Recent advances in deep learning have brought many breakthroughs in medical image analysis by providing more robust and consistent tools for the detection, classification and quantification of patterns in medical images. Specifically, analysis of advanced modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) has benefited most from the data-driven nature of deep learning. This is because the need of knowledge and experience-oriented feature engineering process can be circumvented by automatically deriving representative features from the complex high dimensional medical images with respect to the target tasks. In this paper, we will review recent applications of deep learning in the analysis of CT and MR images in a range of tasks and target organs. While most applications are focused on the enhancement of the productivity and accuracy of current diagnostic analysis, we will also introduce some promising applications which will significantly change the current workflow of medical imaging. We will conclude by discussing opportunities and challenges of applying deep learning to advanced imaging and suggest future directions in this domain.
Classification ; Diagnostic Imaging ; Efficiency ; Learning* ; Magnetic Resonance Imaging*

PURPOSE: To evaluate the impact of temporary internal ureteral stents on the surgical outcomes of dismembered pyeloplasty in children. MATERIALS AND METHODS: The medical records of 70 children (76 renal units) who underwent dismembered pyeloplasty for ureteropelvic junction (UPJ) obstruction at at Asan Medical Center between January 2005 and December 2010 were retrospectively reviewed. We classified the renal units into the stented group (22 renal units) and the nonstented group (54 renal units). Fifty-four of 70 patients were male and their mean age was 2.2+/-3.8 years old. The mean follow-up period was 29.6+/-16.8 months. RESULTS: Sixty-four children had unilateral UPJ obstruction. The mean stent duration was 31.9 days. As shown by evaluation of radiologic images, there were no significant differences between the stented group and the nonstented group during the follow-up period (p>0.05). The mean preoperative and postoperative anteroposterior pelvic diameters (APPDs) of the nonstented group were 31.3 mm and 15.1 mm, respectively (p<0.001). The preoperative and postoperative grades of hydronephrosis were 3.9 and 2.9, respectively (p=0.037). The mean preoperative and postoperative APPDs of the stented group were 36.4 mm and 15.6 mm, respectively (p<0.001). The preoperative and postoperative grades of hydronephrosis were 4 and 3.1, respectively (p<0.001). Repeat obstruction was shown in 4 subjects as a postoperative complication (5.7%). Two children from each group had recurrent UPJ obstruction, with percentages of 3.7% and 9%, respectively (p=0.575). CONCLUSIONS: In a comparison of nonstented and stented groups during pediatric dismembered pyeloplasty for UPJ obstruction, no significant differences were found in the resolution of hydronephrosis or overall postoperative complications.
Child ; Follow-Up Studies ; Humans ; Hydronephrosis ; Male ; Medical Records ; Postoperative Complications ; Retrospective Studies ; Stents ; Ureter ; Ureteral Obstruction

The mutation of the PKD1 gene causes autosomal dominant polycystic kidney disease (ADPKD), and the PKD1 gene encodes polycystin-1 (PC-1). PC-1 is thought to be a cell-cell/matrix adhesion receptor molecule at the cell surface that is widely expressed in the kidney. However, there are controversies about the role of PC-1 protein and its expression when using different antibodies to detect it. We used two PC-1 antibodies; C-20 (Santa Cruz, sc-10372) as the C-terminal antibody, and P-15 (Santa Cruz, sc-10307) as the N-terminal antibody. We evaluated the PC-1 expression by performing immunoblotting on the human embryonic kidney (HEK) 293 cells and the renal proximal tubular epithelial cell (RPTEC) lysates. We characterized the expression of PC-1 in the fetal, adult and polycystic kidneys tissues by performing immunohistochemistry. We confirmed the PC-1 expression in the HEK 293 cells and the RPTEC lysates, but the expression was very low. The PC-1 proteins were diffusely expressed in the tubular epithelial cells cytoplasm in the fetal and adult kidneys, and the PC-1 expression was more prominent in the proximal tubules of the fetal kidney. In the ADPKD kidney, the PC-1 proteins were heterogenously and weakly expressed in the tubular or cyst lining epithelial cells. Our data suggests that the development of the kidney may regulate the expression of PC-1, and an altered PC-1 expression may contribute to cyst formation in ADPKD.
TRPP Cation Channels/chemistry/*metabolism ; Protein Structure, Tertiary ; Polycystic Kidney, Autosomal Dominant/*metabolism ; Middle Aged ; Male ; Kidney/*embryology/metabolism/*pathology ; Immunohistochemistry ; Humans ; *Gene Expression Regulation, Developmental ; *Gene Expression Regulation ; Cytoplasm/metabolism ; Cell Line

Masseter muscle rigidity (MMR), known as the ‘jaw of steel’, sometimes makes laryngoscope unusable due to the stiffness of the jaw. MMR during general anesthesia was previously considered as an early episode of malignant hyperthermia (MH). Generally, MMR occurs in the pediatric patients after induction with succinylcholine and volatile agents. However, MMR following the administration of non-depolarizing muscle relaxants is uncommon, although described in some reports. We report a case of 62-year-old male patient which developed MMR following intravenous administration of rocuronium during induction of anesthesia. Our patient was not found to be vulnerable to MH. Although fiberoptic nasotracheal intubation had been successfully performed in our case, an unanticipated difficult airway due to MMR can be experienced at any time. Therefore, we should be aware that, although rare, MMR can occur after using non-depolarizing muscle relaxant. Additionally, in case of any incident of MMR, anesthesiologists need to recognize the management of a difficult airway and to maintain adequate oxygenation in a variety of methods according to a difficult airway algorithm.

Masseter muscle rigidity (MMR), known as the ‘jaw of steel’, sometimes makes laryngoscope unusable due to the stiffness of the jaw. MMR during general anesthesia was previously considered as an early episode of malignant hyperthermia (MH). Generally, MMR occurs in the pediatric patients after induction with succinylcholine and volatile agents. However, MMR following the administration of non-depolarizing muscle relaxants is uncommon, although described in some reports. We report a case of 62-year-old male patient which developed MMR following intravenous administration of rocuronium during induction of anesthesia. Our patient was not found to be vulnerable to MH. Although fiberoptic nasotracheal intubation had been successfully performed in our case, an unanticipated difficult airway due to MMR can be experienced at any time. Therefore, we should be aware that, although rare, MMR can occur after using non-depolarizing muscle relaxant. Additionally, in case of any incident of MMR, anesthesiologists need to recognize the management of a difficult airway and to maintain adequate oxygenation in a variety of methods according to a difficult airway algorithm.

Pleurisy is an inflammation of the parietal pleura and is characterized by pleuritic pain. The most common cause of pleurisy is infection; other causes include rheumatoidarthritis, malignancy, rib fractures, or trauma. Possible causes of chest pain associated withgolf include costochondritis, stress fractures of the ribs, intercostal muscle strain, or, rarely,Tietze’s syndrome and slipping rib syndrome.Case: A 64-year-old female presented with intractable chest pain that began 4 months priorwhile playing golf. No specific cause was found after various examinations. There was persistent pain despite medical treatment. Ultrasonography (US) was performed over the painful areas, which revealed focal pleural effusions. A mixture of ropivacaine and triamcinolonewas injected into the focal pleural effusions using US guidance, which dramatically relievedher pain.Conclusions: This case demonstrates that US can be used as a diagnostic and therapeuticmodality for intractable chest pain with an undetected pathology.

Precise allergy diagnosis and effective allergen specific immunotherapy are largely dependent on the quality of allergen extract. A new extract of Dermatophagoides farinae was commercially developed by Prolagen. The allergenic properties of the new extract were compared with those of other commercial products. The allergenic properties of the new extract were compared according to protein concentration, protein profiles, major allergen (Der f 1) contents, and allergenic potency to those for three commercially available extracts imported in Korea (Jubilant HollisterStier Allergy, Lofarma S.p.A., and Stallergenes Greer). Protein concentrations varied up to 2.62-fold (0.404 to 1.057 mg/mL), and Der f 1 contents varied up to 11.3-fold (3.597 to 40.688 μg/mL). Protein profiles of the extracts showed no major discrepancies, although there were some differences in SDS-PAGE band intensities, reflecting protein concentrations. Allergen potency ranged from 37038 to 60491 PAU/mL. The Prolagen product was highest in terms of protein concentration and allergen potency. The Lofarma product displayed Der f 1 content similar to that in Prolagen (19.4 μg/mg vs. 19.3 μg/mg). Endotoxin levels varied 8.9-fold (1020 to 8985 EU/mL). The newly developed house dust mite extract showed equal or better allergenic properties than available commercial extracts. This new product may be useful for better diagnostics and allergen-specific immunotherapeutics.

OBJECTIVE: To retrospectively assess the effect of CT slice thickness on the reproducibility of radiomic features (RFs) of lung cancer, and to investigate whether convolutional neural network (CNN)-based super-resolution (SR) algorithms can improve the reproducibility of RFs obtained from images with different slice thicknesses. MATERIALS AND METHODS: CT images with 1-, 3-, and 5-mm slice thicknesses obtained from 100 pathologically proven lung cancers between July 2017 and December 2017 were evaluated. CNN-based SR algorithms using residual learning were developed to convert thick-slice images into 1-mm slices. Lung cancers were semi-automatically segmented and a total of 702 RFs (tumor intensity, texture, and wavelet features) were extracted from 1-, 3-, and 5-mm slices, as well as the 1-mm slices generated from the 3- and 5-mm images. The stabilities of the RFs were evaluated using concordance correlation coefficients (CCCs). RESULTS: The mean CCCs for the comparisons of original 1 mm vs. 3 mm, 1 mm vs. 5 mm, and 3 mm vs. 5 mm images were 0.41, 0.27, and 0.65, respectively (p < 0.001 for all comparisons). Tumor intensity features showed the best reproducibility while wavelets showed the lowest reproducibility. The majority of RFs failed to achieve reproducibility (CCC ≥ 0.85; 3.6%, 1.0%, and 21.5%, respectively). After applying the CNN-based SR algorithms, the reproducibility significantly improved in all three pairings (mean CCCs: 0.58, 0.45, and 0.72; p < 0.001 for all comparisons). The reproducible RFs also increased (36.3%, 17.4%, and 36.9%, respectively). CONCLUSION: The reproducibility of RFs in lung cancer is significantly influenced by CT slice thickness, which can be improved by the CNN-based SR algorithms.
Learning ; Lung Neoplasms ; Lung ; Retrospective Studies

Macrophage infiltration has been observed in the renal biopsy specimens of diabetic nephropathy (DN), and hyperglycemic state stimulates the renal expression of RANTES (regulated upon activation, normal T-cell expressed and secreted) and MCP-1 (monocyte chemoattractant protein-1). Upregulation of RANTES and MCP-1 with infiltrating macrophages may play a crucial role in the development and progression of DN. Genetic polymorphisms of RANTES and its receptors were reported to be independent risk factors for DN. We genotyped single nucleotide polymorphism (SNPs) in the MCP-1 G-2518A, CCR2 G46295A, RANTES C-28G and G-403A in 177 diabetic end-stage renal disease (ESRD) patients and 184 patients without renal involvement (controls) in order to investigate the effects of these SNPs on DN in Korean patients with type 2 DM. There were no differences in the frequencies of SNPs and the distribution of haplotypes of RANTES promoter SNPs between two groups. In conclusion, there were no associations of MCP-1, CCR2 and RANTES promoter SNPs with diabetic ESRD in Korean population. Prospective studies with clearly-defined, homogenous cohorts are needed to confirm the effect of these genetic polymorphisms on DN.
Aged ; Asian Continental Ancestry Group/*genetics ; Chemokine CCL2/*genetics ; Chemokine CCL5/*genetics ; Chi-Square Distribution ; Diabetes Mellitus, Type 2/complications ; Female ; Gene Frequency ; Genotype ; Haplotypes ; Humans ; Kidney Failure, Chronic/ethnology/etiology/*genetics ; Korea ; Male ; Middle Aged ; *Polymorphism, Single Nucleotide ; Promoter Regions, Genetic

The authors report a case of atypical extraventricular neurocytoma (EVN) transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years ago. An 8-year-old boy underwent a surgical resection for a right frontal mass which was initially diagnosed as oligodendroglioma. When the tumor recurred 15 years later, a secondary operation was performed, followed by salvage gamma knife treatment. The recurrent tumor was diagnosed as an atypical EVN. The initial specimen was reviewed and immunohistochemistry revealed a strong positivity for synaptophysin. The diagnosis of the initial tumor was revised as an EVN. The patient maintained a stable disease state for 15 years after the first operation, and was followed up for one year without any complications or disease progression after the second operation. We diagnosed an atypical extraventricular neurocytoma transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years earlier. We emphasize that EVN should be included in the differential diagnosis of oligodendroglioma.
Child ; Diagnosis, Differential ; Disease Progression ; Humans ; Immunohistochemistry ; Neurocytoma ; Oligodendroglioma ; Recurrence ; Synaptophysin