Objective: This study aimed to validate the risk stratification system (RSS) and biopsy criteria for cervical lymph nodes (LNs) proposed by the Korean Society of Thyroid Radiology (KSThR). Materials and Methods: This retrospective study included a consecutive series of preoperative patients with thyroid cancer who underwent LN biopsy, ultrasound (US), and computed tomography (CT) between December 2006 and June 2015. LNs were categorized as probably benign, indeterminate, or suspicious according to the current US- and CT-based RSS and the size thresholds for cervical LN biopsy as suggested by the KSThR. The diagnostic performance and unnecessary biopsy rates were calculated. Results: A total of 277 LNs (53.1% metastatic) in 228 patients (mean age ± standard deviation, 47.4 years ± 14) were analyzed. In US, the malignancy risks were significantly different among the three categories (all P < 0.001); however, CTdetected probably benign and indeterminate LNs showed similarly low malignancy risks (P = 0.468). The combined US + CT criteria stratified the malignancy risks among the three categories (all P < 0.001) and reduced the proportion of indeterminate LNs (from 20.6% to 14.4%) and the malignancy risk in the indeterminate LNs (from 31.6% to 12.5%) compared with US alone. In all image-based classifications, nodal size did not affect the malignancy risks (short diameter [SD] ≤ 5 mm LNs vs. SD > 5 mm LNs, P ≥ 0.177). The criteria covering only suspicious LNs showed higher specificity and lower unnecessary biopsy rates than the current criteria, while maintaining sensitivity in all imaging modalities. Conclusion Integrative evaluation of US and CT helps in reducing the proportion of indeterminate LNs and the malignancy risk among them. Nodal size did not affect the malignancy risk of LNs, and the addition of indeterminate LNs to biopsy candidates did not have an advantage in detecting LN metastases in all imaging modalities.

Objective: The distinction between idiopathic normal pressure hydrocephalus (iNPH) and hydrocephalus ex vacuo caused by encephalic volume loss remains to be established. This study aims to investigate radiological parameters as clinically useful tools to discriminate iNPH from hydrocephalus ex vacuo caused by Alzheimer’s disease (AD). Methods: A total of 54 patients with ventriculomegaly (iNPH, 25; hydrocephalus ex vacuo, 29) were recruited in this study. Consequently, nine radiological parameters were compared between iNPH and hydrocephalus ex vacuo using magnetic resonance imaging (MRI). Results: A small callosal angle (CA), the Sylvian fissure dilatation, and absence of narrowing of superior parietal sulci discriminated the iNPH group from the hydrocephalus ex vacuo group (p<0.05). The final binary logistic regression model included narrowing of superior parietal sulci, degrees of the CA, and height of the Sylvian fissure after controlling for age and global Clinical Dementia Rating (CDR). The composite score made from these three indicators (narrowing of superior parietal sulci, degrees of the CA, and height of the Sylvian fissure) was statistically different between iNPH and hydrocephalus ex vacuo. Conclusion The narrowing of the CA, dilatation of the Sylvain fissure, and narrowing of superior parietal sulci may be used as radiological key indices and noninvasive tools for the differential diagnosis of iNPH from hydrocephalus ex vacuo.

Objective: The distinction between idiopathic normal pressure hydrocephalus (iNPH) and hydrocephalus ex vacuo caused by encephalic volume loss remains to be established. This study aims to investigate radiological parameters as clinically useful tools to discriminate iNPH from hydrocephalus ex vacuo caused by Alzheimer’s disease (AD). Methods: A total of 54 patients with ventriculomegaly (iNPH, 25; hydrocephalus ex vacuo, 29) were recruited in this study. Consequently, nine radiological parameters were compared between iNPH and hydrocephalus ex vacuo using magnetic resonance imaging (MRI). Results: A small callosal angle (CA), the Sylvian fissure dilatation, and absence of narrowing of superior parietal sulci discriminated the iNPH group from the hydrocephalus ex vacuo group (p<0.05). The final binary logistic regression model included narrowing of superior parietal sulci, degrees of the CA, and height of the Sylvian fissure after controlling for age and global Clinical Dementia Rating (CDR). The composite score made from these three indicators (narrowing of superior parietal sulci, degrees of the CA, and height of the Sylvian fissure) was statistically different between iNPH and hydrocephalus ex vacuo. Conclusion The narrowing of the CA, dilatation of the Sylvain fissure, and narrowing of superior parietal sulci may be used as radiological key indices and noninvasive tools for the differential diagnosis of iNPH from hydrocephalus ex vacuo.

Objective: To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on steam popping duringradiofrequency (RF) ablation for treating hepatocellular carcinoma (HCC), and to assess whether popping affects treatmentoutcomes. Materials and Methods: The institutional review board approved this retrospective study, which included 90 consecutivepatients with single HCC, who received percutaneous RF ablation as the first-line treatment. The patients were divided intotwo groups, based on the presence or absence of the popping phenomenon, which was defined as an audible sound with asimultaneous sudden explosion within the ablation zone as detected via ultrasonography during the procedure. The factorscontributing to the popping phenomenon were identified using multivariable logistic regression analysis. Local tumor progression(LTP) and disease-free survival (DFS) were assessed using the Kaplan-Meier method with the log-rank test for performingcomparisons between the two groups. Results: The overall incidence of the popping phenomenon was 25.8% (24/93). Sonazoid® was used in 1 patient (4.2%) inthe popping group (n = 24), while it was used in 15 patients (21.7%) in the non-popping group (n = 69). Multivariableanalysis revealed that the use of Sonazoid® was the only significant factor for absence of the popping phenomenon (oddsratio = 0.10, p= 0.048). There were no significant differences in cumulative LTP and DFS between the two groups (p= 0.479and p= 0.424, respectively). Conclusion The use of Sonazoid® has a suppressive effect on the popping phenomenon during RF ablation in patients withHCC. However, the presence of the popping phenomenon may not affect clinical outcomes.

BACKGROUND: Quantitative susceptibility mapping (QSM) has been used to measure iron accumulation in the deep nuclei of patients with Parkinson's disease (PD). This study examined the relationship between non-motor symptoms (NMSs) and iron accumulation in the deep nuclei of patients with PD. METHODS: The QSM data were acquired from 3-Tesla magnetic resonance imaging (MRI) in 29 patients with early PD and 19 normal controls. The Korean version of the NMS scale (K-NMSS) was used for evaluation of NMSs in patients. The patients were divided into high NMS and low NMS groups. The region-of-interest analyses were performed in the following deep nuclei: red nucleus, substantia nigra pars compacta, substantia nigra pars reticulata, dentate nucleus, globus pallidus, putamen, and head of the caudate nucleus. RESULTS: Thirteen patients had high NMS scores (total K-NMSS score, mean = 32.1), and 16 had low NMS scores (10.6). The QSM values in the deep were not different among the patients with high NMS scores, low NMS scores, and controls. The QSM values were not correlated linearly with K-NMSS total score after adjusting the age at acquisition of brain MRI. CONCLUSION: The study demonstrated that the NMS burdens are not associated with iron accumulation in the deep nuclei of patients with PD. These results suggest that future neuroimaging studies on the pathology of NMSs in PD should use more specific and detailed clinical tools and recruit PD patients with severe NMSs.
Basal Ganglia ; Brain ; Caudate Nucleus ; Cerebellar Nuclei ; Globus Pallidus ; Head ; Humans ; Iron* ; Magnetic Resonance Imaging ; Neuroimaging ; Parkinson Disease* ; Pars Compacta ; Pars Reticulata ; Pathology ; Putamen ; Red Nucleus

BACKGROUND: The purpose of this study was to qualitatively and quantitatively evaluate the effects of a metal artifact reduction for orthopedic implants (O-MAR) for brain computed tomographic angiography (CTA) in patients with aneurysm clips and coils. METHODS: The study included 36 consecutive patients with 47 intracranial metallic implants (42 aneurysm clips, 5 coils) who underwent brain CTA. The computed tomographic images with and without the O-MAR were independently reviewed both quantitatively and qualitatively by two reviewers. For quantitative analysis, image noises near the metallic implants of non-O-MAR and O-MAR images were compared. For qualitative analysis, image quality improvement and the presence of new streak artifacts were assessed. RESULTS: Image noise was significantly reduced near metallic implants (P < 0.01). Improvement of implant-induced streak artifacts was observed in eight objects (17.0%). However, streak artifacts were aggravated in 11 objects (23.4%), and adjacent vessel depiction was worsened in eight objects (17.0%). In addition, new O-MAR-related streak artifacts were observed in 32 objects (68.1%). New streak artifacts were more prevalent in cases with overlapping metallic implants on the same axial plane than in those without (P = 0.018). Qualitative assessment revealed that the overall image quality was not significantly improved in O-MAR images. CONCLUSION: In conclusion, the use of the O-MAR in patients with metallic implants significantly reduces image noise. However, the degree of the streak artifacts and surrounding vessel depiction were not significantly improved on O-MAR images.
Aneurysm ; Angiography* ; Artifacts* ; Brain* ; Humans ; Noise ; Orthopedics* ; Quality Improvement

OBJECTIVE: To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. MATERIALS AND METHODS: A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. RESULTS: The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. CONCLUSION: Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments.
Biopsy ; Biopsy, Large-Core Needle* ; Catheter Ablation ; Electrodes ; Hemorrhage* ; Hemostasis ; Heparin ; Liver* ; Needles ; Pulsed Radiofrequency Treatment ; Swine

PURPOSE: To analyze the improvement of symptoms and signs of dry eye after surgical punctual occlusion and to evaluate the effects of secondary systemic disease in dry eye patients. METHODS: From March 2011 to July 2014, 15 eyes of 8 dry eye patients with a history of punctal plug insertion underwent surgical punctal occlusion. Schirmer test was measured based on mean 2.9 mm. The patients consisted of 4 dry eye patients with Sjogren's disease, 1 with rheumatoid arthritis, 1 with graft-versus-host disease (GVHD), and 2 with no secondary systemic disease. Preoperative and postoperative ophthalmic examinations of log MAR visual acuity, subjective symptoms, corneal staining (National Eye Institute [NEI] score), and tear break-up time (BUT) were performed and the effects of secondary systemic disease in dry eye patients were evaluated. The results of surgical punctual occlusion were analyzed. RESULTS: All patients showed a statistically significant improvement of log MAR visual acuity, subjective symptoms, corneal staining (NEI score), and tear BUT. The patients with rheumatoid-related diseases showed improved symptoms after surgery, but the patient with GVHD showed no significant improvement after surgery. Among the study patients, 80.0% showed completely closed punctum and 20.0% showed partial recanalization. CONCLUSIONS: Surgical punctal occlusion is an effective alternative in patients with severe aqueous deficient dry eye who show recurrent punctal plug loss or complications associated with punctal plugs.
Arthritis, Rheumatoid ; Graft vs Host Disease ; Humans ; Sjogren's Syndrome ; Tears ; Visual Acuity

PURPOSE: To evaluate the objective amplitude of accommodation in various age groups using an autorefractometer and to compare the results with subjective assessments on accommodation. Objective accommodative amplitude of artificial lenses in post-operative cataract patients was also measured. METHODS: In this study, 41 patients who visited Korea University Guro Hospital from July through August 2014 were categorized into 6 different age groups. Accommodative amplitude was measured using long-distance refraction at 5 m and short-distance refraction at 20 cm. In 20 patients, subjective amplitude of accommodation was measured using the minus lens technique and was compared with the measured objective accommodative amplitude. Accommodative amplitude was also measured in 8 patients who received cataract surgery. RESULTS: The mean accommodative ability in normal people was 2.38 D. The age groups of 10-19, 20-29, 30-39, 40-49, 50-59, and over 60 years showed accommodative amplitudes of 3.31 +/- 0.99 D, 3.25 +/- 0.34 D, 3.78 +/- 0.68 D, 1.00 +/- 0.60 D, 0.22 +/- 0.23 D, 0.00 +/- 0.00 D, respectively. The results showed a rapid decrease in accommodative ability of patients older than 40 years and demonstrated a correlation between objective and subjective amplitude of accommodation (Pearson's correlation coefficient 0.838). There was a significant difference between objective and subjective accommodative amplitudes in artificial lenses (p = 0.015), with average objective and subjective measures of 0.10 +/- 0.23 D and 0.59 +/- 0.35 D, respectively. CONCLUSIONS: Measuring amplitude of accommodation using an autorefractometer can be useful in assessing results of presbyopia treatment.
Cataract ; Humans ; Korea ; Presbyopia

PURPOSE: Warm compression using a commercial heat pad was used to evaluate the effects of temperature on the eyelids and tear film lipid layer thickness. METHODS: Targeting 13 patients (26 eyes) with non-specific eye disease such as dry eye syndrome or Meibomian gland dysfunction, we measured the average thickness of the tear film lipid layer in both eyes with the LipiView 2® System (Tearscience®, Morrisville, NY, USA). We performed warm compression on the right eye only in order to evaluate the effectiveness of massage and measured the temperature of the right eye lid immediately, 3 minutes, and 5 minutes after compression in order to compare with the untreated left eye. After warm compression for 5 minutes, we measured tear film lipid layer thickness of both eyes and analyzed the effectiveness of warm compression. RESULTS: The average tear film lipid layer thickness was 55.1 ± 21.0 nm in the right eyes and 53.9 ± 13.9 nm in the left eyes (p = 0.474). Before performing the warm compression, the temperature of the right eye lid was 53.9 ± 13.9 nm, and that of the left was 35.9 ± 0.2℃. The eye lid temperature of the right eye immediately, 3 minutes, and 5 minutes after warm compression was 40.3 ± 1.3℃, 40.3 ± 1.3℃, and 40.3 ± 1.9℃, respectively, and these temperatures were relatively constant during the massage. Tear film lipid layer thickness after warm compression in the right eye was 83.5 ± 18.8 nm, which was increased compared to the original temperature (p = 0.001) and showed significant difference compared with the 65.5 ± 27.1 nm in the left eye (p = 0.005). CONCLUSIONS: Warm compression increased the tear film lipid layer thickness and showed a relatively constant increased temperature of 40.3℃ over 5 minutes. This technique will be helpful for maintaining tear film lipid layer thickness in patients with Meibomian gland dysfunction.
Dry Eye Syndromes ; Eye Diseases ; Eyelids* ; Hot Temperature ; Humans ; Massage ; Meibomian Glands ; Tears*