Texture-based quantification of pulmonary emphysema on high-resolution computed tomography: comparison with density-based quantification and correlation with pulmonary function test

PURPOSE: To develop a system for texture-based quantification of emphysema on high-resolution computed tomography (HRCT) and to compare it with density-based quantification in correlation with pulmonary function test (PFT). MATERIALS AND METHODS: Two hundred sixty-one circular regions of interest (ROI) with 16-pixel diameter [66 ROIs representing typical area of normal lung; 69 representing bronchiolitis obliterans (BO); 64, mild emphysema (ME); and 62, severe emphysema (SE)] were used to train the automated classification system based on the Support Vector Machine classifier and on variable texture and shape features. An automated quantification system was developed with a moving ROI in the lung area, which classified each pixel into 4 categories. To validate the system, the HRCT and standard-kernel-reconstructed volumetric CT data of 39 consecutive patients with emphysema were included. Using this system, the whole lung area was evaluated, and the area fractions of each class were calculated (normal lung%, BO%, ME%, SE%, respectively). The emphysema index (EI) of texture-based quantification was defined as follows: (0.3 x ME% + SE%) (TEI). EIs from density-based quantification with a threshold of -950 Hounsfield Units, were measured on both HRCT (DEI_HR_2D) and on volumetric CT (DEI_standard_3D). The agreement between TEI, DEI_HR_2D, and DEI_standard_3D was assessed using interclass correlation coefficients (ICC). Correlation of the results on the TEI with the PFT results was compared with the results of the DEI_standard_3D and the DEI_HR_2D with Spearman's correlation test. To evaluate the contribution of each texture-based quantification lesion (BO%, ME%, SE%) on PFT, multiple linear regression analysis was performed. RESULTS: The calculated TEI (19.71% +/- 17.98%) was well correlated with the DEI_standard_3D (19.42% +/- 14.30%) (ICC = 0.95), whereas the ICC with DEI_HR_2D (37.22% +/- 9.42%) was 0.43. TEI showed better correlation with PFT than DEI_standard_3D or DEI_HR_2D did [R = 0.71 vs. 0.67 vs. 0.61 for forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC); 0.54 vs. 0.50 vs. 0.43 for diffusing capacity (DLco), respectively]. Multiple linear regression analysis revealed that the BO% and SE% areas were independent determinants of FEV(1)/FVC, whereas the ME% and the SE% were determinants of DLco. CONCLUSION: Texture-based quantification of emphysema using an automated system showed better correlation with the PFT results than density-based quantification. Separate quantification of the BO, ME, and SE areas showed a different contribution of each component to the FEV(1)/FVC and the DLco. The proposed system can be successfully used for detailed regional and global evaluation of lung lesions on HRCT scanning for emphysema.     

High glucose increases inducible NO production in cultured rat mesangial cells. Possible role in fibronectin production.

BACKGROUND/AIM: Increased nitric oxide (NO) generation and action have been suggested to be associated with glomerular hyperfiltration and increased vascular permeability early in diabetes. However, previous studies have primarily focused on the constitutive nitric oxide synthase (cNOS) pathway present in endothelial cells, and the role of the inducible NOS (iNOS) pathway in diabetic nephropathy has remained unclear. This study examined whether high glucose modulates NO synthesis by the iNOS pathway in rat mesangial cells. In addition, the effect of inhibition of the iNOS pathway on fibronectin production was determined to examine the role of the iNOS pathway in high glucose-induced extracellular expansion by mesangial cells. METHODS: NO synthesis by the iNOS pathway was evaluated by nitrite and iNOS mRNA and protein productions. The effects of protein kinase C (PKC) inhibitor and aldose reductase inhibitor on the iNOS mRNA expression and aminoguanidine, a relatively specific inhibitor of the iNOS on fibronectin protein production were examined. RESULTS: High 30 mM glucose concentration led to significant increases in nitrite production of rat mesangial cells upon stimulation with lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma) compared with control 5.6 mM glucose concentration. Mesangial iNOS mRNA expression and protein production also increased significantly in response to high glucose. The addition of calphostin C, a PKC inhibitor, and 6-bromo-1,3-dioxo-1H-benz[d,e]isoquinoline-2(3H)-acetic acid, an aldose reductase inhibitor, significantly suppressed the enhancement of iNOS mRNA expression in high glucose concentration. High glucose also significantly increased fibronectin protein production of mesangial cells upon stimulation with LPS plus IFN-gamma compared to control glucose. Aminoguanidine reversed this high glucose-induced fibronectin production at dose inhibiting iNOS mRNA expression. CONCLUSIONS: These results indicate that high glucose enhances cytokine-induced NO production by rat mesangial cells, and that the activation of PKC and aldose reductase pathway may play a role in this enhancement. In addition, high glucose-induced NO production by the iNOS pathway may promote extracellular matrix accumulation by mesangial cells under certain condition.     

Impact of graft type on remnant liver regeneration: right hepatectomy versus extended right hepatectomy

Right hepatectomy with the middle hepatic vein (MHV) affects venous return and function of the remaining liver. We compared the remnant liver volume in the donors of resection with or without the MHV on the remnant liver volume regeneration. Living donors who had undergone right hepatectomy without MHV (RH group; n = 36) and those with MHV (ERH group; n = 19) were reviewed. Volume regeneration of segments I-III, segment IV, and total remnant liver volume was assessed at postoperative day (POD) 7 and 30 using a computed tomography-based volumetry program. According to the measured volume data, we calculated the liver remnant volume and the rate of liver remnant volume increase. The regeneration rate of segment IV was significantly low in the ERH group compared with that in the RH group at POD 7 and POD 30 (160% vs 141%; P = .018 and 189% vs 154%; P = .007). In contrast, the regeneration rate of the total remnant liver volume was not significantly different between the 2 groups (173% vs 175%; P = .758 and 199% vs 198%; P = .880). In conclusion, extended right hepatectomy can be safely performed with careful preoperative evaluation without significant impairment of remnant liver regeneration.     

Robotic total mesorectal excision for the treatment of rectal cancer

Robotic techniques have been developed to facilitate endoscopic surgery and to overcome its disadvantages. Thus, we performed robotic total mesorectal excison (TME) in a patient with rectal cancer, using the da Vinci^® Surgical System. To our knowledge, this is the first robotic low anterior resection, based on standard TME principles, with pelvic autonomic nerve preservation. In conclusion, this robotic system is an excellent instrument for performing the standard TME procedure in rectal cancer patients.     

Anterior lumbar instrumentation improves correction of severe lumbar Lenke C curves in double major idiopathic scoliosis

Fifteen skeletally immature patients with double major adolescent idiopathic scoliosis with large lumbar curves and notable L4 and L5 coronal plane obliquity were retrospectively studied. Seven patients who underwent anterior release and fusion of the lumbar curve with segmental anterior instrumentation and subsequent posterior instrumentation ending at L3 were compared with eight patients treated with anterior release and fusion without anterior instrumentation followed by posterior instrumentation to L3 or L4. At 4.5 years follow-up (range 2.5-7 years), curve correction, coronal balance and fusion rate were not statistically different between the two groups; however, the group with anterior instrumentation had improved coronal plane, near normalangulation in the distal unfused segment compared with the group without anterior instrumentation. In cases involving severe lumbar curvatures in the context of double major scoliosis, when as a first stage anterior release is chosen, the addition of instrumentation appears to restore normal coronal alignment of the distal unfused lumbar segment, and may in certain cases save a level compared with traditional fusions to L4.     

Application of the Ilizarov Technique to the Correction of Neurologic Equinocavovarus Foot Deformity

Background  

The treatment of rigid equinocavovarus foot deformities caused by neurologic disorders is often difficult and relapse is common.     

Laparoscopic mini-gastric bypass for type 2 diabetes: the preliminary report

Background  

Type 2 diabetes mellitus (T2DM) has become an epidemic health problem worldwide. Compared to Western countries, in Asia, T2DM occurs in patients with a lower body mass index (BMI) due to central obesity and decreased pancreatic β-cell function. The efficacy of laparoscopic mini-gastric bypass (LMGB) in obese patients with T2DM has been proven by numerous studies. Treatment outcomes of LMGB for non-obese T2DM patients are also estimated to be excellent. The aim of the present pilot study was to evaluate the efficacy and safety of LMBG in non-obese T2DM patients (BMI 25–30 kg/m²).