Background: and Purpose It is challenging to detect Parkinson’s disease (PD) in its early stages, which has prompted researchers to develop techniques based on machine learning methods for detecting PD. However, previous studies did not fully incorporate the slow progression of PD over a long period of time nor consider that its symptoms occur in a time-sequential manner. Contributing to the literature on PD, which has relied heavily on cross-sectional data, this study aimed to develop a method for detecting PD early that can process time-series information using the long short-term memory (LSTM) algorithm. Methods: We sampled 926 patients with PD and 9,260 subjects without PD using medicalclaims data. The LSTM algorithm was tested using diagnostic histories, which contained the diagnostic codes and their respective time information. We compared the prediction power of the 12-month diagnostic codes under two different settings over the 4 years prior to the first PD diagnosis. Results: The model that was trained using the most-recent 12-month diagnostic codes had the best performance, with an accuracy of 94.25%, a sensitivity of 82.91%, and a specificity of 95.26%. The other three models (12-month codes from 2, 3, and 4 years prior) were found to have comparable performances, with accuracies of 92.27%, 91.86%, and 91.81%, respectively.The areas under the curve from our data settings ranged from 0.839 to 0.923. Conclusions We explored the possibility that PD specialists could benefit from our proposed machine learning method as an early detection method for PD.

A 44-year-old man with a past medical history of splenectomy came to hospital because of epigastric pain. Abdominopelvic computed tomography(CT) showed a soft tissue mass and multifocal variable-sized nodules as well as findings suggestive of cholecystitis. Subsequently, he underwent Tc-99m-labeled heat-denatured red blood cell(RBC) scintigraphy to evaluate the mass and nodules. The scintigraphy confirmed multifocal peritoneal splenosis in the abdominopelvic cavity.
Adult ; Cholecystitis ; Erythrocytes* ; Humans ; Radionuclide Imaging* ; Spleen ; Splenectomy ; Splenosis*

A tail-on-detector (TOD) view has been used to see the symphysis pubis or sacrococcyx in skeletal scintigraphy, but it is inconvenient to acquire because a patient must sit or lean on a detector. The TOD views are still frequently performed in training hospitals in Korea, although it is becoming almost impossible to sit on a camera in this age of dual-headed cameras. The authors show cases with lateral views obtained in supine position that were acquired for the same reason; they are easier and more useful than the TOD views.
Coccyx ; Humans ; Korea ; Radionuclide Imaging* ; Sacrococcygeal Region* ; Sacrum ; Supine Position ; Technetium Tc 99m Medronate

PURPOSE: Aspiration scintigraphy is a procedure of nuclear imaging to evaluate aspiration and of quantifying the amount of aspirate. The ultimate goal of our study is to define the correlation between aspiration and aspiration pneumonia by aspiration scintigraphy, and this is a preliminary report of its trial. MATERIALS AND METHODS: Ten patients with positive findings by videofluoroscopy were selected. The patients ingested semi-solid food containing Tc-99m tin colloid 92.5 MBq (2.5 mCi) and images were acquired immediately after the ingestion and 3 hrs later. A fraction of aspiration to the ingested was calculated using an equation with a decay correction. RESULTS: Five patients were interpreted positive by aspiration scintigraphy. Four patients were positive at initial images and the fractions of aspiration were 0.11%, 0.11%, 0.81%, and 0.11%. The one patient who was shown aspirated at both images had initial 5.82% and delayed 2.26%. CONCLUSION: Aspiration scintigraphy enables us to localize the aspiration at any desired time of the test and to quantify its amount. Follow-up studies are warranted.
Colloids ; Eating ; Humans ; Pneumonia, Aspiration ; Radionuclide Imaging* ; Tin

BACKGROUND: Late-onset neutropenia (LON) following rituximab therapy has been reported in recent years. However, its incidence has not been reported in Korea. The aim of this study is to investigate the incidence of LON after rituximab therapy in Korean patients with diffuse large B-cell lymphoma (DLBCL). METHODS: Ninety-eight cases of DLBCL treated with rituximab between 2004 and 2008 were evaluated. We identified LON as defined by the neutrophil count of <1.5x10(9)/L without apparent cause after the recovery of neutrophil count following rituximab therapy. Bone marrow aspiration and biopsy specimens at the time of neutropenia were available for retrospective review in only 5 of the patients. RESULTS: LON was observed in 15 (15.3%) of the 98 patients. In the bone marrow specimens of the 5 patients, promyelocytes were relatively increased and the maturation index of the granulopoiesis was 2:1-3:1, which reflects maturation arrest. CONCLUSIONS: The incidence of LON following rituximab therapy was 15.3% in Korean patients with DLBCL. Although there are several hypotheses about the causative mechanisms of LON, we suggest that maturation arrest at the promyelocyte stage of granulopoiesis may be one of the mechanisms involved in the development of LON.
Adult ; Aged ; Antibodies, Monoclonal, Murine-Derived/adverse effects/*therapeutic use ; Antineoplastic Agents/adverse effects/*therapeutic use ; Bone Marrow Cells/pathology ; Cell Differentiation ; Female ; Humans ; Lymphoma, Large B-Cell, Diffuse/*drug therapy ; Male ; Middle Aged ; Neutropenia/diagnosis/*epidemiology ; Retrospective Studies

PURPOSE: Gastric emptying scan (GES) is usually acquired up to 2 hours. Our study investigated whether a fraction of meal-retention in the stomach at 120 minutes (FR120) was predicted from the data measured for 90 minutes by using non-linear curve fitting. We aimed at saving the delayed imaging by utilizing mathematical models. MATERIALS AND METHODS: Ninety-six patients underwent GES immediately after taking a boiled egg with 74 MBq (2 mCi) Tc-99m DTPA. The patients were divided into Group I (T1/2 < or=90 min) and Group II (90 min< T1/2< or=120 min). Group I (n=51) had 21 men and 30 women, and Group II (n=45) 15 men and 30 women. There was no significant difference in age and sex between the two groups. Simple exponential, power exponential, and modified power exponential curves were acquired from the measured fraction of meal-retention at each time (0, 15, 30, 45, 60, 75, and 90 min) by non-linear curve fitting (MATLAB (R) 5.3) and another simple exponential fitting was performed on the fractions at late times (60, 75, and 90 min). A predicted FR120 was calculated from the acquired functional formulas. A correlation coefficient between the measured FR120 and the predicted FR120 was computed (MedCalc (R) 6.0). RESULTS: Correlation coefficients (r) between the measured FR120 and the predicted FR120 of each mathematical functions were as follows: simple exponential function (Group I: 0.8858, Group II: 0.5982, p< 0.0001), power exponential function (Group I: 0.8755, Group II: 0.6008, p< 0.0001), modified power exponential function (Group I: 0.8892, Group II: 0.5882, p< 0.0001), and simple exponential function at the late times (Group I: 0.9085, Group II: 0.6832, p< 0.0001). In all the fitting models, the predicted FR120 were significantly correlated with the measured FR120 in Group I but not in Group II. There was no statistically significant difference in correlation among the 4 mathematical models. CONCLUSION: In the cases with T1/2 < or=90 min, the predicted FR120 is significantly correlated with the measured FR120. Therefore, FR120 can be predicted from the data measured for 90 minutes by using non-linear curve fitting, saving the delayed imaging after 90 minutes when T1/2 < or=90 min is ascertained.
Female ; Gastric Emptying* ; Humans ; Male ; Models, Theoretical* ; Ovum ; Pentetic Acid ; Radionuclide Imaging* ; Stomach

Although prostatic calculi are common, complications are fortunately rare. Here, we report a case of prostatic calculi causing urethral obstruction. A 66-year-old man presented with severe voiding difficulty and urge incontinence. He was found to have multiple large prostatic calculi obstructing the prostatic urethra as well as several bladder calculi. Attempts at endoscopic removal were unsuccessful, which resulted in an iatrogenic urethral diverticulum due to fragmented calculi. The residual calculi and diverticulum were removed successfully by open surgery.
Aged ; Calculi ; Diverticulum ; Humans ; Prostate ; Urethra ; Urethral Obstruction ; Urinary Bladder ; Urinary Bladder Calculi ; Urinary Incontinence, Urge

Sarcomatoid urothelial carcinoma is a rare malignancy with a poor prognosis. We experienced a case of sarcomatoid urothelial carcinoma of the renal pelvis with extremely aggressive clinical behavior. An 81-year-old woman underwent a laparoscopic radical nephroureterectomy to remove a 4.5x3.1 cm sized localized left renal pelvis mass. The mass was pathologically confirmed as a sarcomatoid urothelial carcinoma. Although the operation was successful, the patient died 2 months postoperatively with widely metastatic disease.
Aged, 80 and over ; Female ; Humans ; Kidney Pelvis ; Prognosis

BACKGROUND: Real-time PCR has been widely used not only for quantification?of disease-related genes but also for detection of bacteria or viruses. In this study, we evaluated the performance of Artus HBV LC PCR kit (Qiagen, Hilden, Germany) using recently developed SLAN real-time PCR detection system (Shanghai Hongshi Medical Technology Co., Shanghai, China) to assess clinical relevance of the new instrument. METHODS: Precision, linearity and detection limit of Artus HBV LC PCR kit were evaluated using SLAN real-time PCR detection system. We also compared the SLAN real-time PCR detection system with LightCycler 1.5 (Roche Molecular System, Branchburg, NJ, USA) and ABI PRISM 7500 (Applied Biosystems, Foster City, CA, USA). WHO International Standard for HBV DNA Nucleic Acid Amplification Techniques (NIBSC code:97/750) and 40 HBV DNA positive sera were tested for this evaluation. RESULTS: Within-run and between-day coefficients of variation were 5.63%, 4.01% at 6.2x10(3) IU/mL and 1.12%, 0.80% at 2.1x10(1) IU/mL, respectively. Linearity was verified from 1.0x10(1) to 1.0x10(5) IU/mL (r(2)=1.000; slope=1.1412). Detection limit for HBV DNA was verified to be 7.54 IU/mL. It showed a good correlation with LightCycler 1.5 (r=0.9723) and ABI PRISM 7500 (r=0.9768). CONCLUSIONS: Artus HBV LC PCR kit using SLAN real-time PCR detection system showed a good precision, linearity and assay sensitivity. It correlated well with LightCycler 1.5 and ABI PRISM 7500. We conclude that it can be used in clinical laboratories for nucleic acid quantification.
Bacteria ; DNA ; Limit of Detection ; Nucleic Acid Amplification Techniques ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction

PURPOSE: We intended to evaluate myocardial oxygen consumption (MVO2) by applying recirculation correction and modified one-compartment model to have a reference range of MVO2 in normal young population and to reveal the effect of recirculation on time-activity curve (TAC). Materials and METHODS: In nine normal male volunteers with mean age of 26.3+/-4.0, MVO2 was estimated with 925 MBq (25mCi) of 11C-Acetate (Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea) and PET/CT (Biograph 6, Siemens Medical Solution, Germany). Analysis software such as MATLAB(R) v7.1 (Mathworks, Inc., United States), Excel(R) 2007 (Microsoft, United States), and SPSS(R) v12.0 (Apache Software Foundation, United States) were used. Twenty three frames were of 12 x 10, 5 x 60, 3 x 120, 2 x 300's duration, respectively. The modified one-compartmental model and the recirculation correction method were applied. Statistical analysis was performed by using Test of Normality, ANOVA and Post-Hoc (Scheffe's) analysis, and p-value less than 0.05 was considered as significant. RESULTS: The normal reference ranges of MVO2 were presented as 3.18-4.64 x 10(-4) ml/g/sec, 1.91-3.94 x 10(-4) ml/g/sec, 4.31-6.40 x 10(-4) ml/g/sec, 2.84-4.53 x 10(-4) ml/g/sec and 3.42-5.00 x 10(-4) ml/g/sec in the septum, the inferior wall, the lateral wall, the anterior wall and the entire wall, respectively. In addition, it was noted that the dual exponentiality of the clearance curve is due to the recirculation effect and that the characteristic of the curve is essentially mono-exponential. CONCLUSION: 11C-Acetate is a radiotracer worthwhile to assess MVO2. Re-circulated 11C can influence TAC of 11C in myocadia and so the recirculation correction must be considered when measuring MVO2.
Academies and Institutes ; Acetates ; Carbon ; Humans ; Male ; Oxygen ; Oxygen Consumption ; Positron-Emission Tomography ; Reference Values