The spectrum of imaging findings in pulmonary hydatid disease and the additive value of T2-weighted magnetic resonance imaging in its diagnosis.

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.

Preoperative Staging of Gastric Cancer Using Computed Tomography and Its Correlation with Histopathology with Emphasis on Multi-planar Reformations and Virtual Gastroscopy.

BACKGROUND: Gastric cancer is the fifth most common cancer in the world. Preoperative staging of gastric cancer has assumed pivotal role in deciding appropriate management of gastric cancer with multi-detector computed tomography (MDCT) using hydro- and gaseous distension of stomach superseding endoscopic ultrasound in tumor (T) and nodal (N) staging. We undertook this study to evaluate the diagnostic accuracy of MDCT in the T and N staging of gastric cancer with an attempt to differentiate between early and advanced gastric carcinomas. METHODS: A total of 160 patients with endoscopically diagnosed and biopsy-proven gastric cancer were subjected to MDCT after adequate gaseous and hydro-distention of stomach. Multi-planar reformatted (MPR) as well as virtual gastroscopy images were also obtained. Gastric lesions were categorized into T1 to T4 stages with N staging from N0 to N3. Preoperative CT findings were correlated with histopathological findings. RESULTS: Overall diagnostic accuracy of T staging in our study was 82.5% (132/160) with an accuracy of 75% (120/160) for N staging. The diagnostic accuracy of CT for early gastric carcinoma in our study was 93.75% with high specificity of 96% but low sensitivity of 66.7%. CONCLUSION: MDCT using gaseous and hydro-distension of stomach is an excellent modality for near accurate preoperative T staging of gastric cancer. However, CT has a limited role in the N staging of gastric cancer. This study also suggested that the combined use of virtual gastroscopy and MPR images helps in better detection of early gastric cancers.

The spectrum of multimodality imaging findings in hepatic alveolar echinococcosis and the potential role of diffusion-weighted imaging in its characterisation.

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 mm2/s (range: 1.39 × 10-3 mm2/s to 2.3 × 10-3 mm2/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.

Preoperative contrast-enhanced computed tomographic characterisation of pancreatic cystic lesions: A prospective study.

BACKGROUND: Characterisation of pancreatic cystic lesions has a direct role in their management and computed tomography is the mainstay of investigation for diagnosing and characterising them. OBJECTIVES: The aim of this study was to prospectively assess the diagnostic accuracy of contrast-enhanced computed tomography (CECT) in preoperative characterisation of pancreatic cystic lesions with histopathology as the reference standard. METHOD: A total of 38 patients with cystic pancreatic lesions diagnosed after clinical, laboratory and sonographic evaluation, irrespective of age, were preoperatively evaluated with CECT. Images were reviewed for the general characteristics of the lesions on pre-contrast and portal venous phase images and overall diagnostic accuracy calculated. Imaging findings were compared with histopathology, or cytology and/or intra-operative findings. RESULTS: Serous cystadenoma (SCA) was the most common cystic pancreatic lesion found in 31.6% of patients followed by mucinous cystadenoma (MCA) (26.3%), solid pseudo-papillary tumour (SPT) (21.1%) and intra-ductal papillary mucinous neoplasm (IPMN) (10.5%). Three patients (7.9%) had simple cysts and one patient (2.6%) had a lymphangioma. The diagnostic accuracy of CECT for pancreatic cystic lesions was found to be 72.5. CONCLUSION: The diagnostic accuracy of computed tomography (CT) was high for SCA, IPMN and pancreatic cysts, and low for MCA and SPT. Combination of a multiloculated cystic lesion with locule size of less than 20 mm, septal enhancement with relative lack of wall enhancement, central scar and lobulated outline are highly specific for SCA. Unilocular or macro-cystic pattern with locule size of more than 20 mm, female gender and wall enhancement with smooth external contour are pointers towards MCA. Solid cystic pancreatic head lesions in young females may be suggestive of SPT. A dilated main pancreatic duct in a cystic lesion with internal septations may point towards IPMN. Fluid attenuation lesions with imperceptible non-enhancing wall indicate pancreatic cysts. Lastly, pseudocysts and neuroendocrine tumours with cystic components are great mimickers of pancreatic cystic lesions, and a history of pancreatitis and hormonal profile of patients should always be sought.

Evaluation of various patient-, lesion-, and procedure-related factors on the occurrence of pneumothorax as a complication of CT-guided percutaneous transthoracic needle biopsy.

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.

Preoperative contrast-enhanced computed tomographic characterisation of pancreatic cystic lesions: a prospective study

Background: Characterisation of pancreatic cystic lesions has a direct role in their management and computed tomography is the mainstay of investigation for diagnosing and characterising them. Objectives: The aim of this study was to prospectively assess the diagnostic accuracy of contrast-enhanced computed tomography (CECT) in preoperative characterisation of pancreatic cystic lesions with histopathology as the reference standard. Method: A total of 38 patients with cystic pancreatic lesions diagnosed after clinical, laboratory and sonographic evaluation, irrespective of age, were preoperatively evaluated with CECT. Images were reviewed for the general characteristics of the lesions on pre-contrast and portal venous phase images and overall diagnostic accuracy calculated. Imaging findings were compared with histopathology, or cytology and/or intra-operative findings. Results: Serous cystadenoma (SCA) was the most common cystic pancreatic lesion found in 31.6% of patients followed by mucinous cystadenoma (MCA) (26.3%), solid pseudo-papillary tumour (SPT) (21.1%) and intra-ductal papillary mucinous neoplasm (IPMN) (10.5%). Three patients (7.9%) had simple cysts and one patient (2.6%) had a lymphangioma. The diagnostic accuracy of CECT for pancreatic cystic lesions was found to be 72.5%. Conclusion: The diagnostic accuracy of computed tomography (CT) was high for SCA, IPMN and pancreatic cysts, and low for MCA and SPT. Combination of a multiloculated cystic lesion with locule size of less than 20 mm, septal enhancement with relative lack of wall enhancement, central scar and lobulated outline are highly specific for SCA. Unilocular or macro-cystic pattern with locule size of more than 20 mm, female gender and wall enhancement with smooth external contour are pointers towards MCA. Solid cystic pancreatic head lesions in young females may be suggestive of SPT. A dilated main pancreatic duct in a cystic lesion with internal septations may point towards IPMN. Fluid attenuation lesions with imperceptible non-enhancing wall indicate pancreatic cysts. Lastly, pseudocysts and neuroendocrine tumours with cystic components are great mimickers of pancreatic cystic lesions, and a history of pancreatitis and hormonal profile of patients should always be sought

Utility of Computed Tomography-guided Biopsy in Evaluation of Metastatic Spinal Lesions.

INTRODUCTION: Computed tomography (CT)-guided biopsy of spine is currently a valuable diagnostic tool and effective technique for diagnosing and planning a proper therapeutic strategy for certain spinal lesions. The reported diagnostic accuracy of core biopsy ranges from 77% to 97%. MATERIALS AND METHODS: We included all patients with spinal lesions suspicious of metastasis on magnetic resonance imaging, who presented between May 2012 and April 2014 and underwent CT-guided biopsy in our study. A total of thirty patients with spinal lesions were evaluated. RESULTS: Majority presented in the seventh decade of their life (average age = 53.93; age range = 10-72 years). Male:female ratio was 1.5:1. Pain was the most common presenting symptom (100%). Lumbar spine was the most common site of lesion followed by dorsal spine. Biopsy is the gold standard in histopathological evaluation of spinal lesions. Metastatic lesion was diagnosed in 12 (40%) cases, plasmacytoma in 12 (40%) cases, non-Hodgkin's lymphoma in 2 (6.66%) cases, small round cell tumor in 1 (3.33%) case, nonspecific chronic inflammation in two patients, and necrosis with no viable cells in one patient. The most common malignancy to metastasize to spine was adenocarcinoma. The most common primary tumor of spine was plasmacytoma - multiple myeloma. CONCLUSION: CCT-guided biopsy is a safe procedure, and no procedure-related complication was seen in any patient.

Renal hydatid cyst presenting as an intrarenal-pelvic mass.

Intra-renal-pelvic hydatid cyst is a rare manifestation of renal hydatid disease, as most of the renal hydatid cysts are based in the renal cortex. We present and discuss the clinical and radiological findings of a 55-year-old woman who presented with left flank pain, frequency, dysuria, and hydatiduria. She was thoroughly investigated radiologically, and the diagnosis of intra-renal-pelvic hydatid cyst was confirmed surgically.

Evaluation of intracranial tuberculomas using diffusion-weighted imaging (DWI), magnetic resonance spectroscopy (MRS) and susceptibility weighted imaging (SWI).

OBJECTIVE:: The present study was aimed to evaluate patients of suspected intracranial tuberculomas with diffusion-weighted imaging (DWI), magnetic resonance spectroscopy (MRS) and susceptibility-weighted imaging (SWI). METHODS:: The present study evaluated 116 patients known or suspected of having central nervous system tuberculosis with advanced MRI techniques comprising of DWI, MRS and SWI in addition to the conventional MRI. RESULTS:: Apparent diffusion coefficient value of tuberculomas was not significantly different (p > 0.05) from apparent diffusion coefficient value of metastatic lesions and high-grade gliomas. MRS revealed that NAA/Cr and NAA/Cho ratios of tuberculomas were not significantly different (p > 0.05) from that of malignant brain lesions. However, Cho/Cr ratio of tuberculomas (1.36 ± 0.41) was significantly lower from that of malignant brain lesions (2.63 ± 0.99). SWI revealed a complete and regular hypointense peripheral ring in 42 cases of tuberculomas (58%) and in none of the malignant brain lesions. CONCLUSION:: DWI offers no clear advantage in differentiating tuberculomas from metastasis and gliomas. Tuberculomas may be differentiated from metastases and gliomas by their unique metabolite pattern on MRS. Presence of a complete and regular peripheral hypointense ring in SWI favors the diagnosis of tuberculomas. ADVANCES IN KNOWLEDGE:: 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.