Sustainable low-field cardiovascular magnetic resonance in changing healthcare systems.

Cardiovascular disease continues to be a major burden facing healthcare systems worldwide. In the developed world, cardiovascular magnetic resonance (CMR) is a well-established non-invasive imaging modality in the diagnosis of cardiovascular disease. However, there is significant global inequality in availability and access to CMR due to its high cost, technical demands as well as existing disparities in healthcare and technical infrastructures across high-income and low-income countries. Recent renewed interest in low-field CMR has been spurred by the clinical need to provide sustainable imaging technology capable of yielding diagnosticquality images whilst also being tailored to the local populations and healthcare ecosystems. This review aims to evaluate the technical, practical and cost considerations of low field CMR whilst also exploring the key barriers to implementing sustainable MRI in both the developing and developed world

Magnetic Resonance Imaging (MRI) and MR Spectroscopic Methods in Understanding Breast Cancer Biology and Metabolism

A common malignancy that affects women is breast cancer. It is the second leading cause of cancer-related death among women. Metabolic reprogramming occurs during cancer growth, invasion, and metastases. Functional magnetic resonance (MR) methods comprising an array of techniques have shown potential for illustrating physiological and molecular processes changes before anatomical manifestations on conventional MR imaging. Among these, in vivo proton (1H) MR spectroscopy (MRS) is widely used for differentiating breast malignancy from benign diseases by measuring elevated choline-containing compounds. Further, the use of hyperpolarized 13C and 31P MRS enhanced the understanding of glucose and phospholipid metabolism. The metabolic profiling of an array of biological specimens (intact tissues, tissue extracts, and various biofluids such as blood, urine, nipple aspirates, and fine needle aspirates) can also be investigated through in vitro high-resolution NMR spectroscopy and high-resolution magic angle spectroscopy (HRMAS). Such studies can provide information on more metabolites than what is seen by in vivo MRS, thus providing a deeper insight into cancer biology and metabolism. The analysis of a large number of NMR spectral data sets through multivariate statistical methods classified the tumor sub-types. It showed enormous potential in the development of new therapeutic approaches. Recently, multiparametric MRI approaches were found to be helpful in elucidating the pathophysiology of cancer by quantifying structural, vasculature, diffusion, perfusion, and metabolic abnormalities in vivo. This review focuses on the applications of NMR, MRS, and MRI methods in understanding breast cancer biology and in the diagnosis and therapeutic monitoring of breast cancer

Magnetic Resonance Imaging (MRI) and MR Spectroscopic Methods in Understanding Breast Cancer Biology and Metabolism

A common malignancy that affects women is breast cancer. It is the second leading cause of cancer-related death among women. Metabolic reprogramming occurs during cancer growth, invasion, and metastases. Functional magnetic resonance (MR) methods comprising an array of techniques have shown potential for illustrating physiological and molecular processes changes before anatomical manifestations on conventional MR imaging. Among these, in vivo proton (1H) MR spectroscopy (MRS) is widely used for differentiating breast malignancy from benign diseases by measuring elevated choline-containing compounds. Further, the use of hyperpolarized 13C and 31P MRS enhanced the understanding of glucose and phospholipid metabolism. The metabolic profiling of an array of biological specimens (intact tissues, tissue extracts, and various biofluids such as blood, urine, nipple aspirates, and fine needle aspirates) can also be investigated through in vitro high-resolution NMR spectroscopy and high-resolution magic angle spectroscopy (HRMAS). Such studies can provide information on more metabolites than what is seen by in vivo MRS, thus providing a deeper insight into cancer biology and metabolism. The analysis of a large number of NMR spectral data sets through multivariate statistical methods classified the tumor sub-types. It showed enormous potential in the development of new therapeutic approaches. Recently, multiparametric MRI approaches were found to be helpful in elucidating the pathophysiology of cancer by quantifying structural, vasculature, diffusion, perfusion, and metabolic abnormalities in vivo. This review focuses on the applications of NMR, MRS, and MRI methods in understanding breast cancer biology and in the diagnosis and therapeutic monitoring of breast cancer

Biochemical characterization of breast tumors by in vivo and in vitro magnetic resonance spectroscopy (MRS)

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) have evolved as sensitive tools for anatomic and metabolic evaluation of breast cancer. In vivo MRS studies have documented the presence of choline containing compounds (tCho) as a reliable biochemical marker of malignancy and also useful for monitoring the tumor response to therapy. Recent studies on the absolute quantification of tCho are expected to provide cut-off values for discrimination of various breast pathologies. Addition of MRS investigation was also reported to increase the specificity of MRI. Further, ex vivo and in vitro MRS studies of intact tissues and tissue extracts provided several metabolites that were not be detected in vivo and provided insight into underlying biochemistry of the disease processes. In this review, we present briefly the role of various H MRS methods used in breast cancer research and their potential in relation to diagnosis, monitoring of therapeutic response and metabolism

Characterization of breast lesions by magnetic resonance imaging (MRI) and spectroscopy (MRS)

Breast cancer is a major health problem in women, worldwide. A combination of physical examination, mammography, ultrasound and fine needle aspiration cytology (FNAC) or core biopsy is currently the mainstay for preoperative diagnosis of breast lesions. Magnetic resonance imaging (MRI) has been proposed as a useful complimentary modality to provide additional information. It has shown potential in the detection, diagnosis and management of breast cancer. It can be used to improve preoperative staging, follow response to therapy, and to detect local recurrences. Contrast enhanced MRI (CEMRI) has evolved as an important tool in the evaluation of breast abnormalities with high sensitivity (94-100%), but with poor specificity. Recently, diffusion and perfusion MRI techniques have been applied to breast lesion characterization and show promise but warrant further investigations. Characterization of breast lesions may also be assisted by using information of the cellular chemistry provided by in vivo proton MR spectroscopy (MRS). Recent reports have shown that neoplastic breast tissue contains elevated levels of choline containing compounds, which can be used as a biochemical marker for differentiating benign versus malignant tumor and for monitoring treatment response. Presently, the various MR techniques show promise primarily as adjunct to the existing standard detection techniques, and its acceptability as a primary screening method will increase only if specificity can be increased. This review presents the current status of MRI and MRS in breast imaging

Sequential diffusion-weighted magnetic resonance imaging study of lysophosphatidyl choline-induced experimental demyelinating lesion: an animal model of multiple sclerosis

Purpose: To differentiate the surrounding edema from the focal demyelinating lesion during the early phase of the lesion using an apparent diffusion coefficient (ADC), and to monitor the changes in ADCs during the complete progression of a lysophosphatidyl choline (LPC)-induced experimental demyelinating lesion, an animal model of multiple sclerosis (MS). Material and Methods: Eighteen rats divided into two groups-demyelinating lesion (group I, N = 12) and vehicle group (saline injected; group II, N = 6)-were studied. A 0.2-μl quantity of 1% LPC solution in isotonic saline was injected in the rat brain internal capsule (IC) area to create the demyelinating lesion. Six rats were used exclusively for histology. Diffusion-weighted (DW) images were acquired at different diffusion weightings on the 3rd, 5th, 10th, 15th, and 20th days after LPC injection. ADC was measured from three regions of interest (ROIs) within the IC: focal demyelinating lesion (area A), surrounding area of the lesion (area B), and contralateral IC area (area C). Results: Histology revealed demyelination of the IC area during the early phase of lesion progression up to day 10 and remyelination thereafter. Elevated ADCs were observed for the surrounding edematous area (area B), compared to the focal demyelinating lesion (area A) during the early phase of the demyelination process, while substantial reduction of ADCs was noticed during remyelination for both regions. Conclusion: Measurement of ADC showed clear differentiation of the surrounding edema from the LPC-induced focal demyelinating lesion in rats, especially during the early phase of the lesion progression

Evaluation of Withania somnifera in a middle cerebral artery occlusion model of stroke in rats

1. Stroke causes brain injury in millions of people worldwide each year. Despite the enormity of the problem, there is currently no approved therapy that can reduce infarct size or neurological disability. One of the approaches that can be used in limiting the neurological damage after stroke is the use of prophylactic treatment in patients with a high-risk of stroke. The present study was undertaken to investigate the effect of the Indian herbal plant Withania somnifera as a prophylactic treatment in the middle cerebral artery (MCA) occlusion model of stroke in rats. 2. Two groups of male Wistar rats were pretreated with a hydroalcoholic extract of W. somnifera (1 g/kg, p.o.) for 15 and 30 days. Thereafter, rats were subjected to focal ischaemia by occlusion of the MCA using an intraluminal thread. After 2 h MCA occlusion, reperfusion was allowed by retracting the thread. Animals were assessed for ischaemic changes using diffusion-weighted imaging 30 min after reperfusion. Twenty-four hours later, rats were subjected to motor performance tests and were subsequently killed for the estimation of the marker of oxidative stress malondialdehyde (MDA). The control group received vehicle and a similar protocol was followed. 3. Significant motor impairment, with elevated levels of MDA, was observed in vehicle-treated MCA-occluded rats. In addition, diffusion-weighted imaging showed increased signal intensity in the right hemisphere compared with the contralateral hemisphere. Treatment with W. somnifera for 15 days did not improve motor performance or decrease the elevated levels of MDA. However, when the pretreatment time of W. somnifera was increased to 30 days, it prevented motor impairment and significantly decreased the raised levels of MDA compared with vehicle-treated rats. In the W. somnifera (30 days)-pretreated group, the percentage hemispheric lesion area in diffusion-weighted imaging was significantly attenuated (17 ± 2%) compared with the vehicle-treated MCA-occluded group (30 ± 4%). 4. Because W. somnifera has been documented to have anti-oxidant properties, the protection afforded by W. somnifera could be due to its anti-oxidant effect. The present study provides first evidence of the effectiveness of an Indian herb in focal ischaemia

In vivo <SUP>1</SUP>H MRS in the assessment of the therapeutic response of breast cancer patients

MRI and in vivo MRS have rapidly evolved as sensitive tools for diagnosis and therapeutic monitoring in cancer research. In vivo MRS provides information on tumor metabolism, which is clinically valuable in the diagnosis and assessment of tumor response to therapy for the management of women with breast diseases. Several centers complement breast MRI studies with 1H MRS to improve the specificity of diagnosis. Malignant breast tissues show elevated water-to-fat ratio and choline-containing compounds (total choline, tCho), and any effect of therapy on tissue viability or metabolism will be manifested as changes in these levels. Sequential 1H MRS studies have shown significantly reduced tCho levels during the course of therapy in patients who were responders. However, there are challenges in using in vivo MRS because of the relatively low sensitivity in detecting the tCho resonance with decreased lesion size or significant reduction in the tumor volume during therapy. MRS is also technically challenging because of the low signal-to-noise ratio and heterogeneous distribution of fat and glandular tissues in the breast. MRS is best utilized for the diagnosis of focal masses, most commonly seen in patients with ductal-type neoplasms; however, it has limitations in detecting nonfocal masses, such as the linear pattern of tumors seen in invasive lobular carcinoma. Further work is required to assess the clinical utility of quantitative MRS, with the goal of automation, which will reduce the subjectivity currently inherent in both qualitative and semi-quantitative MRS

Role of magnetic resonance methods in the evaluation of prostate cancer: an Indian perspective

The challenges in detection, localization, and staging of prostate cancer have prompted the investigation of the role of various magnetic resonance (MR) methodologies in a large cohort of men prior to biopsy. The identification of suspicious areas of malignancy was carried out using magnetic resonance imaging (MRI), magnetic resonance spectroscopic imaging (MRSI) and diffusion-weighted imaging (DWI). Our data shows that apparent diffusion coefficient (ADC) may be a reliable marker to differentiate normal, benign, and malignant prostate tissues similar to the metabolite ratio. Also, the combined use of MRSI and DWI improves the diagnosis of prostate cancer. In this review, we present our experience on the use of MRI, MRSI and DWI methods in the assessment of prostate cancer in Indian men. Further, analysis of the comparison of the ADC and the metabolite ratio values reported in the literature across various patient populations are presented