Dhiraj Baruah

Intervertebral disc height loss demonstrates the threshold of major pathological changes during degeneration

PurposeQuantitative MRI techniques were utilized to study intervertebral disc degeneration. Main focus was to develop a novel approach to quantify disc height loss associated with disc degeneration. Currently there is no universally accepted metric of degeneration based on measurement of disc height. Such quantitative imaging methods would complement qualitative visual assessment methods currently used and offer a valuable diagnostic tool.Methods51 adult participants took part in this MRI study. T2 weighted images were used to obtain disc height index (DHI) and also a semi-quantitative metric based on relative voxel intensities. For DHI, each disc was given a score based on standard deviations from the mean DHI of healthy discs. Diffusion Weighted MRI was used to assess morphological changes in the nucleus pulposus. Conventional Pfirrmann classification was used as the gold standard to assess these quantitative approaches.ResultsAt deviations of up to 1.5σ below normative disc height, levels of apparent diffusion coefficient (ADC) and normalized T2 intensity were maintained. Once disc compression reached 1.5σ, there was a massive drop in ADC and normalized T2 intensity. Pfirrmann degeneration scores also increased after the 1.5σ mark.ConclusionsThis study provides new, unbiased quantitative imaging tools to assess disc degeneration. We observed that these quantitative MRI measures indicate a threshold beyond which major pathological changes take place concurrently. Combined information from DHI, ADC and T2 images construct a set of novel biomarkers that could be used to identify degenerating discs that are approaching the threshold and possibly intervene before major pathologic changes occur.

Pictorial essay: Orbital tuberculosis

Tuberculosis of the orbit is rare, even in places where tuberculosis is endemic. The disease may involve soft tissue, the lacrimal gland, or the periosteum or bones of the orbital wall. Intracranial extension, in the form of extradural abscess, and infratemporal fossa extension has been described. This pictorial essay illustrates the imaging findings of nine histopathologically confirmed cases of orbital tuberculosis. All these patients responded to antituberculous treatment.

Surveillance imaging after intracranial stent implantation: non-invasive imaging compared with digital subtraction angiography

Background Digital subtraction angiography (DSA) is the gold standard imaging for detection of in-stent restenosis (ISR) but there is limited literature on optimal non-invasive surveillance imaging. In this study, the ability of CT angiography (CTA) and MR angiography (MRA) compared with DSA in recognizing ISR was assessed. Methods A single center database of patients treated with stent implantation for ICAD was accessed. All patients who underwent follow-up imaging with DSA paired with either MRA or CTA within 30 days were included. Two angiography readers and two non-invasive imaging readers measured restenosis with a submillimeter digital caliper. ISR was categorized as: none/minimal, mild (<50%), moderate (≥50–70%) or severe (≥70%). Analysis was performed with weighted κ statistics. Results 17 cases of individual stents that underwent surveillance imaging with paired DSA and CTA and five stents with paired DSA and MRA were identified. Of those undergoing DSA and CTA, inter-reader agreement produced κ=0.68 (95% CI 0.40 to 0.95) for DSA and κ=0.75 (95% CI 0.55 to 0.95) for CTA. Agreement across CTA and DSA was κ=0.36 (95% CI 0.26 to 0.52). Of those undergoing DSA and MRA, inter-reader agreement produced κ=0.71 (95% CI 0.27 to 1.00) for DSA and κ=1.00 (95% CI 1.00 to 1.00) for MRA. Agreement across MRA and DSA was κ=0.34 (95% CI 0.18 to 0.51). Conclusions Good inter-reader agreement exists within DSA, CTA and MRA. However, when comparing non-invasive imaging (CTA and MRA) with DSA, only fair agreement exists. These data suggest that CTA and MRA are not comparable to DSA for evaluation of ISR.

Laparoscopy for liver hydatid disease: where do we stand today?

Hydatid disease mostly affects the liver with Echinococcus granulosus being the most common organism. Surgery remains the gold standard in terms of therapy for patients with echinococcosis of the liver despite significant economic costs, advances in medical treatment, and interventional radiology. Laparoscopy, as a minimally invasive surgery, has well-known clinical advantages over traditional surgery. Several reports have confirmed the benefit of a laparoscopic approach to liver hydatid disease. We describe our technique and analyze numerous reports of laparoscopic hydatid liver surgery along with our results.

A Simplified Algorithm for Diagnosis of Spinal Cord Lesions

Neuroimaging is indispensable for evaluation of Myelopathy not only for localization but also for etiologic determination. MRI is the preferred examination for further characterization of the majority of these conditions. These include traumatic, inflammatory, infections, compressive and neoplastic conditions. This article provides an overview of a variety of pathologies that afflict the spinal cord in an easy to understand format. Their respective imaging manifestations on MRI and differential diagnoses are focused in this review. Early diagnosis and treatment of Myelopathy is critical in preventing or arresting neurological morbidity.

‘Coronary wrap’: IgG4 related disease of coronary artery presenting as a mass lesion

Our patient is a 68-year male who presented with fatigue. He had a past history of liver transplant 13 years back. As per routine evaluation with computed tomography (CT) scan extensive enhancing soft tissue masses surrounding the left anterior descending (LAD) and circumflex coronary arteries (Fig. 1 thin arrows) noted. A magnetic resonance imaging (MRI) was done to further characterize the abnormality. MRI confirmed CT findings and showed heterogeneously enhancing mass lesion with increased perfusion and underlying aneurysmal dilatation of LAD (Fig. 1 thick arrow). Incidental significant aortic valve stenosis was also noted. Differentials of this indeterminate soft tissue ranged from inflammatory disorder to neoplastic etiology like lymphoma. Cross sectional imaging helped cardiac surgeon to plan the biopsy. Open biopsy was performed which revealed IgG4 related disease.

Right ventricular size assessed by cardiovascular MRI may predict mortality after left ventricular assist device placement

Methods Patients were referred for cardiovascular magnetic resonance imaging prior to LVAD placement. We assessed the association of mortality to pre-LVAD right ventricular end systolic volume index (RVESVI), right ventricular end diastolic volume index (RVEDVI), left ventricular ejection fraction (LVEF) by CMR. Right ventricular stroke work index (RVSWI) was determined by preLVAD right heart catheterization.

Ultrasound evaluation of acute bacterial meningitis and its sequale in infants

Objective: Ultrasonographic characterization of intracranial pathologies with respect to acute bacterial meningitis and its sequale. Materials and methods: A prospective study of 70 cases, below 12 months of age within a period of two years, was undertaken to characterize sonographic abnormalities in acute bacterial meningitis and its sequale. Results: Echogenic sulci, ventriculomegaly and ventriculitis were the findings observed on ultrasonography in cases with acute bacterial meningitis and its sequale. Conclusion: Infantile transcranial ultrasonography is an useful diagnostic tool for rapid, safe and fairly accurate evaluation of intracranial pathologies in relation to acute bacterial meningitis and its sequale.

Systematic Review of the Literature: Best Practices

Reviews of published scientific literature are a valuable resource that can underline best practices in medicine and clarify clinical controversies. Among the various types of reviews, the systematic review of the literature is ranked as the most rigorous since it is a high-level summary of existing evidence focused on answering a precise question. Systematic reviews employ a pre-defined protocol to identify relevant and trustworthy literature. Such reviews can accomplish several critical goals that are not easily achievable with typical empirical studies by allowing identification and discussion of best evidence, contradictory findings, and gaps in the literature. The Association of University Radiologists Radiology Research Alliance Systematic Review Task Force convened to explore the methodology and practical considerations involved in performing a systematic review. This article provides a detailed and practical guide for performing a systematic review and discusses its applications in radiology.

A novel computed tomography method to detect normal from abnormal psoas muscle: a pilot feasibility study

Sarcopenia is a syndrome characterized by progressive loss of skeletal muscle which can be detected by computed tomography (CT) by estimating total psoas muscle cross‐sectional area (CSA). Relying on total psoas CSA alone takes into account abnormal muscle and intramuscular fat, both of which may be increased in sarcopenic obesity. We developed a novel CT‐method to identify the proportion of normal to abnormal psoas muscle at the third lumbar (L3) level. The primary objective of our pilot study was to measure inter‐observer agreement between measuring total psoas CSA and proportion of normal and abnormal psoas muscle using a novel CT‐method. We hypothesized total psoas CSA and proportion of normal and abnormal psoas muscle would be reliably quantifiable.