Tumour growth rate predicts overall survival in patients with recurrent WHO grade 4 glioma.

PURPOSE: Accurate prognostication may aid in the selection of patients who will benefit from surgery at recurrent WHO grade 4 glioma. This study aimed to evaluate the role of serial tumour volumetric measurements for prognostication at first tumour recurrence. METHODS: We retrospectively analyzed patients with histologically-diagnosed WHO grade 4 glioma at initial and at first tumour recurrence at a tertiary hospital between May 2000 and September 2018. We performed auto-segmentation using ITK-SNAP software, followed by manual adjustment to measure serial contrast-enhanced T1W (CE-T1W) and T2W lesional volume changes on all MRI images performed between initial resection and repeat surgery. RESULTS: Thirty patients met inclusion criteria; the median overall survival using Kaplan-Meier analysis from second surgery was 10.5 months. Seventeen (56.7%) patients received treatment post second surgery. Univariate cox regression analysis showed that greater rate of increase in lesional volume on CE-T1W (HR = 2.57; 95% CI [1.18, 5.57]; p = 0.02) in the last 2 MRI scans leading up to the second surgery was associated with a higher mortality likelihood. Patients with higher Karnofsky Performance Score (KPS) (HR = 0.97; 95% CI [0.95, 0.99]; p = 0.01) and who received further treatment following second surgery (HR = 0.43; 95% CI [0.19, 0.98]; p = 0.04) were shown to have a better survival. CONCLUSION: Higher rate of CE-T1W lesional growth on the last 2 MRI images prior to surgery at recurrence was associated with increase mortality risk. A larger prospective study is required to determine and validate the threshold to distinguish rapidly progressive tumour with poor prognosis.

Cryptic asymptomatic parasellar high signal on time-of-flight MR angiography: how to resolve the clinical conundrum.

PURPOSE: Hyperintense parasellar signal on time-of-flight MR angiography (TOF-MRA) in asymptomatic patients may be due to a variety of nonpathological causes and mimic parasellar high flow signal in pathological arteriovenous shunts at the cavernous sinus (CSAVS). This creates a clinical conundrum between diagnosing an aggressive yet asymptomatic CSAVS subtype against exposing patients without CSAVS to potential complications of an invasive angiographic evaluation. We reviewed common nonpathological causes of hyperintense parasellar signal and contrast their imaging features against those of pathological CSAVS and proposed a systemic approach to resolve such conundrum. METHODS: The anatomy of the cavernous sinus (CS) and causes of nonpathological parasellar hyperintense TOF-MRA signal are described and explained with case reviews, illustrations, and reference to published literature where appropriate. Imaging features of proven CSAVS are juxtaposed to aid in radiological differentiation. An algorithm is proposed to manage patients with such incidental TOF-MRA findings. RESULTS: The margins, contour, extent, intensity, and stippling appearance aid in evaluation of pathological versus incidental TOF-MRA parasellar signal, and differentiation of CSAVS from nonpathological causes. Pertinent radiological features are summarized in a table. For unresolved cases suspected for CSAVS, further evaluation with dynamic time-resolved contrast-enhanced MRA is proposed and depicted in a decision tree flow chart. CONCLUSION: Familiarity with the differentiating radiological features and a systematic management workflow could aid in resolving the clinical conundrum of findings of cryptic asymptomatic parasellar TOF-MRA high signal, while facilitating timely detection of the asymptomatic CSAVS.

Cost-effectiveness analysis of liver resection versus transplantation for early hepatocellular carcinoma within the Milan criteria.

UNLABELLED: Both liver resection (LR) and cadaveric liver transplantation (CLT) are potentially curative treatments for patients with hepatocellular carcinoma (HCC) within the Milan criteria and with adequate liver function. Adopting either as a first-line therapy carries major cost and resource implications. The objective of this study was to estimate the relative cost-effectiveness of LR against CLT for patients with HCC within the Milan criteria using a decision analytic model. A Markov cohort model was developed to simulate a cohort of patients aged 55 years with HCC within the Milan criteria and Child-Pugh A/B cirrhosis, undergoing LR or CLT, and followed up over their remaining life expectancy. Analysis was performed in different geographical cost settings: the USA, Switzerland and Singapore. Transition probabilities were obtained from systematic literature reviews, supplemented by databases from Singapore and the Organ Procurement and Transplantation Network (USA). Utility and cost data were obtained from open sources. LR produced 3.9 quality-adjusted life years (QALYs) while CLT had an additional 1.4 QALYs. The incremental cost-effectiveness ratio (ICER) of CLT versus LR ranged from $111,821/QALY in Singapore to $156,300/QALY in Switzerland, and was above thresholds for cost-effectiveness in all three countries. Sensitivity analysis revealed that CLT-related 5-year cumulative survival, one-time cost of CLT, and post-LR 5-year cumulative recurrence rates were the most sensitive parameters in all cost scenarios. ICERs were reduced below threshold when CLT-related 5-year cumulative survival exceeded 84.9% and 87.6% in Singapore and the USA, respectively. For Switzerland, the ICER remained above the cost-effectiveness threshold regardless of the variations. CONCLUSION: In patients with HCC within the Milan criteria and Child-Pugh A/B cirrhosis, LR is more cost-effective than CLT across three different costing scenarios: the USA, Switzerland, Singapore.

Evaluation of Compressed SENSE on Image Quality and Reduction of MRI Acquisition Time: A Clinical Validation Study.

RATIONALE AND OBJECTIVES: To evaluate the effect of compressed SENSE (CS) in clinical settings on scan time reduction and image quality. MATERIALS AND METHODS: Ninety-five magnetic resonance imaging (MRI) scans from different anatomical regions were acquired, consisting of a standard protocol sequence (SS) and sequence accelerated with CS. Anonymized paired sequences were randomly displayed and rated by six blinded subspecialty radiologists. Side-by-side evaluation on perceived sharpness, perceived signal-to-noise-ratio (SNR), lesion conspicuity, and artifacts were compared and scored on a five-point Likert scale, and individual image quality was evaluated on a four-point Likert scale. RESULTS: CS reduced overall scan time by 32% while maintaining acceptable MRI quality for all regions. The largest time savings were seen in the spine (mean = 68 seconds, 44% reduction) followed by the brain (mean = 86 seconds, 37% reduction). The sequence with maximum time savings was intracranial 3D-time-of-flight magnetic resonance angiography (202 seconds, 56% reduction). CS was mildly inferior to SS on perceived sharpness, perceived SNR, and lesion conspicuity (mean scores = 2.32-2.96, P < .001 [1: SS superior; 3: equivalent; 5: CS superior]). CS was equivalent to SS for joint and body scans on overall image quality (CS = 3.02-3.37, SS = 3.04-3.68, P > .05, [1: lowest quality and 4: highest quality]). The overall image quality of CS was slightly less for brain and spine scans (mean CS = 2.79-3.05, mean SS = 3.13-3.43, P = .021) but still diagnostic. Good overall clinical acceptance for CS (88%) was noted with full clinical acceptance for body scans (100%) and high acceptance for other regions (68%-95%). CONCLUSION: CS significantly reduced MR acquisition time while maintaining acceptable image quality. The implementation of CS may improve departmental workflows and enhance patient care.

Non-Invasive Assessment of Isocitrate Dehydrogenase-Mutant Gliomas Using Optimized Proton Magnetic Resonance Spectroscopy on a Routine Clinical 3-Tesla MRI.

PURPOSE: The isocitrate dehydrogenase (IDH) mutation has become one of the most important prognostic biomarkers in glioma management, indicating better treatment response and prognosis. IDH mutations confer neomorphic activity leading to the conversion of alpha-ketoglutarate (α-KG) to 2-hydroxyglutarate (2HG). The purpose of this study was to investigate the clinical potential of proton MR spectroscopy (1H-MRS) in identifying IDH-mutant gliomas by detecting characteristic resonances of 2HG and its complex interplay with other clinically relevant metabolites. MATERIALS AND METHODS: Thirty-two patients with suspected infiltrative glioma underwent a single-voxel (SVS, n = 17) and/or single-slice-multivoxel (1H-MRSI, n = 15) proton MR spectroscopy (1H-MRS) sequence with an optimized echo-time (97 ms) on 3T-MRI. Spectroscopy data were analyzed using the linear combination (LC) model. Cramér-Rao lower bound (CRLB) values of <40% were considered acceptable for detecting 2HG and <20% for other metabolites. Immunohistochemical analyses for determining IDH mutational status were subsequently performed from resected tumor specimens and findings were compared with the results from spectral data. Mann-Whitney and chi-squared tests were performed to ascertain differences in metabolite levels between IDH-mutant and IDH-wild-type gliomas. Receiver operating characteristic (ROC) curve analyses were also performed. RESULTS: Data from eight cases were excluded due to poor spectral quality or non-tumor-related etiology, and final data analyses were performed from 24 cases. Of these cases, 9/12 (75%) were correctly identified as IDH-mutant or IDH-wildtype gliomas through SVS and 10/12 (83%) through 1H-MRSI with an overall concordance rate of 79% (19/24). The sensitivity, specificity, positive predictive value, and negative predictive value were 80%, 77%, 86%, and 70%, respectively. The metabolite 2HG was found to be significant in predicting IDH-mutant gliomas through the chi-squared test (p < 0.01). The IDH-mutant gliomas also had a significantly higher NAA/Cr ratio (1.20 ± 0.09 vs. 0.75 ± 0.12 p = 0.016) and lower Glx/Cr ratio (0.86 ± 0.078 vs. 1.88 ± 0.66; p = 0.029) than those with IDH wild-type gliomas. The areas under the ROC curves for NAA/Cr and Glx/Cr were 0.808 and 0.786, respectively. CONCLUSIONS: Noninvasive optimized 1H-MRS may be useful in predicting IDH mutational status and 2HG may serve as a valuable diagnostic and prognostic biomarker in patients with gliomas.

Microvascular invasion is a better predictor of tumor recurrence and overall survival following surgical resection for hepatocellular carcinoma compared to the Milan criteria.

OBJECTIVE: To compare microvascular invasion (McVI) with parameters defined by the Milan criteria in predicting tumor recurrence and overall survival (OS) in patients with surgical resection (SR) for hepatocellular carcinoma (HCC). SUMMARY BACKGROUND DATA: Although the Milan criteria is discriminatory for selecting patients with good outcomes in liver transplantation and SR for HCC, it neither adequately predict tumor recurrence nor explain differences in survival for patients with good liver function. McVI is a strong indicator of intrahepatic metastasis in HCC, but its relative significance for predicting clinical outcomes compared to the Milan criteria is unclear. METHODS: Patients undergoing SR with curative intent from January 2000 to March 2009 at the Singapore General Hospital were followed up for long-term outcomes till January 1, 2010. They were stratified first by the Milan criteria and then by the presence of McVI and compared relative to OS. RESULTS: Altogether, 454 of the 515 patients received curative SR. There were stratified into 4 groups (Milan+, McVI-), (Milan+, McVI+), (Milan-, McVI-), and (Milan-, McVI+). All pair-wise comparisons between groups relative to OS were significant except (Milan+, McVI-) (OS, 90%, 73%, and 60% at 1, 3, and 5 years) with (Milan-, McVI-) (OS, 86%, 71%, and 61% at 1, 3, 5 years) and (Milan+, McVI+) with (Milan-, McVI+). Multivariate Cox regression analysis showed that McVI was predictive of OS, after which Milan status did not add additional discriminative information. CONCLUSIONS: McVI is a better predictor of tumor recurrence and OS than the Milan criteria after SR for HCC. Assessment of McVI should aid in patient selection for adjuvant treatments to improve outcomes after SR.

Thymosin ß4 increases cardiac cell proliferation, cell engraftment, and the reparative potency of human induced-pluripotent stem cell-derived cardiomyocytes in a porcine model of acute myocardial infarction.

Rationale: Previous studies have shown that human embryonic stem cell-derived cardiomyocytes improved myocardial recovery when administered to infarcted pig and non-human primate hearts. However, the engraftment of intramyocardially delivered cells is poor and the effectiveness of clinically relevant doses of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in large animal models of myocardial injury remains unknown. Here, we determined whether thymosin ß4 (Tb4) could improve the engraftment and reparative potency of transplanted hiPSC-CMs in a porcine model of myocardial infarction (MI). Methods: Tb4 was delivered from injected gelatin microspheres, which extended the duration of Tb4 administration for up to two weeks in vitro. After MI induction, pigs were randomly distributed into 4 treatment groups: the MI Group was injected with basal medium; the Tb4 Group received gelatin microspheres carrying Tb4; the CM Group was treated with 1.2 × 108 hiPSC-CMs; and the Tb4+CM Group received both the Tb4 microspheres and hiPSC-CMs. Myocardial recovery was assessed by cardiac magnetic resonance imaging (MRI), arrhythmogenesis was monitored with implanted loop recorders, and tumorigenesis was evaluated via whole-body MRI. Results: In vitro, 600 ng/mL of Tb4 protected cultured hiPSC-CMs from hypoxic damage by upregulating AKT activity and BcL-XL and promoted hiPSC-CM and hiPSC-EC proliferation. In infarcted pig hearts, hiPSC-CM transplantation alone had a minimal effect on myocardial recovery, but co-treatment with Tb4 significantly enhanced hiPSC-CM engraftment, induced vasculogenesis and the proliferation of cardiomyocytes and endothelial cells, improved left ventricular systolic function, and reduced infarct size. hiPSC-CM implantation did not increase incidence of ventricular arrhythmia and did not induce tumorigenesis in the immunosuppressed pigs. Conclusions: Co-treatment with Tb4-microspheres and hiPSC-CMs was safe and enhanced the reparative potency of hiPSC-CMs for myocardial repair in a large-animal model of MI.

Radiology Preparedness in the Ongoing Battle against COVID-19: Experiences from Large to Small Public Hospitals in Singapore.

The coronavirus disease 2019 (COVID-19) pandemic presents an unprecedented challenge to the health care systems of the world. In Singapore, early experiences of the radiology community on managing this pandemic was shaped by lessons learned from the severe acute respiratory syndrome outbreak in 2003. This article surveys the operational responses of radiology departments from six public hospitals in Singapore. © RSNA, 2020.

Starvation-induced diplopia and weakness: a case of beriberi and Wernicke's encephalopathy.

A 56-year-old teetotaller man with hypertension and gout presented with a week duration of painless worsening diplopia on a background of loss of weight and appetite, generalised lethargy and weakness for 1 year. On examination, he was noted to be hypothermic and tachycardic with generalised muscle wasting. Proximal myopathy, lower limb fasciculations and areflexia, restricted bilateral eye abduction and nystagmus were observed. Blood investigations demonstrated compensated lactic acidosis, acute kidney injury and leucocytosis. A nerve conduction study showed severe length-dependent axonal sensorimotor polyneuropathy. This was a diagnostic dilemma until an MRI brain revealed symmetrical signal abnormality and enhancement in the periaqueductal area indicative of Wernicke's encephalopathy, caused by thiamine deficiency from poor nutrition. Beriberi, also caused by thiamine deficiency, accounted for his tachycardia, polyneuropathy, areflexia, hypothermia and biochemical abnormalities. Both beriberi and Wernicke's encephalopathy are medical emergencies, which were treated with intravenous thiamine to good effect.

Clinics in diagnostic imaging (193). Sporadic Creutzfeldt-Jakob disease (sCJD).

A 68-year-old man presented with a three-week history of rapidly progressive dementia, gait ataxia and myoclonus. Subsequent electroencephalography showed periodic sharp wave complexes, and cerebrospinal fluid assay revealed the presence of a 14-3-3 protein. A probable diagnosis of sporadic Creutzfeldt-Jakob disease was made, which was further supported by magnetic resonance (MR) imaging of the brain showing asymmetric signal abnormality in the cerebral cortices and basal ganglia. The aetiology, clinical features, diagnostic criteria, various MR imaging patterns and radiologic differential diagnosis of sporadic Creutzfeldt-Jakob disease are discussed in this article.

Multimodal assessments of Zika virus immune pathophysiological responses in marmosets.

Animal models that recapitulate the human pathophysiology have been developed as useful research tools. Although laboratory mice are widely used, they are phylogenetically "distant" to humans. New world monkeys, such as the common marmoset (Callithrix jacchus) have steadily gained prominence. In this report, marmosets are explored as an alternate in vivo model to investigate infection and immunity of Zika virus (ZIKV). Multimodal platforms, including ultrasound and magnetic resonance imaging (MRI), flow cytometry, and multiplex microbead immunoassays were established to comprehensively decipher immune responses and pathophysiological outcomes. While ZIKV-infected marmosets had detectable ZIKV RNA load in various body fluids, animals did not develop any observable lesions in their testes and brains as shown by ultrasound and MRI. Immune-phenotyping detected differences in the numbers of B cells, CD8+ T cells and HLADR+ NK cells during the first two weeks of infection. Neutralizing ZIKV-specific antibodies were elicited to high levels and targeted epitopes in the E protein. This study presents a one-stop-shop platform to study infection and pathophysiology in marmosets. While marmoset-specific research tools are being refined, the research values of these animals present them as a good model for immune-based therapies.