Han-Feng Yang

CT-guided percutaneous core needle biopsy for small (≤20 mm) pulmonary lesions

AIM To assess the accuracy and risk factors for complications of computed tomography (CT)-guided percutaneous core needle biopsy (CNB) for small (≤20 mm) pulmonary lesions. MATERIALS AND METHODS A retrospective study was undertaken comprising 169 patients who underwent CT-guided CNB for small (≤20 mm) pulmonary lesions. To assess the accuracy of the procedure, the diagnosis at biopsy was compared with the diagnosis after definitive surgery or clinical follow-up. The risk factors for pneumothorax and bleeding were determined by multivariate analysis of variables. RESULTS The overall diagnostic accuracy was 93.5%. The sensitivity for malignancy and specificity for benign lesions were 90.4% and 100%, respectively. Positive and negative predictive values were 100% and 83.3%, respectively. Twenty-five patients (14.8%) had pneumothorax after CT percutaneous CNB of the lung. The significant risk factors affecting the incidence of pneumothorax were lesion-pleural distance (p = 0.008) and needle-pleural angle (p = 0.012). The highest rate of pneumothorax correlated with a lesion-pleural distance ≥21 mm (OR = 18.46; 95%CI: 2.27-149.95) and a needle-pleural angle ≥51° (OR = 8.22; 95%CI: 2.14-31.49). Bleeding occurred in 30 patients (17.8%). The only significant risk factor affecting the incidence of bleeding was lesion-pleural distance (p = 0.011). The highest bleeding rate correlated with a lesion-pleural distance ≥21 mm (OR = 7.93; 95%CI: 1.73-36.43). CONCLUSION CT-guided percutaneous CNB of small (≤20 mm) pulmonary lesions provides high diagnostic accuracy with acceptable complications. A lesion-pleural distance of ≥21 mm and needle-pleural angle of ≥51° are identified as the risk factors for highest pneumothorax rate. In addition, the needle-pleural angle is a novel predictor of pneumothorax. A lesion-pleural distance of ≥21 mm is also identified as a risk factor for the highest bleeding rate.

Can diffusion-weighted imaging be used to differentiate brain abscess from other ring-enhancing brain lesions? A meta-analysis.

AIM To explore the role of diffusion-weighted imaging (DWI) in the discrimination of brain abscess from other ring-enhancing brain lesions through meta-analysis. MATERIALS AND METHODS The PUMBED, OVID, and China National Knowledge Infrastructure (CNKI) databases, from January 1995 to March 2013, were searched for studies evaluating the diagnostic performance of DWI in the discrimination of brain abscess lesions. Using the data collected, pooled sensitivities and specificities across studies were determined, positive and negative likelihood ratios (LR) were calculated, and summary receiver operating characteristic (SROC) curves were constructed. RESULTS A total of 11 studies fulfilled all of the inclusion criteria and were considered for the analysis. The pooled sensitivity values and pooled specificity values including 95% confidence intervals (CI) were 0.95 (0.87-0.98) and 0.94 (0.88-0.97). The pooled positive LR (95% CI) was 4.13(2.55-6.7); the pooled negative LR (95% CI) was 0.01 (0-1.7); and the area under the curve of the symmetric SROC was 0.98. CONCLUSIONS DWI has high sensitivity and specificity for the differentiation of brain abscess from other intracranial cystic mass lesions.

Factors influencing diagnostic yield of CT-guided percutaneous core needle biopsy for bone lesions

AIM To evaluate the factors influencing diagnostic yield of computed tomography (CT)-guided percutaneous core needle biopsy (CNB) for bone lesions. MATERIALS AND METHODS Between September 2005 and July 2011, 162 consecutive CT-guided CNB procedures were performed in 155 patients. The variables analysed were age, sex, lesion location, lesion type, lesion size, specimen size, biopsy needle gauge, and individual radiologist. The factors influencing diagnostic yield of CT-guided percutaneous CNB for bone lesions were determined by multivariate analysis of variables. RESULTS The diagnostic yield was 81.5%. Diagnostic yield was 89.9% for lytic bone lesions and 48.5% for sclerotic bone lesions (p < 0.001), and 89.2% for lesions ≥3 cm and 73.4% for lesions <3 cm (p = 0.010). The significant factors influencing diagnostic yield of CT-guided percutaneous CNB for bone lesions were lesion type [p < 0.001; odds ratio (OR) for a lytic lesion was approximately 12 times higher than that for a sclerotic lesion; 95% confidence interval (CI): 4.22-34.01], and lesion size (p = 0.012; OR for a lesion size ≥3 cm was about five-times higher than that for a lesion size <3 cm; 95% CI: 1.42-16.71). CONCLUSION Lesion type and lesion size are determining factors in diagnostic yield. The higher diagnostic yield is correlated with lytic lesion and lesion size ≥3 cm.

Gadobenate dimeglumine-enhanced liver magnetic resonance imaging: value of hepatobiliary phase for the detection of focal liver lesions.

Objective The objective of the study was to determine the value of addition of hepatobiliary phase to dynamic gadobenate dimeglumine (Gd-BOPTA)–enhanced imaging for the detection of focal liver lesions (nodules with diameter ⩽3.0 cm). Methods Routine nonenhanced magnetic resonance images were obtained in 25 patients with focal liver lesions suggested by ultrasonography and/or computed tomography. T1-weighted dynamic gradient-echo images were acquired immediately and 100 minutes after bolus injection of Gd-BOPTA. The number of the lesions detected by T1-weighted imaging, T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced, and delayed hepatobiliary-phase imaging was counted, respectively. Contrast-to-noise ratios were measured for all the sequences including delayed hepatobiliary-phase imaging. The signal intensity and morphologic features of liver parenchyma and lesions were recorded and analyzed. Results There were 7 patients with hepatocellular carcinomas, 6 with hemangiomas, 7 with metastases, and 5 with cholangiocarcinomas. The delayed hepatobiliary-phase imaging showed a homogeneous enhancement of liver parenchyma and distinctive enhancement features of focal liver lesions. The delayed hepatobiliary-phase imaging was better than diffusion-weighted imaging for the detection of focal liver lesions (P < 0.05). Conclusion The addition of hepatobiliary-phase imaging to Gd-BOPTA–enhanced dynamic imaging increased the sensitivity and accuracy for the detection of focal hepatic lesions.

Application of magnetic resonance imaging in cervical spondylotic myelopathy

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction and is caused by static or dynamic repeated compression of the spinal cord resulting from degenerative arthritis of the cervical spine and some biological injuries to the cervical spine. The T2 signal change on conventional magnetic resonance imaging (MRI) is most commonly associated with neurological deficits. Diffusion tensor imaging and MR spectroscopy show altered microstructure and biochemistry that reflect patient-specific pathogenesis and can be used to predict neurological outcome and response to intervention. Functional MRI can help to assess the neurological functional recovery after decompression surgery for CSM.

Thoracic epidural angiolipoma: A case report and review of the literature

Angiolipoma of the spine is a benign neoplasm consisting of both mature fatty tissue and abnormal vascular elements, and usually presents with a slow progressive clinical course. Our patient presented with bilateral lower extremity weakness and chest-back numbness. Physical examination revealed adipose elements superficial hypesthesia below the T5 level and analgesia below the T6 level. Magnetic resonance imaging (MRI) scan showed an avidly and heterogeneously enhancing mass which was located in the posterior epidural space. Compression of the thoracic cord by the fusiform mass was seen between T3-T4. During the operation, a flesh pink vascular mass (4.7 cm × 1.0 cm × 1.0 cm) with obscure margin and strong but pliable texture was found in the posterior epidural space extending from T3 to T4. There was no infiltration of the dura or the adjacent bony spine. Histopathological study of the surgical specimen showed a typical angiolipoma. We review the previously documented cases of spinal extradural angiolipomas performed with MRI.

Regional Values of Diffusional Kurtosis Estimates in the Healthy Brain during Normal Aging.

ObjectiveTo provide estimates of the diffusional kurtosis in different anatomical regions of a healthy brain and to assess age dependency of diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) derived parametric values in these regions.Materials and MethodsEighty healthy volunteers underwent DKI of the brain with 3.0 T magnetic resonance imaging. The DKI was obtained by using three b values of 0, 1000, 2000 s/mm2, and with 50 diffusion directions. The regions of interest-based measurements were calculated to obtain several DKI estimates of 21 different locations of brain, and then, the age dependency for DKI- and DTI-derived parameters in these regions were assessed by using linear and nonlinear regressions.ResultsThe mean kurtosis varied from 0.73 ± 0.01 (head of caudate nucleus) to 1.07 ± 0.08 (splenium of corpus callosum (CC)). The radial kurtosis varied from 0.84 ± 0.06 (head of caudate nucleus) to 1.05 ± 0.07 (splenium of CC), and axial kurtosis from 0.41 ± 0.02 (genu of CC) to 0.78 ± 0.02 (pallidum). DTI-derived parametric values also varied across the region. Age dependence was found for DKI-derived parameters in almost all measured regions except for corona radiata and centrum semiovale. On the contrary, DTI failed to show age dependency in many regions including gray matter structure.ConclusionIn conclusion, the knowledge of range of diffusion kurtosis parameters in each anatomical region in different age group is important before its clinical application to diagnose the pathology.

Magnetic resonance imaging for prostate cancer clinical application.

As prostate cancer is a biologically heterogeneous disease for which a variety of treatment options are available, the major objective of prostate cancer imaging is to achieve more precise disease characterization. In clinical practice, magnetic resonance imaging (MRI) is one of the imaging tools for the evaluation of prostate cancer, the fusion of MRI or dynamic contrast-enhanced MRI (DCE-MRI) with magnetic resonance spectroscopic imaging (MRSI) is improving the evaluation of cancer location, size, and extent, while providing an indication of tumor aggressiveness. This review summarizes the role of MRI in the application of prostate cancer and describes molecular MRI techniques (including MRSI and DCE-MRI) for aiding prostate cancer management.

Diffusion-Weighted Imaging for Pretreatment Evaluation and Prediction of Treatment Effect in Patients Undergoing CT-Guided Injection for Lumbar Disc Herniation.

Objective To determine whether a change in apparent diffusion coefficient (ADC) value could predict early response to CT-guided Oxygen-Ozone (O2-O3) injection therapy in patients with unilateral mono-radiculopathy due to lumbar disc herniation. Materials and Methods A total of 52 patients with unilateral mono-radiculopathy received a single intradiscal (3 mL) and periganglionic (5 mL) injection of an O2-O3 mixture. An ADC index of the involved side to the intact side was calculated using the following formula: pre-treatment ADC index = ([ADC involved side - ADC intact side] / ADC intact side) × 100. We analyzed the relationship between the pre-treatment Oswestry Disability Index (ODI) and the ADC index. In addition, the correlation between ODI recovery ratio and ADC index was investigated. The sensitivity and specificity of the ADC index for predicting response in O2-O3 therapy was determined. Results Oswestry Disability Index and the ADC index was not significantly correlated (r = -0.125, p = 0.093). The ADC index and ODI recovery ratio was significantly correlated (r = 0.819, p < 0.001). When using 7.10 as the cut-off value, the ADC index obtained a sensitivity of 86.3% and a specificity of 82.9% for predicting successful response to therapy around the first month of follow-up. Conclusion This preliminary study demonstrates that the patients with decreased ADC index tend to show poor improvement of clinical symptoms. The ADC index may be a useful indicator to predict early response to CT-guided O2-O3 injection therapy in patients with unilateral mono-radiculopathy due to lumbar disc herniation.

CT-Guided Core Needle Biopsy of Pleural Lesions: Evaluating Diagnostic Yield and Associated Complications

Objective The purpose of this study was to retrospectively evaluate the diagnostic accuracy and complications of CT-guided core needle biopsy (CT-guided CNB) of pleural lesion and the possible effects of influencing factors. Materials and Methods From September 2007 to June 2013, 88 consecutive patients (60 men and 28 women; mean [± standard deviation] age, 51.1 ± 14.4 years; range, 19-78 years) underwent CT-guided CNB, which was performed by two experienced chest radiologists in our medical center. Out of 88 cases, 56 (63%) were diagnosed as malignant, 28 (31%) as benign and 4 (5%) as indeterminate for CNB of pleural lesions. The final diagnosis was confirmed by either histopathological diagnosis or clinical follow-up. The diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and complication rates were statistically evaluated. Influencing factors (patient age, sex, lesion size, pleural-puncture angle, patient position, pleural effusion, and number of pleural punctures) were assessed for their effect on accuracy of CT-guided CNB using univariate and subsequent multivariate analysis. Results Diagnostic accuracy, sensitivity, specificity, PPV, and NPV were 89.2%, 86.1%, 100%, 100%, and 67.8%, respectively. The influencing factors had no significant effect in altering diagnostic accuracy. As far as complications were concerned, occurrence of pneumothorax was observed in 14 (16%) out of 88 patients. Multivariate analysis revealed lesion size/pleural thickening as a significant risk factor (odds ratio [OR]: 8.744, p = 0.005) for occurrence of pneumothorax. Moreover, presence of pleural effusion was noted as a significant protective factor (OR: 0.171, p = 0.037) for pneumothorax. Conclusion CT-guided CNB of pleural lesion is a safe procedure with high diagnostic yield and low risk of significant complications.