Evaluation of an artificial intelligence U-net algorithm for pulmonary nodule tracking on chest computed tomography images.

OBJECTIVES: To apply image registration in the follow up of lung nodules and verify the feasibility of automatic tracking of lung nodules using an artificial intelligence (AI) method. METHODS: For this retrospective, observational study, patients with pulmonary nodules 5-30 mm in diameter on computed tomography (CT) and who had at least six months follow-up were identified. Two radiologists defined a 'correct' cuboid circumscribing each nodule which was used to judge the success/failure of nodule tracking. An AI algorithm was applied in which a U-net type neural network model was trained to predict the deformation vector field between two examinations. When the estimated position was within a defined cuboid, the AI algorithm was judged a success. RESULTS: In total, 49 lung nodules in 40 patients, with a total of 368 follow-up CT examinations were examined. The success rate for each time evaluation was 94% (345/368) and for 'nodule-by-nodule evaluation' was 78% (38/49). Reasons for a decrease in success rate were related to small nodules and those that decreased in size. CONCLUSION: Automatic tracking of lung nodules is highly feasible.

The impact of background liver disease on the long-term prognosis of very-early-stage HCC after ablation therapy.

BACKGROUND AND AIM: The long-term prognosis of hepatocellular carcinoma (HCC) treated at a very-early-stage (the Barcelona Clinical Liver Cancer (BCLC) classification stage 0) was unclear, especially in terms of background liver disease. METHODS: This single-center, retrospective study included 302 patients with BCLC stage 0 HCC treated with radiofrequency ablation (RFA) and followed for at least six months. We examined the impact of background liver disease on overall survival and recurrence. RESULTS: The median age was 72 (range; 36-91) years; the median tumor diameter was 15 (range; 8-20) mm. The etiologies of background liver disease were hepatitis B virus infection (HBV) in 24 cases, hepatitis C virus infection (HCV) in 195 cases, and non-viral (NBNC) in 83 cases. Among the patients with HCV, 63 had achieved sustained virological response (SVR) by antiviral therapy (HCV SVR) before developing HCC (n = 37) or after HCC treatment (n = 26), and 132 had active HCV infection (HCV non-SVR). The median overall survival was 85 (95% CI; 72-98) months, and the median recurrence-free survival was 26 (95% CI; 20-30) months. Active infection with hepatitis C virus negatively contributed to overall survival (HR 2.91, 95% CI 1.31-3.60, p = 0.003) and recurrence-free survival (HR 1.47, 95% CI 1.06-2.05, p = 0.011). CONCLUSIONS: The prognosis of RFA treatment for very early-stage HCC was favorable. Achieving SVR in hepatitis C was important for further prognosis improvement.

Effectiveness of new sedation and rehabilitation methods for critically ill patients receiving mechanical ventilation.

[Purpose] The purpose of this study was to investigate the effects of new sedation management methods and cooperation between nurses and physical therapists on the duration of mechanical ventilation and hospitalization. [Subjects and Methods] Patients who had been treated at the study hospital 2 years before and after the implementation of the new methods were analyzed retrospectively and classified into a "control group" and an "intervention group", respectively. Both groups were analyzed and subsequently compared regarding the effects of the new sedation and cooperative rehabilitation. [Results] A total of 70 patients met the inclusion criteria and were divided evenly into the two groups. No significant differences were found between the groups in age, APACHE II score, or duration of stay in hospital. On the other hand, significant decreases were seen in the duration of sedation and intubation, mechanical ventilation, and stay in the emergency ward, as well as time until standing. In addition, after intervention, three patients undergoing ventilator treatment were able to be ambulated. [Conclusion] These results suggest that the new sedation and cooperative rehabilitation methods for critically ill patients were effective in the early stage of treatment and shortened the duration of stay in the ward.

Contralateral breast cancer adjacent to a fibroadenoma: report of a case.

A 64-year-old woman noticed a lump of the right breast and consulted our outpatient clinic. She had undergone multiple excisional biopsies of fibroadenomas in both breasts and mastectomy for invasive ductal carcinoma (IDC) of the left breast. After completing 5 years of treatment with adjuvant tamoxifen, she had undergone screening with annual physical examinations and occasional computed tomography. She was declared recurrence-free 13 years after breast cancer surgery, although lumps were detected in the right breast, probably due to fibroadenomas. Mammography, ultrasonography, and magnetic resonance imaging revealed that the lump was irregularly shaped, 2 cm in diameter, and adjacent to a fibroadenoma with macrocalcification. Two axillary lymph nodes were enlarged and suggestive of metastasis. A core needle biopsy revealed IDC of the right breast. She underwent a right partial mastectomy with axillary lymph node dissection. The IDC was 2 cm in diameter, of nuclear grade 2, and adjacent to a 0.7-cm fibroadenoma with a macrocalcification. The margins of the IDC close to the fibroadenoma were clearly demarcated by the fibrous capsule of the fibroadenoma. Four axillary lymph nodes were positive for metastasis. In the present case the presence of fibroadenoma might have interfered with the early detection of the contralateral IDC. The history of multiple excisions of fibroadenomas and mastectomy for breast cancer suggests an increased risk of contralateral breast cancer for the patient's entire life; therefore, regular annual follow-up, such as physical examinations and mammography, is recommended.

A case of giant cell glioblastoma: a mimicker of a cerebral metastasis.

We report a rare case of giant cell glioblastoma that was difficult to distinguish from cerebral metastasis. The MRI finding was a ring-enhancing well-circumscribed solitary brain tumor that was very similar to cerebral metastasis. Even when MRI results were considered together with the findings by magnet resonance spectroscopy and perfusion-weighted MRI, it was hard to distinguish between giant cell glioblastoma and cerebral metastasis before surgery. When we find a solitary ring-enhancing intracranial mass with little tendency of invasion, we need to consider the possibility of giant cell GBM as a differential diagnosis.

Intraarterial therapy for acute ischemic stroke: investigation of prognostic factors.

BACKGROUND: Intraarterial therapy (IAT) for acute cerebral infarction has been proven to be profitable. However, the criteria for the indications, the choice of the thrombolytic agents, and the use of adjunctive agents are controversial. We retrospectively analyzed the prognostic factors of IAT. MATERIALS AND METHODS: From 1994 to 2003, 28 patients underwent IAT due to middle cerebral artery occlusion (17 women and 11 men; median age, 69 years old). We evaluated the following prognostic parameters: institution of treatment, degree of paralysis at visit, size of high-intensity area on diffusion-weighted images, dose of intraarterial urokinase administration, elapsed time from symptom onset to completion of IAT, presence of penetration of embolus by microcatheter and microguidewire, recanalization after IAT, intracranial hemorrhage (ICH) within 24 hours after IAT, and intravenous heparin administration after IAT. The outcome was evaluated at discharge and was classified into the following categories according to the modified Rankin Scale: independence (0 to 2), dependence (3 to 5), and death (6). RESULTS: Seven patients were judged to be independent, 16 patients were judged to be dependent, and five patients died. Patients with recanalization after IAT had a better outcome than those without (p < 0.05); patients with intracranial hemorrhage had a worse outcome than those without (p < 0.05); and patients with intravenous heparin administration after IAT had a better outcome in activities of daily living than those without (p < 0.05). CONCLUSION: In addition to ICH and recanalization, our results suggested that intravenous heparin administration after IAT had a favorable effect on patient outcome.

Surface shape measurement by phase-shifting digital holography with a wavelength shift.

Surface contouring by phase-shifting digital holography is proposed and verified by experiments and numerical simulations. Digital holograms are recorded before and after mode hopping of a laser diode subject to current tuning, and the difference of the reconstructed phases at each wavelength is computed to deliver surface contours of a diffusely reflecting surface. Since normal incidence on the object is employed, the method does not need the removal of the tilt component and is free from the shadowing effect as advantages over the dual-incidence method proposed before by the first author.

Left retroperitoneal approach using a retractor to repair abdominal aortic aneurysms: a comparison with the transperitoneal approach.

PURPOSE: The purpose of this study was to compare the effectiveness of the retroperitoneal approach (RP) using a Thompson retractor with the conventional transperitoneal approach (TP), to repair infrarenal abdominal aortic aneurysms (AAA). METHODS: A total of 91 consecutive patients were divided into two groups; group A ( n = 21) underwent surgery using the TP, and group B ( n = 70) underwent surgery using the RP with a Thompson retractor. RESULTS: There were no significant differences in the operation time, aortic cross-clamp time, incidence of postoperative cardiac events, or the development of wound complications; however, a significantly higher rate of postoperative respiratory complications and ileus was observed in group A. Moreover, oral feeding was commenced later and the hospital stay was prolonged in group A ( P < 0.01). CONCLUSION: These findings clearly demonstrate that our RP method, especially when using a Thompson retractor, is a preferable alternative to TP for AAA surgery.