Comparison of sensitivity of lung nodule detection between radiologists and technologists on low-dose CT lung cancer screening images

OBJECTIVES

The objective of this study was to compare the sensitivity of detection of lung nodules on low-dose screening CT images between radiologists and technologists.

METHODS

11 radiologists and 10 technologists read the low-dose screening CT images of 78 subjects. On images with a slice thickness of 5 mm, there were 60 lung nodules that were ≥5 mm in diameter: 26 nodules with pure ground-glass opacity (GGO), 7 nodules with mixed ground-glass opacity (GGO with a solid component) and 27 solid nodules. On images with a slice thickness of 2 mm, 69 lung nodules were ≥5 mm in diameter: 35 pure GGOs, 7 mixed GGOs and 27 solid nodules. The 21 observers read screening CT images of 5-mm slice thickness at first; then, 6 months later, they read screening CT images of 2-mm slice thickness from the 78 subjects.

RESULTS

The differences in the mean sensitivities of detection of the pure GGOs, mixed GGOs and solid nodules between radiologists and technologists were not statistically significant, except for the case of solid nodules; the p-values of the differences for pure GGOs, mixed GGOs and solid nodules on the CT images with 5-mm slice thickness were 0.095, 0.461 and 0.005, respectively, and the corresponding p-values on CT images of 2-mm slice thickness were 0.971, 0.722 and 0.0037, respectively.

CONCLUSION

Well-trained technologists may contribute to the detection of pure and mixed GGOs ≥5 mm in diameter on low-dose screening CT images.

Formation of porcine hepatocyte spherical multicellular aggregates (spheroids) and analysis of drug metabolic functions

Porcine hepatocytes are used in the hybrid artificial liver support system that we are developing because of their high level of liver functions in vitro and because human hepatocytes can not be used in Japan for ethical reasons. Spherical multicellular aggregates or spheroids have been found to be effective in vitro for long-term maintenance of liver functions. Therefore, we formed spherical multicellular aggregates (spheroids) of primary porcine hepatocytes using a polyurethane foam (PUF) as a culture substratum and analyzed their drug metabolic functions in vitro. Primary porcine hepatocytes inoculated into the pores of a flat PUF plate (25 x 25 x 1 mm), spontaneously formed spheroids within the range of 100 to 150 mum in diameter 24 to 36 h after inoculation. The formed spheroids were attached to the bottom surface of the PUF pores, and their morphology and viability were maintained for more than 12 days. The P-450 activity in the spheroids of porcine hepatocytes was demonstrated by detecting production of monoethylglycinexylidide from lidocaine. In addition, the conjugation enzyme activity was demonstrated by detecting glucuronidation and sulfation of acetaminophen. These activities were maintained for 12 days at a level twice as high as in the monolayer culture. This result shows that the porcine hepatocyte spheroids formed by using PUF can maintain the drug metabolic functions important in a hybrid artificial liver device. Consequently, culturing porcine hepatocyte spheroids using PUF seems to be promising for development of a hybrid artificial liver.

Electromagnetic drive of microrobot geometrically constrained in blood vessel

We propose new electromagnetic actuation of a microrobot by utilizing geometric constraints in a blood vessel. In our concept, a microrobot travels in a vascular network while keeping the contact to the vascular wall. In the paper, forces working on the microrobot are modeled in two dimensions, and conditions to propel the microrobot while pushing it against the vascular wall are described. The design of the microrobot composed of three permanent magnets is also presented. The feasibility of the 2D actuation of the microrobot was confirmed using an experimental setup composed of four pairs of coils generating both uniform magnetic fields and uniform magnetic field gradients. Finally, the model was extended to 3D in order to investigate 3D actuation of the microrobot.

Aging curve of neuromotor function by pronation and supination of forearms using three-dimensional wireless acceleration and angular velocity sensors

We have developed an evaluation system for pronation and supination of forearms. The motion of pronation and supination of the forearm is used as a diagnosis method of developmental disability, etc. However, this diagnosis method has a demerit in which diagnosis results between doctors are not consistent. It is hoped that a more quantitative and simple evaluation method is established. Moreover it is hoped a diagnostic criteria obtained from healthy subjects can be established to diagnose developmental disorder patients. We developed a simple and portable evaluation system for pronation and supination of forearms. Three-dimensional wireless acceleration and angular velocity sensors are used for this system. In this study, pronation and supination of forearms of 570 subjects (subjects aged 6-12, 21-100) were examined. We could obtain aging curves in the neuromotor function of pronation and supination. These aging curves obtained by our developed system, has the potential to become diagnostic criteria for a developmental disability, etc.

A case of hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease) with multiple polyps arising in the cecum and appendix

We present the case of a 32-year-old female with cecal and appendiceal polyps that were removed by laparoscopy-assisted surgery. She also had recurrent nosebleeds due to telangiectases in the nasal mucosa and arteriovenous malformations in the lung, all of which contributed to the diagnosis of hereditary hemorrhagic telangiectasia.

Effect of low-intensity pulsed ultrasound stimulation on callus remodelling in a gap-healing model

We evaluated the effect of low-intensity pulsed ultrasound stimulation (LIPUS) on the remodelling of callus in a rabbit gap-healing model by bone morphometric analyses using three-dimensional quantitative micro-CT. A tibial osteotomy with a 2 mm gap was immobilised by rigid external fixation and LIPUS was applied using active translucent devices. A control group had sham inactive transducers applied. A region of interest of micro-CT was set at the centre of the osteotomy gap with a width of 1 mm. The morphometric parameters used for evaluation were the volume of mineralised callus (BV) and the volumetric bone mineral density of mineralised tissue (mBMD). The whole region of interest was measured and subdivided into three zones as follows: the periosteal callus zone (external), the medullary callus zone (endosteal) and the cortical gap zone (intercortical). The BV and mBMD were measured for each zone.

In the endosteal area, there was a significant increase in the density of newly formed callus which was subsequently diminished by bone resorption that overwhelmed bone formation in this area as the intramedullary canal was restored. In the intercortical area, LIPUS was considered to enhance bone formation throughout the period of observation. These findings indicate that LIPUS could shorten the time required for remodelling and enhance the mineralisation of callus.

Neuron-immune interactions in the sensitized thalamus induced by mustard oil application to rat molar pulp

We have reported that mustard oil application to the rat dental pulp induces neuronal activation in the thalamus. To address the mechanisms involved in the thalamic changes, we performed neuronal responsiveness recording, immunohistochemistry, and molecular biological analysis. After mustard oil application, neuronal responsiveness was increased in the mediodorsal nucleus. When MK801 (an N-methyl-D-aspartate receptor antagonist) was applied to the mediodorsal nucleus, the enhanced responsiveness was decreased. N-methyl-D-aspartate receptor 2D, glial fibrillary acidic protein, and antigen-presenting cell-related gene mRNAs in the contralateral thalamus were up-regulated at 10 minutes after mustard oil application, but were down-regulated within 10 minutes after the antagonist application. OX6-expressing microglia and glial fibrillary acidic protein-expressing astrocytes did not increase until 60 minutes after mustard oil application. These results suggested that the thalamic neurons play some roles in regulating the glial cell activation in the mediodorsal nucleus via N-methyl-D-aspartate receptor 2D during pulp inflammation-induced central sensitization.

Sensitivity and specificity of photopic negative response of focal electoretinogram to detect glaucomatous eyes

AIMS

To determine the sensitivity and specificity of the photopic negative response (PhNR) of the focal electroretinograms (ERG; focal PhNR) to detect glaucomatous eyes with different degrees of visual field defects.

METHODS

One-hundred and fourteen eyes of 114 patients with open angle glaucoma and 42 eyes of 42 normal controls were studied. The focal ERGs were elicited by a 15 degrees stimulus spot centred on the macula, and on the supero-temporal and on the infero-temporal areas of the macula. The receiver operating characteristic curves were determined to obtain optimal cut-off values. Eyes were classified as being glaucomatous when their focal PhNRs were less than the cut-off values in either retinal area (combined criterion).

RESULTS

The focal PhNR amplitudes were significantly reduced with an advance in the stage of glaucoma. In early glaucoma, the sensitivities of the PhNR measured for each retinal area ranged from 58.1% to 80.7%. The sensitivities were significantly increased to 90.6% and 96.9% for the focal PhNR amplitude and the focal PhNR/b-wave amplitude ratio, respectively, when the combined criterion was employed. The specificity was >90%.

CONCLUSIONS

Focal PhNRs have diagnostic ability in detecting early glaucoma with high sensitivity and specificity, especially when the combined criterion is used.

Factors influencing 3D-MRI diagnosis in preoperative breast cancer patients

620

Background: We presented 3D-MRI will be the useful breast imaging tool in diagnosing intraductal spread and tumor size in breast cancer patients. (ASCO 2008).To do breast conserving surgery, careful management was needed in cases with widely ductal spreading and multifocal lesion. This study was to evaluate factors influencing false negative diagnosis and multifocal types of 3D-MRI, retrospectively. Methods: From July 2000, pre-operative 3D-MRI was underwent 488 cases and images were obtained 479 cases (98%). These patients could be divided into three groups according to 3D-MRI images: pattern 1) localized type (273 cases), 2) widely enhanced type (106 cases) and 3) multi-focal type (100 cases). From April 2005, resected specimen was serially step cut and total specimens were microscopically evaluated. Tumor size in 3D-MRI was 1cm over smaller than resected specimens were defined false negative cases. Investigated factors influencing 3D-MRI were age, patterns of 3D-MRI images, presence of pre-operative chemotherapy, histological type, histological grade, microscopical invasive tumor size (mm) and presence of ductal spreading. Results: The rate of histological confirmed intraductal spread were seen in 58% (158/273cases), 89% (94/106 cases) of patients with 3D-MRI pattern 1) and 2), respectively. Tumor size was correlated between MRI and specimens, significantly (n = 162, r = 06706, p < 0.001). Factors influencing false negative diagnosis of 3D-MRI were presence of pre-operative chemotherapy (p < 0.05), presence of ductal spreading (p < 0.001) and patterns of 3D-MRI images (p < 0.05). In the cases with multi-focal 3D- images, there were only 11(11/41, 26%) cases with true multifocal lesions by total specimens examination. Selection for breast conserving surgery and margin width were based by 3D-MRI images. The proportion of breast-conserved surgery were obtained 90% (437/488 cases) and local failure seen only 6 cases (local failure rate 1.4%) in 3D-MRI guided surgery. (median follow up 52 months). Conclusions: These results suggest that MRI will be the useful breast imaging tool, but caution will be needed in cases with pre-operative systemic therapy, cases expected intraductal spread by imaging tools and cases with multi-focal 3D- images.

No significant financial relationships to disclose.

Stage-size relationship in long-term repeated CT screening for lung cancer: Anti-Lung Cancer Association project

1540

Background: We have investigated the individualized benefit of CT screening as Anti-Lung Cancer Association projects (presented at ASCO 2006–2008). However, there has not been enough information about the relationship of lung cancer stage to tumor size in repeated CT screening. Therefore, we evaluated the stage-size relationship of these asymptomatic lung cancer cases diagnosed by long-term repeated screening with low-dose helical CT. Methods: Among 2,120 participants (mean age 63 years, 87% male, and 83% smoker) at baseline screening, 1,877 underwent semiannually repeated screening from 1993 to 2004. Nineteen (0.90%) prevalence cancers and 57 (0.32%) incidence cancers were detected. Within categories of tumor size, the distribution of pathological stage, histology, lymph node status, and distant metastases was determined. Results: Pathological stage has a strong relationship to tumor size at baseline screening (spearman r = 0.63, p = 0.013) and repeated screening (r = 0.65, p < 0.001). In the analysis of all 76 cases, lymph node status (r = 0.59, p < 0.001) and distant metastases (r = 0.55, p = 0.005) have also a strong relationship to tumor size. The percentages of cases with no metastases (N0M0) were 100% (0/21), 89% (17/19), 62% (8/13), 83% (10/12), 50% (4/8), and 33% (1/3) for the categories 10 mm or less, 11 mm to 15 mm, 16 mm to 20 mm, 21 mm to 30 mm, 31 mm to 40 mm, and 41 mm or greater, respectively. Histology for the categories 15 mm or less was localized bronchioloalveolar carcinoma in 13 cases, adenocarcinoma with mixed subtype in 11 cases, invasive adenocarcinoma in five cases, other non-small cell carcinoma in 10 cases, and small cell carcinoma in one case. Accumulated 10-year hazard ratio of above histology was 2.4, 2.5, 2.6, 4.1, and 0.7. In multivariate analyses, pathological stage was related to only tumor size (standardized regression coefficient beta = 0.59, p < 0.001) whereas histology was related to tumor size (beta = 0.43, p < 0.001) and smoking index (beta = 0.28, p = 0.016). Conclusions: These results provide direct evidence of a stage-size relationship in long-term repeated CT screening for lung cancer. Furthermore, early detection of lung cancer of 15 mm or less in diameter leads to the detection of early-stage (N0M0) lung cancer in repeated CT screening.

No significant financial relationships to disclose.

Factors influencing false negative diagnosis of 3D-MRI in pre-operative breast cancer patients

Abstract #4005

Introduction: We presented 3D-MRI will be the useful breast imaging tool in diagnosing intraductal spread and tumor size in breast cancer patients (ASCO 2008). But, false negative cases were very important in breast conserving surgery and careful management was needed in 3D-MRI guided surgery. This study was to review imaging diagnosis using 3D-MRI and to evaluate factors influencing false negative diagnosis of 3D-MRI, retrospectively. Material and methods: From July 2000, pre-operative 3D-MRI was underwent 433 cases of breast cancer patients. Images were obtained 426 cases (98%). Tumor size between 3D-MRI and resected specimens were evaluated retrospectively. Cases with tumor size difference between 3D-MRI and resected specimens less than 1cm were defined related cases and cases with tumor size in 3D-MRI was 1cm more smaller than resected specimens were defined false negative cases. Investigated factors influencing false negative diagnosis of 3D-MRI were age, patterns of 3D-MRI images, presence of pre-operative chemotherapy, histological type, histological grade, microscopical invasive tumor size (mm) and presence of ductal spreading. From April 2005, the entire specimen was serially step cut and evaluated. Results: Tumor diameter from nipple side to lateral margin were measured by MRI and specimens, tumor size was correlated between MRI and specimens, significantly (n=118, r=07186, P &lt; 0.001). On Multivariate analysis revealed that factors influencing 3D-MRI diagnosis were presence of ductal spreading (p=0.0002), patterns of 3D-MRI images (p=0.06) and presence of pre-operative chemotherapy (P=0.04). Factors influencing false negative diagnosis of 3D-MRI were presence of pre-operative chemotherapy (P&lt;0.05), presence of ductal spreading (P&lt;0.01) and infiltration of lymphocyte in the edge of ductal spreading (P&lt;0.05). Selection for breast conserving surgery and margin width were based by 3D-MRI images. The proportion of breast-conserved surgery were obtained 89% (380/426 cases) and local failure seen only 6 cases (local failure rate 1.4%) in 3D-MRI guided surgery. (6-94 months, median follow up 51 months).&#x2028; Conclusion: These results suggest that MRI will be the useful breast imaging tool in diagnosing intraductal spread and tumor size in breast cancer patients. But, caution will be needed in cases with pre-operative systemic therapy and cases expected ductal spreading by other imaging tools.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4005.