A review of cytokine-based pathophysiology of Long COVID symptoms.

The Long COVID/Post Acute Sequelae of COVID-19 (PASC) group includes patients with initial mild-to-moderate symptoms during the acute phase of the illness, in whom recovery is prolonged, or new symptoms are developed over months. Here, we propose a description of the pathophysiology of the Long COVID presentation based on inflammatory cytokine cascades and the p38 MAP kinase signaling pathways that regulate cytokine production. In this model, the SARS-CoV-2 viral infection is hypothesized to trigger a dysregulated peripheral immune system activation with subsequent cytokine release.

Detection of Mesenteric Tumor Using Dynamic Contrast Enhanced MRI.

Purpose: This study was designed to evaluate the use of a novel imaging technique, dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), for detecting mesenteric peritoneal metastases.

Methods: Thirty-four patients underwent preoperative conventional MRI, including T1, T2, diffusion-weighted (DWI), and delayed gadolinium MRI, as well as DCE MRI. DCE MRI involved imaging the peritoneal cavity every 9 s for 6 min.

Peritoneal MRI in patients undergoing cytoreductive surgery and HIPEC: History, clinical applications, and implementation.

MR imaging provides considerable advantages in the evaluation of patients with peritoneal metastases. A standardized peritoneal MRI protocol, including diffusion-weighted and gadolinium-enhanced sequences, allows an efficient exploration of small peritoneal tumors that are often missed on other imaging tests. In experienced hands, a dedicated reading allows producing a quantitative and qualitative evaluation of lesional localization to better assist surgeons in the selection of candidates for curative surgery by evaluating the possibility of complete resection, and to plan the surgical procedure.

Imaging for Peritoneal Metastases.

MRI provides considerable advantages for imaging of patients with peritoneal tumor. Its inherently superior contrast resolution compared with computed tomography allows MRI to more accurately depict small peritoneal tumors that are often missed on other imaging tests. Combining different contrast mechanisms, including diffusion-weighted MRI and gadolinium-enhanced MRI, provides a powerful tool for preoperative and surveillance imaging in patients being considered for cytoreductive surgery and heated intraperitoneal chemotherapy.

A flexible fast spin echo triple-echo Dixon technique.

Purpose: To develop a flexible fast spin echo (FSE) triple-echo Dixon (FTED) technique.

Methods: An FSE pulse sequence was modified by replacing each readout gradient with three fast-switching bipolar readout gradients with minimal interecho dead time. The corresponding three echoes were used to generate three raw images with relative phase shifts of -θ, 0, and θ between water and fat signals.

Preoperative and surveillance MR imaging of patients undergoing cytoreductive surgery and heated intraperitoneal chemotherapy.

MR imaging provides considerable advantages for imaging patients with peritoneal tumor. Its inherently superior contrast resolution compared to CT allows MRI to more accurately depict small peritoneal tumors that are often missed on other imaging tests. Combining different contrast mechanisms including diffusion-weighted (DW) MRI and gadolinium-enhanced MRI provides a powerful tool for preoperative and surveillance imaging in patients being considered for cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC).

Magnetic resonance elastography for staging liver fibrosis in non-alcoholic fatty liver disease: a diagnostic accuracy systematic review and individual participant data pooled analysis.

Objectives: We conducted an individual participant data (IPD) pooled analysis on diagnostic accuracy of MRE to detect fibrosis stage in patients with non-alcoholic fatty liver disease (NAFLD).

Methods: Through a systematic literature search, we identified studies of MRE (at 60-62.5 Hz) for staging fibrosis in patients with NAFLD, using liver biopsy as gold standard, and contacted study authors for IPD.

Diagnostic performance of magnetic resonance elastography in staging liver fibrosis: a systematic review and meta-analysis of individual participant data.

Background & Aims: Magnetic resonance elastography (MRE) is a noninvasive tool for staging liver fibrosis. We conducted a meta-analysis of individual participant data collected from published studies to assess the diagnostic accuracy of MRE for staging liver fibrosis in patients with chronic liver diseases (CLD).

Methods: Through a systematic literature search of multiple databases (2003-2013), we identified studies on diagnostic performance of MRE for staging liver fibrosis in patients with CLD with native anatomy, using liver biopsy as the standard.

Comparison of MRI and CT for predicting the Peritoneal Cancer Index (PCI) preoperatively in patients being considered for cytoreductive surgical procedures.

Purpose: To compare the accuracy of MRI and CT for predicting the Peritoneal Cancer Index (PCI) preoperatively compared with the PCI tabulated at surgery.

Methods: Twenty-two patients underwent preoperative MRI and CT scanning followed by cytoreductive surgery for appendiceal (n = 17) and ovarian (n = 5) cancer. MR and CT examinations were retrospectively reviewed to determine the PCI.

Surveillance MR imaging is superior to serum tumor markers for detecting early tumor recurrence in patients with appendiceal cancer treated with surgical cytoreduction and HIPEC.

Background: The purpose of this study was to determine if MRI surveillance is better than serum tumor makers in detecting early recurrence in patients with mucinous appendiceal neoplasm.

Materials And Methods: A total of 50 patients with appendiceal neoplasm (DPAM 11, PMCA 39) underwent abdominal and pelvic MRI prior to surgical cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC). Patients then entered follow-up surveillance with serial MRI every 6 months and serial laboratory studies including CA 125, CEA, and CA19-9.

Combined diffusion-weighted and gadolinium-enhanced MRI can accurately predict the peritoneal cancer index preoperatively in patients being considered for cytoreductive surgical procedures.

Purpose: To determine whether abdominal and pelvic magnetic resonance imaging (MRI) with diffusion-weighted and dynamic gadolinium-enhanced imaging can be used to accurately calculate the peritoneal cancer index (PCI) before surgery compared to the PCI tabulated at surgery.

Methods: Thirty-three patients underwent preoperative MRI followed by cytoreductive surgery for primary tumors of the appendix (n = 25), ovary (n = 5), colon (n = 2), and mesothelioma (n = 1). MRIs were retrospectively reviewed to determine the MRI PCI.

Dynamic gadolinium-enhanced perfusion MRI of prostate cancer: assessment of response to hypofractionated robotic stereotactic body radiation therapy.

Objective: The purpose of this study was to evaluate the utility of dynamic gadolinium-enhanced perfusion MRI for monitoring the response to robotic stereotactic body radiation therapy for prostate cancer.

Materials And Methods: Eighty-seven patients with prostate cancer underwent dynamic gadolinium-enhanced MRI before robotic stereotactic body radiation therapy, and prostate volume was calculated. Pharmacokinetic analysis postprocessing software was used to generate colorized parametric maps showing perfusion of enhancing tumors.

Fast spin-echo triple echo dixon: Initial clinical experience with a novel pulse sequence for simultaneous fat-suppressed and nonfat-suppressed T2-weighted spine magnetic resonance imaging.

Purpose: To evaluate a prototype fast spin-echo (FSE) triple-echo Dixon (FTED) technique for T2-weighted spine imaging with and without fat suppression compared to conventional T2-weighted fast recovery (FR) FSE and short-tau inversion recovery (STIR) imaging.

Materials And Methods: Sixty-one patients were referred for spine magnetic resonance imaging (MRI) including sagittal FTED (time 2:26), STIR (time 2:42), and T2 FRFSE (time 2:55). Two observers compared STIR and FTED water images and T2 FRFSE and FTED T2 images for overall image quality, fat suppression, anatomic sharpness, motion, cerebrospinal fluid (CSF) flow artifact, susceptibility, and disease depiction.

High-resolution double arterial phase hepatic MRI using adaptive 2D centric view ordering: initial clinical experience.

Objective: The objective of our study was to evaluate a new 3D fast spoiled gradient-recalled echo (FSPGR) sequence referred to as modified liver acceleration volume acquisition (LAVA) for high-resolution gadolinium-enhanced dual arterial phase liver MRI and to determine the effect of this technique on the timing of the contrast bolus and lesion detection.

Materials And Methods: Gadolinium-enhanced dual arterial phase liver MRI was performed in 109 patients using a modified LAVA sequence that supports adaptive 2D centric view ordering, efficient 2D autocalibrated acceleration, and partial-Fourier to achieve faster scan times while maintaining the same slice thickness, resolution, and coverage as single-phase imaging. After a fixed 20-second scan delay, a modified LAVA acquisition required a single 24- to 26-second breath-hold for two arterial phases with 56-60 slices per pass.

Fast spin-echo triple-echo Dixon: initial clinical experience with a novel pulse sequence for fat-suppressed T2-weighted abdominal MR imaging.

Purpose: To evaluate a prototype fast spin echo (FSE) triple-echo-Dixon (fTED) technique for breath-hold, fat-suppressed, T2-weighted abdominal imaging.

Materials And Methods: Forty patients underwent breath-hold T2-weighted abdominal imaging with fTED and conventional fast recovery (FR) FSE with chemical shift-selective saturation (CHESS). FRFSE and fTED images were compared for overall image quality, homogeneity of fat suppression, image sharpness, anatomic detail, and phase artifact.

Diffusion-weighted MRI of peritoneal tumors: comparison with conventional MRI and surgical and histopathologic findings--a feasibility study.

Objective: The purpose of our study was to evaluate the utility of single-shot spin-echo echo-planar diffusion-weighted imaging (DWI) using a b value of 400-500 s/mm(2) for depicting peritoneal tumors.

Materials And Methods: Thirty-four consecutive oncology patients underwent preoperative abdominal and pelvic MRI for tumor staging. MRI included breath-hold DWI with a b value of 400-500 s/mm(2), T1-weighted spoiled gradient-echo, T2-weighted fast spin-echo, and 0- and 5-minute delayed gadolinium-enhanced imaging.

Diffusion-weighted MR imaging for whole body metastatic disease and lymphadenopathy.

Diffusion-weighted (DW) imaging provides a new contrast mechanism for evaluation of tumors of the chest, abdominal, and pelvis. By imaging microscopic motion of water molecules, DW imaging yields new qualitative and quantitative information about tumors that can be used to improve tumor detection, characterize some tumors, and monitor and predict response to treatment. DW imaging techniques provide a host of new tools for the body imager including: magnitude DW images; ADC maps with quantitative analysis; and volumetric display of data including whole body diffusion with background suppression.

Three-dimensional fast spoiled gradient-echo dual echo (3D-FSPGR-DE) with water reconstruction: preliminary experience with a novel pulse sequence for gadolinium-enhanced abdominal MR imaging.

Purpose: To compare three-dimensional fast spoiled gradient-echo dual-echo (3D-FSPGR-DE) with water reconstruction to conventional 3D-FSPGR for gadolinium-enhanced abdominal imaging.

Materials And Methods: Sixty-five patients underwent abdominal MRI on a 1.5T GE-HDx MR scanner using gadolinium-enhanced 3D-FSPGR and 3D-FSPGR-DE imaging.

Mucinous appendiceal neoplasms: preoperative MR staging and classification compared with surgical and histopathologic findings.

Objective: The objective of our study was to determine the accuracy of MRI in the preoperative staging and classification of mucinous appendiceal neoplasms and to describe the MRI features that are useful for selecting patients for surgical resection.

Materials And Methods: Twenty-two patients underwent preoperative MRI including T1-weighted, T2-weighted, immediate gadolinium-enhanced, and delayed gadolinium-enhanced imaging. Two observers reviewed the images for peritoneal tumor at 13 sites, tumor size and distribution, and degree of tumor enhancement.

Abdominal MRI advances in the detection of liver tumours and characterisation.

With recent technical advances in hardware, software, and intravenous contrast agents, MRI has evolved into a clinically useful procedure to detect and characterise liver tumours. The combination of MRI systems with larger gradients, improved surface coils, and parallel imaging techniques have produced substantial improvements in MRI quality and speed of image acquisition. Images that previously needed several minutes to acquire can now be obtained in several seconds.

Diffusion-weighted MRI (DWI) in the oncology patient: value of breathhold DWI compared to unenhanced and gadolinium-enhanced MRI.

Purpose: To evaluate the feasibility and added value of single breathhold diffusion-weighted (DW) imaging (DWI) in oncology patients undergoing abdominal MRI.

Materials And Methods: A total of 169 patients with malignancy underwent abdominal MRI at 1.5T, including T1-weighted (T1W), T2-weighted (T2W), and dynamic gadolinium-enhanced imaging.

MR imaging of the peritoneal spread of malignancy.

MR imaging provides a highly sensitive and accurate means to depict tumor involving the peritoneum and bowel serosa. The ability of MR imaging to depict subtle peritoneal metastases plays a critical role in diagnosing and monitoring the oncologic patient with known or suspected peritoneal spread of malignancy. In this review I will describe the mechanisms of peritoneal tumor spread, and MR techniques and protocols for peritoneal imaging.

Magnetic resonance imaging in the oncology patient: evaluation of the extrahepatic abdomen.

In the oncology patient MR imaging provides excellent depiction of all forms of extrahepatic tumor. Rapid breath-hold imaging techniques are combined with intravenous and intraluminal contrast material to demonstrate tumors of the solid visceral organs, the gastrointestinal tract, peritoneum, mesentery, omentum, bile ducts, lymph nodes, and osseous structures. The unmatched soft tissue contrast of MR imaging allows one to depict subtle tumors involving all of these extrahepatic sites.

Treated ovarian cancer: MR imaging, laparotomy reassessment, and serum CA-125 values compared with clinical outcome at 1 year.

Purpose: To compare retrospectively the use of magnetic resonance (MR) imaging, laparotomy reassessment, and serum CA-125 values in predicting the presence of residual tumor in women who have been treated for ovarian cancer.

Materials And Methods: This study was approved by the institutional review board, and informed consent was waived. The study was compliant with the Health Insurance Portability and Accountability Act.