Purpose To assess the influence of various patient-, lesion-, and procedure-related variables on the occurrence of pneumothorax as a complication of CT-guided percutaneous transthoracic needle biopsy. Material and methods In a total of 208 patients, 215 lung/mediastinal lesions (seven patients were biopsied twice) were sampled under CT guidance using coaxial biopsy set via percutaneous transthoracic approach. Incidence of post procedure pneumothorax was seen and the influence of various patient-, lesion-, and procedure-related variables on the frequency of pneumothorax with special emphasis on procedural factors like dwell time and needle-pleural angle was analysed. Results Pneumothorax occurred in 25.12% (54/215) of patients. Increased incidence of pneumothorax had a statistically significant correlation with age of the patient ( p = 0.0020), size ( p = 0.0044) and depth ( p = 0.0001) of the lesion, and needle-pleural angle ( p = 0.0200). Gender of the patient ( p = 0.7761), emphysema ( p = 0.2724), site of the lesion ( p = 0.9320), needle gauge ( p = 0.7250), patient position ( p = 0.9839), and dwell time ( p = 0.9330) had no significant impact on the pneumothorax rate. Conclusions This study demonstrated a significant effect of the age of the patient, size and depth of the lesion, and needle-pleural angle on the incidence of post-procedural pneumothorax. Emphysema as such had no effect on pneumothorax rate, but once pneumothorax occurred, emphysematous patients were more likely to be symptomatic, necessitating chest tube placement. Gender of the patient, site of the lesion, patient position during the procedure, and dwell time had no statistically significant relation with the frequency of post-procedural pneumothorax. Surprisingly, needle gauge had no significant effect on pneumothorax frequency, but due to the small sample size, non-randomisation, and bias in needle size selection as per lesion size, further studies are required to fully elucidate the causal relationship between needle size and post-procedural pneumothorax rate. The needle should be as perpendicular as possible to the pleura (needle-pleural angle close to 90°), to minimise the possibility of pneumothorax after percutaneous transthoracic needle biopsy.

The results from the present study suggest promising role of SWI in the discrimination of tuberculomas from metastatic brain lesions and gliomas with the presence of a complete and regular peripheral hypointense ring favoring the diagnosis of tuberculomas.

No abstract

Purpose To describe the spectrum of imaging findings in pulmonary echinococcosis and to study the additive value of T2-weighted magnetic resonance imaging (MRI) in the characterisation of pulmonary hydatid disease. Material and methods This was a descriptive, prospective study conducted for a period of 3 years from December 2016 to November 2019. Patients suspected of having pulmonary echinococcosis ( n = 110) on preliminary chest radiography were examined with chest computed tomography (CT). Among them 41 cases were additionally examined with T2-weighted MRI of thorax. Final diagnosis was based on surgery or histopathology. Results Of the 110 patients enrolled for the study 15 were lost to attrition, and among the final cohort of 95 patients CT correctly diagnosed 68/84 (80.9%) as hydatid cyst, whereas 16/84 (19.1%) received an erroneous alternate diagnosis on CT. Based on the classical findings of hyperintense pulmonary cystic lesion with T2-weighted hypointense rim or detached internal T2-weighted hypointense membrane, a correct diagnosis of hydatid cyst was possible in 30 patients whereas a correct alternate diagnosis was made in 8 cases. T2-weighted MRI was found to have sensitivity of 96.7%, specificity of 80%, positive predictive value (PPV) of 93.7% and negative predictive value (NPV) of 88.9% with an overall diagnostic accuracy of 92.6%. Using the McNemar test, MRI was found to be diagnostically superior to CT ( p = 0.019). Conclusions Most of the pulmonary hydatid cysts can be diagnosed on CT; however, sometimes the findings may be indeterminate or atypical, leading to a diagnostic dilemma. MRI, owing to its ability to demonstrate hypointense endocyst, can act as a useful adjunct to correctly diagnose hydatid cyst or suggest an alternative diagnosis.

Purpose To study the spectrum of imaging findings in hepatic alveolar echinococcosis (HAE) and to evaluate the potential role of diffusion-weighted imaging (DWI) in its characterisation. Material and methods Two radiologists with more than seven years of experience retrospectively studied ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) findings in 23 histopathologically proven cases of HAE with emphasis on the appearance and extent of disease. DWI characteristics of lesions were noted, and their apparent diffusion values (ADC) were calculated. Results Ultrasonography features of HAE included heterogeneous, hyperechoic hepatic mass with or without calcification ( n = 20), or heterogeneous mass with solid-cystic appearance ( n = 2). CT revealed heterogeneous density infiltrative hepatic mass with no contrast enhancement in 19 patients or thick-walled cystic mass ( n = 4). Following Kodama classification one type 1, six type 2, two type 3, eight type 4, and two type 5 lesions were identified on T2-weighted MRI. No enhancement was seen on post-contrast T1-weighted images. Mean ADC values were 1.74 ± 0.48 × 10 -3 mm 2 /s (range: 1.39 × 10 -3 mm 2 /s to 2.3 × 10 -3 mm 2 /s). Conclusions HAE by virtue of its infiltrative growth pattern with a tendency to involve biliary, vascular, and extra hepatic structures can be easily misdiagnosed as malignant hepatic neoplasm. Knowledge of varied imaging appearances of HAE is essential to suspect the condition and to make an appropriate diagnosis. Diffusion-weighted imaging is a useful adjunct with relatively high diffusivity (high ADC values) suggesting diagnosis of alveolar hydatid.