Preprocedural determination of an occlusion pathomechanism in endovascular treatment of acute stroke: a machine learning-based decision.

OBJECTIVE: To evaluate whether an occlusion pathomechanism can be accurately determined by common preprocedural findings through a machine learning-based prediction model (ML-PM). METHODS: A total of 476 patients with acute stroke who underwent endovascular treatment were retrospectively included to derive an ML-PM. For external validation, 152 patients from another tertiary stroke center were additionally included. An ML algorithm was trained to classify an occlusion pathomechanism into embolic or intracranial atherosclerosis. Various common preprocedural findings were entered into the model. Model performance was evaluated based on accuracy and area under the receiver operating characteristic curve (AUC). For practical utility, a decision flowchart was devised from an ML-PM with a few key preprocedural findings. Accuracy of the decision flowchart was validated internally and externally. RESULTS: An ML-PM could determine an occlusion pathomechanism with an accuracy of 96.9% (AUC=0.95). In the model, CT angiography-determined occlusion type, atrial fibrillation, hyperdense artery sign, and occlusion location were top-ranked contributors. With these four findings only, an ML-PM had an accuracy of 93.8% (AUC=0.92). With a decision flowchart, an occlusion pathomechanism could be determined with an accuracy of 91.2% for the study cohort and 94.7% for the external validation cohort. The decision flowchart was more accurate than single preprocedural findings for determining an occlusion pathomechanism. CONCLUSIONS: An ML-PM could accurately determine an occlusion pathomechanism with common preprocedural findings. A decision flowchart consisting of the four most influential findings was clinically applicable and superior to single common preprocedural findings for determining an occlusion pathomechanism.

Disconnection-Based Prediction of Poststroke Dysphagia.

BACKGROUND AND PURPOSE: Dysphagia is a common deficit after a stroke and is associated with serious complications. It is not yet fully clear which brain regions are directly related to swallowing. Previous lesion symptom mapping studies may have overlooked structural disconnections that could be responsible for poststroke dysphagia. Here, we aimed to predict and explain the relationship between poststroke dysphagia and the topologic distribution of structural disconnection via a multivariate predictive framework. MATERIALS AND METHODS: We enrolled first-ever ischemic stroke patients classified as full per-oral nutrition (71 patients) and nonoral nutrition necessary (43 patients). After propensity score matching, 43 patients for each group were enrolled (full per-oral nutrition group with 17 women, 68 ± 15 years; nonoral nutrition necessary group with 13 women, 75 ± 11 years). The structural disconnectome was estimated by using the lesion segmented from acute phase diffusion-weighted images. The prediction of poststroke dysphagia by using the structural disconnectome and demographics was performed in a leave-one-out manner. RESULTS: Using both direct and indirect disconnection matrices of the motor network, the disconnectome-based prediction model could predict poststroke dysphagia above the level of chance (accuracy = 68.6%, permutation P = .001). When combined with demographic data, the classification accuracy reached 72.1%. The edges connecting the right insula and left motor strip were the most informative in prediction. CONCLUSIONS: Poststroke dysphagia could be predicted by using the structural disconnectome derived from acute phase diffusion-weighted images. Specifically, the direct and indirect disconnection within the motor network was the most informative in predicting poststroke dysphagia.

Hyperattenuations on flat-panel computed tomography after successful recanalization of mechanical thrombectomy for anterior circulation occlusion.

BACKGROUND: To evaluate intraparenchymal hyperattenuation (IPH) on flat-panel computed tomography (FPCT) findings and their clinical usefulness for predicting prognosis after successful mechanical thrombectomy (MT) for acute occlusion of anterior circulation. METHODS: A retrospective review was conducted for 158 consecutive patients undergoing mechanical thrombectomy during the last six years. After excluding those with posterior circulation occlusion or incomplete recanalization and those without FPCT, 82 patients were finally included. Immediate post-procedural IPH on FPCT was categorized into four patterns (none, striatal, cortical, or combined pattern). Follow-up magnetic resonance images or CT scans after 48 hours from MT were analyzed according to FPCT findings. The existence of hemorrhagic transformation, intracerebral hemorrhage, and brain swelling was evaluated. Functional clinical outcomes were accessed with post-procedural 3-month modified Rankin scales (mRS). RESULTS: Of 82 patients, 34 patients were found to have IPH (16 with a striatal pattern, 8 with a cortical pattern, and 10 with a combined pattern). Hemorrhagic complication (P<0.001), brain swelling (P<0.001), and poor mRS scores (P=0.042) showed significant differences according to IPH patterns. Multivariate logistic regression analysis revealed that the presence of a striatal pattern (OR: 13.26, P<0.001), cortical pattern (OR: 11.61, P=0.009), and combined pattern (OR: 45.34, P<0.001) independently predicted hemorrhagic complications. The location of the occlusion (OR: 4.13, P=0.034), cortical pattern (OR: 5.94, P=0.039), and combined pattern (OR: 39.85, P=0.001) predicted brain swelling. Age (OR: 1.07, P=0.006) and the presence of a combined pattern (OR: 10.58, P=0.046) predicted poor clinical outcomes. CONCLUSIONS: FPCT is a rapid and effective tool for a prompt follow-up just after MT to predict prognosis. Those with striatal patterns showed relatively good clinical outcomes despite significant hemorrhage. Cortical IPH patterns independently predicted a high rate of post-procedural hemorrhage or brain swelling. Combined pattern is a strong predictor for both radiologic and poor clinical outcomes.

Wedging of vertebral bodies at the thoracolumbar spine in healthy individuals on whole body MRI screening: correlation with disc degeneration and disc herniation.

BACKGROUND: There have been no reports on the relationship between wedging of vertebral bodies at the thoracolumbar spine and disc herniation in healthy individuals on magnetic resonance imaging (MRI). PURPOSE: To investigate the degree of wedging of vertebral bodies at the thoracolumbar spine in healthy individuals who underwent whole-body (WB) MRI. We also assessed the correlation between wedging and adjacent disc pathology. MATERIAL AND METHODS: This retrospective study comprised 200 healthy patients who underwent WB MRI as part of a regular health check from January 2019 to February 2019. We measured anterior and posterior vertical heights of each vertebral body between T10 and L2. The ratio of anterior height to posterior height (APR) was calculated, and we evaluated disc degeneration or disc herniation using WB MRI. RESULTS: The APR of T10 was significantly higher than at the other levels (P < 0.05), and the APR of L1 was significantly lower (P < 0.05). Men had a significantly smaller APR than women at T12 to L2 (P < 0.05). Regarding the relationship between APR and disc degeneration, the group without disc degeneration had a higher APR, with statistical significance at T12, L1, and L2. Regarding the relationship between APR and disc herniation, the group without disc herniation had a higher APR, with statistical significance at T11, T12, L1, and L2. CONCLUSION: Wedging of vertebral bodies is most prominent at L1. Although the values were statistically significant only at some levels, the patients with disc degeneration or herniation had more prominent wedge deformity of thoracolumbar spine.

Ultrasound and MRI findings as predictors of propranolol therapy response in patients with infantile hemangioma.

OBJECTIVES: To evaluate the prognostic value of ultrasound and MRI findings in patients with infantile hemangioma undergoing propranolol therapy. METHODS: This study was based on retrospective interpretation of prospectively acquired data. Thirty-eight consecutive patients (28 females and 10 males; mean age ± standard deviation, 3.2 ± 2.2 months) who underwent propranolol treatment for infantile hemangioma were included. Pre-treatment ultrasound images were assessed in terms of echogenicity, lesion height and vascularity. Presence of prominent intratumoral fat, non-fat septa, and enhancement pattern on MRI were retrospectively evaluated. Mann-Whitney test, chi-square, and Fisher's exact tests were used to compare imaging parameters between patients with treatment success and failure. RESULTS: All patients underwent ultrasound and 15 patients underwent MRI. A total of 24 patients showed successful treatment. Between patients with treatment success and failure, there were significant differences in increased vascularity on pre-treatment ultrasound (19/24 vs. 6/14, p = 0.025), decreased vascularity on post-treatment ultrasound (21/24 vs. 5/14, p = 0.001), and prominent intratumoral fat on MRI (1/8 vs. 5/7 p = 0.033). There were no significant differences in echogenicity, lesion height on ultrasound, non-fat septa and MR enhancement pattern. CONCLUSIONS: Increased vascularity on pre-treatment ultrasound was significantly associated with successful treatment for propranolol therapy in patients with infantile hemangioma, whereas prominent fat component on MRI was significantly associated with treatment failure.

Comparison of Embolic Protection with Proximal and Distal Protection Devices: Periprocedural Complications, Clinical Outcomes, and Cerebral Embolic Lesions on Diffusion-Weighted Magnetic Resonance Imaging.

OBJECTIVE: Two main types of embolic protection devices have been used during carotid artery stenting (CAS): distal protection devices (DPDs) and proximal protection devices (PPDs). We compared the complications, clinical outcomes, and new ischemic lesions on diffusion-weighted magnetic resonance imaging (DWI) studies between patients who had undergone CAS using a DPD or PPD. METHODS: We performed a retrospective review of the data from patients who had undergone CAS from March 2010 to January 2016. The periprocedural and 30-day adverse events and new ischemic lesions on DWI studies after CAS were evaluated. RESULTS: CAS was performed in 103 patients (DPD, n = 60; PPD, n = 43). The number of patients with new ischemic lesions was greater in the DPD than in the PPD group (78% vs. 56%; P = 0.014). Most lesions (>90%) were tiny (≤3 mm), and the average number of new tiny lesions per patient was significantly greater in the DPD than in the PPD group (mean, 9.6 vs. 4.0; P = 0.008). No significant differences in the periprocedural or 30-day adverse rates were noted between the 2 groups. Intolerance during the procedure occurred in 5 patients (12%) in the PPD group, 4 of whom had poor collateral circulation. CONCLUSIONS: The number of new ischemic lesions per patient and the incidence of ischemic lesions found on DWI were significantly greater in the DPD than in the PPD group. The lack of differences in the periprocedural and 30-day adverse rates between the 2 groups suggests that cerebral microemboli might not be associated with the clinical outcomes. For patients with poor collateral status, DPDs should be used preferentially to avoid the neurologic compromise associated with PPDs.

Massive Cerebral Microemboli after Protected Carotid Artery Angioplasty and Stenting Using a Distal Filter Embolic Protection Device for a Vulnerable Plaque with a Lipid Rich Necrotic Core and Intraplaque Hemorrhage: A Case Report.

A major concern associated with carotid artery angioplasty and stenting (CAS) is a periprocedural distal cerebral embolization. To prevent distal embolization, embolic protection devices (EPDs) have been developed. However, the risk of cerebral embolism after protected CAS in patents with a vulnerable plaque is controversial and either a silent or a symptomatic stroke can occur despite the use of EPDs. Here, we report a case of a massive cerebral microemboli after a protected CAS using a distal filter EPD for a vulnerable plaque with a lipid rich necrotic core and intraplaque hemorrhage.

Prospective Multicenter Study of the Safety of Gadoteridol in 6163 Patients.

BACKGROUND: The safety of gadolinium-based contrast agents is of fundamental importance. PURPOSE: To determine the frequency and severity of immediate-type adverse reactions to approved doses of gadoteridol in patients referred for routine gadoteridol-enhanced MRI in actual clinical practice settings. STUDY TYPE: Prospective, observational. POPULATION: In all, 6163 subjects were enrolled (mean age: 56.7 ± 15.4 years; range: 6-93 years). FIELD STRENGTH/SEQUENCE: 1.5T and 3.0T. ASSESSMENT: Assessment was of immediate adverse reactions by the investigating radiologist using the MedDRA System Organ Class and preferred term. STATISTICAL TESTS: Summary statistics for continuous variables, descriptive statistics for demographic characteristics. RESULTS: Overall, 19 adverse events occurred in 13 (0.21%) patients, of which 15 in 10 (0.16%) patients were considered related to gadoteridol administration. These events were evenly distributed between male and female subjects and all occurred in adults. Twelve of the 15 related events in eight (0.13%) patients were considered mild in intensity (rapidly self-resolving), while the remaining three events in two patients (0.03%) were considered moderate in intensity. None were of severe intensity and no serious adverse events occurred. DATA CONCLUSION: The rate of immediate-type adverse events following exposure to approved doses of gadoteridol is extremely low, and mostly limited to transient and self-resolving symptoms. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;51:861-868.

An initial experience with the use of whole body MRI for cancer screening and regular health checks.

OBJECTIVES: We evaluated the utility of whole-body MRI (WB MRI) for cancer screening and other regular health evaluations. METHODS: This retrospective study included 229 patients who underwent whole-body MRI as part of a routine health examination and cancer screening. The WB MRIs and radiologic reports were evaluated by a musculoskeletal radiologist, a neuroradiologist, and an abdominal radiologist. The consensus of their findings was characterized into three categories, as follows: suspicion of malignancy (category I); need for follow-up (category II); and no need for follow-up (category III). Any correlations between the abnormal findings and each study group were evaluated using the Mann-Whitney U test and chi-square test. RESULTS: There were six category I lesions, among which two cases were found to involve malignancy. The most common category II findings were annular tears of the disc (14% of category II findings) and severe disc bulging or protrusion, followed by shoulder bursitis and uterine myoma. The most common category III finding was mild disc bulging or protrusion (47% of category III findings). CONCLUSIONS: WB MRI can be used in cancer screening and for regular health evaluations. WB MRI not only provides information about potential malignancy, but also provides information regarding nonmalignant abnormalities that require further evaluation.

Usefulness of multiecho fast field echo MRI in the evaluation of ossification of the posterior longitudinal ligament and dural ossification of the cervical spine.

OBJECTIVES: The diagnosis of ossification of the posterior longitudinal ligament (OPLL) on magnetic resonance imaging (MRI) is challenging. The purpose of this study is to evaluate the usefulness of the multiecho fast field echo (mFFE) MRI in the detection of ossification of the posterior longitudinal ligament and dural ossification (DO) of the cervical spine. METHODS: Sixty-three patients who underwent MRI with mFFE and CT for cervical spine were retrospectively evaluated. The presence of OPLL and DO on MR images was assessed by two independent readers. The sensitivity, specificity, and accuracy of MRI for detecting OPLL and DO were determined using CT as a reference standard. Image contrast ratios were obtained between the OPLL and perilesional structures on each sequence. RESULTS: There were 31 patients with OPLL and 13 DO lesions. The mean sensitivity, specificity, and accuracy of both readers were 94%, 81%, 88% for OPLL and 92%, 81%, 86% for DO, respectively. The contrast ratios for OPLL and intervertebral disc, spinal cord and cerebrospinal fluid were significantly superior on mFFE images, whereas those for OPLL and bone marrow were significantly inferior on mFFE images than those of T1-and T2-weighted images (p ≤ 0.016). CONCLUSIONS: MRI with mFFE may be sufficient for the assessment of OPLL and DO, with good contrasts between OPLL and intervertebral disc, spinal cord, and cerebrospinal fluid.

Radiation dose reduction in multidetector CT in fracture evaluation.

OBJECTIVE: To evaluate whether multidetector CT with low-dose radiation (low-dose CT) of joints can be useful when evaluating fractures. METHODS: Our study included CT scans of 398 patients, 103 shoulder cases, 109 wrist cases, 98 pelvis cases and 88 ankle cases. There were 191 females and 207 males. The low-dose CTs were performed using identical voltage and parameters with the exception of decreased (half of standard dose) tube current. Low-dose and standard-dose images were compared with regards to objective image quality, subjective evaluation of image quality and diagnostic performance for the fractures. RESULTS: There was no significant difference of image noise between standard-dose CT and low-dose CT in every joint (p > 0.05). Each mean value of subjective score did not show significant difference according to the dosage of the CT scan. There were no statistically significant differences in the sensitivity (96-100%), specificity (95.2-100%) or accuracy (97.9-100%) between standard-dose CT and low-dose CT (p values, 0.1336-1.000). CONCLUSION: The evaluation of extremities for fractures using low-dose CT can reduce radiation exposure by about 50% compared with standard-dose CT without affecting image quality or diagnostic performance. Advances in knowledge: Low-dose CT of the extremities (shoulder, pelvis, ankle and wrist) can reduce radiation dose by about 50% compared with standard-dose CT and does not significantly affect image quality or diagnostic performance in fracture detection.

Single-Shot Echo-Planar Diffusion-Weighted MR Imaging at 3T and 1.5T for Differentiation of Benign Vertebral Fracture Edema and Tumor Infiltration.

OBJECTIVE: To compare the apparent diffusion coefficient (ADC) value using single-shot echo-planar imaging sequences at 3T and 1.5T for differentiation of benign fracture edema and tumor infiltration of the vertebral body. MATERIALS AND METHODS: A total of 46 spinal examinations were included in the 1.5T MRI group, and a total of 40 spinal examinations were included in the 3T MRI group. The ADC values of the lesion were measured and calculated. The diagnostic performance of the conventional MR image containing sagittal T2-weighted fat saturated image and each diffusion weighted image (DWI) with an ADC value with different b values were evaluated. RESULTS: The mean ADC value of the benign lesions was higher than that of the malignant lesions on 1.5T and 3T (p < 0.05). The sensitivity of the diagnostic performance was higher with an additional DWI in both 1.5T and 3T, but the sensitivities were similar with the addition of b values of 400 and 1000. The specificities of the diagnostic performances did not show significant differences (p value > 0.05). The diagnostic accuracies were higher when either of the DWIs (b values of 400 and 1000) was added to routine MR image for 1.5T and 3T. Statistical differences between 1.5T and 3T or between b values of 400 and 1000 were not seen. CONCLUSION: The ADC values of the benign lesions were significantly higher than those of the malignant lesions on 1.5T and 3T. There was no statistically significant difference in the diagnostic performances when either of the DWIs (b values of 400 and 1000) was added to the routine MR image for 1.5T and 3T.

Cost-Effectiveness Analysis of Endovascular Coiling versus Neurosurgical Clipping for Intracranial Aneurysms in Republic of Korea.

PURPOSE: The International Subarachnoid Aneurysm Trial (ISAT) revealed that in ruptured intracranial aneurysms (RA), endovascular coiling (EC) yields better clinical outcomes than neurosurgical clipping (NC) at 1 year. In unruptured aneurysms (UIA), EC is being increasingly used as an alternative to NC due to patients' preference. There is a lot of difference in treatment cost (EC vs. NC) between countries. There is one recently published study dealing with the comparative cost analysis only in UIAs in South Korea. But it is a hospital-based study. So, the authors performed a nation-wide cost effective comparison in our country. MATERIALS AND METHODS: This study was a retrospective analysis of healthcare big data open systems in Health Insurance Review & Assessment Service (HIRA). Hospital cost data of the recent 5 years (from January 2010 to December 2014) were analyzed according to patients' age and sex and the presence of subarachnoid hemorrhage. RESULTS: When comparing the total hospital costs for NC of a UIA (n=13,756) and EC of a UIA (n=17,666), NC [mean±standard deviation (SD): ￦7,987,179±3,855,029] resulted in significantly lower total hospital costs than EC [￦10,201,645±5,001,626, p<0.0001], although a shorter hospital stay with EC of a UIA [8.6 ±7.4 days] vs. NC [15.0 ±8.3 days, p<0.0001]. When comparing the total hospital costs for NC of a RA (n=7,293) and EC of a RA (n=6,954), NC [￦13,914,993±6,247,914] resulted in significantly lower total hospital costs than EC [￦16,702,446±7,841,141, p<0.0001], although shorter hospital stays for EC of a RA [19.8 ±11.4] vs. NC [23.0 ±10.3, p<0.0001]. CONCLUSION: The total hospital costs for the NC of both UIAs and RAs were found to be lower than those for EC in South Korea.

Usefulness of the oblique view of three-dimensional isotropic T2-weighted fast spin-echo (VISTA) in the evaluation of anterior cruciate ligament reconstruction.

BACKGROUND: To compare the diagnostic performance of the oblique sagittal and oblique coronal views of the anterior cruciate ligament (ACL) on three-dimensional (3D) volume isotropic turbo spin-echo acquisition (VISTA) images with two-dimensional (2D) fast spin-echo (FSE) T2-weighted images in the diagnosis of complications in ACL reconstruction. MATERIALS AND METHODS: This retrospective study included 74 patients. Both sequences were independently interpreted by two radiologists. RESULT: There were no statistically significant differences in the sensitivity, specificity, or accuracy between the two images. CONCLUSION: The diagnostic performance of the two oblique views on 3D VISTA imaging was comparable to that of 2D FSE.

Usefulness of the quantitative evaluation of diffusion-weighted mri in the diagnosis of anterior cruciate ligament tears.

PURPOSE: To evaluate the usefulness of the diffusion-weighted imaging (DWI) in the diagnosis of anterior cruciate ligament (ACL) tear using the contrast-to-noise ratio (CNR) and apparent diffusion coefficient (ADC) values according to the different b values. MATERIALS AND METHODS: Institutional review board approval was acquired. We evaluated 74 patients (M:F = 43:31, mean age of 44 years) who underwent 3.0 Tesla knee MR with DWI because of the possibility of ACL tear due to trauma. Region of interest measurements were performed. We (two radiologists) measured the signals of the DWI and derived ADC values on the oblique sagittal DWI with b values of 0, 600, and 1000. The diagnostic accuracies of the conventional MR image and each DWI with an ADC value with a different b value were evaluated. The CNR and ADC values were compared using the Mann-Whitney U-test. The diagnostic performances of the various imaging methods were evaluated using the sensitivity, specificity, and accuracy for differentiating between normal and ACL injury as determined by the use of conventional MRI with additional DWIs with McNemar test. The arthroscopic or clinical findings were used as the reference standard. RESULTS: The mean CNRs of ligament tears with b values of 600 and 1000 were significantly higher than those of normal ligament (22 versus 7 and 9 versus 4, P value < 0.05). The sensitivities and the accuracies of the DWI were significantly lower than the conventional MRIs (P value < 0.001). CONCLUSIONS: The CNRs of the torn ACL with each b value (600 and 1000) were significantly higher those of than normal ligament, although the ADC values of the torn ligament were not different from normal ligament. Addition of the DWI to the conventional MRI did not improve diagnostic performance. J. Magn. Reson. Imaging 2016;44:1116-1122.

Delayed Ischemic Stroke after Flow Diversion of Large Posterior Communicating Artery Aneurysm.

For securing large, giant, and wide-neck aneurysms, conventional coil embolization has substantial limitations, such as incomplete occlusion, recanalization, and a high recurrence rate. To overcome these limitations, a novel paradigm was suggested and, as a result, flow-diverting device was developed. The flow-diverting device is an innovative and effective technique to allow securing of large, giant, and wide-neck aneurysms. In numerous studies, the flow-diverting device has shown better outcomes than coil embolization. However, the flow-diverting device has also some risks, including rupture of aneurysm, intracerebral hemorrhage, and ischemic stroke. In addition, with more experience, unexpected complications are also reported.5)7) In the present case, we experienced a delayed ischemic stroke at 27 days after endovascular treatment. The patient had multiple aneurysms and, among them, we treated a large posterior communicating artery aneurysm using Pipeline™ Embolization Device. The patient was tolerable for 25 days, but then suddenly presented intermittent right hemiparesis. In the initial diffusion magnetic resonance imaging (MRI), there was no acute lesion; however, in the follow-up MRI, an acute ischemic stroke was found in the territory of anterior choroidal artery which was covered by Pipeline Embolization Device. We suspect that neo-intimal overgrowth or a tiny thrombus have led to this delayed complication. Through our case, we learned that the neurosurgeon should be aware of the possibility of delayed ischemic stroke after flow diversion, as well as, long-term close observation and follow-up angiography are necessary even in the event of no acute complications.

Discordance between conventional ultrasonography and ElastPQ for assessing hepatic fibrosis in chronic hepatitis B: frequency and independent factors.

PURPOSE: To investigate the frequency of discordance and to identify factors associated with discordance between ultrasonographic and elastographic grades for assessing hepatic fibrosis in Asian patients with chronic hepatitis B. METHODS: Three hundred thirty-four patients with chronic hepatitis B for which both conventional ultrasonography and liver stiffness measurements using elastography were available were included. Patients were graded as 'normal', 'chronic liver disease', or 'liver cirrhosis' by ultrasonography, and as 'no significant fibrosis', 'significant fibrosis', or 'liver cirrhosis' by elastography, and the results of these two modalities were compared. Logistic regression analyses were performed to identify independent factors associated with discordant results. RESULTS: Of the 334 patients, 153 (45.8 %), 115 (34.4 %), and 66 (19.8 %) patients were 'normal', 'chronic liver disease', and 'liver cirrhosis', respectively, based on the ultrasonographic grades, and 290 (86.8 %), 29 (8.7 %), and 15 (4.5 %) patients were 'no significant fibrosis,' 'significant fibrosis', and 'liver cirrhosis', respectively, based on the elastographic values. Among them, 173 (51.8 %) showed discordance with respect to severity of hepatic fibrosis. In multivariable analysis, discordance was more frequent in patients with ultrasonographic grades of 'chronic liver disease' [adjusted odds ratio (AOR), 1924; P < 0.001] and 'liver cirrhosis' (AOR, 4498; P < 0.001), whereas patients with an elastographic grade of 'liver cirrhosis' showed a negative association with discordance (AOR, 0.002; P = 0.007). CONCLUSION: There was a high rate of discordance between hepatic fibrosis grades determined by ultrasonography and elastography. Considering the accuracy of liver stiffness evaluation by elastography, conventional ultrasonography might overestimate hepatic fibrosis in chronic hepatitis B.

Modified thoracolumbar injury classification and severity score (TLICS) and its clinical usefulness.

BACKGROUND: Thoracolumbar injury classification and severity score (TLICS) is not very reliable for assessment of injury to the posterior ligament complex, even when scored by experts. It is not reasonable to score every compression fracture or burst fracture the same as there is great variety in the severity of compression fractures and burst fractures. PURPOSE: To propose a modified TLICS (mTLICS) and evaluate the performance of the mTLICS system by measuring the agreement between scores determined by radiologists using both systems and actual treatment procedure delivered. MATERIAL AND METHODS: We retrospectively evaluated 134 patients with acute lumbar and thoracic spinal trauma after undergoing magnetic resonance imaging (MRI) using new mTLICS and conventional TLICS system. Inter-observer agreements of TLICS and mTLICS scores were analyzed using the kappa statistic. Nonparametric correlation analysis was used to determine correlation (R) among each score and the surgical intervention. RESULTS: The mTLICS system showed slightly higher correlation than TLICS (Rs, TLICS, 0.592 and 0.613 vs. mTLICS, 0.628 and 0.639). If we consider a total maximal score of 4 to be a negative surgical indication, mTLICS showed significantly higher sensitivities than TLICS, and if we consider a total minimal score of 4 to be a positive surgical indication, mTLICS showed significantly higher specificities than TLICS. CONCLUSION: The mTLICS score corrects deficiencies in the TLICS system that lead to ambiguity in the radiological diagnostic criteria. mTLICS is a more suitable scoring system than TLICS for predicting surgical management accurately, especially for morphological injuries.

Long-Term Ultrasonography Follow-Up of Thyroid Colloid Cysts at the Health Center: A Single-Center Study.

Objective. No previous study has employed long-term follow-up ultrasonography (US) examinations for evaluating thyroid colloid cysts (TCCs) in the general population. This study aimed to assess the interval changes of TCCs at the health center by evaluating long-term US follow-up examinations. Methods. For evaluation of the thyroid gland at our health center from 2006 to 2010, 3692 individuals underwent 4 or more thyroid US examinations at an interval of 1 year or 2 years. We assessed the interval changes of TCCs ≥ 5 mm on US follow-up examinations. Results. Of the 3692 subjects, only 115 (3.1%) showed TCCs ≥ 5 mm on one or more thyroid US examinations. The interval changes in TCCs, as shown by the thyroid US examinations performed during the study period, were classified as follows: no interval change (n = 60), gradual increase (n = 37), gradual decrease (n = 6), positive fluctuation (n = 10), negative fluctuation (n = 0), and disappearance (n = 2). No subject reported any relevant symptom pertaining to TCCs. Conclusions. Overall, follow-up US examinations showed various interval changes in TCCs, but a majority of TCCs showed no interval change or a gradual increase in size.

Ultrasound-Guided Percutaneous Removal of Wooden Foreign Bodies in the Extremities with Hydro-Dissection Technique.

OBJECTIVE: We described the technique of ultrasound (US)-guided percutaneous removal of the foreign bodies (FB) with hydro-dissection in the radiologic department and presented video files of several cases. MATERIALS AND METHODS: Four patients referred to the radiology department for US evaluation and US-guided percutaneous removal of the FBs in the upper and lower extremities between November, 2006 and November, 2013 were included in this study. The procedures started with US evaluation for the exact location and shape of the FB. A 5 mm-sized skin incision was made at the site of the nearest point from the FB where no passing arteries or tendons were present. We adopted a hydrodissection technique to separate the FB from adjacent tissue using a 2% lidocaine solution. Injected anesthetics detached the FBs from surrounding tissue and thereby facilitated removal. After the tip of the mosquito forceps reached the FB, the wooden FBs were removed. RESULTS: The mean time required for the entire procedure was approximately 20 minutes. There were no significant complications during the US-guided removal or long-term complications after the procedure. All 4 FBs were successfully removed from the soft tissue under US guidance. CONCLUSION: Ultrasound-guided percutaneous removal of the FBs with hydro-dissection in the radiology department is a less invasive and safe method over surgical removal in the operating room. Additionally, the use of a guide wire and serial dilator may help minimize soft tissue injury and facilitate the introduction of forceps.