Applications of Artificial Intelligence in Mammography from a Development and Validation Perspective

Mammography is the primary imaging modality for breast cancer detection; however, a high level of expertise is needed for its interpretation. To overcome this difficulty, artificial intelligence (AI) algorithms for breast cancer detection have recently been investigated. In this review, we describe the characteristics of AI algorithms compared to conventional computer-aided diagnosis software and share our thoughts on the best methods to develop and validate the algorithms. Additionally, several AI algorithms have introduced for triaging screening mammograms, breast density assessment, and prediction of breast cancer risk have been introduced.Finally, we emphasize the need for interest and guidance from radiologists regarding AI research in mammography, considering the possibility that AI will be introduced shortly into clinical practice.

The Effect of Adalimumab on Refractory Uveitis

Purpose@#To assess the efficacy and safety of Adalimumab (Humira®, AbbVie, Chicago, IL, USA) for repeated refractory uveitis during systemic steroid or immunosuppressive therapy. @*Methods@#We retrospectively reviewed clinical records on 30 eyes of 18 patients with non-infectious refractory uveitis who underwent Adalimumab injection therapy from December 2017 to July 2019. The therapeutic effect was assessed based on intraocular inflammation grade, central macular thickness, and best corrected visual acuity, and the efficacy was assessed based on control of inflammation and macular edema, as well as corticosteroid sparing effects. The safety was assessed based on adverse events. @*Results@#The mean duration of uveitis at baseline was 55.4 months (13-121 months) and the mean follow-up was 9.2 months (6-18 months). All 30 eyes of 18 patients stopped using systemic steroids and maintained clinical quiescence. Anterior chamber inflammation, vitreous inflammation, and best corrected visual acuity showed significant improvement, and there was no difference in central macular thickness. Uveitis recurred in 5 eyes, but 4 eyes showed controlled inflammation after single posterior sub-tenon steroid injection. One eye was controlled after methotrexate co-administration. Ulticaria (two patients) and injection- site reaction (one patient) were reported as adverse events. @*Conclusions@#Adalimumab is an effective treatment for decreasing inflammatory activity and reducing corticosteroid burden in refractory uveitis.

Fat Quantification in the Vertebral Body: Comparison of Modified Dixon Technique with Single-Voxel Magnetic Resonance Spectroscopy

OBJECTIVE: To compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain. MATERIALS AND METHODS: Vertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm³ voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results. RESULTS: There was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R² = 0.88, p 20%). CONCLUSION: Given its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.

Distinguishing between Thymic Epithelial Tumors and Benign Cysts via Computed Tomography

OBJECTIVE: To investigate whether computed tomography (CT) and fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) may be applied to distinguish thymic epithelial tumors (TETs) from benign cysts in the anterior mediastinum. MATERIALS AND METHODS: We included 262 consecutive patients with pathologically proven TETs and benign cysts 5 cm or smaller who underwent preoperative CT scans. In addition to conventional morphological and ancillary CT findings, the relationship between the lesion and the adjacent mediastinal pleura was evaluated qualitatively and quantitatively. Mean lesion attenuation was measured on CT images. The maximum standardized uptake value (SUVmax) was obtained with FDG-PET scans in 40 patients. CT predictors for TETs were identified with multivariate logistic regression analysis. For validation, we assessed the diagnostic accuracy and inter-observer agreement between four radiologists in a size-matched set of 24 cysts and 24 TETs using a receiver operating characteristic curve before and after being informed of the study findings. RESULTS: The multivariate analysis showed that post-contrast attenuation of 60 Hounsfield unit or higher (odds ratio [OR], 12.734; 95% confidence interval [CI], 2.506–64.705; p = 0.002) and the presence of protrusion from the mediastinal pleura (OR, 9.855; 95% CI, 1.749–55.535; p = 0.009) were the strongest CT predictors for TETs. SUVmax was significantly higher in TETs than in cysts (5.3 ± 2.4 vs. 1.1 ± 0.3; p < 0.001). After being informed of the study findings, the readers' area under the curve improved from 0.872–0.955 to 0.949–0.999 (p = 0.066–0.149). Inter-observer kappa values for protrusion were 0.630–0.941. CONCLUSION: Post-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.

Volumetric change of the latissimus dorsi muscle after immediate breast reconstruction with an extended latissimus dorsi musculocutaneous flap

BACKGROUND: In immediate breast reconstruction using an extended latissimus dorsi musculocutaneous (eLDMC) flap, the volume of the flap decreases, which causes a secondary deformity of the breast shape. Since little research has investigated this decrease in muscle volume, the authors conducted an objective study to characterize the decrease in muscle volume after breast reconstruction using an eLDMC flap. METHODS: Research was conducted from October 2011 to November 2016. The subjects included 23 patients who underwent mastectomy due to breast cancer, received immediate reconstruction using an eLDMC flap without any adjuvant chemotherapy or radiotherapy, and received a computed tomography (CT) scan from days 7 to 10 after surgery and 6 to 8 months postoperatively. In 10 patients, an additional CT scan was conducted 18 months postoperatively. Axial CT scans were utilized to measure the volumetric change of the latissimus dorsi muscle during the follow-up period. RESULTS: In the 23 patients, an average decrease of 54.5% was observed in the latissimus dorsi muscle volume between the images obtained immediately postoperatively and the scans obtained 6 to 8 months after surgery. Ten patients showed an average additional decrease of 11.9% from 6–8 months to 18 months after surgery. CONCLUSIONS: We studied changes in the volume of the latissimus dorsi muscle after surgery using an eLDMC flap performed after a mastectomy without adjuvant chemotherapy or radiotherapy. In this study, we found that immediate breast reconstruction using a latissimus dorsi muscle flap led to a decrease in muscle volume of up to 50%.

Clinical Utility of Shear Wave Elastography Patterns for Differentiating between Benign and Malignant Breast Lesions

PURPOSE: This retrospective study evaluated the utility of shear wave elastography (SWE), Tozaki's visual pattern classification, and conventional Breast Imaging Reporting and Data System (BI-RADS) classification for differentiating between benign and malignant lesions. METHODS: Between May 2015 and July 2016, 388 patients underwent SWE and B-mode ultrasonography. The BI-RADS system was used to exclude cases with category 1–2 lesions or unbiopsied category 3 lesions. A total of 100 patients with 100 solid breast masses underwent tissue sampling (ultrasonography-guided core biopsy or vacuum-assisted biopsy) or surgical excision. The quantitative elasticity was measured for each lesion, and the imaging and histological findings were compared. RESULTS: The mean age of the patients was 51 years (range, 18–79 years). Histological examination identified 50 malignant lesions and 50 benign lesions. According to the BI-RADS classification, 20 lesions were classified as category 3, 56 as category 4, and 24 as category 5. Based on the Tozaki classification, 39 lesions were classified as pattern 1, seven as pattern 2, 23 as pattern 3, and 31 as pattern 4. If patterns 1 and 2 were assumed to be benign, and patterns 3 and 4 were assumed to be malignant, the combination of BI-RADS and SWE provided a sensitivity of 100% (50/50), a specificity of 92.0% (46/50), a positive predictive value of 92.5% (50/54), and a negative predictive value of 100% (50/50). CONCLUSION: The combination of SWE and BI-RADS was useful for evaluating breast lesions, improved the specificity of ultrasonography and may help facilitate appropriate treatment planning.

Stereotactic vacuum-assisted breast biopsy under lateral decubitus position

PURPOSE: Stereotactic vacuum-assisted breast biopsy (VAB) has been established as a standard method for histological diagnosis of microcalcification or nonpalpable breast lesions on mammography. Generally, the procedure has been done under the prone position or upright sitting position. We herein attempt to evaluate clinical utility of Stereotactic VAB under lateral decubitus position. METHODS: One hundred six women (mean age, 51.2 years) with mammographically detected microcalcification underwent lateral decubitus positioning VAB using the 8G probe. In all cases, we obtained mammography specimens for identification of microcalcification and postprocedure mammography. We reviewed mean procedure time, pieces of specimen, pathology and follow-up mammography. RESULTS: The procedure took approximately 20 minutes (range, 15-24 minutes). Average number of obtained specimens was 8.5 pieces (range, 6-12 pieces). Microcalcifications were confirmed in both specimen mammography and microscopic slides. Of 106 cases, 10 cases were diagnosed as ductal carcinoma in situ. Additional surgical management was performed. Atypical ductal hyperplasias were found in 8 cases, and fibrocystic changes in 88 cases. CONCLUSION: Stereotactic VAB using the 8G probe under lateral decubitus position does not need a dedicated table, and is easier to maintain the position. Also, this procedure is accurate and safe. Thus, stereotactic VAB using the 8G probe under lateral decubitus position will be a useful method for diagnosis of microcalcification or nonpalpable breast lesions on mammography.

Transscleral Fixation of Intraocular Lenses Using Modified Injector

PURPOSE: To evaluate the clinical stability and outcomes of 3-piece intraocular lens (IOL) transscleral fixation surgery using a modified injector. METHODS: We have modified and used the Sapphire unfolder injector system (Allergan(R), USA). This involved, cutting a slit longitudinally at the terminal part of the injector so that a thread could pass through it freely. After a conjunctival peritomy created at 2 and 8 o'clock, a long curved needle with double-armed 10-0 polypropylene is passed through the exposed sclera. Two pieces of suture are withdrawn through the 2.8 mm corneal incision and 1 suture (from 8 o'clock) is passed through the opening of the cartridge and then tied to the leading haptic. Next, the IOL was implanted with the cartridge and then inserted through the corneal incision site. The other suture (from 2 o'clock) is tied to the haptic on the opposite side and inserted. RESULTS: The study included 20 eyes of 20 patients with a mean age of 62.8 years at the initial visit. There were no complications, such as vitreous hemorrhage, retinal detachment, glaucoma, corneal edema, or iris injury. While the knot fixed to the leading haptic of IOL passed by the cartridge, there was no change of position. During the follow-up period, IOL dislocation did not occur and the corrected visual acuity and corneal astigmatism improved significantly. CONCLUSIONS: This technique is an effective procedure for minimizing entangled thread and corneal astigmatism.

Intravitreal Bevacizumab Injection for the Treatment of Choroidal Neovascularization Secondary to Candida Chorioretinitis

PURPOSE: To report a case of choroidal neovascularization (CNV) secondary to candida chorioretinitis initially treated with an intravitreal bevacizumab injection. CASE SUMMARY: A 50-year-old female presented at our clinic with decreased vision and metamorphopsia in her left eye of 5 days duration. She received an anti-fungal treatment 2 months prior due to the presence of endogenous candida choroiditis in both eyes. Fluorescein angiography and optical coherence tomography (OCT) revealed juxtafoveal CNV in her left eye. Three monthly intravitreal injections of bevacizumab were administered as the initial loading dosage. Her visual symptoms improved and CNV regression was observed on OCT. No recurrence or complications were observed during the 6 month follow-up. CONCLUSIONS: Based on the present study results we suggest that intravitreal bevacizumab injection can be used to effectively treat CNV and improve visual symptoms during the treatment of juxtafoveal CNV associated with candida choroiditis.

Peripheral Vascular Leakage Findings of Asymptomatic Eyes Based on Fluorescein Angiography

PURPOSE: To report peripheral vascular retinal leakage findings of asymptomatic eyes based on fluorescein angiography, and investigate the associated factors. METHODS: Data were collected retrospectively from 47 subjects (94 eyes) and the peripheral leakage results based on fluorescein angiography were analyzed. The relationship between peripheral leakage findings and other factors including-arm-retinal circulation time (ARCT) and venous filling time (VFT), refractive error, age, hypertension, and diabetes- was evaluated. RESULTS: Ten eyes had peripheral leakage (21.3%). The mean age was 34.7 +/- 7.86 years in the non-leakage group and 44.3 +/- 9.63 years in the leakage group; the difference between the groups was statistically significant (p = 0.001). The mean spherical equivalent was -2.85 +/- 2.71 diopter in the non-leakage group and -3.46 +/- 3.62 diopter in the leakage group; the difference between the groups were not significant (p = 0.471). The mean ARCT was 10.50 +/- 2.06 seconds in the non-leakage group and 11.76 +/- 2.47 seconds in the leakage group; the difference between the groups was statistically significant (p = 0.041). The mean VFT was 9.70 +/- 1.91 seconds in the non-leakage group and 10.75 +/- 1.40 seconds in the leakage group; the difference between the groups was statistically significant (p = 0.048). CONCLUSIONS: Peripheral leakage can be found in asymptomatic eyes. Age, VFT, and ARCT were correlated to peripheral leakage findings based on angiography. These leakage findings were thought to be related with histological properties and physiological changes in peripheral retina.

Effectiveness of Flexible Ureteroscopic Stone Removal for Treating Ureteral and Ipsilateral Renal Stones: A Single-Center Experience

PURPOSE: The aim of this study was to evaluate the effectiveness of simultaneous flexible ureteroscopic removal of stones (URS) for ureteral and ipsilateral renal stones and to analyze the predictive factors for renal stone-free status. MATERIALS AND METHODS: We retrospectively reviewed the records of patients who underwent simultaneous flexible URS of ureteral and ipsilateral renal stones from January 2010 to May 2012. All operations used a flexible ureteroscope. We identified 74 cases of retrograde intrarenal surgery and 74 ureteral stones (74 patients). Stone-free status was respectively defined as no visible stones and clinically insignificant residual stones <3 mm on a postoperative image study. Predictive factors for stone-free status were evaluated. RESULTS: The immediate postoperative renal stone-free rate was 70%, which increased to 83% at 1 month after surgery. The immediate postoperative ureteral stone-free rate was 100%. Among all renal stones, 15 (20.3%) were separately located in the renal pelvis, 11 (14.8%) in the upper calyx, 15 (20.3%) in the mid calyx, and 33 (44.6%) in the lower calyx. The mean cumulative stone burden was 92.22+/-105.75 mm2. In a multivariate analysis, cumulative stone burden <100 mm2 was a significant predictive factor for postoperative renal stone-free status after 1 month (p<0.01). CONCLUSIONS: Flexible URS can be considered simultaneously for both ureteral and renal stones in selected patients. Flexible URS is a favorable option that promises high stone-free status without significant complications for patients with a stone burden <100 mm2.

Comparison among Conventional 4 L Polyethylene Glycol, Split Method of 4 L Polyethylene Glycol and Combination of 2 L Polyethylene Glycol and Sodium Phosphate Solution for Colonoscopy Preparation / 대한소화기학회지

BACKGROUND/AIMS: The aim of this study was to compare polyethylene glycol (PEG) 4 L, split method of PEG 4 L and PEG 2 L plus sodium phosphate (NaP) in the aspect of bowel preparation quality, safety, patients' compliance and preference. METHODS: Total 249 subjects were prospectively enrolled and received bowel preparation for colonoscopy from August to October in 2010; PEG 4 L (93 subjects), split method of 4 L PEG (74 subjects) and PEG 2 L plus NaP 90 mL group (82 subjects). To investigate the completion, preference for bowel preparation and safety, a questionnaire survey was conducted before colonoscopy. RESULTS: There were no significant intergroup differences in the aspect of completion of preparation, cecal intubation time and success rate. Satisfaction and preference were higher in PEG 2 L plus NaP 90 mL and split method of 4 L PEG compared with PEG 4 L. In the aspect of the bowel preparation quality PEG 4 L showed significantly higher quality in the morning colonoscopy (p<0.001). However, in the afternoon colonoscopy PEG 2 L plus NaP 90 mL showed better result than PEG 4 L (p=0.009). Hyperphosphatemia was most frequently observed in PEG 2 L plus NaP 90 mL, but no severe adverse events occurred (p<0.001). CONCLUSIONS: PEG 4 L showed better result than split method of 4 L PEG or PEG 2 L plus NaP 90 mL in the aspect of bowel preparation quality and safety.

Clinical Characteristics of Patients Diagnosed as Peptic Ulcer Disease in the Third Referral Center in 2007 / 대한소화기학회지

BACKGROUND/AIMS: In spite of the improvement of medical treatment for the peptic ulcer disease (PUD), PUD is still one of the common upper gastrointestinal diseases. The purpose of this study was to evaluate the risk factors and general characteristics of Korean patients diagnosed as PUD at a single third referral center. METHODS: A total of 310 patients, diagnosed as PUD through endoscopy during one year of 2007 at Seoul National University Bundang Hospital were, retrospectively, evaluated regarding age, gender, Helicobacter pylori (H. pylori) positivity, clinical manifestations, comorbidities and medications. In addition, PUD was analyzed in the aspect of ulcer location, type of visit, gastrointestinal bleeding, and age. RESULTS: The mean age was 61.5 years old (48.1% over 65) and 208 (66.7%) patients were men. The rate of H. pylori infection was 47.8%, and any ulcerogenic medication history such as antiplatelet agents and NSAIDs was found to be 21.0% (65 patients). The rate of idiopathic peptic ulcer without evidence of H. pylori and NSAIDs was found to be 40.6% (126 patients). Among 310 PUD patients, bleeding symptoms such as melena, hematemesis and hematochezia occurred in 110 patients (35.5%). CONCLUSIONS: PUD was more prevalent in the elderly patients and frequently associated with bleeding. Substantial proportion of PUD patients had neither H. pylori infection nor history of ulcerogenic medications, suggesting of increasing prevalence of idiopathic PUD.

Effects of Proton Pump Inhibitors in Asthmatics with Gastroesophageal Reflux Disease / 대한소화기학회지

BACKGROUND/AIMS: Gastroesophageal reflux disease (GERD) is common in asthma patients. Proton pump inhibitor (PPI) therapy improves symptoms of asthma in some patients. The objective of this study was to investigate endoscopic findings of GERD in asthma patients and to assess the effect of gastric acid suppression with the PPIs on symptom improvement and pulmonary function. METHODS: From 105 consecutive patients with GERD symptoms during follow up for asthma, 45 patients were enrolled. Patients enrolled to this study were asked about GERD symptoms before and after treating with PPI. Endoscopic findings were described according to Los Angeles classification. The improvement of asthma symptoms and follow-up pulmonary function test were investigated after administration of PPIs. RESULTS: Esophageal symptoms such as heartburn and acid reflux were present in 25 patients (55.6%), and patients without esophageal symptoms were 20 (44.4%). The degree of endoscopic abnormality was not significantly different between groups with or without esophageal symptoms. The improvement of symptoms was seen in 44 patients (97.8%) except 1 patient after administration of PPIs. The number of patients classified to the low-dose group was 7 patients (15.6%) and that of patients classified to the standard-dose group was 38 patients (84.4%). The follow-up pulmonary function test, peak expiratory flow rate (L/sec) was improved in 3 patients (3 of 7, 42.9%) of the low-dose group, and in 24 patients (24 of 38, 63.2%) of the standard-dose group. The improvement of ventilatory function was not significantly different according to dose of PPIs. CONCLUSIONS: Treatment with PPIs is expected to improve subjective symptoms and ventilatory function in asthma patients.

Laparoscopic Resection of a 12 cm Sized Retroperitoneal Schwannoma Adjacent to Retroperitoneal Vital Vessels: Are Large Retroperitoneal Schwannomas Not Suitable for the Laparoscopic Approach?

There are a lot of advantages to laparoscopic surgery, including early recovery, less postoperative pain, better cosmesis, shorter hospital stay and an early return to normal activities because of its minimal invasiveness. So, most surgeons have agreed on these points and have accepted the various indications for laparoscopic surgery. Despite these advantages and the recent advances in laparoscopic surgery, there are few cases using the laparoscopic approach for treating retroperitoneal schwannomas. Laparoscopic resection of a large retroperitoneal schwannoma has some difficulties for tumor retraction, dissecting around the large vessels, and removal of the resected tumor. Sometimes these difficulties may cause complications and a lengthened hospital stay. However, if appropriate methods are used, long hospital stay and complication can be prevented while maintaining the advantages of laparoscopic surgery.

Risk Factors for Development and Recurrence of Peptic Ulcer Disease / 대한소화기학회지

BACKGROUND/AIMS: Peptic ulcer disease (PUD) is one of the common gastrointestinal diseases, and its medical management has been developed so much that the incidence of its serious complications, such as bleeding and perforation, are declining significantly. Its prevalence in Korea is not definitely decreased, probably due to increasing proportion of elderly patients and their rising usage of non-steroidal anti-inflammatory drugs (NSAIDs) and aspirins. This study was conducted to identify the risk factors for development and recurrence of peptic ulcer disease in Korea. METHODS: From 2003 to 2008, upper gastrointestinal endoscopy and detailed personal questionnaires were performed for patients who visited Department of Gastroenterology at Seoul National University Bundang Hospital. In total, 475 PUD patients and 335 non-ulcer dyspepsia patients were included. The results of questionnaires and repeated upper gastrointestinal endoscopy at initial diagnosis time and follow-up periods were analyzed. RESULTS: Multivariable analysis showed that male, H. pylori infection, NSAIDs use and smoking were risk factors for the development of PUD. The use of proton pump inhibitors (PPIs) and H2 receptor antagonists has significantly reduced the risk of PUD in patients who had taken NSAIDs and/or aspirins. H. pylori infection was found as the only risk factor for the recurrence of PUD. CONCLUSIONS: For the old patients who are taking drugs, such as NSAIDs and aspirins, concomitant use of PPIs or H2 receptor antagonists should be considered to protect from the development of PUD. H. pylori eradication has been confirmed again to be essential for the treatment of PUD patients infected with H. pylori.

Revision Total Hip Arthroplasty Using an Extensively Porous Coated Femoral Stem

BACKGROUND: To determine the benefit of an extensively porous coated femoral stem in patients receiving revision total hip arthroplasty. METHODS: This study reviewed the results of 35 patients who received a revision total hip arthroplasty with extensively porous coated femoral stem between August, 1996, and December, 2002. The mean follow-up period was 77.5 months. The clinical and radiological results were evaluated by the Harris hip score and serial roentgenographic findings. RESULTS: The preoperative and postoperative Harris hip score was 68.3 and 92.5, respectively. Radiographically, none of the acetabular components showed any evidence of migration, tilt, rotation, or shedding of metal particles. In addition, none of the femoral components showed evidence of subsidence, pedestal, or shedding of metal particles. Twenty-two hips had a mild stress shield and 2 hips had a moderate stress shield. The perioperative complications encountered were deep vein thrombosis (1 case), mild heterotopic ossification (4 cases), intraoperative periprosthetic fractures (1 case), and nonunion of the trochanteric osteotomy site (2 cases). CONCLUSIONS: Extensively porous coated femoral stems and acetabular components produce excellent clinical and radiological results in revision total hip arthroplasty.

Colonic Intussusception as a Complication after Colonoscopic Polypectomy / 대한소화기내시경학회지

Intussusception in adults is not common unlike in pediatrics. It also differs from the pediatric intussusception in its origins, symptoms, and treatment. Since more than half of intussusception cases come from malignancy, laparotomy is considered to be the treatment of choice in most cases. This report deals with a patient who visited our hospital complaining of abdominal pain after colonoscopic polypectomy. The patient was diagnosed with colonic intussusception. After a conservative treatment regimen including antibiotics and fluid therapy, the intussusception was spontaneously reduced.

Assessment of Factors Affecting the Accuracy of Endoscopic Ultrasonography in T2 Stage Gastric Cancer / 대한소화기학회지

BACKGROUND/AIMS: To minimize injury, less invasive surgery including laparascopic surgery and endoscopic mucosal resection are increasingly used for the treatment of gastric cancer nowadays. Therefore, accurate preoperative staging is important to decide adequate treatment modality. Endoscopic ultrasonography (EUS) is reported to be an accurate diagnostic modality to evaluate the depth of tumor invasion. Especially, evaluation of T-2 stage is important to determine operation. We tried to reveal the factors affecting the accuracy of EUS for the evaluation of T-2 stage gastric cancer. METHODS: Among 367 patients who underwent EUS to evaluate preoperative stage, we compared EUS findings and histopathological findings retrospectively. RESULTS: A total of 270 patients were diagnosed as early gastric cancer, and 97 patients as advanced gastric cancer. The overall concordance rate was 78.2% (287/367), over-estimation rate 14.2% (52/367), and under-estimation rate 7.6% (28/367). Among T-2 stage cancer, over-estimation rate was 27.0% (20/74), and under-estimation rate 21.6% (16/74). These were relatively high compared with those with over-estimation. Among T1 lesions, 20.6% (22/107) were over-estimated as the invasion into proper muscle layer. Compared with sm1 lesion (17.9%), sm3 lesions showed higher over-estimateion rate (25.7%). In the presence of submucosal fibrosis, sm1 lesions were over-estimated as T-2 lesion. Sm2 and sm3 lesions were not related to submucosal fibrosis. Factors affecting over-estimation as T-2 lesions were the size of tumor, the presence of submucosal fibrosis and connective tissue hyperplasia, and ulcer (p<0.05). Microscopic invasion did not affect the accuracy of EUS findings. CONCLUSIONS: In T-2 gastric cancer, the presence of submucosal fibrosis, tumor size, and ulcer were the affecting factors for the over-estimation of the depth of invasion using EUS in gastric cancer. To improve preoperative diagnostic accuracy in T-2 stage cancer, a new diagnostic improvement in EUS is needed.

Relationship between the Retinal Thickness Analyzer and the GDx VCC Scanning Laser Polarimeter, Stratus OCT Optical Coherence Tomograph, and Heidelberg Retina Tomograph II Confocal Scanning Laser Ophthalmoscopy

PURPOSE: To assess the relationship between the retinal thickness analyzer (RTA) parameters, and those of the GDx VCC scanning laser polarimeter (GDx VCC), Stratus OCT optical coherence tomography (Stratus OCT), and Heidelberg retinal tomograph II confocal scanning laser ophthalmoscopy (HRT II). METHODS: Twenty-nine primary open-angle glaucoma patients were retrospectively included in this study. Measurements were obtained using the RTA, GDx VCC, Stratus OCT, and HRT II. We calculated the correlation coefficients between the parameters of RTA and those of the other studies. RESULTS: Among the optic disc parameters of RTA, the cup volume was best correlated with Stratus OCT (R=0.780, p<0.001) and HRT II (R=0.896, p<0.001). Among the posterior pole retinal thickness parameters, the posterior pole abnormally thin area (PPAT) of the RTA and the inferior average of the GDx VCC were best correlated (R=-0.596, p=0.001). The PPAT of the RTA and the inferior maximum of the Stratus OCT were best correlated (R=-0.489, p=0.006). The perifoveal minimum thickness (PFMT) of the RTA and the cup shape measurement of the HRT II were best correlated (R=-0.565, p=0.004). CONCLUSIONS: Many RTA optic disc parameters were significantly correlated with those of the Stratus OCT and HRT II. The RTA posterior pole retinal thickness parameters were significantly correlated with those of the GDx VCC, Stratus OCT and HRT II. The RTA optic disc and posterior pole retinal thickness parameters may be valuable in the diagnosis of glaucoma.