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493 result(s) for "Jung, Dae Chul"
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Non-contrast magnetic resonance imaging for bladder cancer: fused high b value diffusion-weighted imaging and T2-weighted imaging helps evaluate depth of invasion
Objects To investigate the utility of fused high b value diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) for evaluating depth of invasion in bladder cancer. Methods We included 62 patients with magnetic resonance imaging (MRI) and surgically confirmed urothelial carcinoma in the urinary bladder. An experienced genitourinary radiologist analysed the depth of invasion (T stage <2 or ≥2) using T2WI, DWI, T2WI plus DWI, and fused DWI and T2WI (fusion MRI). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were investigated. Area under the curve (AUC) was analysed to identify T stage ≥2. Results The rate of patients with surgically confirmed T stage ≥2 was 41.9% (26/62). Sensitivity, specificity, PPV, NPV and accuracy were 50.0%, 55.6%, 44.8%, 60.6% and 53.2%, respectively, with T2WI; 57.7%, 77.8%, 65.2%, 71.8% and 69.4%, respectively, with DWI; 65.4%, 80.6%, 70.8%, 76.3% and 74.2%, respectively, with T2WI plus DWI and 80.8%, 77.8%, 72.4%, 84.9% and 79.0%, respectively, with fusion MRI. AUC was 0.528 with T2WI, 0.677 with DWI, 0.730 with T2WI plus DWI and 0.793 with fusion MRI for T stage ≥2. Conclusion Fused high b value DWI and T2WI may be a promising non-contrast MRI technique for assessing depth of invasion in bladder cancer. Key Points • Accuracy of fusion MRI was 79.0% for T stage ≥2 in bladder cancer . • AUC of fusion MRI was 0.793 for T stage ≥2 in bladder cancer . • Diagnostic performance of fusion MRI was comparable with T2WI plus DWI . • As a non-contrast MRI technique, fusion MRI is useful for bladder cancer .
Ultrasonography-assisted near-infrared spectroscopy imaging enhanced by gold nanorods in a xenograft mouse model of prostate cancer
Purpose: This study aimed to develop and evaluate a near-infrared spectroscopy (NIRS) system enhanced by gold nanorods (GNRs) for the detection of prostate cancer using phantom and xenograft mouse models.Methods: A hybrid ultrasound-NIRS (US-NIRS) system was created with a 785 nm wavelength, integrating eight laser diodes and four detectors with a linear ultrasound probe. Software for processing near-infrared (NIR) signals was developed using an engineering toolkit and an image reconstruction package. Two optical phantoms simulating prostate cancer were constructed using TiO 2 for scattering effects and India ink for absorption effects, each containing a cylindrical cavity for GNRs positioned at depths of 1 cm and 2 cm. A xenograft mouse model was prepared by injecting PC-3 cells into the right flank of nude mice. PEGylated GNRs (GNR-PEG) were synthesized. US-NIRS imaging was performed on mice before and after intravenous injection of GNR-PEG.Results: Ultrasonography revealed solid, vascular tumors without necrosis or hemorrhage. Preinjection NIRS showed higher baseline NIR absorbance in tumors compared to normal tissue (optical depths: 0.26, 1.52, and 0.24 for the 1.5 cm, 1.4 cm, and 0.5 cm tumors, respectively). After GNR-PEG injection, tumor optical depths significantly increased (3.36, 4.39, and 1.69 for the 1.5 cm, 1.4 cm, and 0.5 cm tumors, respectively), peaking around 5 minutes, and subsequently decreasing towards baseline levels by 60 minutes.Conclusion: A US-NIRS hybrid imaging system enhanced by GNR-PEG demonstrated increased NIR absorption in prostate cancer xenografts. This fusion imaging technique holds potential for future clinical applications in detecting prostate cancer.
Can measurement of apparent diffusion coefficient before treatment predict the response to uterine artery embolization for adenomyosis?
Objectives To determine the usefulness of the apparent diffusion coefficient (ADC) in predicting response to uterine artery embolization (UAE) for symptomatic adenomyosis. Methods A prospective study was performed on 25 patients who underwent diffusion-weighted (DW) magnetic resonance imaging (MRI) before UAE between June 2011 and December 2012. All patients underwent 3-month follow-up MRI after UAE using non-spherical polyvinyl alcohol (PVA) particles ranging from 150 to 500 μm. Quantitative measurement of the ADC was performed for each adenomyosis. Complete response and incomplete response were defined as ≥90 % or <90 %, respectively, of the non-perfusion area with adenomyosis at the follow-up MRI. The ADC values were compared between patients who achieved complete or incomplete response which was assessed according to the MRI findings after UAE. Results Nineteen patients showed complete response, and six showed incomplete response. The ADC value ranged from 0.842 to 1.346 × 10 -3  mm 2 /s (mean 1.075 ± 0.117). The mean ADC was 1.043 ± 0.237 in the complete response group and 1.176 ± 0.429 in the incomplete response group (0.012). Using a threshold of <1.147 × 10 -3  mm 2 /s, the sensitivity and specificity of the ADC to predict success after UAE were 83.3 % and 84.2 %. Conclusion The ADC of adenomyosis may potentially predict a successful response to UAE for adenomyosis. Key Points • Pre-procedural MRI might help clinicians predict response of UAE in adenomyosis • ADC might help predict UAE outcomes in adenomyosis • MR predictors might be used to counsel patients with symptomatic adenomyosis
Preoperative Prediction Model of Lymph Node Metastasis in Endometrial Cancer
Background:We aimed to develop a preoperative prediction model identifying the low-risk group for lymph node metastasis in endometrial cancer.Methods:In 110 patients who underwent preoperative magnetic resonance imaging and serum CA-125 test, logistic analysis was performed to identify predictors. The coefficients obtained from logistic regression were used to construct a scoring system, and a receiver operator characteristic curve was created.Results:Lymph node metastases were found in 14 (12.7%) of 110 patients. After multivariate logistic regression analysis, histologic grade, preoperative CA-125 levels, disease extent, and myometrial invasion assessed by magnetic resonance imaging were selected as viable predictors. The scoring system was internally validated using bootstrapping (P < 0.001), and receiver operator characteristic curve yielded the area under the curve of 0.902. The patients with the score of 0 or 1 (57.3%) were identified as a low-risk group, and no nodal metastasis was observed among them (negative predictive value, 100%: 95% confidence interval, 94.3%-100%).Conclusion:The current study suggests that preoperative prediction system to identify the risk of lymph node metastasis is feasible. This model may be useful in preoperative counseling about cost and benefit of systemic lymph node dissection.
Imaging Patterns of Bacillus Calmette–Guérin-Related Granulomatous Prostatitis Based on Multiparametric MRI
To categorize multiparametric MRI features of Bacillus Calmette-Guérin (BCG)-related granulomatous prostatitis (GP) and discover potential manifestations for its differential diagnosis from prostate cancer. The cases of BCG-related GP in 24 male (mean age ± standard deviation, 66.0 ± 9.4 years; range, 50-88 years) pathologically confirmed between January 2011 and April 2019 were retrospectively reviewed. All patients underwent intravesical BCG therapy followed by a MRI scan. Additional follow-up MRI scans, including diffusion-weighted imaging (DWI), were performed in 19 patients. The BCG-related GP cases were categorized into three: A, B, or C. The lesions with diffusion restriction and homogeneous enhancement were classified as type A. The lesions with diffusion restriction and a poorly enhancing component were classified as type B. A low signal intensity on high b-value DWI (b = 1000 s/mm²) was considered characteristic of type C. Two radiologists independently interpreted the MRI scans before making a consensus about the types. The median lesion size was 22 mm with the interquartile range (IQR) of 18-26 mm as measured using the initial MRI scans. The lesion types were A, B, and C in 7, 15, and 2 patients, respectively. Cohen's kappa value for the inter-reader agreement for the interpretation of the lesion types was 0.837. On the last follow-up MRI scans of 19 patients, the size decreased (median, 5.8 mm; IQR, 3.4-8.5 mm), and the type changed from A or B to C in 11 patients. The lesions resolved in four patients. In five patients who underwent prostatectomy, caseous necrosis on histopathology matched with the non-enhancing components of type B lesions and the entire type C lesions. BCG-related GP demonstrated three imaging patterns on multiparametric MRI. Contrast-enhanced T1-weighted imaging and DWI may play a role in its differential diagnosis from prostate cancer.
A potential imaging-based predictor for renal functional outcomes after partial nephrectomy for localized renal masses
Background To determine whether postoperative renal parenchymal volume from first post-operative computed tomography (CT) is a significant prognostic factor for chronic kidney disease (CKD) on the long-term follow up after partial nephrectomy (PN). Methods This retrospective study included 319 patients who underwent PN for T1 localized renal cell carcinoma (RCC) between September 2006 and December 2020. Kidney volume data of first postoperative CT and preoperative CT was made with a three-dimensional rendering software. Time-dependent cox proportional-hazards regression analysis was used to find important risk factors that indicate the development of new-onset CKD following PN, adding kidney volume data to various clinical parameters. Results Of the 319 patients who underwent PN for T1 localized RCC, a total of 13 patients (4.0%) had new-onset CKD at last follow up and developed it at a median follow up of 46 months. Univariate analyses of the Cox proportional hazards model showed that age, hypertension, preoperative/postoperative eGFR, and total kidney volume/kilogram body weight were potential risk factors associated with new-onset CKD development. In multivariable cox proportional models, the likelihood-ratio test confirmed that overall performance of models was improved by including total kidney volume ( p  = 0.008). Conclusions Renal parenchymal volume of first postoperative CT was a significant risk factor of CKD development on long-term follow up in patients with T1 RCC after PN. Therefore, first postoperative imaging studies will be able to help predict CKD development, as well as to assess the success of the surgery and to monitor recurrence or complications.
Prediction of biochemical recurrence after radical prostatectomy with PI-RADS version 2 in prostate cancers: initial results
Objectives To determine whether the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) helps predict biochemical recurrence (BCR) after radical prostatectomy for prostate cancer (PCa). Methods We included 158 patients with PCa who underwent magnetic resonance imaging (MRI) and radical prostatectomy (RP). Clinical (prostate-specific antigen, greatest percentage of core, and percentage of positive core number), PI-RADSv2 score on MRI, and surgical parameters (Gleason score, extracapsular extension, seminal vesicle invasion, and tumour volume) were investigated. Univariate and multivariate analyses using Cox’s proportional hazards model were performed to assess parameters predictive of BCR (two consecutive prostate specific antigens ≥0.2 ng/ml). Kaplan-Meier survival curves were analyzed. Results The rate of BCR was 13.3 % (21/158) after surgery (median follow-up, 25 months; range, 12–36). No subject with a PI-RADS score <4 had BCR. In univariate analysis, all parameters were significant for BCR ( p  < 0.05), except seminal vesicle invasion ( p  = 0.254). Meanwhile, PI-RADS score was the only independent parameter for BCR in multivariate analysis ( p  < 0.05). Two-year, BCR-free survival post-RP was significantly lower for PI-RADS ≥4 (84.7–85.5 %) than for PI-RADS <4 (100 %; p  < 0.05). Conclusion As a preoperative imaging tool, PI-RADSv2 may be useful to predict BCR after radical prostatectomy for PCa. Key Points • No subject with PI-RADS <4 had BCR after RP • PI-RADSv2 was the only predictor of BCR in multivariate analysis • Two-year, BCR-free survival following RP was lower for PI-RADS≥4 than for PI-RADS<4 • Inter-rater agreement was good for PI-RADS ≥4 or not
Predicting Urinary Stone Composition in Single-Use Flexible Ureteroscopic Images with a Convolutional Neural Network
Background and Objectives: Analysis of urine stone composition is one of the most important factors in urolithiasis treatment. This study investigated whether a convolutional neural network (CNN) can show decent results in predicting urinary stone composition even in single-use flexible ureterorenoscopic (fURS) images with relatively low resolution. Materials and Methods: This study retrospectively used surgical images from fURS lithotripsy performed by a single surgeon between January 2018 and December 2021. The ureterorenoscope was a single-use flexible ureteroscope (LithoVue, Boston Scientific). Among the images taken during surgery, a single image satisfying the inclusion and exclusion criteria was selected for each stone. Cases were divided into two groups according to whether they contained any calcium oxalate (the Calcium group) or none (the Non-calcium group). From 506 total cases, 207 stone surface images were finally included in the study. In the CNN model, the transfer learning method using Resnet-18 as a pre-trained model was used, and only endoscopic digital images and stone classification data were input to achieve minimally supervised learning. Results: There were 175 cases in the Calcium group and 32 in the Non-calcium group. After training and validation, the model was tested using the test set, and the total accuracy was 81.8%. Recall and precision of the test results were 88.2% and 88.2% in the Calcium group and 60.0% and 60.0% in the Non-calcium group, respectively. The area under the receiver operating characteristic curve of the model, which represents its classification performance, was 0.82. Conclusions: Single-use flexible ureteroscopes have financial benefits but low vision quality compared with reusable digital flexible ureteroscopes. As far as we know, this is the first artificial intelligence study using single-use fURS images. It is meaningful that the CNN performed well even under these difficult conditions because these results can further expand the possibilities of its use.
The Consecutive 200 Cases of Endoscopic-Combined Intrarenal Surgery: Comparison between Standard and Miniature Surgeries
Background and Objectives: Percutaneous nephrolithotomy (PCNL) is still the gold-standard treatment for large and/or complex renal stones. Endoscopic combined intrarenal surgery (ECIRS) was developed with the goal of minimizing the number of access tracts of PCNL while simultaneously improving the one-step stone-free rate (SFR). The aim of this study was to share the experience of the consecutive 200 cases of ECIRS in one institute and analyze surgical outcomes of mini-ECIRS and standard ECIRS. Materials and Methods: We performed ECIRS for 200 adult patients between July 2017 and January 2020. An ECIRS was performed with the patient under general anesthesia in the intermediate-supine position. Surgeries were finished using a tubeless technique with a simple ureteral stent insertion. Results: There were significant differences in the mean maximal stone length (MSL), the variation coefficient of stone density (VCSD), the linear calculus density (LCD), the Seoul National University Renal Stone Complexity (S-ReSC), and the modified S-ReSC scores in stone characteristics, and estimated blood loss (EBL) and operation time in peri-operative outcomes between conventional and mini-ECIRS. After propensity-score matching, there was only a difference in EBL between the two groups. In logistic regression models, MSL [odds ratio (OR) 0.953; 95% confidence interval (CI) 0.926–0.979; p < 0.001], LCD (OR 4.702; 95% CI 1.613–18.655; p = 0.013) were significant factors for the success rate after ECIRS. Conclusions: In patients who underwent a mini-ECIRS, the stones were relatively smaller and less complex, and the operation time was shorter. However, if the size of stones was similar, there was no difference in the success rate, but EBL was lower in mini-ECIRS than in standard surgery.
PI-RADS version 2: quantitative analysis aids reliable interpretation of diffusion-weighted imaging for prostate cancer
Objectives To determine whether apparent diffusion coefficient (ADC) ratio aids reliable interpretation of diffusion-weighted imaging (DWI) for prostate cancer (PCa). Methods Seventy-six consecutive patients with PCa who underwent DWI and surgery were included. Based on pathologic tumour location, two readers independently performed DWI scoring according to the revised Prostate Imaging Reporting and Data System (PI-RADSv2). ADC ratios of benign to cancerous prostatic tissue were then measured independently and compared between cases showing concordant and discordant DWI scores ≥4. Area under the curve (AUC) and threshold of ADC ratio were analyzed for DWI scores ≥4. Results The rate of inter-reader disagreement for DWI score ≥4 was 11.8% (9/76). ADC ratios were higher in concordant vs. discordant DWI scores ≥4 (median, 1.7 vs. 1.1–1.2; p  < 0.001). For DWI scores ≥4, the AUCs of ADC ratios were 0.970 for reader 1 and 0.959 for reader 2. In patients with an ADC ratio >1.3, the rate of inter-reader disagreement for DWI score ≥4 decreased to 5.9–6.0%. An ADC ratio >1.3 yielded 100% (reader 1, 54/54; reader 2, 51/51) positive predictive value for clinically significant cancer. Conclusion ADC ratios may be useful for reliable interpretation of DWI score ≥4 in PI-RADSv2. Key points • The ADC ratio correlated positively with DWI score of PI - RADSv2 . • ADC ratio > 1.3 was associated with concordant interpretation of DWI score ≥ 4 . • ADC ratio > 1.3 was associated with high PPV for clinically significant cancer . • ADC ratio is useful for reliable interpretation of DWI scoring in PI - RADSv2 .