Medical image rendering

Three-dimensional (3-D) visualization has recently become an established discipline in medicine. Although numerous visualization methods are currently available, a unified framework to describe and study them has been lacking. Often, the functionally independent operations in a method are integrated among themselves or with the method itself for computational efficiency. The two main aims of this article are (1) to review the methods in a unified way in a general setting so that it becomes possible to appreciate the interrelationship and interdependence of methods, and (2) to show how a variety of new methods emerge with potentially improved renditions in this unified treatment. To this end, we introduce an operator notation to describe concisely the basic 3-D imaging transforms commonly used in visualization and identify a comprehensive set of basic transforms. We describe several new basic transforms for filtering and interpolating structures and scenes, and for rendering surfaces and volumes. We show the power of the principle of treating 3-D imaging methodologies as comprising an appropriate combination of the basic operators. We show how such a treatment leads to a great variety of new rendering methods and how many such methods can lead to improved portrayal. We develop separate transform sequences to optimally render robust and frail structures (ie, structures represented in scenes with well-defined and ill-defined boundaries, respectively).     

Sentinel lymphnode biopsy in early breast cancer using methylene blue dye and radioactive sulphur colloid — a single institution Indian experience

Background  

Axillary lymph node dissection is an established procedure in breast cancer staging. However, it is associated with unpleasant side effects. A promising alternative to assess axillary lymph node status in early breast cancer patients is Sentinel Lymph Node Biopsy (SLNB). Isosulfan blue has traditionally been the dye used to identify the Sentinel Lymph Node (SLN). This article is a validation study of SLNB using methylene blue dye and radioactive sulphur colloid in early breast cancer Indian patients.     

Differences between relapsing-remitting and chronic progressive multiple sclerosis as determined with quantitative MR imaging

PURPOSE: To investigate the cross-sectional relationships among multiple quantitative brain magnetic resonance (MR) imaging measurements in patients with relapsing-remitting versus chronic progressive multiple sclerosis (MS). MATERIALS AND METHODS: Thirty-eight patients with MS (relapsing-remitting, 26, chronic progressive, 12) were examined. Lesion volume on T2-weighted MR images, contrast material-enhancing lesion volume, percentage of brain parenchymal volume (brain volume/[brain volume + cerebrospinal fluid volume), and magnetization transfer ratio histogram peak height for the whole brain were calculated. RESULTS: Significant negative correlation was noted between volume on T2-weighted images and magnetization transfer ratio histogram peak height for both the relapsing-remitting and chronic progressive groups (P < .001 for both). A positive correlation was demonstrated for lesion volume on T2-weighted images and enhancing lesion volume in the relapsing-remitting group (P < .01) but not in the chronic progressive group. Negative correlations were demonstrated for enhancing lesion volume and magnetization transfer ratio histogram peak height (P = .02), for Expanded Disability Status Scale score and magnetization transfer histogram peak height (P = .02), and for Expanded Disability Status Scale score and percentage of brain parenchymal volume in the relapsing-remitting group (P = .004) but not in the chronic progressive group. CONCLUSION: The cross-sectional relationships among multiple quantitative brain MR imaging measurements are different between relapsing-remitting and chronic progressive MS.     

Late-onset minor and major depression: early evidence for common neuroanatomical substrates detected by using MRI

The purpose of our study was to examine the neuroanatomical correlates of late-onset minor and major depression and to compare them with similar measures obtained from nondepressed controls. Our study groups were comprised of 18 patients with late-onset minor depression, 35 patients diagnosed with late-onset major depression, and 30 nondepressed controls. All subjects were scanned by using a 1.5-tesla MRI scanner. Absolute whole brain volume and normalized measures of prefrontal and temporal lobe volumes were obtained and used for comparison among groups. Our findings indicate that patients with minor depression present with specific neuroanatomical abnormalities that are comparable with the major depression group but significantly different from the controls. Normalized prefrontal lobe volumes show a significant linear trend with severity of depression, with volumes decreasing with illness severity. Whole brain volumes did not differ significantly among groups. These findings have broad implications for the biology of late-life depression and suggest that there may be common neurobiological substrates that underlie all clinically significant forms of late-onset mood disturbances.     

Effectiveness of delayed second dose of AZD1222 vaccine in patients with autoimmune rheumatic disease

Clinical Rheumatology - There is paucity of data on extended dosing interval between two doses of AZD1222 (AstraZeneca) in patients with Autoimmune Rheumatic Diseases (AIRD). We aimed to study the...     

Smart Polymers in Nasal Drug Delivery

Nasal drug delivery has now been recognized as a promising route for drug delivery due to its capability of transporting a drug to systemic circulation and central nervous system. Though nasal mucosa offers improved bioavailability and quick onset of action of the drug, main disadvantage associated with nasal drug delivery is mucocilliary clearance due to which drug particles get cleared from the nose before complete absorption through nasal mucosa. Therefore, mucoadhesive polymeric approach can be successfully used to enhance the retention of the drug on nasal mucosal surface. Here, some of the aspects of the stimuli responsive polymers have been discussed which possess liquid state at the room temperature and in response to nasal temperature, pH and ions present in mucous, can undergo in situ gelation in nasal cavity. In this review, several temperature responsive, pH responsive and ion responsive polymers used in nasal delivery, their gelling mechanisms have been discussed. Smart polymers not only able to enhance the retention of the drug in nasal cavity but also provide controlled release, ease of administration, enhanced permeation of the drug and protection of the drug from mucosal enzymes. Thus smart polymeric approach can be effectively used for nasal delivery of peptide drugs, central nervous system dugs and hormones.     

Evaluation of Antioxidant and Wound Healing Effects of Alcoholic and Aqueous Extract of Ocimum sanctum Linn in Rats

In recent years, oxidative stress and free radicals have been implicated in impaired wound healing. Ocimum sanctum (O. sanctum), a plant widely used in Ayurveda, possesses anti-inflammatory and antioxidant properties. The present study was undertaken to assess the potential of alcoholic and aqueous extracts in wound healing in Wistar albino rats. The rats were divided into five groups of six animals each. Group 1 is normal wounded control and the other four groups were treated with two different doses each of alcoholic and aqueous extract of O. sanctum. The wound healing parameters were evaluated by using incision, excision and dead space wounds in extract-treated rats and controls. Both the doses of alcoholic and aqueous extract significantly increased wound breaking strength, hydroxyproline, hexuronic acid, hexosamines, superoxide dismutase, catalase, reduced glutathione and significantly decreased percentage of wound contraction and lipid peroxidation when compared with the control group. The results suggest that O. sanctum has antioxidant properties, which may be responsible and favorable for faster wound healing and this plant extract may be useful in the management of abnormal healing and hypertropic scars.     

Cytotoxic,genotoxic and oxidative stress induced by 1,4-naphthoquinone in B16F1 melanoma tumor cells

Quinones have diverse pharmacological properties including antibacterial, antifungal, antiviral, anti-inflammatory, antipyretic and anticancer activity. The cytotoxic potential of 1,4-naphthoquinone (NQ14) was studied against B16F1 melanoma cells grown in vitro. NQ14 treatment resulted in a concentration-dependent cytotoxicity as indicated by MTT assay and lactate dehydrogenase leakage assay. Depletion in cellular glutathione levels after 1 h incubation with NQ14 correlated with the corresponding increase in reactive oxygen species generation as determined by 2′,7′-dicholorofluorescein diacetate assay suggests the role of oxidative stress in cell death. The frequency of micronucleated binucleate cells increased with increasing doses of NQ14 with a corresponding decrease in the cytokinesis block proliferation index indicating the drug induced genotoxicity and cell division delay. Further, a dose-dependent decrease in the clonogenic cell survival indicated the potential of NQ14 to inhibit cell proliferation contributing to cell death. The cell death after NQ14 treatment may be attributed to apoptosis as seen in DNA ladder pattern along with necrosis as indicated in flow cytometric analysis of Annexin V/PI stained cells. Results of the present study demonstrate the cytotoxic and genotoxic potential of NQ14 by the induction of oxidative stress mediated mechanisms leading to tumor cell kill.