Chandan Jyoti Das

Imaging in bronchopulmonary sequestration

Bronchopulmonary sequestration is an uncommon pulmonary disorder characterized by an area of non‐functioning abnormal lung tissue, which receives its blood supply from a systemic artery and characteristically has no connection with the tracheobronchial tree. The abnormal lung tissue is located within the visceral pleura of a pulmonary lobe in the intralobar variety, whereas the extralobar form has its own visceral pleura. The venous drainage of the extralobar type is usually into the systemic veins, whereas the intralobar type drains into the pulmonary veins. Radiological imaging plays a vital role in establishing the diagnosis, and even more importantly, in providing to the clinician a vascular roadmap essential for surgical planning. We present here a review of bronchopulmonary sequestration and also discuss the role of various imaging methods in the early diagnosis and management of these cases.

Imaging of paediatric liver tumours with pathological correlation

Paediatric hepatic tumours are relatively rare with malignant lesions being twice as frequent as benign neoplasms and are mostly metastases. Imaging has a significant role in the evaluation of most paediatric liver tumours. Differentiating benign from malignant tumours is important as it significantly affects treatment decisions. We present the characteristic radiological and pathological features of the most common paediatric liver tumours.

Fibromuscular dysplasia of the renal arteries: a radiological review

Fibromuscular dysplasia is the most common cause of renovascular hypertension in young patients. Digital subtraction angiography is still the best investigation used to determine the location, extent and complication of renal artery involvement. String of beads appearance (reflecting multiple stenoses), aneurysms, focal or tubular stenosis are classic angiographic appearances. The aim of this pictorial essay is to illustrate the various imaging findings of renal artery fibromuscular dysplasia.

Imaging of non alcoholic fatty liver disease: A road less travelled

Non alcoholic fatty liver disease (NAFLD) is a spectrum that includes simple steatosis, nonalcoholic steatohepatitis and cirrhosis. It is increasingly emerging as a cause of elevated liver enzymes, cryptogenic cirrhosis and hepatocellular carcinoma. The morbidity and mortality related to NAFLD is expected to rise with the upsurge of obesity and type 2 diabetes mellitus. The need of the hour is to devise techniques to estimate and then accurately follow-up hepatic fat content in patients with NAFLD. There are lots of imaging modalities in the radiological armamentarium, namely, ultrasonography with the extra edge of elastography, computed tomography, and magnetic resonance imaging with chemical shift imaging and spectroscopy to provide an estimation of hepatic fat content.

Detection of brain metastasis with 68Ga-labeled PSMA ligand PET/CT: a novel radiotracer for imaging of prostate carcinoma.

Brain metastasis in prostate cancer is rare and not expected at initial presentation especially when the patient is asymptomatic for the same. A 45-year-old male patient undergoing initial evaluation for newly diagnosed prostatic adenocarcinoma was referred to our department for 99mTc-MDP bone scintigraphy. As part of the study protocol, he also underwent Glu-NH-CO-NH-Lys-(Ahx)-[Ga-68(HBED-CC)] (68Ga-PSMA) PET/CT, which revealed tracer accumulation in brain lesions, apart from localization in the primary, lymph node, and bone metastases. A subsequent MR evaluation confirmed brain metastases.

Acute necrotizing encephalopathy

Acute necrotizing encephalopathy (ANEC) is a rare disease well recognized in Japan but has not yet been reported from Indian subcontinent. We describe here a case of ANEC with the neuroimaging findings. P. vivax infection was detected as an associated finding and the treatment given.

Endovascular Embolization of Pulmonary Sequestration in an Adult

Angio-Seal set was then deployed. The intravascular component was positioned as usual in the common femoral artery as an anchor while the collagen plug was intended to be deployed in the neck of the pseudoaneurysm. The procedure technique is diagramed in the Figure. US showed immediate closure of the pseudoaneurysm. Follow-up US scans obtained 1 day, 7 days, 1 month, 2 months, and 12 months after the procedure demonstrated successful closure without further recurrence. The formation and recurrence of the pseudoaneurysms might be related to severe calcification in the femoral arteries that may inhibit the healing of vascular wall after intubation. Thrombin injection induced thrombosis and temporary discontinued blood flow in the cavity of pseudoaneurysm but had no effect on the healing process of vascular wall. If the crevasse did not heal in time, impulse of blood pressure in femoral artery might break through a new tunnel and lead to recurrence of pseudoaneurysm. Although the pseudoaneurysm of the right femoral artery was successfully sealed with a covered stent, it was not suitable for the left femoral pseudoaneurysm due to lack of available vascular approach and the probability of inducing a new pseudoaneurysm. Embolization was also not suitable for the same reason. Surgical repair would have been a reasonable choice but was refused by the patient. This case provided a new approach using a closure device to close a femoral pseudoaneurysm when thrombin injection failed. In addition to Angio-Seal, the only available vascular closure device in the hospital, other vascular closure devices such as Perclose (Abbott Laboratories, Abbott Park, Illinois) might also be considered. The incidence of pseudoaneurysm is approximately 1% in endovascular procedures (1), whereas the failure rate of US- guided thrombin injection has been reported to be 4%–9% (2,3). Therefore, this technique of deploying a closure device to close a pseudoaneurysm may be considered in 0.05% of patients undergoing endovascular procedures.

Ruptured intracranial dermoid

A 48-year-old man presented with sudden-onset headache and vomiting for 6 h and altered sensorium for 2 h. He was febrile with tachycardia, neck rigidity and positive Kernig’s sign. Cerebrospinal fluid examination showed neutrophilic pleocytosis, raised protein and low glucose. Non-contrast CT revealed a large, well-circumscribed hypodense mass measuring 5×3 cm involving the right frontobasal area with subtle peripheral calcification. The mean attenuation value of the hypodense area measured 87 Hounsfield units. MRI was performed to characterise the mass further (figs 1, 2). Figure 1  T1-weighted (TR/TE, 450/20) axial image showing a hyperintense soft tissue mass in the right frontobasal region with brightly hyperintense foci in the quadrigeminal cistern and subarachnoid space. Axial section at a higher …

Diffusion-weighted imaging in urinary tract lesions

Diffusion-weighted imaging (DWI) utilizes the signal contrast provided by the regional differences in the Brownian motion of water molecules, which is a direct reflection of the cellular micro-environment. DWI emerged as a revolutionary magnetic resonance imaging (MRI) technique in the field of stroke imaging. As far as body imaging is concerned, DWI has come a long way from being an experimental technique to an essential element of almost all abdominal MRI examinations. This progress has been made possible by technical advancements in MRI systems, as well as a better understanding of MRI physics. DWI is quick to perform and has the potential to provide crucial information about the disease process without adding much to the total imaging time. This article provides a brief review of the basic principles of DWI with insights to the information that DWI provides in the evaluation of various diseases of the urinary tract at both 1.5 and 3 T. DWI is helpful for differentiation of various histopathological subtypes of renal cell carcinoma (RCC). Prediction of histopathological grade of RCC is also becoming possible solely based on DWI. Assessment of response to chemotherapeutic agents is possible based on the change in the ADC (apparent diffusion coefficient) value. DWI performed with high b-values increases the confidence in diagnosing prostatic carcinoma. This article highlights the emerging role of DWI in the evaluation of urinary tract lesions.

Rheumatoid Arthritis: Spectrum of Computed Tomographic Findings in Pulmonary Diseases

Rheumatoid arthritis (RA) is a common systemic disease that manifests as inflammatory arthritis of multiple joints. Interstitial lung disease (ILD) is the most common manifestation of rheumatoid lung disease. The ILDs associated with RA are diverse and it is very important for the general radiologist to differentiate one from another. There are many other pulmonary diseases apart from ILD. These are associated with a wide spectrum of morphologic changes with substantially different prognoses. The diagnosis of most of these diseases is by clinicoradiological correlation and some of them need pathologic correlation. High-resolution computed tomography helps to characterize and determine the extent of ILD in RA. When interpreting the high-resolution computed tomography of the chest in RA, the radiologist should be familiar with the findings in each entity and comment on activity of the disease, which helps in assessing the prognosis and need for active intervention. This pictorial essay reviews the spectrum of pulmonary diseases in RA and their differential diagnosis.