The diagnostic work-up for myocarditis largely depends on non-invasive imaging because of the low yield of endomyocardial biopsy. In addition, differentiation among possible impressions is essential because of its non-specific clinical presentations.This ambiguity has led to the predominant use of cardiac magnetic resonance imaging techniques in the management of myocarditis, particularly during the global pandemic. Despite the unique ability of F-18 fluorodeoxyglucose positron emission tomography to visualize and quantify active myocardial inflammation, which has been well established in cardiac sarcoidosis, its diagnostic contribution in non-sarcoidotic myocarditis remains uncertain. This article reviews the current evidence on the non-invasive imaging diagnosis of non-sarcoidotic myocarditis and discusses the potential role of F-18 fluorodeoxyglucose positron emission tomography as a clinically relevant imaging tool.

The diagnostic work-up for myocarditis largely depends on non-invasive imaging because of the low yield of endomyocardial biopsy. In addition, differentiation among possible impressions is essential because of its non-specific clinical presentations.This ambiguity has led to the predominant use of cardiac magnetic resonance imaging techniques in the management of myocarditis, particularly during the global pandemic. Despite the unique ability of F-18 fluorodeoxyglucose positron emission tomography to visualize and quantify active myocardial inflammation, which has been well established in cardiac sarcoidosis, its diagnostic contribution in non-sarcoidotic myocarditis remains uncertain. This article reviews the current evidence on the non-invasive imaging diagnosis of non-sarcoidotic myocarditis and discusses the potential role of F-18 fluorodeoxyglucose positron emission tomography as a clinically relevant imaging tool.

The diagnostic work-up for myocarditis largely depends on non-invasive imaging because of the low yield of endomyocardial biopsy. In addition, differentiation among possible impressions is essential because of its non-specific clinical presentations.This ambiguity has led to the predominant use of cardiac magnetic resonance imaging techniques in the management of myocarditis, particularly during the global pandemic. Despite the unique ability of F-18 fluorodeoxyglucose positron emission tomography to visualize and quantify active myocardial inflammation, which has been well established in cardiac sarcoidosis, its diagnostic contribution in non-sarcoidotic myocarditis remains uncertain. This article reviews the current evidence on the non-invasive imaging diagnosis of non-sarcoidotic myocarditis and discusses the potential role of F-18 fluorodeoxyglucose positron emission tomography as a clinically relevant imaging tool.

The diagnostic work-up for myocarditis largely depends on non-invasive imaging because of the low yield of endomyocardial biopsy. In addition, differentiation among possible impressions is essential because of its non-specific clinical presentations.This ambiguity has led to the predominant use of cardiac magnetic resonance imaging techniques in the management of myocarditis, particularly during the global pandemic. Despite the unique ability of F-18 fluorodeoxyglucose positron emission tomography to visualize and quantify active myocardial inflammation, which has been well established in cardiac sarcoidosis, its diagnostic contribution in non-sarcoidotic myocarditis remains uncertain. This article reviews the current evidence on the non-invasive imaging diagnosis of non-sarcoidotic myocarditis and discusses the potential role of F-18 fluorodeoxyglucose positron emission tomography as a clinically relevant imaging tool.

The diagnostic work-up for myocarditis largely depends on non-invasive imaging because of the low yield of endomyocardial biopsy. In addition, differentiation among possible impressions is essential because of its non-specific clinical presentations.This ambiguity has led to the predominant use of cardiac magnetic resonance imaging techniques in the management of myocarditis, particularly during the global pandemic. Despite the unique ability of F-18 fluorodeoxyglucose positron emission tomography to visualize and quantify active myocardial inflammation, which has been well established in cardiac sarcoidosis, its diagnostic contribution in non-sarcoidotic myocarditis remains uncertain. This article reviews the current evidence on the non-invasive imaging diagnosis of non-sarcoidotic myocarditis and discusses the potential role of F-18 fluorodeoxyglucose positron emission tomography as a clinically relevant imaging tool.

Objective: The assessment of cortical integrity following renal injuries with planar Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy depends on measuring relatively decreased cortical uptake (i.e., split renal function [SRF]). We analyzed the additive values of the volumetric and quantitative analyses of the residual cortical integrity using single-photon emission computed tomography (SPECT) compared to the planar scintigraphy. Materials and Methods: This prospective study included 47 patients (male:female, 32:15; age, 47 ± 22 years) who had nonoperatively managed renal injuries and underwent DMSA planar and SPECT imaging 3–6 months after the index injury. In addition to planar SRF, SPECT SRF, cortical volume, and absolute cortical uptake were measured for the injured kidney and both kidneys together. The correlations of planar SRF with SPECT SRF and those of SRF with volumetric/quantitative parameters obtained with SPECT were analyzed. The association of SPECT parameters with renal function, grades of renal injuries, and the risk of renal failure was also analyzed. Results: SPECT SRF was significantly lower than planar SRF, with particularly higher biases in severe renal injuries. Planar and SPECT SRF (dichotomized with a cutoff of 45%) showed 19%–36% of discrepancies with volumetric and quantitative DMSA indices (when dichotomized as either high or low). Absolute cortical uptake of the injured kidney best correlated with glomerular filtration rate (GFR) at follow-up (ρ = 0.687, P < 0.001) with significant stepwise decreases by GFR strata (90 and 60 mL/min/1.73 m2 ). Total renal cortical uptake was significantly lower in patients with moderate-to-high risk of renal failure than those with low risk. However, SRF did not reflect GFR decrease below 60 mL/min/1.73 m2 or the risk of renal failure, regardless of planar or SPECT (count- or volume-based SRF) imaging. Conclusion Quantitative measurements of renal cortical integrity assessed with DMSA SPECT can provide more clinically relevant and comprehensive information than planar imaging or SRF alone.

Purpose: Delayed images may not be acquired due to severe pain, drowsiness, or worsening vital signs while waiting after blood pool imaging in three-phase bone scintigraphy. If the hyperemia in the blood pool image contains information from which increased uptake on the delayed images can be inferred, the generative adversarial network (GAN) can generate the increased uptake from the hyperemia. We attempted to apply pix2pix, a type of conditional GAN, to transform hyperemia into increased bone uptake. Methods: We enrolled 1464 patients who underwent three-phase bone scintigraphy for inflammatory arthritis, osteomyelitis, complex regional pain syndrome (CRPS), cellulitis, and recent bone injury. Blood pool images were acquired 10 min after intravenous injection of Tc-99 m hydroxymethylene diphosphonate, and delayed bone images were obtained after 3 h.The model was based on the open-source code of the pix2pix model with perceptual loss. Increased uptake in the delayed images generated by the model was evaluated using lesion-based analysis by a nuclear radiologist in areas consistent with hyperemia in the blood pool images. Results: The model showed sensitivities of 77.8% and 87.5% for inflammatory arthritis and CRPS, respectively. In osteomyelitis and cellulitis, their sensitivities of about 44% were observed. However, in cases of recent bone injury, the sensitivity was only 6.3% in areas consistent with focal hyperemia. Conclusion The model based on pix2pix generated increased uptake in delayed images matching the hyperemia in the blood pool image in inflammatory arthritis and CRPS.