Computer-aided diagnosis with a convolutional neural network algorithm for automated detection of urinary tract stones on plain X-ray

BACKGROUND

Recent increased use of medical images induces further burden of their interpretation for physicians. A plain X-ray is a low-cost examination that has low-dose radiation exposure and high availability, although diagnosing urolithiasis using this method is not always easy. Since the advent of a convolutional neural network via deep learning in the 2000s, computer-aided diagnosis (CAD) has had a great impact on automatic image analysis in the urological field. The objective of our study was to develop a CAD system with deep learning architecture to detect urinary tract stones on a plain X-ray and to evaluate the model's accuracy.

METHODS

We collected plain X-ray images of 1017 patients with a radio-opaque upper urinary tract stone. X-ray images (n = 827 and 190) were used as the training and test data, respectively. We used a 17-layer Residual Network as a convolutional neural network architecture for patch-wise training. The training data were repeatedly used until the best model accuracy was achieved within 300 runs. The F score, which is a harmonic mean of the sensitivity and positive predictive value (PPV) and represents the balance of the accuracy, was measured to evaluate the model's accuracy.

RESULTS

Using deep learning, we developed a CAD model that needed 110 ms to provide an answer for each X-ray image. The best F score was 0.752, and the sensitivity and PPV were 0.872 and 0.662, respectively. When limited to a proximal ureter stone, the sensitivity and PPV were 0.925 and 0.876, respectively, and they were the lowest at mid-ureter.

CONCLUSION

CAD of a plain X-ray may be a promising method to detect radio-opaque urinary tract stones with satisfactory sensitivity although the PPV could still be improved. The CAD model detects urinary tract stones quickly and automatically and has the potential to become a helpful screening modality especially for primary care physicians for diagnosing urolithiasis. Further study using a higher volume of data would improve the diagnostic performance of CAD models to detect urinary tract stones on a plain X-ray.

[Early results of the Ponseti method for the treatment of idiopathic clubfoot]

AIM

The Ponseti method for the treatment of congenital clubfeet has been propagated due to the sometimes disappointing functional results after surgical treatment. The aim of our study was to evaluate our early results and experiences with the Ponseti method.

METHOD

Between December 2002 and December 2004 a total of 87 clubfeet in 59 patients were treated using the Ponseti method at our department. Only patients in whom treatment was initiated within the first three weeks of life were included in this study. Rate of successful correction without open release surgery, radiological findings, classification according to Pirani at the time of the last follow up, recurrence rate and duration of treatment were defined as outcome measures for this prospective study.

RESULTS

Fifty-nine cases in 37 patients met the inclusion criteria. Ninety-three percent of all cases (55 feet) were corrected without open surgery. The mean duration of active treatment was 11.4 weeks (8-20 weeks). The mean tibiocalcaneal angle 3-4 weeks after the percutaneous tenotomy of the Achilles tendon was 69 degrees, the mean a.-p.-talocalcaneal angle measured 33 degrees and the lateral talocalcaneal angle 36 degrees. A recurrence was seen in one patient with bilateral clubfeet (3.6 %).

CONCLUSION

Open release surgery can be averted in most cases of idiopathic clubfoot using the Ponseti method. Scarring of the soft tissue and especially of the joint capsule can thereby be avoided.

The effect of adding calcium lactate to xylitol chewing gum on remineralization of enamel lesions

The purpose of the study was to determine whether adding calcium lactate to chewing gum containing xylitol enhances remineralization of enamel surfaces using an early caries lesion model. Enamel slabs were cut from human extracted sound teeth and artificial subsurface lesions created within each. Half the enamel slabs were used as controls and stored in a humidifier while half were mounted into oral appliances worn by 10 volunteers (22-27 years old, 2 males and 8 females) in a three-leg trial, during which they wore the appliance without chewing gum, chewed gum containing xylitol + calcium lactate or chewed gum containing only xylitol 4 times a day for 2 weeks. Calcium concentrations in the enamel surfaces of control and test slabs were measured by X-ray spectrometry and degrees of remineralization were calculated. The mean degree of remineralization was greater after chewing xylitol-Ca gum (0.46 +/- 0.10) than after no gum (0.16 +/- 0.14) or after chewing xylitol gum (0.33 +/- 0.10) (p < 0.01). In conclusion, chewing gum containing xylitol + calcium lactate could enhance remineralization of enamel surface compared to chewing gum containing only xylitol or no gum chewing.

Relationship ofActinobacillus actinomycetemcomitansSerotype b to Aggressive Periodontitis: Frequency in Pure Cultured Isolates

BACKGROUND

To our knowledge, the association of the five serotypes of Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) to the new diagnostic classification scheme defined by the American Academy of Periodontology in 1999 has not yet been described. The goal of this study was to characterize the frequencies of the five serotypes of A. actinomycetemcomitans in A. actinomycetemcomitans isolates from various forms of periodontitis using both old and new diagnostic classifications and to determine the relationships between serotype and age and clinical diagnosis.

METHODS

A total of 345 A. actinomycetemcomitans isolates from 115 A. actinomycetemcomitans culture-positive subjects (mean age 38.0 +/- 18.3 years, 59% female) were collected. Based on the new classifications, 33 subjects had aggressive periodontitis and 82 chronic periodontitis. According to old classifications, there were six prepubertal periodontitis (PPP), 12 localized juvenile periodontitis (LJP), 15 post-localized juvenile periodontitis (PLJP), 28 refractory periodontitis (Ref-P), and 54 adult periodontitis (AP) cases. Serotypes of A. actinomycetemcomitans were determined by an indirect immunofluorescence assay using serotype-specific polyclonal antisera to A. actinomycetemcomitans strains ATCC 29523, ATCC 43728, ATCC 33384, IDH 781 and IDH 1705 (serotype a, b, c, d, and e, respectively). Proportions of serotype b were examined between different diagnostic and age groups with a Z-test for proportions.

RESULTS

Most subjects (n = 100, 86.96%) were infected with a single serotype (22 serotype a, 44 serotype b, 30 serotype c, 1 serotype d, and 3 serotype e). There were 11 subjects (9.57%) with two serotypes and two subjects (1.74%) with 3 serotypes. Two individuals had isolates lacking any detectable serotype antigen. Serotype b was the predominant serotype in children under 18 years of age and young adults between 19 to 35 years, although serotype b status was not significantly associated with age. Serotypes d and e were not found in patients under 35 years old. In 62 adult patients, one subject had serotype d and three had serotype e. Serotype b was the most common serotype in aggressive periodontitis (60.61%). The proportion of cases with serotype b was significantly higher in aggressive periodontitis compared to chronic periodontitis (P = 0.031). Other serotypes were not significantly associated with new diagnostic categories. Serotypes d and e were not detected in aggressive periodontitis.

CONCLUSION

The results of this study show that proportions of serotype b of A. actinomycetemcomitans are significantly greater in culture-positive patients with aggressive periodontitis than those with chronic periodontitis.

2-year observation of attachment loss in a rural Chinese population

BACKGROUND

Risk indicators for periodontitis seem to vary with study population. The purpose of this study was to determine whether risk indicators of additional attachment loss differ between generations of Chinese villagers in a rural area of China over a 2-year period.

METHODS

The study population consisted of 310 subjects aged 15 to 44. In each subject, 2 quadrants from either the upper or lower jaw were randomly selected and 6 sites on each tooth were examined. Clinical parameters included plaque scoring system (PSS), calculus index (CI), probing depth (PD), attachment level (AL), and sulcus bleeding index (SBI). The second examination was done 2 years after the first.

RESULTS

In the 15- to 24-year-old age group, mean PSS, CI, and SBI were significantly higher in subjects with additional attachment loss > or =3 mm (AL+) than in those without attachment loss (AL-). In the 25- to 34-year-old age group, mean PD was significantly higher in AL+ than in AL-, and mean PD and AL were significantly higher in AL+ than in AL- in the 35- to 44-year-old age group. Although the number of subjects with AL+ increased with age, the mean number of sites with AL+ per subject did not differ by generation. In addition, smokers tended to exhibit attachment loss more often than non-smokers.

CONCLUSIONS

The present results suggest that the clinical parameters associated with attachment loss differ between generations and that gingival inflammation is likely associated with the onset of periodontitis more strongly than progression of periodontitis, whereas PD and/or AL are associated with the progression of periodontitis.

Attachment loss in rural Chinese children over a 3-year period

OBJECTIVES

The periodontal condition of 84 children (9-14 years old, 38 males and 46 females) in a rural area of China was monitored over a 3-year period in order to determine the clinical parameters that act as risk factors for attachment loss.

METHODS

Plaque and calculus accumulation (PSS and CI), modified gingival index (MGI), pocket depth (PD) and attachment level (AL) of two quadrants of each child were examined in 1993 and 1996. Following calculation of the mean of each of these parameters and statistical analysis of the change in each of the clinical parameters over the 3-year period, the relationship between attachment loss and clinical parameters was analyzed using multiple regression analysis.

RESULTS

At the beginning of this study, the mean values for males and females were 3.66 and 3.58 for PSS, 1.22 and 1.17 for MGI, 1.07 and 0.90 for CI, 2.21 and 2.22 for PD, and both 0.02 for AL respectively. No significant difference between males and females was observed. After 3 years, all except mean PSS had increased significantly. Multiple regression analysis indicated that AL correlated only to age (P<0.01). In 1993, although the AL was > or =1 mm for at least one site in 21 children, none had an AL> or =3 mm. In 1996, the number of children with an AL> or =1 mm had increased to 63, and nine of these children exhibited 3 mm AL (one to six sites per child). No other significant differences were observed between the clinical data of these nine children and those of the other children.

CONCLUSION

Although attachment loss tended to increase with age, no clinical parameters correlated with attachment loss in children.

Clinical evaluation of the sedative effect of HEMA solution on the hypersensitivity of dentin

The sedative effect of the dentin primer, 35% hydroxyethyl methacrylate (HEMA) solution, on dentin hypersensitivity was clinically evaluated. Exposed root surfaces of teeth were cleaned with neutralized 0.5 mol/L EDTA and treated with 35% HEMA solution followed by the application of a commercial dentin bonding agent. The extent of sedation was estimated by comparison of the responses before and after treatment to irritation by a cold water spray, compressed air blast and scratching with an explorer. The degree of the response to these irritations was decreased significantly upon the combined application of HEMA and commercially available dentin bonding agents though it was still ineffective in nearly 30% of the 48 cases tested.

[Study of the penetration of extrinsic tracers into exposed cementum in vitro]

The purpose of the experiment was to study the possible penetration of extrinsic tracers with different molecular weights into exposed cementum in vitro and pathway of penetration. 75 human extracted teeth-55 periodontally diseased teeth and 20 embedded 3rd molars-were used. Each tooth was maintained in 0.005% fluorecein isothiocyanate (FITC) solution (M.W. 400), 0.05% FITC conjugated peroxidase solution (M.W. 40,000), or 0.01% FITC conjugated human IgG solution (M.W. 160,000) for 10 days. Morphological observations were made by means of fluorescence microscopy. Other extracted teeth were maintained in 0.05% microperoxidase solution (M.W. 1,900) for 5 days. Observations were then made using the TEM, and micrographs were taken and analyzed with an image analyzer. As a result, solutions of higher molecular weight showed lower penetration, and unexposed cementum showed a tendency toward greater penetration. Furthermore, the penetration of tracers on the surface of the cementum was along collagen fibers, but in the inner cementum, was into cementocyte lacunae and canaliculi.

Metastatic adenocarcinoma of the lung complicating pregnancy. A case report

A case of large cell undifferentiated adenocarcinoma of the lung was complicated by an aggressive clinical course and documented placental metastases. The management of these neoplasms is complex, requiring one to pay attention to the maternal, as well as fetal and neonatal, prognosis.