Imaging of Alcohol-Associated Liver Disease.

Alcohol-associated liver disease (ALD) continues to be a global health concern, responsible for a significant number of deaths worldwide. Although most individuals who consume alcohol do not develop ALD, heavy drinkers and binge drinkers are at increased risk. Unfortunately, ALD is often undetected until it reaches advanced stages, frequently associated with portal hypertension and hepatocellular carcinoma (HCC). ALD is now the leading indication for liver transplant. The incidence of alcohol-associated hepatitis (AH) surged during the COVID-19 pandemic. Early diagnosis of ALD is therefore important in patient management and determination of prognosis, as abstinence can halt disease progression. The spectrum of ALD includes steatosis, steatohepatitis, and cirrhosis, with steatosis the most common manifestation. Diagnostic techniques including ultrasound, CT, and MRI provide useful information for identifying ALD and excluding other causes of liver dysfunction. Heterogeneous steatosis and transient perfusion changes on CT and MRI in the clinical setting of alcohol-use disorder are diagnostic of severe AH. Elastography techniques are useful for assessing fibrosis and monitoring treatment response. These various imaging modalities are also useful in HCC surveillance and diagnosis. This review discusses the imaging modalities currently used in the evaluation of ALD, highlighting their strengths, limitations, and clinical applications.

Stabilization of Dinuclear Rhodium and Iridium Clusters on Layered Titanate and Niobate Supports.

Atomically dispersed organometallic clusters can provide well-defined nuclearity of active sites for both fundamental studies as well as new regimes of activity and selectivity in chemical transformations. More recently, dinuclear clusters adsorbed onto solid surfaces have shown novel catalytic properties resulting from the synergistic effect of two metal centers to anchor different reactant species. Difficulty in synthesizing, stabilizing, and characterizing isolated atoms and clusters without agglomeration challenges allocating catalytic performance to atomic structure. Here, we explore the stability of dinuclear rhodium and iridium clusters adsorbed onto layered titanate and niobate supports using molecular precursors. Both systems maintain their nuclearity when characterized using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Statistical analysis of HAADF-STEM images revealed that rhodium and iridium dimers had mean cluster-to-cluster distances very similar to what is expected from a random distribution of atoms over a large area, indicating that they are dispersed without aggregation. The stability of dinuclear rhodium clusters supported on titanate nanosheets was also investigated by X-ray absorption fine structure (EXAFS), DRIFTS, and first-principles calculations. Both X-ray absorption spectroscopy and HAADF-STEM simulations, guided by density functional theory (DFT)-optimized structure models, suggested that rhodium dimers adsorb onto the nanosheets in an end-on binding mode that is stable up to 100 °C under reducing conditions. This study highlights that crystalline nanosheets derived from layered metal oxides can be used as model supports to selectively stabilize dinuclear clusters, which could have implications for heterogeneous catalysis.

Comparative study of perioperative and survival outcomes after video endoscopic inguinal lymphadenectomy (VEIL) and open inguinal lymph node dissection (O-ILND) in the management of inguinal lymph nodes in carcinoma of the penis.

Open inguinal lymph node dissection (O-ILND) is the gold standard in the management of lymph nodes in carcinoma penis; however, video endoscopic inguinal lymphadenectomy (VEIL) is performed in some centers. Our primary objective is to compare perioperative and survival outcomes in patients undergoing VEIL with O-ILND, as very few studies have reported long-term survival outcomes till date. We analyzed patients who underwent O-ILND and VEIL (laparoscopic or robot-assisted) from January 2009 to January 2020 in our institute for carcinoma of the penis. Patient details, perioperative complications, and survival outcomes were analyzed. Perioperative outcomes were analyzed by logistic regression and survival outcomes by log-rank and Cox regression methods. We analyzed 79 patients (32 O-ILND, 47 VEIL) with a median follow-up of 51 (IQR 25.5-75.5) and 42 months (IQR 21-62). Wound complications were common in O-ILND group (65.6%) compared to VEIL group (27.7%) (p = 0.001), predominantly skin flap necrosis in 14 groins (23.73%) after O-ILND and none after VEIL. Median overall survival was 80 and 88 months (p = 0.840) with five-year survival of 65% and 66.8% (p = 0.636) and five-year DSS of 76.6% and 73.9% (p = 0.96) in O-ILND and VEIL, respectively. Multivariate analysis showed that grade and pathological node status were significant (HR-2.650, p = 0.040; HR-3.218, p = 0.024) factors for survival. The retrospective nature of the study design is the limitation. Management of inguinal lymph nodes in carcinoma penis by VEIL is safe, associated with lesser wound-related complications, and equivalent survival outcomes compared to O-ILND. It should be considered as an alternative option for inguinal lymph node dissection.

Elementary kinetics of nitrogen electroreduction on Fe surfaces.

Electrochemical ammonia synthesis could provide a sustainable and efficient alternative to the energy intensive Haber-Bosch process. Development of an active and selective N2 electroreduction catalyst requires mechanism determination to aid in connecting the catalyst composition and structure to performance. Density functional theory (DFT) calculations are used to examine the elementary step energetics of associative N2 reduction mechanisms on two low index Fe surfaces. Interfacial water molecules in the Heyrovsky-like mechanism help lower some of the elementary activation barriers. Electrode potential dependent barriers show that cathodic potentials below -1.5 V-RHE (reversible hydrogen electrode) are necessary to give a significant rate of N2 electroreduction. DFT barriers suggest a larger overpotential than expected based on elementary reaction free energies. Linear Brønsted-Evans-Polanyi relationships do not hold across N-H formation steps on these surfaces, further confirming that explicit barriers should be considered in DFT studies of the nitrogen reduction reaction.

Abernethy malformation: Single-center experience from India with review of literature.

Abernethy malformation is a rare congenital anomaly in which there is direct communication between the portal and systemic venous circulation. The clinical presentation ranges from asymptomatic with incidental detection on imaging to secondary complications of disease or related to associate anomalies. This is a retrospective analysis of data from nine patients with Abernethy malformation at a single center. This is a referral center for Pediatric Cardiology and for Hepatobiliary and Pancreatic Surgery. The patients presented to the Pulmonary Hypertension Clinic/the Hepatobiliary Surgery Clinic. Out of nine patients, four were male. Type II Abernethy malformation was present in five patients whereas three patients had type I malformation. One of the patients had communication between inferior mesenteric vein and internal iliac vein. Five out of nine patients were erroneously diagnosed as idiopathic primary pulmonary hypertension and were treated with vasodilators. One patient required living donor liver transplant. One patient was managed with surgical shunt closure whereas two patients required transcatheter shunt closure. The rest of the patients were managed conservatively. Abernethy malformation is more common than previously thought and the diagnosis is often missed. There are various management options for Abernethy malformation, which includes surgical or transcatheter shunt closure and liver transplant. Management of Abernethy malformation depends upon type, presentation, and size of shunt.

Kinetics of liver regeneration in donors after living donor liver transplantation: A retrospective analysis of "2/3rd partial hepatectomy" model at 3 months.

BACKGROUND/AIM: Right lobe living donor (2/3rd partial hepatectomy) model is the best way to accurately study liver regeneration process in human beings. We aimed to study the kinetics of liver regeneration after 2/3rd partial hepatectomy in donors. METHODS: Retrospective analysis of prospectively maintained volumetric recovery data in donors was performed in 23 donors, who underwent 29 contrast-enhanced computed tomography within 3 months for various clinical indications. RESULTS: The absolute volumetric growth percentages were as follows: 37.60 ± 21.74 at 1st week, 92 ± 53.27 at 2nd week, 115.55 ± 59.65 at 4th week, and 110.79 ± 64.47 at 3 months. On sub-group analysis of our cohort, we found that 4.3%, 17%, 30.4%, and 39% donors attended ≥ 90% volumetric recovery at 1st, 2nd, 4th week, and 3 months, respectively. One patient at 4th week revealed 128% volumetric recovery. There was one more patient who exceeded original total liver volumes (TLV) (111% of TLV) at 2.5 months. The serum bilirubin and INR values peaked at postoperative day (POD) 3rd and then started showing a downward trend from POD 5th onwards. CONCLUSION: Our study is the first to document complete volumetric recovery in donors as early as 3 weeks. Two of the donors overshot their original TLV during the early regenerative phase.

Transmural colonic ischemia: clinical features and computed tomography findings.

Our purpose was to describe the computed tomography features of transmural colonic ischemia in correlation with clinical, laboratory and histopathological findings of 14 patients who underwent colectomy (9 female and 5 male; mean age, 68 years). Seven patients died (50%). Transmural necrosis involved the right colon in 10 patients (10/14, or 72%). Eleven patients showed thickened colonic wall (11/14, or 79%), 10 pneumatosis (10/14, or 71%), 5 gas in the portal venous system (5/14, or 36%), and 14 fat stranding (14/14, or 100%).

Artifacts and pitfalls in MR imaging of the pelvis.

Artifacts are intimately intertwined with MRI. For the practicing radiologist, effective supervision, troubleshooting, and interpretation of diagnostic MR studies require a solid knowledge of the pertinent artifacts. This article seeks to familiarize the reader with commonly encountered artifacts and pitfalls in pelvic imaging, the mechanism behind their generation, and methods of minimizing their negative impact or maximizing their diagnostic yield. It also serves as an exciting tool to learn many aspects of basic and advanced MR physics. Artifacts are categorized into patient- and sequence-related artifacts. Various manifestations of motion and vascular artifacts, susceptibility, altered tissue contrast, blurring, chemical shift artifact, volume averaging, and gadolinium (Gd) pseudolayering are explained, along with their proposed remedies.

Magnetic resonance imaging of the cervix.

Due to deficiencies of clinical staging, magnetic resonance (MR) imaging is being increasingly used in the pre-treatment work-up of cervical cancer. Lymph node status, as evaluated by advanced imaging modalities, is also being incorporated into management algorithms. Familiarity with MR imaging features will lead to more accurate staging of cervical cancer. Awareness of impact of staging on management will enable the radiologists to tailor the report to clinically and surgically relevant information. This article emphasizes the guidelines on the MR staging criteria, dependence of newer treatments on imaging staging and lymph node involvement, and MR imaging in post-treatment surveillance of cervical cancer.

Magnetic resonance spectroscopy.

Magnetic resonance spectroscopy (MRS) complements magnetic resonance imaging (MRI) as a non-invasive means for the characterization of tissue. While MRI uses the signal from hydrogen protons to form anatomic images, proton MRS uses this information to determine the concentration of brain metabolites such as N-acetyl aspartate (NAA), choline (Cho), creatine (Cr) and lactate in the tissue examined. The most widely used clinical application of MRS has been in the evaluation of central nervous system disorders.MRS has its limitations and is not always specific but, with good technique and in combination with clinical information and conventional MRI, can be very helpful in diagnosing certain entities. For example, a specific pattern of metabolites can be seen in disorders such as Canavan's disease, creatine deficiency, and untreated bacterial brain abscess. MRS may also be helpful in the differentiation of high grade from low grade brain tumors, and perhaps in separating recurrent brain neoplasm from radiation injury.

Magnetic resonance imaging findings in an unusual case of atlanto axial dislocation and vertebral artery-vein fistulas in a patient of neurofibromatosis-1.

Vertebral arteriovenous fistulas are uncommon in neurofibromatosis. We describe MRI findings of a patient with an unusual association of bilateral vertebral arteriovenous fistulas with an atlantoaxial dislocation in the setting of neurofibromatosis.

Diffusion-weighted imaging for differentiating recurrent cholesteatoma from granulation tissue after mastoidectomy: case report.

Identification of recurrent cholesteatoma and differentiation from postoperative granulation tissue is important in a patient who has undergone mastoidectomy for cholesteatoma. We describe the diffusion-weighted imaging findings and apparent diffusion coefficient values in a case of recurrent cholesteatoma. This case suggests possible differentiation of cholesteatoma from granulation tissue on the basis of diffusion-weighted imaging findings.