Proton Conducting Neuromorphic Materials and Devices.

Neuromorphic computing and artificial intelligence hardware generally aims to emulate features found in biological neural circuit components and to enable the development of energy-efficient machines. In the biological brain, ionic currents and temporal concentration gradients control information flow and storage. It is therefore of interest to examine materials and devices for neuromorphic computing wherein ionic and electronic currents can propagate. Protons being mobile under an external electric field offers a compelling avenue for facilitating biological functionalities in artificial synapses and neurons. In this review, we first highlight the interesting biological analog of protons as neurotransmitters in various animals. We then discuss the experimental approaches and mechanisms of proton doping in various classes of inorganic and organic proton-conducting materials for the advancement of neuromorphic architectures. Since hydrogen is among the lightest of elements, characterization in a solid matrix requires advanced techniques. We review powerful synchrotron-based spectroscopic techniques for characterizing hydrogen doping in various materials as well as complementary scattering techniques to detect hydrogen. First-principles calculations are then discussed as they help provide an understanding of proton migration and electronic structure modification. Outstanding scientific challenges to further our understanding of proton doping and its use in emerging neuromorphic electronics are pointed out.

Role of Interventional Radiology (IR) in vascular emergencies among cirrhotic patients.

Gastrointestinal hemorrhage remains one of the most common causes of morbidity and mortality among patients with liver cirrhosis. Mostly, these patients bleed from the gastroesophageal varices. However, nonvariceal bleeding is also more likely to occur in these patients. Because of frequent co-existing coagulopathy, cirrhotics are more prone to bleed from a minor vascular injury while performing percutaneous interventions. Ultrasound-guided bedside vascular access is an essential procedure in liver critical care units. Transjugular portosystemic shunts (TIPS) with/without variceal embolization is a life-saving measure in patients with refractory variceal bleeding. Whenever feasible, balloon-assisted retrograde transvenous obliteration (BRTO) is an alternative to TIPS in managing gastric variceal bleeding, but without a risk of hepatic encephalopathy. In cases of failed or unfeasible endotherapy, transarterial embolization using various embolic agents remains the cornerstone therapy in patients with nonvariceal bleeding such as ruptured hepatocellular carcinoma, gastroduodenal ulcer bleeding, and procedure-related hemorrhagic complications. Among various embolic agents, N-butyl cyanoacrylate (NBCA) enables better vascular occlusion in cirrhotics, even in coagulopathy, making it a more suitable embolic agent in an expert hand. This article briefly entails the different interventional radiological procedures in vascular emergencies among patients with liver cirrhosis.

Emergency endovascular and percutaneous urological interventions: A pictorial review.

Emergency endovascular and percutaneous urological interventions encompass various diagnostic and therapeutic procedures to address various genitourinary conditions. These urological interventions are life-saving in addressing complications following biopsy, post-nephrectomy, post-transplant, and post-trauma. Compared to other surgical fields, there are relatively fewer urological emergencies. However, they require prompt radiological diagnosis and urgent interventions. This pictorial essay emphasizes various urological emergencies and urgent interventional management.

Is salvage Plug-Assisted Retrograde Transvenous Obliteration (PARTO) safe and effective for bleeding gastric varices ?- A preliminary single-center experience.

BACKGROUND: Vascular plug-assisted retrograde transvenous obliteration (PARTO) obliterates the gastric varices and portosystemic shunt, thus resulting in a lower rebleeding rate than endoscopic glue/sclerotherapy. AIMS: To evaluate the safety and efficacy of PARTO as salvage therapy in liver cirrhosis with gastric variceal bleed (GVB) after failed endotherapy. We assessed the clinical success rate and changes in liver function at 6- months. MATERIALS AND METHODS: Patients who underwent salvage PARTO after failed endotherapy for GVB (between December 2021 and November 2022) were searched and analyzed from the hospital database. Clinical success rate and rebleed rate were obtained at six months. Child-Pugh score (CTP) and Model for end-stage liver disease (MELD) score were calculated and compared between baseline and 6-month follow-up. RESULTS: Fourteen patients (n = 14, Child-Pugh class A/B) underwent salvage PARTO. Nine had GOV-2, and five had IGV-1 varices. The mean shunt diameter was 11.6 ± 1.6 mm. The clinical success rate of PARTO was 100% (no recurrent gastric variceal hemorrhage within six months). No significant deterioration in CTP (6.79 ± 0.98 vs. 6.21 ± 1.52; p = 0.12) and MELD scores (11.5 ± 4.05 vs. 10.21 ± 3.19; p = 0.36) was noted at 6 months. All patients were alive at 6 months. One patient (n = 1, 7.1%) bled from esophageal varices after three days of PARTO and was managed with variceal banding. 21.4% (3/14) patients had progression of esophageal varices at 6 months requiring prophylactic band ligation. Three patients (21.4%) had new onset or worsening ascites and responded to low-dose diuretics therapy. CONCLUSIONS: PARTO is a safe and effective procedure for bleeding gastric varices without any deterioration in liver function even after six months. Patient selection is critical to prevent complications. Further prospective studies with larger sample size are required to validate our findings.

Lower extremity pseudoaneurysms and their interventional radiological management: a pictorial review.

Lower extremity pseudoaneurysms (PsAs) are mostly developed after traumatic or iatrogenic injury to the arteries. Unless treated, they can be complicated by adjacent mass effects, distal embolism, secondary infection, and rupture. Imaging helps in the diagnosis and planning of therapeutic intervention. Ultrasonography (USG) is often diagnostic, while CT angiography aids in vascular mapping required for intervention. Image-guided therapy offers to manage these pseudoaneurysms in a minimally invasive approach, obviating the need for surgery. A smaller, superficial, and narrow-necked PsA can easily be managed with local USG-guided compression or thrombin injection. When the percutaneous approach is not a feasible option, PsA from expendable arteries can also be managed with coiling or glue injection. Wide-necked PsA from an unexpendable artery necessitates stent graft placement, although coiling of the neck may be a viable and cheaper alternative for a long- and narrow-necked PsA. Presently, vascular closure devices are also used to seal a small arterial rent through a direct percutaneous approach. This pictorial review entails various techniques to deal with lower extremity pseudoaneurysms. An idea about the various intervention radiological approaches will help in choosing appropriate methods to tackle lower extremity pseudoaneurysms.

Bedside USG-Guided Paracentesis - A Technical Note for Beginners.

Paracentesis is a routinely performed low-risk daycare procedure most commonly performed in patients with cirrhosis. Although uncommon, devastating bleeding complications may occur, particularly in patients with coagulopathy. Hence to avoid any such complication, it is important for the intervention radiologists, as well as clinicians, particularly beginners, to have basic knowledge of the major anterior abdominal wall arteries, their course, and their sonographic appearance. Here, we briefly describe the relevant abdominal wall anatomy and sonographic planes to use for paracentesis.

The role of "penumbra sign" and diffusion-weighted imaging in adnexal masses: do they provide a clue in differentiating tubo-ovarian abscess from ovarian malignancy?

PURPOSE: To evaluate the role of "penumbra sign", diffusion-weighted imaging (DWI), and the apparent diffusion coefficient (ADC) value in differentiating tubo-ovarian abscess (TOA) from ovarian malignancy. MATERIAL AND METHODS: Thirty-six patients with 50 adnexal masses (tubo-ovarian abscess, n = 24; ovarian malignancy, n = 26), who underwent magnetic resonance imaging (MRI) with DWI, were retrospectively evaluated. "Penumbra sign" (hyperintense rim on T1W images), diffusion restriction, and mean apparent diffusion coefficient (ADC) values from cystic (c-ADC) and solid (s-ADC) components were evaluated for all the masses. RESULTS: "Penumbra sign" on T1W images was significantly more common in the TOA group (n = 21, 87.5%) than in the ovarian malignancy group (n = 2, 7.7%) (p < 0.001). Similarly, diffusion restriction in the cystic component was more frequent in the TOA group (n = 24, 100% vs. n = 2, 10.5%; p < 0.001). In contrast, diffusion restriction in the solid component was more common in the ovarian malignancy group (n = 5, 20.8% vs. n = 26, 100%; p < 0.001). The mean c-ADC value was significantly lower in TOAs (p < 0.001). A c-ADC value of 1.31 × 10-3 mm2/s may be an optimal cut-off in distinguishing TOAs from ovarian malignancies. Conversely, the mean s-ADC value was significantly lower in the ovarian malignancy group (p < 0.001). An s-ADC value of 0.869 × 10-3 mm2/s may be an optimal cut-off in differentiating ovarian malignancies from TOAs (p < 0.001). ROC curve analysis showed that c-ADC values had a higher diagnostic accuracy than s-ADC values. CONCLUSIONS: "Penumbra sign" on T1W images, diffusion characteristics, and ADC values provide important clues in addition to conventional MR imaging features in differentiating TOA from ovarian malignancy.

A lung cyst harbouring a congenital pulmonary varix.

A non-smoker man in his second decade presented to a medical centre with intermittent haemoptysis over 2 years. The haemoptysis was infrequent initially to be ignored, but later, the episodes increased in amount and frequency. Routine blood tests including coagulation profile showed normal results. The chest radiography and echocardiography were normal. The contrast-enhanced CT scan of the chest showed a cystic lesion with intracystic abnormality and surrounding ground-glass opacity in the left upper lobe. The CT pulmonary angiography and invasive pulmonary angiography showed the abnormality to be a dilated pulmonary vessel draining into the left atrium, thereby confirming the diagnosis of congenital pulmonary varix contained within a lung cyst. The patient underwent a successful lobectomy following which he experienced no further haemoptysis.

Acute ischaemic stroke and deep vein thrombosis following snakebite.

Snakebite envenomation remains a neglected tropical public health issue claiming thousands of lives every year. It is a common medical emergency and a threat to the impoverished populations of low-income and middle-income countries including India. A combination of ischaemic stroke and deep vein thrombosis is a devastating duo complication of snake bite, with no literature report to date. Here, the authors report an unusual case of a young woman developing ischaemic stroke and deep vein thrombosis following snakebite even after the use of antivenom. MRI brain showed right thalamic infarct with haemorrhagic transformation and, ultrasound Doppler revealed right lower limb deep vein thrombosis. The pathophysiology of deep vein thrombosis and ischaemic stroke is complex. It is believed that the activation of the coagulation cascade, complement system together with endothelial injury and immune activation leads to inflammation, thrombosis and occlusion of smaller and even larger vessels.

Incidental 68Ga-PSMA Uptake in the Benign Enchondroma-A Rare Finding on 68Ga-PSMA PET/CT.

ABSTRACT: 68Ga-PSMA (prostate-specific membrane antigen)-HBED-CC (N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid) PET/CT is the new advancement in oncological imaging. However, false-positive uptake can be seen in benign lesions on 68Ga-PSMA PET/CT. We describe a rare case of intense 68Ga-PSMA uptake in an enchondroma confirmed on MRI.

Radioiodine Uptake at Suture Site Granuloma Mimicking Neck Node Metastasis on 131 I Whole-Body Iodine Scintigraphy.

ABSTRACT: Differentiated thyroid carcinoma constitutes over 90% of all thyroid cancers. The standard treatment approach involves total or near-total thyroidectomy with or without neck dissection followed by 131 I whole-body scintigraphy (WBS) to detect local or distant metastases. Radioiodine offers high sensitivity and specificity for detection of metastatic disease in well differentiated thyroid carcinoma. However, despite its high accuracy, 131 I WBS demonstrates false-positive results, mostly at inflammatory or infective site. These false-positive radioiodine accumulation can lead to misdiagnosis and unwarranted radioiodine treatment. This case presents localization of 131 I to the suture site granuloma leading to false-positive results on 131 I WBS.

Liver volumetry in cirrhotic patients with or without hepatocellular carcinoma: Its correlation with Child-Pugh, model for end-stage liver diseases and indocyanine green dye test.

BACKGROUND AND OBJECTIVES: To evaluate the correlation between non-tumoral liver volume (NTLV) by computed tomography (CT) volumetry and indocyanine green retention at 15 minutes (ICG-r15%), Child-Pugh score (CTP) and model for end-stage liver diseases (MELD) score in cirrhotic patients having hepatocellular carcinoma (HCC) (group A) and in cirrhotics without HCC (group B). METHODS: As many as 111 consecutive patients with liver cirrhosis, who underwent triple-phase CT abdomen, were retrospectively included in our study. They were classified into group A (cirrhosis with HCC, n = 69) and group B (cirrhosis only, n = 42). Segmental liver volume, tumor and NTLV were calculated using Myrian XP-Liver segmentation software. In group B, NTLV was the same as the total liver volume (TLV). The correlation of NTLV with ICG-r15%, CTP and MELD scores was analyzed using appropriate correlation tests for each group. RESULTS: NTLV had a good and significant negative correlation with ICG-r15% (ρ = - 512; p < 0.001) in group A, but not in group B. It also had a significant negative correlation with CTP (ρ = - 251; p = 0.038) and MELD (ρ = - 323; p = 0.007) scores only in group A. Furthermore, ICG-r15% had a good and significant positive correlation with CTP and MELD scores in both groups (p < 0.05). CONCLUSION: NTLV showed a significant negative correlation with ICG-r15% in cirrhotic patients with HCC, but not in cirrhotic patients without HCC. Therefore, CT volumetry can be a valuable tool to predict the functional hepatic volume in patients of cirrhosis with HCC subjected for hepatectomy, where a facility of ICG-r15% is not available. However, further studies are needed to validate our findings in cirrhotic only patients.

Impact of nutritional status on the outcome of transjugular intrahepatic portosystemic shunt in patients with cirrhosis: a systematic review.

OBJECTIVES: Malnutrition and sarcopenia have been reported to adversely affect the outcome of patients with cirrhosis of the liver. There is an emerging body of evidence suggesting malnutrition and sarcopenia increase the risk of hepatic encephalopathy (HE) and mortality after transjugular intrahepatic portosystemic shunt (TIPS). The current systematic review aims to determine whether the body of evidence supports an association between nutritional status and post-TIPS outcomes in patients with cirrhosis. METHODS: Electronic databases of PubMed, Embase, and Scopus were searched from inception to June 3, 2023, for studies analysing the effect of nutritional status on post-TIPS outcomes in patients with cirrhosis. RESULTS: A total of 22 studies were included in the systemic review. Assessment of sarcopenia was done by skeletal muscle index (SMI) at the L3 level, transversal psoas muscle thickness, psoas muscle density, malnutrition as per ICD, relative sarcopenia with excess adiposity, lipid profile, controlling nutritional status score, body composition analysis, hospital frailty risk score, and visceral and subcutaneous fat area index. Ten out of 12 studies in this systematic review showed a significant association with the incidence of post-TIPS HE. Thirteen out of 14 studies reported that the presence of malnutrition was associated with increased odds of mortality following TIPS. One study reported sarcopenia as an independent predictor of liver failure, and another study reported that Pre-TIPS SMI was an independent predictor of substantial improvement in post-TIPS SMI. CONCLUSIONS: The current systematic review shows that the presence of pre-TIPS malnutrition or sarcopenia is an independent predictor of adverse outcomes after TIPS. Incorporating these parameters into present prediction models can provide additional prognostic information. ADVANCES IN KNOWLEDGE: Nutritional assessment should be part of the evaluation of patients planned for TIPS for prediction of adverse events after the procedure.