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.     

Typical carcinoids and neuroendocrine carcinomas of the stomach: differing clinical courses and prognoses

Background

Gastric endocrine tumors are usually classified as 3 types of well-differentiated endocrine tumors (typical carcinoids or carcinoids) and poorly differentiated carcinomas (neuroendocrine carcinomas [NECs]).

Methods

From 1993 to 2008, 97 patients (73 men and 24 women) were diagnosed with gastric neuroendocrine tumors at the Asan Medical Center.

Results

Of the 45 patients with typical carcinoids, 37 underwent surgery (eg, endoscopic resection). Of the 52 patients with NECs, 43 underwent surgery (eg, radical gastrectomy). One patient died of recurrence of the typical carcinoids, whereas 26 patients with NECs died of related diseases (P < .05). The rates of survival and recurrence did not significantly differ by type of typical carcinoid (P > .05).

Conclusions

Regardless of the type, carcinoids that are not yet advanced can be effectively treated with minimal endoscopic or laparoscopic surgery. However, all NECs and advanced carcinoids should be treated with radical gastrectomy.     

Promoter Methylation of Specific Genes is Associated with the Phenotype and Progression of Colorectal Adenocarcinomas

Background

Promoter methylation of colorectal cancer-related genes were examined with respect to phenotype and tumor progression.

Materials and Methods

We assayed promoter methylation of 11 genes including established CpG island methylator phenotype (CIMP) markers (MLH1, MINT1, MINT2, MINT31, p16 ^INK4a , p14 ^ARF , and CACNA1G) and four genes (COX2, DAPK, MGMT, and APC) frequently methylated in colorectal cancer in 285 patients with sporadic colorectal cancer.

Results

CIMP+ tumors were more than two times more frequent among high-frequency microsatellite instability tumors (MSI-H) than in tumors without MSI (P ≤ .0001–.002). COX2 and DAPK methylation were significantly associated with CIMP+ and MSI. KRAS showed tendency toward more frequent codon 12-13 mutations identified in tumors with APC and p16 ^INK4a methylation than in those with unmethylation (P = .033 and .05, respectively). Additionally, tumors with synchronous adenoma were associated with p16 ^INK4a methylation (P = .004). The p16 ^INK4a methylation was significantly associated with poor overall and disease-free survival in 131 rectal cancer patients who underwent curative operation, according to multivariate analyses (relative risk [RR] = 0.317 and 0.349; P = .033 and .024, respectively). Specifically, in 175 stage II and III patients receiving adjuvant-based fluoropyrimidine chemotherapy, p16 ^INK4a methylation and MINT31 unmethylation showed a significant or tendency toward an association with recurrence and DFS (P = .007–.032).

Conclusions

The study suggests that specific CIMP markers, such as p16 ^INK4a and MINT31, should be further verified as potential epigenetic targets for the design of efficient chemotherapy regimens. We also identified a subset of colorectal cancer, possibly comprising APC methylation-KRAS mutation-p16 ^INK4a methylation.     

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.     

Total arch repair versus hemiarch repair in the management of acute DeBakey type I aortic dissection

Objective: In acute DeBakey type I aortic dissection, it is still controversial whether to perform extended aortic replacement to improve long-term outcome or to use a conservative strategy with ascending aortic and hemiarch replacement to palliate a life-threatening condition. Methods: Between 1999 and 2009, 188 consecutive patients (93 women; mean age, 57.4 ± 11.7 years) with acute DeBakey type I aortic dissection underwent hemiarch (Hemiarch group; n = 144) or total arch replacement (Total arch group; n = 44) in conjunction with ascending aorta replacement. Clinical outcomes were compared after adjustment for baseline characteristics using inverse-probability-of-treatment weighting. Results: Median follow-up was 47.5 months (range 0–130.4 months) and was 92.0% (n = 173) complete. Five-year unadjusted survival and permanent-neurologic-injury-free survival rates were 65.8 ± 8.3% and 43.1 ± 9.7% in the Total arch group, and 83.2 ± 3.3% and 75.2 ± 4.0% in the Hemiarch group, respectively (P = 0.013 and <0.001). After adjustment, the Total arch group patients were at greater risks of death (hazard ratio (HR) 2.38, 95% confidence interval (CI) 1.21–4.67; P = 0.012), and permanent neurologic injury (HR 3.25, 95% CI 1.31–8.04; P = 0.011) compared to the Hemiarch group patients. The risks of the re-operation for aortic pathology or distal aortic dilatation (>55 mm) were similar for both groups (HR 0.33, 95% CI 0.08–1.43; P = 0.14). Conclusions: Total arch repair was associated with greater morbidity and mortality compared with hemiarch repair in acute DeBakey type I aortic dissection. Rates of aortic re-operation or aortic dilatation were not significantly different between the two surgical strategies. These findings support a conservative surgical approach to circumvent this life-threatening situation.     

Characteristics and Trends of Orthopedic Publications between 2000 and 2009

Background

This study was undertaken to investigate the trends of orthopedic publications during the last decade, and to document the country of origin, journal, funding source, and language of contribution using PubMed.

Methods

Orthopedic articles published between 2000 and 2009 were retrieved from PubMed using the following search terms: "orthopaedic[Affiliation] AND ("2000/1/1"[PDAT]: "2009/12/31"[PDAT])" and "orthopedic[Affiliation] AND ("2000/1/1"[PDAT]: "2009/12/31"[PDAT])." The articles were downloaded in XML file format, which contained the following information: article title, author names, journal names, publication dates, article types, languages, authors'' affiliations and funding sources. These information was extracted, sorted, and rearranged using the database''s management software. We investigated the annual number of published orthopedic articles worldwide and the annual rate of increase. Furthermore, the country of publication origin, journal, funding source, and language of contribution were also investigated.

Results

A total of 46,322 orthopedic articles were published and registered in PubMed in the last 10 years. The worldwide number of published orthopedic articles increased from 2,889 in 2000 to 6,909 in 2009, showing an annual increase of 384.6 articles, or an annualized compound rate of 10.2%. The United States ranked highest in the number of published orthopedic articles, followed by Japan, the United Kingdom, Germany, and the Republic of Korea. Among the orthopedic articles published worldwide during the last 10 years, 37.9% pertained studies performed in the United States. Fifty-seven point three percent (57.3%) of articles were published in journals established in the United States. Among the published orthopaedic articles, 4,747 articles (10.2%) disclosed financial support by research funds, of which 4,688 (98.8%) articles utilized research funds from the United States. Most articles were published in English (97.2%, 45,030 articles).

Conclusions

The number of published orthopedic articles has been increasing over the last decade. The number of orthopedic articles, journals publication, and funding sources were dominated by research conducted in the United States, while share and growth of Asian countries including Japan, the Republic of Korea, and China were notable.     

Unusual gastric tumors: radiologic-pathologic correlation.

The overlap of radiologic findings in many gastric tumors makes differentiation difficult. However, some unusual gastric tumors have characteristic radiologic features that may suggest a specific diagnosis. At barium study, lipomas typically manifest as a smooth submucosal mass or an ulcerated lesion with a "bull's-eye" appearance that is indistinguishable from other mesenchymal tumors. At computed tomography (CT), lipomas usually manifest as well-circumscribed submucosal masses with fat attenuation. At radiology, glomus tumors appear as smooth submucosal masses with or without ulceration and may contain tiny flecks of calcification. These tumors frequently demonstrate strong enhancement on early-phase contrast material-enhanced images. At barium study, lymphangiomas may appear as smooth intramural masses that are indistinguishable from other mesenchymal tumors. At CT, they manifest as non-enhancing extramucosal masses with homogeneous low attenuation. Diffuse lesions in Brunner gland hamartoma manifest as multiple small nodules, producing a characteristic "cobblestone" appearance. Lymphomas may have typical imaging features (eg, more pronounced and homogeneous mural thickening) that can help differentiate them from adenocarcinoma. In addition, adenocarcinomas may demonstrate unusual findings such as transpyloric spread, unusually large polyps, or intratumoral calcifications. Familiarity with these radiologic features of gastric tumors can help ensure correct diagnosis and proper management.     

Laparoscopic resection of retroperitoneal benign schwannoma

Schwannomas are particularly rare neoplasms among tumors of the retroperitoneal space. Only 0.3-3.2% of benign schwannomas are found in retroperitoneal locations. As these tumors are usually asymptomatic and discovered by chance or in the course of the evaluation of an unrelated health problem, they may cause the delay of early diagnosis and treatment. With recent advances in the field of minimally invasive surgery, several laparoscopic approaches to retroperitoneal schwannomas have been reported. In this paper, we present the case of a 59-year-old female patient with an asymptomatic retroperitoneal mass that was found during a regular medical checkup. The mass was located between the inferior vena cava (IVC) and aorta under the pancreaticoduodenal unit (site of lymph node 16b1), compressing the IVC. She underwent successful laparoscopic surgery for retroperitoneal schwannoma. In addition, we summarized the literature on cases regarding the laparoscopic management of the retroperitoneal schwannoma.