CT Extracellular Volume Fraction versus Myocardium-to-Lumen Signal Ratio for Cardiac Amyloidosis.

Background Large studies on the diagnostic performance of CT-derived myocardial extracellular volume fraction (ECV) for detecting cardiac amyloidosis are lacking. A simple and practical index as a surrogate for CT ECV would be clinically useful. Purpose To compare the diagnostic performances between CT-derived myocardial ECV and myocardium-to-lumen signal ratio for the detection of cardiac amyloidosis in a large patient sample. Materials and Methods This retrospective study included patients who underwent CT ECV analysis because of suspected heart failure or cardiomyopathy between January 2018 and July 2021. CT ECV was quantified using routine pre-transcatheter aortic valve replacement planning cardiac CT, pre-atrial fibrillation ablation planning cardiac CT, or coronary CT angiography with the addition of unenhanced and delayed phase cardiac CT scans. The diagnostic performances of CT ECV and myocardium-to-lumen signal ratio in delayed phase cardiac CT (a simplified index not requiring unenhanced CT and hematocrit) for detecting cardiac amyloidosis were evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Results Of 552 patients (mean age, 69 years ± 14 [SD]; 295 men), 41 had cardiac amyloidosis. The sensitivity of CT ECV for amyloidosis was 90% (37 of 41 patients [95% CI: 77, 97]), with a specificity of 92% (472 of 511 patients [95% CI: 90, 95]) and optimal ECV cutoff value of 37% (AUC, 0.97 [95% CI: 0.96, 0.99]). The sensitivity of myocardium-to-lumen signal ratio was 88% (36 of 41 patients [95% CI: 74, 96]), with a specificity of 92% (469 of 511 patients [95% CI: 89, 94]) and optimal myocardium-to-lumen signal ratio cutoff value of 0.87 (AUC, 0.96 [95% CI: 0.94, 0.97]; P = .27 for comparison with ECV). Conclusion CT-derived myocardial extracellular volume fraction and myocardium-to-lumen signal ratio showed comparable and excellent diagnostic performance in detecting cardiac amyloidosis in a large patient sample. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Williams in this issue.

Prognostic value of 18F-fluorodeoxyglucose uptake in the bone marrow on pretreatment positron emission tomography/computed tomography in patients with esophageal cancer who underwent esophagectomy.

BACKGROUND: Increased 18F-fluorodeoxyglucose (FDG) uptake in the bone marrow (BM) on positron emission tomography/computed tomography (PET/CT) clinically reflects increased BM metabolism owing to systemic inflammation, bacterial infection, anemia, and cytokine-producing tumors. The association between FDG uptake in the BM and prognosis after esophagectomy for esophageal cancer has not been investigated. METHODS: This study included 651 patients who underwent PET/CT before any treatment and McKeown esophagectomy for esophageal cancer between June 2007 and August 2021. The pretreatment degree of FDG uptake in the BM was evaluated using a visual assessment criterion. Patients were divided into low- and high-FDG uptake groups. We retrospectively investigated whether the degree of FDG uptake in the BM was associated with clinicopathological and surgical backgrounds, blood parameters, and prognosis. RESULTS: High FDG uptake in the BM was significantly associated with elevated white blood cell and neutrophil counts, increased C-reactive protein levels, decreased hemoglobin, serum albumin, and total cholesterol levels. High FDG uptake in the BM was an independent predictor of worse overall survival in clinical stages 0-II esophageal cancer (hazard ratio, 2.27; 95% confidence interval, 1.097-4.695; P = 0.027). Worse overall survival was also associated with advanced age, low American Society of Anesthesiologists physical status, an advanced clinical stage, and high intraoperative blood loss. CONCLUSION: Increased FDG uptake in the BM on pretreatment PET/CT may be a surrogate indicator of various clinically disadvantageous backgrounds and may act as a predictor of poor prognosis after esophageal cancer surgery.

Novel Criterion Using Esophageal Major and Minor Axes is Useful to Evaluate the Therapeutic Effect and Prognosis After Neoadjuvant Chemotherapy Followed by Surgery in Locally Advanced Esophageal Cancer.

BACKGROUND: An appropriate strategy is needed to determine the therapeutic effect of chemotherapy on primary lesions in esophageal cancer. This multicenter cohort study aimed to examine the usefulness of a novel criterion obtained by multiplying the lengths of the major and minor esophageal axes from helical computed tomography as a tool to evaluate the therapeutic effect of neoadjuvant chemotherapy and to predict prognosis after surgery in locally advanced esophageal cancer. MATERIALS AND METHODS: A first investigation evaluated the reproducibility of the new criterion between two independent examiners. In a second investigation, we examined the association of the novel criterion with pathological tumor regression grade and long-term outcomes. Pretreatment primary lesions less than 20 mm on computed tomography were excluded. RESULTS: In an initial cohort of 81 patients, the intraclass correlation coefficient for the novel criterion was higher than that for the tumor major axis both before and after neoadjuvant chemotherapy. In the second cohort of 255 patients, the novel criterion significantly correlated with tumor regression grade (p = 0.0003), overall survival (p < 0.0001), and disease-free survival (p < 0.0001). It was also an independent predictor for overall survival (p = 0.0023), along with age, tumor regression grade, and pathological stage. CONCLUSIONS: The measurement derived by multiplying the esophageal major and minor axes on computed tomography is easy to obtain and has better objectivity and reproducibility for tumors of any shape. This novel criterion may be clinically useful because it can estimate therapeutic effect, tumor regression grade, and prognosis after neoadjuvant chemotherapy followed by surgery for esophageal cancer.

Total Lesion Glycolysis Ratio in Positron Emission Tomography/Computed Tomography Images During Neoadjuvant Chemotherapy Can Predict Pathological Tumor Regression Grade and Prognosis in Patients with Locally Advanced Squamous Cell Carcinoma of the Esophagus.

BACKGROUND: The usefulness of quantitating tumor lesion glycolysis (TLG) from 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) findings as a tool for determining the effect of neoadjuvant chemotherapy (NAC) in esophageal squamous cell carcinoma (ESCC) has not yet been established. METHODS: The cohort of this retrospective study comprised 46 patients who had undergone NAC and subsequent esophagectomy for locally advanced ESCC between January 2008 and December 2017. PET/CT was conducted before and after NAC to assess its therapeutic effect. Associations between changes in TLG values during NAC and clinicopathological findings, pathological tumor regression grade (TRG), and prognosis were assessed. RESULTS: Most patients received two courses of DCF (Docetaxel, Cisplatin, and Fluorouracil) as NAC. The mean TLG value of the primary tumor decreased significantly after NAC. The median follow-up period was 41 months. The Kaplan-Meier method, analyzed by log-rank test, showed that low TLG ratio (≤ 0.4) and low SUVmax ratio (≤ 0.6) were associated with favorable survival outcomes (P = 0.0073 and P = 0.032, respectively). Univariate and multivariate analysis revealed that TLG ratio and achievement of pathological cure were independent prognostic factors for overall survival. TLG ratio was also associated with pathological TRG (TRG 0-1a vs 1b-3) (P = 0.0016). CONCLUSIONS: TLG ratio before and after NAC is clinically useful in predicting both histological response and survival outcome after NAC and subsequent esophagectomy in patients with ESCC.

Diagnostic Performance of 123I-FPCIT SPECT Specific Binding Ratio in Progressive Supranuclear Palsy: Use of Core Clinical Features and MRI for Comparison.

OBJECTIVE. Progressive supranuclear palsy (PSP) is listed as a core clinical feature in the Movement Disorder Society 2017 criteria, along with ocular motor dysfunction, postural instability, akinesia, and cognitive dysfunction. Imaging evidence shows predominant mid-brain atrophy and postsynaptic striatal dopaminergic degeneration as two supportive features. The purpose of this study was to investigate the diagnostic performance of 123I-N- ω-fluoropropyl-2ß-carbomethoxy-3ß-(4-iodophenyl) nortropane (123I-FP-CIT) SPECT by comparing it with evaluation of core clinical features and MRI in the diagnosis of PSP. MATERIALS AND METHODS. The study included 53 patients with clinically suspected PSP who had undergone 123I-FP-CIT SPECT and MRI examinations. MR parkinsonism index (MRPI) was used as the MRI index. For the 123I-FP-CIT SPECT index, specific binding ratio (SBR) was calculated as the average of the right and left SBRs. RESULTS. In regard to core clinical features, ocular motor dysfunction was present in 15 of 20 (75.0%) patients with the diagnosis of probable PSP (p < 0.0001). Calculation of the diagnostic performance of the imaging parameters showed that MRPI (cutoff > 11.6) had 85.0% sensitivity, 100% specificity, and 94.3% accuracy. SBR (cutoff < 3.7) had 95.0% sensitivity, 36.4% specificity, and 58.5% accuracy. CONCLUSION. Iodine-123-labeled FP-CIT SPECT has high sensitivity, and MRI has high specificity in the diagnosis of PSP. Because these tools have complementary roles, reach ing a more confident clinical diagnosis of PSP may be possible when both are used.

Predictive value of 18F-FDG PET/CT for acute exacerbation of interstitial lung disease in patients with lung cancer and interstitial lung disease treated with chemotherapy.

BACKGROUND: We examined whether fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) performed before chemotherapy could predict the onset of acute exacerbation of interstitial lung disease (AE-ILD) in patients with lung cancer and ILD treated with chemotherapy. METHODS: Thirty-three patients with lung cancer and ILD who underwent 18F-FDG PET/CT and were treated with chemotherapy at Kumamoto University Hospital between April 2006 and March 2018 were retrospectively analyzed. The maximum standardized uptake value (SUVmax) of interstitial lesions was measured to quantify the background ILD activity. A prediction model of AE-ILD was developed using logistic regression analyses for the SUVmax, and receiver operating characteristic (ROC) curve analyses were conducted. RESULTS: Among the 33 patients, 7 experienced AE-ILD. The SUVmax of contralateral interstitial lesions was significantly higher in patients with vs. without AE-ILD (median SUVmax: 2.220 vs. 1.795, P = 0.025). Univariable logistic regression analyses showed that the SUVmax of contralateral interstitial lesions trended towards being significantly associated with the onset of AE-ILD [odds ratio: 8.683, 95% confidence interval (CI) 0.88-85.83, P = 0.064]. The area under the ROC curve of the SUVmax for predicting AE-ILD was 0.780 (95% CI 0.579-0.982, P = 0.025). The optimal cut-off value for SUVmax was 2.005, with sensitivity and specificity values of 0.857 and 0.769, respectively. CONCLUSIONS: The SUVmax of contralateral interstitial lesions in 18F-FDG PET/CT images might be useful for predicting the onset of AE-ILD in patients with lung cancer and ILD treated with chemotherapy.

Combination of Commonly Examined Parameters Is a Useful Predictor of Positive 99 mTc-Labeled Pyrophosphate Scintigraphy Findings in Elderly Patients With Suspected Transthyretin Cardiac Amyloidosis.

BACKGROUND: A recent study revealed a high prevalence of transthyretin (TTR) cardiac amyloidosis (CA) in elderly patients. 99 mTc-labeled pyrophosphate (99 mTc-PYP) scintigraphy is a remarkably sensitive and specific modality for TTR-CA, but is only available in specialist centres; thus, it is important to raise the pretest probability. The aim of this study was to evaluate the characteristics of patients with 99 mTc-PYP positivity and make recommendations about patient selection for 99 mTc-PYP scintigraphy.Methods and Results:We examined 181 consecutive patients aged ≥70 years who underwent 99 mTc-PYP scintigraphy at Kumamoto University Hospital between January 2012 and December 2018. Logistic regression analyses showed that high-sensitivity cardiac troponin T (hs-cTnT) ≥0.0308 ng/mL, left ventricular posterior wall thickness ≥13.6 mm, and wide QRS (QRS ≥120 ms) were strongly associated with 99 mTc-PYP positivity. We developed a new index for predicting 99 mTc-PYP positivity by adding 1 point for each of the 3 factors. The 99 mTc-PYP positive rate increased by a factor of 4.57 for each 1-point increase (P<0.001). Zero points corresponded to a negative predictive value of 87% and 3 points corresponded to a positive predictive value of 96% for 99 mTc-PYP positivity. CONCLUSIONS: The combination of biochemical (hs-cTnT), physiological (wide QRS), and structural (left ventricular posterior wall thickness) findings can raise the pretest probability for 99 mTc-PYP scintigraphy. It can assist clinicians in determining management strategies for elderly patients with suspected CA.

Is 123I-MIBG Scintigraphy Beneficial or Excessive for the Diagnosis of Parkinson's Disease in the Early Phase?

INTRODUCTION/OBJECTIVE: In most cases, abnormal cardiac 123I-meta-iodobenzylguanidine (MIBG) scintigraphy increases the probability of a diagnosis of Parkinson's disease (PD) in patients with parkinsonian features. In our study, we validated the additional value of 123I-MIBG scintigraphy beyond providing information on neurological findings and response to dopaminergic therapy for the diagnosis of PDin the early phase. METHODS: We investigated 77 cases of PD (Hoehn and Yahr Stages I-III) and 73 cases of atypical parkinsonian disorder (APD), including 35 patients with multiple system atrophy, 19 with corticobasal syndrome, and 19 with progressive supranuclear palsy. Two multiple logistic regression models were developed to predict the probability of PD based on APD. Common covariates were resting tremor, vertical supranuclear palsy, apraxia, cerebellar symptoms, and response to dopaminergic therapy with MIBG scintigraphy (reference model) or without it (MIBG-added model). The net reclassification index (NRI) was examined and net benefit using decision curve analysis was performed to examine the additional clinical value of MIBG scintigraphy. Finally, we estimated the cost-effectiveness of MIBG scintigraphy. RESULTS: The MIBG-added model significantly improved the ability to classify PD or APD compared with the reference model (NRI index 1.390, p < 0.001). However, the decision curve of the reference model ranked equally with the MIBG-added model up to a risk threshold of 0.8. In addition, MIBG scintigraphy was not cost-effective. CONCLUSIONS: Although MIBG scintigraphy has statistical usefulness for PD diagnosis, there may be little additional benefit in the early phase of PD beyond the neurological findings and response to dopaminergic therapy regarding clinical effectiveness and cost-effectiveness. It may be of greatest value when neurological findings that do not match PD are observed during the clinical course.

Correlation of left ventricular dyssynchrony on gated myocardial perfusion SPECT analysis with extent of late gadolinium enhancement on cardiac magnetic resonance imaging in hypertrophic cardiomyopathy.

Myocardial perfusion-single-photon emission computed tomography (MP-SPECT) is used to evaluate microvascular dysfunction and coexisting coronary artery disease in patients with hypertrophic cardiomyopathy (HCM). Phase analysis in gated MP-SPECT can provide additional information on left ventricular (LV) dyssynchrony, while the extent of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging is an important prognostic factor in patients with HCM. We, therefore, sought to investigate the relationship of dyssynchrony by phase analysis on gated MP-SPECT and LGE on CMR imaging in 22 patients with HCM who underwent both stress/rest-gated MP-SPECT and contrast-enhanced CMR imaging. LV dyssynchrony parameters [phase standard deviation (SD) and histogram bandwidth] from gated MP-SPECT were compared with LGE parameters from CMR imaging [L/C contrast and %LGE calculated, respectively, as LGE intensity/LV cavity intensity and (LGE volume/myocardial volume) × 100]. Phase SD and histogram bandwidth showed strong correlation with %LGE (r = 0.73, p < 0.0001 and r = 0.73, p < 0.0001, respectively), although they did not significantly correlate with L/C contrast (r = 0.30, p = 0.17 and r = 0.26, p < 0.25, respectively). The LV dyssynchrony derived from gated MP-SPECT strongly correlated with the extent of LGE on CMR imaging. In conclusion, our investigation suggests that gated MP-SPECT may be useful not only for the assessment of myocardial ischemia but also the extent of myocardial replacement fibrosis.

Preoperative High Maximum Standardized Uptake Value in Association with Glucose Transporter 1 Predicts Poor Prognosis in Pancreatic Cancer.

BACKGROUND: The diagnosis of malignant diseases worldwide has been determined using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Glucose transporter type 1 (Glut-1) is a key protein associated with the accumulation of FDG in cancer cells. This study evaluated the relationship between Glut-1 expression and FDG accumulation to determine the usefulness of FDG-PET for prediction of long-term outcomes of pancreatic cancer. METHODS: The expression of Glut-1 was immunohistochemically examined in 138 surgically resected pancreatic cancer specimens. The Glut-1-positive and Glut-1-negative groups were analyzed with respect to their clinicopathologic characteristics and prognosis. Before surgery, 93 patients underwent FDG-PET and measurement of the corrected maximum standardized uptake value (cSUVmax). The relationship between Glut-1 expression and cSUVmax were examined, and prognostic factors were identified using uni- and multivariate analyses. RESULTS: Glut-1 was positive in 69 patients (50%). The median relapse-free and overall survival times were significantly shorter in the Glut-1-positive group (11 vs. 22 months, respectively) than in the Glut-1-negative group (23 vs. 42 months, respectively). The cSUVmax was significantly associated with long-term survival. The relapse-free and overall survival rates were significantly poorer in the high-cSUVmax group than in the low-cSUVmax group. Glut-1 expression was associated with cSUVmax accumulation. In the multivariate Cox regression analysis using forward stepwise selection, male gender, positive lymph node metastases, high CA19-9, and high cSUVmax were identified as independent prognostic factors for pancreatic cancer. CONCLUSION: A significant relationship exists between high preoperative cSUVmax and Glut-1 expression. High cSUVmax is one of the prognostic factors for overall survival after resection of pancreatic cancer.

Cardiovascular magnetic resonance myocardial T1 mapping to detect and quantify cardiac involvement in familial amyloid polyneuropathy.

OBJECTIVES: This study sought to explore the potential role of non-contrast T1 mapping for the detection and quantification of cardiac involvement in familial amyloid polyneuropathy (FAP). METHODS: Japanese patients with FAP [n = 41, age 53.2 ± 13.9 years, genotype Val30Met (n = 25), non-Val30Met (n = 16)] underwent cardiac magnetic resonance imaging that included T1 mapping (saturation-recovery method) and late gadolinium-enhanced (LGE) imaging on a 3.0-T MR scanner. Their native T1 was measured on mid-ventricular short-axis images and compared with 30 controls. RESULTS: Of the 41 FAP patients 29 were LGE positive. The native T1 was significantly higher in FAP patients than in the controls (1,634.1 ± 126.3 ms vs. 1,432.4 ± 69.0 ms, p < 0.01), significantly higher in LGE-positive- than LGE-negative FAP patients (1,687.1 ± 104.4 ms vs. 1,505.4 ± 68.5 ms, p < 0.01), and significantly higher in LGE-negative FAP patients than the controls (p < 0.01). A native T1 cutoff value of 1,610 ms yielded 85.4% accuracy for identifying LGE-positive FAP. The native T1 significantly correlated with the interventricular septum wall thickness, the left ventricular mass, the LGE volume, the plasma B-type natriuretic peptide level, and the E/e' ratio (all p < 0.01). CONCLUSION: T1 mapping is of high diagnostic accuracy for the detection of LGE-positive FAP. The native myocardial T1 may be correlated with the severity of cardiac amyloid deposition. KEY POINTS: • The native T1 was higher in FAP patients than the controls. • The native T1 was higher in LGE-positive- than LGE-negative FAP patients. • The native T1 was higher in LGE-negative FAP patients than the controls. • The native T1 correlated with clinical markers of systolic and diastolic dysfunction. • Myocardial T1 mapping is of high diagnostic accuracy for detecting LGE-positive FAP.

Prolonged Mean Transit Time Detected by Dynamic Susceptibility Contrast Magnetic Resonance Imaging Predicts Cerebrovascular Reserve Impairment in Patients with Moyamoya Disease.

BACKGROUND: Evaluating cerebrovascular reserve (CVR) is important for patients with moyamoya disease (MMD). 123I-iodoamphetamine single-photon emission CT (SPECT) with acetazolamide (ACZ) challenge is widely carried out, but using ACZ becomes problematic owing to its off-label use and its adverse effects. Here, we report the efficacy of dynamic susceptibility contrast MRI (DSC-MRI) for the evaluation of CVR in MMD patients. METHODS: All 33 MMD patients underwent both SPECT and DSC-MRI at an interval of <10 days from each other (mean age 38.3 years). The region of interest (ROI) was the anterior cerebral artery (ACA) territory, middle cerebral artery (MCA) territory, basal ganglia and cerebellum hemisphere for cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) images. The ratios of the ROIs to the ipsilateral cerebellum were calculated for each parameter and evaluated. The CVR was calculated using images acquired by SPECT before and after ACZ administration. The ratios of DSC-MRI parameters and CVR were compared and evaluated for each ROI. RESULTS: The MTT of the ACA and MCA territories significantly correlated with CVR (p < 0.0001). However, CBF and CBV had no correlation with CVR. The MTT ratio had a threshold of 1.966, with a sensitivity of 68.4% and a specificity of 91.5% for predicting decreased CVR (<10%). CONCLUSION: MTT had a negative correlation with CVR. DSC-MRI is easy, safe and useful for detecting decreased CVR and can be used as a standard examination in MMD patient's care.

Prediction of sentinel lymph node status using single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging of breast cancer.

PURPOSE: Single-photon emission computed tomography (SPECT)/computed tomography (CT) improves the anatomical identification of sentinel lymph nodes (SNs). We aimed to evaluate the possibility of predicting the SN status using SPECT/CT. METHODS: SN mapping using a SPECT/CT system was performed in 381 cases of clinically node-negative, operable invasive breast cancer. We evaluated and compared the values of SN mapping on SPECT/CT, the findings of other modalities and clinicopathological factors in predicting the SN status. RESULTS: Patients with SNs located in the Level I area were evaluated. Of the 355 lesions (94.8 %) assessed, six cases (1.6 %) were not detected using any imaging method. According to the final histological diagnosis, 298 lesions (78.2 %) were node negative and 83 lesions (21.7 %) were node positive. The univariate analysis showed that SN status was significantly correlated with the number of SNs detected on SPECT/CT in the Level I area (P = 0.0048), total number of SNs detected on SPECT/CT (P = 0.011), findings of planar lymphoscintigraphy (P = 0.011) and findings of a handheld gamma probe during surgery (P = 0.012). According to the multivariate analysis, the detection of multiple SNs on SPECT/CT imaging helped to predict SN metastasis. CONCLUSIONS: The number of SNs located in the Level I area detected using the SPECT/CT system may be a predictive factor for SN metastasis.

Prediction of left main or 3-vessel disease using myocardial perfusion reserve on dynamic thallium-201 single-photon emission computed tomography with a semiconductor gamma camera.

BACKGROUND: Myocardial perfusion imaging (MPI) may fail to detect balanced ischemia. We evaluated myocardial perfusion reserve (MPR) using Tl dynamic single-photon emission computed tomography (SPECT) and a novel cadmium zinc telluride (CZT) camera for predicting 3-vessel or left main coronary artery disease (CAD). METHODS AND RESULTS: A total of 55 consecutive patients with suspected CAD underwent SPECT-MPI and coronary angiography. The MPR index was calculated using the standard 2-compartment kinetic model. We analyzed the utility of MPR index, other SPECT findings, and various clinical variables. On multivariate analysis, MPR index and history of previous myocardial infarction (MI) predicted left main and 3-vessel disease. The area under the receiver operating characteristic curve was 0.81 for MPR index, 0.699 for history of previous MI, and 0.86 for MPR index plus history of previous MI. MPR index ≤1.5 yielded the highest diagnostic accuracy. Sensitivity, specificity, and accuracy were 86%, 78%, and 80%, respectively, for MPR index, 64%, 76%, 73% for previous MI, and 57%, 93%, and 84% for MPR index plus history of previous MI. CONCLUSIONS: Quantification of MPR using dynamic SPECT and a novel CZT camera may identify balanced ischemia in patients with left main or 3-vessel disease.

Quantitative index calculated by (99m)Tc-GSA scintigraphy.

(99m)Tc-galactosyl human serum albumin (GSA) scintigraphy is useful to evaluate hepatic function and hepatic functional reserve. A reliable SPECT and CT integrated system is now commercially available. Using this system, we can obtain (99m)Tc-GSA SPECT/CT fused imaging with a small registration error. Therefore, the (99m)Tc-GSA scintigraphy techniques prove more useful in clinical practice than have been previously reported. In the latest Annals of Surgical Oncology on Oct 2014, the uptake index (UI) values calculated from (99m)Tc-GSA scintigraphy are reported to be useful for predicting the functional reserve of the future remnant liver. In this paper, we describe the usefulness of (99m)Tc-GSA scintigraphy as well as some cautions that are necessary as regards using the system.

Development of an automated region-of-interest-setting method based on a deep neural network for brain perfusion single photon emission computed tomography quantification methods.

Objectives: A simple noninvasive microsphere (SIMS) method using 123I-IMP and an improved brain uptake ratio (IBUR) method using 99mTc-ECD for the quantitative measurement of regional cerebral blood flow have been recently reported. The input functions of these methods were determined using the administered dose, which was obtained by analyzing the time activity curve of the pulmonary artery (PA) for SIMS and the ascending aorta (AAo) for the IBUR methods for dynamic chest images. If the PA and AAo regions of interest (ROIs) can be determined using deep convolutional neural networks (DCNN) for segmentation, the accuracy of these ROI-setting methods can be improved through simple analytical operations to ensure repeatability and reproducibility. The purpose of this study was to develop new PA and AAo-ROI setting methods using a DCNN (DCNN-ROI method). Methods: A U-Net architecture based on convolutional neural networks was used to determine the PA and AAo candidate regions. Images of 290 patients who underwent 123I-IMP RI-angiography and 108 patients who underwent 99mTc-ECD RI-angiography were used. The PA and AAo-ROI results for the DCNN-ROI method were compared to those obtained using manual methods. The counts for the input function on the PA and AAo-ROI were determined by integrating the area under the curve (AUC) counts of the time-activity curve of PA and AAo-ROI, respectively. The effectiveness of the DCNN-ROI method was elucidated through a comparison with the integrated AUC counts of the DCNN-ROI and the manual ROI. Results: The coincidence ratio for the locations of the PA and AAo-ROI obtained using the DCNN method and that for the manual method was 100%. Strong correlations were observed between the AUC counts using the DCNN and manual methods. Conclusion: New ROI- setting programs were developed using a deep convolution neural network DCNN to determine the input functions for the SIMS and IBUR methods. The accuracy of these methods is comparable to that of the manual method.

Feasibility of direct brain 18F-fluorodeoxyglucose-positron emission tomography attenuation and high-resolution correction methods using deep learning.

Objectives: To develop the following three attenuation correction (AC) methods for brain 18F-fluorodeoxyglucose-positron emission tomography (PET), using deep learning, and to ascertain their precision levels: (i) indirect method; (ii) direct method; and (iii) direct and high-resolution correction (direct+HRC) method. Methods: We included 53 patients who underwent cranial magnetic resonance imaging (MRI) and computed tomography (CT) and 27 patients who underwent cranial MRI, CT, and PET. After fusion of the magnetic resonance, CT, and PET images, resampling was performed to standardize the field of view and matrix size and prepare the data set. In the indirect method, synthetic CT (SCT) images were generated, whereas in the direct and direct+HRC methods, a U-net structure was used to generate AC images. In the indirect method, attenuation correction was performed using SCT images generated from MRI findings using U-net instead of CT images. In the direct and direct+HRC methods, AC images were generated directly from non-AC images using U-net, followed by image evaluation. The precision levels of AC images generated using the indirect and direct methods were compared based on the normalized mean squared error (NMSE) and structural similarity (SSIM). Results: Visual inspection revealed no difference between the AC images prepared using CT-based attenuation correction and those prepared using the three methods. The NMSE increased in the order indirect, direct, and direct+HRC methods, with values of 0.281×10-3, 4.62×10-3, and 12.7×10-3, respectively. Moreover, the SSIM of the direct+HRC method was 0.975. Conclusion: The direct+HRC method enables accurate attenuation without CT exposure and high-resolution correction without dedicated correction programs.

18F-FDG accumulation at the early onset of acute exacerbation of idiopathic interstitial pneumonia on 18F-FDG PET/CT: A case report.

Acute exacerbation of idiopathic interstitial pneumonias (AE-IIPs) is a disease associated with a poor prognosis in patients with IIPs. However, the specific characteristics of fluorine-18 2-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging for AE-IIPs remain unclear. Herein, we present the case of a patient with lung cancer combined with IIPs who underwent 18F-FDG PET/CT at the early onset of AE-IIPs. The scan, conducted 18 days post-bronchoscopy for lung cancer evaluation, revealed AE-IIPs before the onset of respiratory failure. New ground-glass opacities appeared, accompanied by significant 18F-FDG accumulation extending beyond these regions. To the best of our knowledge, this report represents the first assessment of 18F-FDG PET/CT images at the early onset of AE-IIPs before respiratory failure in humans. The observed features in this PET image could potentially contribute to our understanding of the pathophysiology of AE-IIPs.

Inverse correlation between age of onset and myocardial amyloid deposition quantified by 99mTc-PYP scintigraphy in patients with wild-type transthyretin amyloid cardiomyopathy.

OBJECTIVE: Wild-type transthyretin amyloidosis cardiomyopathy (ATTRwt-CM) is increasingly recognized as a contributing factor to cardiac insufficiency in the elderly population. We aimed to identify the factors affecting age of onset of ATTRwt-CM, encompassing the assessment of amyloid deposition in myocardial tissue through the use of 99mTc-pyrophosphate (PYP) and clinical parameters. METHODS: A retrospective investigation involving a consecutive cohort of 107 cases, each having been diagnosed with ATTRwt-CM confirmed through histopathological and genetic analysis, was performed. All patients underwent PYP scintigraphy, and the heart-to-contralateral (H/CL) ratio was calculated to measure amyloid deposition in the myocardium. Univariate and multivariate analyses were performed to identify independent predictors of the age of onset of ATTRwt-CM, considering the H/CL ratio and various clinical risk factors for heart failure. RESULTS: Gender (p = 0.03), Creatinine (Cr) (r = 0.32, p < 0.01), hemoglobin (Hb) (r = - 0.44, p < 0.01), albumin (Alb) (r = - 0.32, p < 0.01), brain natriuretic peptide (BNP) (r = 0.21, p = 0.03), low-density lipoprotein-cholesterol (LDL-C) (r = - 0.27, p < 0.01), and H/CL ratio (r = - 0.44, p < 0.01) were all significantly associated with the onset age. In multiple regression analysis, the independent predictive factors for the onset age of ATTRwt-CM were identified as the H/CL ratio (p < 0.01), Hb (p < 0.01), and Cr (p < 0.01). CONCLUSION: The H/CL ratio, Hb, and Cr independently affect age of onset in patients with ATTRwt-CM. The H/CL ratio is inversely correlated with age of onset, and may be the sole factor in the development of heart failure in early onset patients, while it may have a synergistic effect on heart failure with anemia and renal dysfunction in late-onset patients.

Relationship between the severity of emphysematous change in the lung and morbidity after esophagectomy for esophageal cancer: A retrospective study on a novel strategy for risk prediction.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) prevalence increases post-esophagectomy morbidity. However, the association between COPD severity and post-esophagectomy morbidity remains unclear because of the lack of an objective method to classify COPD severity. Low attenuation volume ratio (LAVR) estimated using Ziostation2 may reflect the extent of emphysematous changes in the lungs and COPD severity, thereby predicting post-esophagectomy morbidity. METHODS: A total of 776 patients who underwent curative McKeown esophagectomy for esophageal cancer between April 2005 and June 2021 were included. The patients were divided into high and low preoperative LAVR groups. Short-term outcomes between the groups were compared for patients who underwent open esophagectomy (OE) and minimally invasive esophagectomy (MIE). RESULTS: A total of 219 (28%) patients were classified into the high LAVR group. High LAVR was significantly associated with disadvantageous patient characteristics such as advanced age, heavy smoking, and impaired respiratory function. Patients with high LAVR had a significantly higher incidence of severe morbidity and pneumonia after OE. High LAVR was an independent risk factor for severe morbidity (odds ratio [OR], 2.52; 95% confidence interval [CI]: 1.237-5.143; p = 0.011) and pneumonia (OR, 2.12; 95% CI: 1.003-4.493; p = 0.049) after OE. Meanwhile, LAVR was not correlated with the incidence of post-MIE morbidity. CONCLUSIONS: LAVR may reflect COPD severity and predict severe morbidity and pneumonia after OE, but not after MIE. Less invasiveness of MIE may alleviate the effects of various disadvantageous backgrounds associated with high LAVR on worse short-term outcomes.