal periventricular echogenicity (PVE) in very preterm infants and evaluated the early predictive values of texture analysis (TA) for PVL. Ten individuals with PVL and 10 control individuals with PVE assessed with an initial cUS within 1 wk of birth and follow-up cUS at 2-3 and 4-6 wk of life were included. TA was performed on the region of interest of PVE at the parieto-occipital area on serial cUS. Opposite changes in variance were obtained between the first two cUS sessions in both groups (p = 0.017 in PVL and p = 0.005 in PVE). The variance-to-mean ratio (VMR) between the second and first cUS sessions differed (p = 0.016) and reliably stratified the groups (area under the receiver operating characteristic curve: 0.820, 95% confidence interval: 0.587-1.000, sensitivity: 100%, specificity: 60%). TA of serial cUS helps to predict PVL within 3 wk of life.

Cardiac magnetic resonance-tissue tracking for the early prediction of adverse left ventricular remodeling after ST-segment elevation myocardial infarction.

Cardiac magnetic resonance-tissue tracking (CMR-TT)-derived myocardial strain after ST-elevation myocardial infarction (STEMI) is related to adverse cardiac events. We aimed to investigate the feasibility of CMR-TT for the early prediction of adverse left ventricular (LV) remodeling after STEMI. We retrospectively searched our institution's STEMI registry for patients who underwent reperfusion therapy, post-reperfusion CMR within 1 week after STEMI, and follow-up CMR. CMR-TT analysis was performed using cine imaging of post-reperfusion CMR. Adverse LV remodeling was defined as an increase in end-diastolic LV volume by 20% or more on follow-up CMR (median interval between serial CMR exams, 197 days; interquartile, 174-241 days). A total of 82 patients (age, 59.2 ± 11.1 years; male:female = 73:9) were included and divided into two groups: STEMI without (n = 62) and with (n = 20) adverse LV remodeling. Patients with LV remodeling showed significantly higher peak creatine kinase-MB and troponin I levels and a larger infarct size compared with those without LV remodeling (p = 0.001, p = 0.001, and p = 0.010, respectively). Global circumferential, radial, and longitudinal strain (GLS) also differed significantly between the groups (p = 0.001, p = 0.004, and p < 0.001, respectively). Logistic regression and receiver operating characteristic curve analyses demonstrated that GLS was an independent predictor of LV remodeling [odds ratio (OR) = 1.282, 95% confidence interval (CI) = 1.060-1.55 p = 0.011] with an optimal cut-off of - 12.84 (AUC = 0.756, 95% CI = 0.636-0.887, p < 0.001). CMR-TT-derived GLS may aid the early prediction of adverse LV remodeling after reperfusion, within 1 week after STEMI.

Comparison of clinicoradiological findings between patients with recovering diplopia and those with residual diplopia after surgery for pure orbital blowout fracture.

PURPOSE: Diplopia is a common symptom of blowout fracture (BOF), and can persist after proper surgical management. We compared clinicoradiological findings between patients with recovering diplopia and those with residual diplopia after surgery for orbital BOF. MATERIALS AND METHODS: We retrospectively evaluated the CT images of 170 patients with orbital BOF and preoperative diplopia. We reviewed the following factors: sex, age, mechanism of injury, presence of diplopia before surgery, presence of enophthalmos before surgery, presence of an ocular motility abnormality before surgery, time interval between the trauma and surgery, fracture type, fracture size, volume of herniated orbital soft tissue, ratio of the volume of herniated orbital soft tissue to fracture size, number of points of contact between the extraocular muscle (EOM) and bony edge, EOM swelling, EOM swelling ratio, EOM displacement, EOM circling, EOM tenting, and EOM entrapment. The associations between the presence of diplopia 6 months after surgical repair and various clinicoradiological findings were analyzed using Wilcoxon rank-sum tests, Student's t-tests, Fisher's exact tests for univariable analysis, and logistic regression analysis for multivariable analysis. A Kaplan-Meier curve and log-rank test were used to identify the recovery status from diplopia. RESULTS: The following findings were significantly different between patients with recovering diplopia and those with residual diplopia on univariable analysis (p < 0.05 for each): patient age, EOM entrapment, EOM circling, and EOM tenting. Multivariable analyses showed that patients who were older or those who had EOM circling or tenting on CT images had a greater probability of residual diplopia after surgery [p-values: 0.006, 0.013, and <0.001, respectively; odds ratio (95% confidence interval): 1.035 (1.010-1.061), 14.809 (1.775-123.556), and 4.851 (2.069-11.375), respectively]. The recovery rate for diplopia was significantly different between patients with EOM tenting and those without (p = 0.02). Additionally, young patients (0-12 years) showed a shorter recovery time from diplopia compared with older patients (>24 years) (p < 0.05). CONCLUSION: Patients with residual diplopia after surgical management have different clinicoradiological findings compared with patients with recovering diplopia. Patients who are older, or those who have circling or tenting of the EOM on CT scans, are more likely to have residual diplopia.

Comparison of quantitative imaging parameters using cardiovascular magnetic resonance between cardiac amyloidosis and hypertrophic cardiomyopathy: inversion time scout versus T1 mapping.

To compare inversion time (TI) parameters, native T1, and extracellular volume (ECV) on cardiac magnetic resonance (CMR) imaging between patients with cardiac amyloidosis (CA) or hypertrophic cardiomyopathy (HCMP). Forty six patients with biopsy-confirmed CA and 30 patients with HCMP who underwent CMR were included. T1 and TI values were measured in the septum and cavity of the left ventricle on T1 mapping and TI scout images. TI values were selected at nulling point for each myocardium and blood pool. Native T1, ECV, and TI interval values were significantly different between the CA (1170.5 ± 86.4 ms, 56.7 ± 12.2, - 11.5 ± 28.4 ms) and HCMP (1059.5 ± 63.4 ms, 28.5 ± 5.8, 66.2 ± 25.4 ms) (all p < 0.001). The diagnostic performance of the TI interval (area under the ROC curve, 0.975) was not inferior to that of the ECV (0.980, p = 0.776), and it was superior to that of the native T1 (0.845, p = 0.004). The diagnostic performance of TI interval was comparable to that of ECV for differential diagnosis between CA and HCMP. TI interval showed the feasibility as quantitative CMR parameter when T1 mapping images are not available.

Discrepant lesion size estimated on T1- and fat-suppressed T2-weighted MRI: diagnostic value for differentiation between inflammatory pseudotumor and carcinoma of the nasopharynx.

PURPOSE: Nasopharyngeal inflammatory pseudotumor (NIPT) is hard to differentiate from infiltrating nasopharyngeal carcinoma (NPC) on conventional magnetic resonance imaging (MRI). The purpose of this study is to determine whether discrepant lesion sizes estimated on T1- and fat-suppressed T2-weighted images can help distinguish between NIPT and NPC. METHODS: We retrospectively reviewed MRI data of histologically proven 14 NIPTs and 18 infiltrating NPCs. We measured the area of the lesion on contrast-enhanced T1-weighted, unenhanced T1-weighted, and fat-suppressed T2-weighted images by placing the largest possible polygonal region-of-interest within the lesion at the same level. Using lesion size measured on contrast-enhanced T1-weighted image as the reference, we calculated and compared area ratio of T1 (ART1) and area ratio of T2 (ART2) between NIPTs and NPCs. For validation, we also undertook a double-blinded study by two reviewers and assessed the diagnostic performance and interobserver agreement. RESULTS: For NIPTs, ART2 (median, 0.48; range, 0.18-0.97) was statistically significantly less than ART1 (median, 1.01; range, 0.80-1.99), while these values were not significantly different for NPCs. The interobserver agreement in differentiating between NIPT and NPC was good, with a sensitivity of 93% and a specificity of 83%-94%. CONCLUSION: In contrast to NPCs, NIPTs appear smaller on fat-suppressed T2-weighted images than on T1-weighted images. This discrepancy in the lesion size estimated on T1-weighted and fat-suppressed T2-weighted images may provide a simple and consistent way to differentiate between NIPTs and NPCs on conventional MRI.

Initial experience with magnetic resonance-guided vacuum-assisted biopsy in korean women with breast cancer.

PURPOSE: The aim of this study is to describe our initial experience with magnetic resonance (MR)-guided biopsy and to determine the malignancy rate of additional lesions identified by MR only in Korean women with breast cancer. METHODS: A retrospective review identified 22 consecutive patients with breast cancer who had undergone MR-guided vacuum-assisted biopsies (VAB) of MR-only identified lesions from May 2009 to October 2011.We evaluated the rate of compliance, the technical success for MR-guided VAB and the MR imaging findings of the target lesions. VAB histology was compared with surgical histology and follow-up imaging findings. RESULTS: The biopsy recommendations for MR-only identified lesions were accepted in 46.8% (22/47) of patients. One of 22 procedures failed due to the target's posterior location. Among 21 MR-guided VAB procedures, the target lesions were considered as a mass in 12 cases and a nonmass enhancement in nine cases. VAB histology revealed malignancies in 14% (3/21) of cases, high-risk lesions in 24% (5/21) and benign lesions in 62% (13/21). Eleven cases (52%, 11/21) had a positive surgical correlation, and one of them was upgraded from atypical ductal hyperplasia to invasive ductal carcinoma. In the remaining 10 lesions, follow-up breast ultrasound and mammography were available (range, 15-44 months; mean, 32.1 months) and did not show suspicious lesions. The final malignancy rate was 19% (4/21). CONCLUSION: MR-guided VAB for MR-only identified lesions yielded a 19% malignancy rate in Korean women with breast cancer. MR-guided VAB helps surgeons avoid an unnecessary wide excision or additional excisional biopsy.

Are the imaging features of the pleomorphic variant of invasive lobular carcinoma different from classic ILC of the breast?

The aim of this study was to evaluate whether pleomorphic invasive lobular carcinoma (PILC) is different from classic invasive lobular carcinoma (CILC) in terms of radiologic and clinicopathologic features. We compared the radiologic and clinicopathologic features of 22 surgically confirmed PILCs in 21 patients from 2004 to 2009 and 47 CILCs from 47 consecutive patients. For all cases, we reviewed the imaging findings, medical records and pathological results. PILC had a higher T stage, N stage, nuclear and histologic grade compared to CILC. PILC was more commonly negative for estrogen receptors and positive for HER2 than CILC (all p < 0.05). However, there were no significant differences in age, symptoms, tumor size, extensive intraductal component, lymphovascular invasion, triple negative profile, or multiplicity between the two groups. PILC was not detected on mammography in 1 (4.5%) of 22 cases, whereas CILC was not detected on mammography in 7 (14.9%) of 47 cases and on MRI in 2 (5.0%) of 40 (p = 0.42 and p = 1.000, respectively). MRI identified more frequent multiplicity than mammography for both PILC and CILC (p < 0.001), but was similar to US (p = 0.066). Most lesions showed a spiculated mass or architectural distortion with or without calcifications on mammography and ultrasound. No differences in mass and/or non-mass lesions or kinetics on MRI were observed between the two groups. PILC shows more pathologically aggressive features, but cannot be differentiated from CILC based on imaging findings.

Digital tomosynthesis for PNS evaluation: comparisons of patient exposure and image quality with plain radiography.

OBJECTIVE: We investigated low dose digital tomosynthesis (DT) for the evaluation of the paranasal sinus (PNS), and compared its diagnostic accuracy with a PNS radiography series (XR). MATERIALS AND METHODS: We enrolled 43 patients for whom XR, PNS DT, and OMU CT were performed. We measured effective doses (EDs) of XR, DT, and OMU CT using Monte Carlo simulation software. Two radiologists performed independent observation of both XR and DT. For seven PNSs, they scored anatomic conspicuity of sinuses and confidence on the presence of sinusitis using nine point scales. OMU CT was observed by the third radiologist and the findings were regarded as reference standard. We compared scores for conspicuity and sinusitis confidence between XR and DT. RESULTS: Mean EDs were 29 ± 6 µSv, 48 ± 10 µSv, and 980 ± 250 µSv, respectively, for XR, DT, and CT. Mean scores for conspicuity were 6.3 and 7.4, respectively, for XR and DT. Sensitivity per patient basis for sinusitis detection were 52% and 96%, respectively, for XR and DT in observer 1 (p = 0.001) and 80% and 92% for observer 2 (p = 0.25). Specificities for sinusitis exclusion were 100% for both XR and DT for observer 1 and 89% and 100% for observer 2 (p = 0.50). Accuracies for sinusitis diagnosis were 72% and 98%, respectively, for XR and DT for observer 1 (p = 0.001) and 84% and 95% for observer 2 (p = 0.125). CONCLUSION: Patient radiation dose from low dose DT is comparable with that of PNS XR. Diagnostic sensitivity of DT for sinusitis was superior to PNS XR.