Diffusion-weighted MR imaging and utility of ADC measurements in characterizing nerve and muscle changes in diabetic patients on ankle DWI studies: a cross-sectional study.

OBJECTIVE: To evaluate the utility of apparent diffusion coefficient (ADC) measurements from ankle MRI diffusion-weighted imaging (DWI) studies in identifying neuropathic changes in diabetic patients. METHODS: In total, 109 consecutive ankle MRI scans (n = 101 patients) at a single tertiary care county hospital from November 1, 2019, to July 11, 2021, who met the inclusion criteria were identified. Patients were divided into 2 cohorts: diabetic (n = 62) and non-diabetic (n = 39). Demographics, HgbA1c, neuropathy diagnosis, and image quality data were collected. Abductor hallucis (AH) ADC mean and minimum (min) values and posterior tibial nerve (PTN) ADC mean and minimum values were measured. Student t-test and Pearson's correlation coefficient analysis were performed using R. RESULTS: Diabetic patients had significantly higher mean and min ADC values (× 10-3 mm2/s) of the AH muscle (mean: 1.77 vs 1.39, p < 0.001; min: 1.51 vs 1.06, p < 0.001) and PTN (mean: 1.65 vs 1.18, p < 0.001; min: 1.33 vs 0.95, p < 0.001) compared to non-diabetic patients. HgbA1c positively correlated with AH and PTN ADC mean values (AH: p = 0.036; PTN: p = 0.004). CONCLUSION: Our data suggests that an increasing diffusivity of water as quantified by ADC across neuronal and muscular membranes is a consequence of the pathophysiology of the disease. Thus, ankle MRI-DWI studies are useful in identifying neuropathic changes in diabetic patients and quantifying the severity noninvasively. KEY POINTS: • Diabetic patients had significantly higher mean and minimum ADC values of the abductor hallucis muscle and posterior tibial nerve compared to non-diabetic patients. • HgbA1c positively correlated with ADC mean values (AH: p = 0.036; PTN: p = 0.004) suggesting that an increasing diffusivity of water across neuronal and muscular membranes is a consequence of the pathophysiology of diabetic neuropathy. • Ankle MRI DWI can be used clinically to non-invasively identify neuropathic changes due to diabetes mellitus.

Characterizing conventional ankle MRI findings of nerve and muscle changes in diabetic patients: a case-control study.

BACKGROUND: Foot and ankle amputation is a feared complication of diabetic neuropathy and diabetes mellitus (DM) accounts for 80% of all in-hospital amputations. Magnetic resonance neurography is an effective tool in characterizing neuromuscular sequelae of the disease. However, conventional ankle MRI is more commonly performed and has not been studied to assess neuromuscular changes of DM. OBJECTIVE: The objective is to characterize neuromuscular changes of diabetic patients in a case-control study using conventional ankle MRI. METHODS: Between November 2019 and July 2021, 110 consecutive ankle MRI scans (n = 102 patients) at our county hospital were reviewed and met the inclusion criteria. Patients were divided into two cohorts, diabetic (N = 63) and non-diabetic (N = 39). Demographics, HgbA1c, and reason for MRI study were collected via retrospective chart review. The presence of intramuscular edema-like signal, pattern of the edema, muscle fatty infiltration, and measurements of the cross-sectional area of the posterior, medial, and lateral tibial nerves (PTN, MPN, and LPN) was recorded blinded to the clinical findings by two readers. RESULTS: Muscle edema-like signal was much more likely to be found in DM (odds ratio 19.5, 95% CI 7.0-54.6, p < 0.001). DM also showed increase of 0.87 in the mean grade of muscle fatty infiltration (p < 0.001). There were higher rates of nerve T2 hyperintensity (odds ratio 14.0, 95% CI 3.1-62.7, p < 0.001) and the measured areas of the PTN, MPN, and LPN were also larger in DM compared to their non-diabetic counterparts (PTN: 0.16 cm2 vs. 0.10 cm2, p < 0.01; MPN: 0.09 cm2 vs. 0.05 cm2, p < 0.01; LPN: 0.07 cm2 vs. 0.04 cm2, p < 0.05). CONCLUSION: Conventional ankle MRIs can be used to detect DM-related neuromuscular changes.

Gender Differences in Diagnosis, Prevention, and Treatment of Cardiotoxicity in Cardio-Oncology.

Gender differences exist throughout the medical field and significant progress has been made in understanding the effects of gender in many aspects of healthcare. The field of cardio-oncology is diverse and dynamic with new oncologic and cardiovascular therapies approved each year; however, there is limited knowledge regarding the effects of gender within cardio-oncology, particularly the impact of gender on cardiotoxicities. The relationship between gender and cardio-oncology is unique in that gender likely affects not only the biological underpinnings of cancer susceptibility, but also the response to both oncologic and cardiovascular therapies. Furthermore, gender has significant socioeconomic and psychosocial implications which may impact cancer and cardiovascular risk factor profiles, cancer susceptibility, and the delivery of healthcare. In this review, we summarize the effects of gender on susceptibility of cancer, response to cardiovascular and cancer therapies, delivery of healthcare, and highlight the need for further gender specific studies regarding the cardiovascular effects of current and future oncological treatments.

Acoustically targeted chemogenetics for the non-invasive control of neural circuits.

Neurological and psychiatric disorders are often characterized by dysfunctional neural circuits in specific regions of the brain. Existing treatment strategies, including the use of drugs and implantable brain stimulators, aim to modulate the activity of these circuits. However, they are not cell-type-specific, lack spatial targeting or require invasive procedures. Here, we report a cell-type-specific and non-invasive approach based on acoustically targeted chemogenetics that enables the modulation of neural circuits with spatiotemporal specificity. The approach uses ultrasound waves to transiently open the blood-brain barrier and transduce neurons at specific locations in the brain with virally encoded engineered G-protein-coupled receptors. The engineered neurons subsequently respond to systemically administered designer compounds to activate or inhibit their activity. In a mouse model of memory formation, the approach can modify and subsequently activate or inhibit excitatory neurons within the hippocampus, with selective control over individual brain regions. This technology overcomes some of the key limitations associated with conventional brain therapies.