CBM drilling technical parameter optimization methodology and software development: a case study of LUAN mining area.

Based on the leakage of the coalbed methane (CBM) drilling engineering practice of Luan mining area in China, the author determines the safe drilling fluid density range for the stable borehole wall based on borehole wall collapse and fracture pressure. Such parameters as the drilling fluid hydraulic parameters (including pump pressure, pump power and displacement, nozzle diameter, bit pressure drop, bit hydraulic horsepower, circulation pressure drop, impact force and jet velocity) and drilling parameters (including weight-on-bit, drilling rotary speed, bit tooth wear) in each borehole section are optimized. Taking the lowest drilling cost as the controlling target, the drilling parameter optimization model is designed and solved by the genetic algorithm.

Differentiation of renal oncocytoma and renal clear cell carcinoma using relative CT enhancement ratio.

Background: The difference between renal oncocytomas (RO) and renal clear cell carcinomas (RCCs) presents the greatest diagnostic challenge. The aim of this study was to retrospectively determine if RO and RCCs could be differentiated on computed tomography (CT) images on the basis of their enhancement patterns with a new enhancement correcting method.

Methods: Forty-six patients with a solitary renal mass who underwent total or partial nephrectomy were included in this study.

The performance of MRI in detecting subarticular bone erosion of sacroiliac joint in patients with spondyloarthropathy: a comparison with X-ray and CT.

Objective: To assess the sensitivity and specificity of detecting subarticular bone erosion of sacroiliac (SI) joint in patients with spondyloarthritis (SpA) using MRI three-dimensional water selective balanced steady-state free precession sequence (3D-WS-bSSFP) and T1-weighted (T1W) sequence.

Materials And Methods: Radiography, CT and MRI of SI joint from 43 SpA patients were retrospectively analyzed. MRI examination sequences include T1W, short tau inversion recovery (STIR) and 3D-WS-bSSFP.

[MR manifestations and clinical significance of iliotibial band friction syndrome].

Objective: To describe the MRI features of Iliotibial band friction syndrome (ITBFS), in order to improve the understanding and diagnosis of ITBFS.

Methods: The MR findings of 16 patients (18 knees )of clinically diagnosis ITBFS were reviewed retrospectively.

Results: The MRI features of ITBFS:(1)Ill- defined abnormal signal intensity extended to the lateral femoral epicondyle.

The application of MR imaging in the detection of hip involvement in patients with ankylosing spondylitis.

Objective: To investigate the changes in hip MR imaging, evaluate the frequency of hip involvement and compare the value of clinical symptoms, radiographs, and MR imaging in the detection of hip involvement in patients with ankylosing spondylitis (AS).

Methods: Anteroposterior radiographs of the pelvis, MR imaging of the hip and clinical evaluation were undertaken in 58 patients with definite AS. All patients were followed up 3 years.

[Diagnostic value of computed tomography in invasive pulmonary fungal infections].

Objective: To analyze the computed tomographic (CT) features of invasive pulmonary fungal infections (IPFI) and evaluate the value of CT-guided percutaneous biopsy.

Methods: Seventeen IPFI cases diagnosed by CT-guided percutaneous biopsy were recruited. The distribution, extent, density and size of IPFI were analyzed in correlation with the final diagnosis retrospectively.

[Avascular necrosis of the femoral head:correlation of imaging and pathological findings].

Objective: To investigate the relationship between imaging and pathological findings of avascular necrotic of the femoral head (ANFH).

Methods: A comparison among of conventional radiography, computerized tomography (CT), magnetic resonance imaging (MRI), gross section and pathological examinations was performed in 20 femoral heads in 15 patients undergoing total hip replacement for established ANFH.

Results: ANFH involved the anterosuperior aspect of femoral head in all hips.

[Study of comparing the multiple MR sequenc in the articular cartilage of knee joint].

Objective: To investigate the value of various MR imaging sequences for the assessment of articular cartilage and to determine the most optional sequence.

Methods: MR sagittal scanning of knee joints were performed in nine fresh bovine models. MR scan sequences consisted of TSE-T(1)WI, TSE-T(2)WI, TSE-PDWI, 3D-FFE-T(1)WI, 3D-BFFE, TSE-T(1)WI-SPIR, TSE-T(2)WI-SPIR, TSE-PDWI-SPIR, 3D-FFE-SPIR, 3D-FFE-WATS, 3D-FFE-MTC, 3D-BFFE-WATS.

[Application of computed tomography guided percutaneous fine-needle aspiration biopsy in examination of pancreas and Vater's ampulla].

Objective: To evaluate the effects of computed tomography (CT) guided percutaneous fine-needle aspiration biopsy (FANB) in examination of pancreas and Vater's ampulla.

Methods: One hundred and six patients, 71 males and 35 females, aged 21 approximately 74, with lesions located in the pancreas and Vater's ampulla, 1.5 approximately 5 cm in size (< 3 cm in 32 cases and >or= 3 cm in 74 cases), underwent CT guided percutaneous FANB with 22-gauge needle (in 84 cases) or 20-gauge needle (in 22 cases) by anterior approach.

[Calculation of articular surface area of osteonecrosis and its application in predicting collapse of the femoral head].

Objective: To explore the program for calculating the necrotic articular surface area (NASA) and the ratio of NASA to whole articular surface area (WASA) of osteonecrosis of the femoral head (ONFH), to verify the accuracy of this calculation and to predict the collapse of the femoral head clinically using this program.

Methods: From June 2001 to June 2003, The specimens of the necrotic femoral head from eight patients (13 hips) were obtained by total hip arthroplasty. The magnetic resonance imaging (MRI) was taken in all patients before operation.

[Vascularized iliac bone grafting for avascular necrosis of the femoral head].

Objective: To evaluate the indications for vascularized iliac bone grafting in the treatment of osteonecrosis of the femoral head and operative results.

Methods: From October 1993 to August 2000, Twenty-six hips of 18 patients with osteonecrosis of the femoral head underwent vascularized iliac bone grafting. Clinical evaluation was made according to Harris Hip Score and ARCO staging system.

[CT-guided percutaneous transthoracic aspiration biopsy of chest lesions: factors influencing the diagnostic accuracy].

Objective: To investigate the factors influencing the diagnostic accuracy of CT-guided percutaneous transthoracic aspiration biopsy of chest lesions.

Methods: Data of pathology and clinical follow-up of 224 patients who had undergone CT-guided percutaneous transthoracic biopsy were collected. Univariate analysis and multivariate stepwise Logistic regression analysis were made to study the influence of the patient-related factors (sex, age, and presence of emphysema), lesion-related factors (histology, size, location, depth, and presence of cavity discovered by CT), and procedure factor (posture of patient during operation) on the diagnostic accuracy of CT-guided biopsy.