Role of Central Hypo-enhancement in the Hepatic Arterial Phase of Dynamic Computed Tomography in Patients with Mass-Forming Intrahepatic Cholangiocarcinoma.

BACKGROUND/PURPOSE: The enhancement pattern in the hepatic arterial phase (HAP) of dynamic computed tomography (CT) is reportedly a prognostic marker in patients with intrahepatic cholangiocarcinoma (IHCC). This study was performed to clarify the significance of central hypo-enhancement in the HAP in patients with mass-forming IHCC. METHODS: Forty patients who had undergone initial surgical resection for mass-forming IHCC were enrolled. The dynamic CT was scanned 40 s after contrast agent injection as the HAP. A radiologist classified the patients into three groups based on the vascular pattern: the hyper-enhancement group (Hyper group), rim-enhancement group (Rim group), and hypo-enhancement group (Hypo group). The surgical specimens were immunohistochemically stained for hypoxia-inducible factor 1 (HIF-1). The correlation with clinicopathological findings and HIF-1 expression was investigated. RESULTS: The Hyper, Rim, and Hypo groups comprised 8, 7, and 25 patients, respectively. There were no significant correlations between the groups and clinicopathological factors. Overall survival (OS) was significantly worse in the Hypo than in the Hyper group (p = 0.03). OS was also significantly worse in the Rim + Hypo group (i.e., hypo-enhancement in the central tumor) than in the Hyper group (p = 0.04). Furthermore, inclusion in the Rim + Hypo group was a prognostic factor for OS (hazard ratio 6.68). High HIF-1 expression in the central part of the tumor was correlated with central hypo-enhancement (Hyper group: 25% and Rim + Hypo group: 72%). CONCLUSIONS: Central hypo-enhancement was a prognostic factor in patients with IHCC. The high malignant potential of tumors with central hypo-enhancement might be associated with HIF-1 upregulation.

Preliminary clinical assessment of dynamic 18F-fluorodeoxyglucose positron emission tomography/computed tomography for evaluating lymph node metastasis in patients with lung cancer: a prospective study.

OBJECTIVE: We assessed the diagnostic capacity of dynamic fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and dual-time-point (DTP) PET/CT to explore the optimal scan timing for nodal staging in lung cancer. METHODS: Thirty-four patients with lung cancer underwent dynamic and consecutive DTP PET/CT scans. Two readers visually evaluated FDG uptake within each lymph node (LN) and pulmonary artery (metastatic LN: n = 10; nonmetastatic LN: n = 121). For each dynamic and DTP scan, we compared the maximum standardized uptake value (SUVmax) and the retention index of the SUVmax (RI-SUVmax) between metastatic and nonmetastatic LNs. We compared the diagnostic capacity of the dynamic and DTP scans using receiver operating characteristic (ROC) analyses. RESULTS: In the visual analyses of LN metastases, a sensitivity of 20.0-60.0% and specificity of 97.5-100.0% were identified for the first to third dynamic scans. The sensitivity of the 1-h early and 2-h delayed scans was 80.0% and 90.0%, respectively, whereas the specificity was 66.9% and 47.9%, respectively. The visual analysis of the dynamic second phase had the highest accuracy. Semiquantitative analyses revealed that the SUVmax was significantly higher for metastatic LNs than for nonmetastatic LNs in the dynamic second and third phases and the 1-h early and 2-h delayed phases (p < 0.05 for all). The RI-SUVmax was higher in metastatic LNs than in nonmetastatic LNs for the dynamic scan (p = 0.004) and the DTP scan (p = 0.002). The ROC analyses showed that SUV2 and SUV3 had higher performances with high specificity, high negative predictive value, and high accuracy than the other parameters. The area under the ROC curve of the RI-SUV-dual-time-point had the highest value (0.794) without any significant differences between the area under the ROC curves for all parameters (p > 0.05 for all). CONCLUSIONS: Based on the visual and semiquantitative analyses, 18F-FDG dynamic PET/CT exhibited excellent performance with extremely high specificity in the dynamic second phase.

Utility of the Virtual Liver Parenchymal Perfusion Area Using a Commercially Available Workstation in Transarterial Chemoembolization for Hepatocellular Carcinoma.

PURPOSE: To evaluate the accuracy of the virtual liver parenchymal perfusion area using a commercially available workstation and liver analysis software in conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This method was retrospectively applied to 29 treated HCCs in 23 patients. The virtual embolic area (VEA) was estimated based on cone beam computed tomography during hepatic arteriography using a commercially available workstation and liver analysis software by two observer groups (group A: experts; group B: semi-experts). The real embolic area (REA) was defined as the area where iodized oil accumulated on computed tomography at 1 week after cTACE. The REA was estimated by each of the two groups, and the mean REA between the groups (mREA) was used as a standard reference. Agreement of volume and cross-sectional area in three orthogonal planes between the VEA and mREA were analyzed using intraclass correlation coefficients (ICCs) and Bland-Altman plots. RESULTS: The ICCs for volume between VEA and mREA were 0.97 and 0.88 for groups A and B, respectively, and those for cross-sectional area were 0.94 and 0.88 for the axial plane, 0.95 and 0.83 for the coronal plane, and 0.87 and 0.74 for the sagittal plane, respectively. Thus, the overall agreement was excellent, except for the sagittal imaging plane in group B. CONCLUSION: This method using a commercially available workstation and liver analysis software can be useful for estimating the embolic area in cTACE.

The diagnostic ability of SPECT/CT fusion imaging for gastrointestinal bleeding: a retrospective study.

BACKGROUND: Blood loss from the gastrointestinal tract can be an acute and life-threatening event. For the treatment of gastrointestinal bleeding, it is important to accurately detect gastrointestinal bleeding and to localize the sites of bleeding. The purpose of this study was to retrospectively assess the capabilities of SPECT/CT in the diagnosis of gastrointestinal bleeding by a comparison with planar imaging alone as well as planar and SPECT. METHODS: We conducted a retrospective analysis of 20 patients (21 examinations) who underwent gastrointestinal bleeding scintigraphy in the past 7 years and in whom the bleeding site was identified by endoscopy or capsule endoscopy, or in whom no evidence of gastrointestinal bleeding was identified during the clinical course. Five patients (5 examinations) were diagnosed by planar imaging (planar group). Eight patients (9 examinations) were diagnosed by planar imaging and SPECT (planar + SPECT group). Seven patients (7 examinations) were diagnosed by planar imaging and SPECT/CT (planar + SPECT/CT group). We calculated the diagnostic ability of each method in detecting the presence of bleeding, as well as the ability of each method to identify the sites of bleeding. The sensitivity, specificity, and accuracy of the methods were compared. RESULTS: The diagnostic ability of the three imaging methods in detecting the presence of gastrointestinal bleeding was as follows. Planar imaging showed 100% sensitivity (3/3), 100% specificity (2/2), and 100% accuracy (5/5). Planar + SPECT imaging showed 85.7% sensitivity (6/7), 100% specificity (2/2), and 88.9% accuracy (8/9). Planar + SPECT/CT imaging showed 100% sensitivity (6/6), 100% specificity (1/1), and 100% accuracy (7/7). The diagnostic ability of the three modalities in detecting the site of bleeding was as follows: planar, 33.3% (1/3); planar + SPECT, 71.4% (5/7); and planar + SPECT/CT, 100% (6/6). CONCLUSIONS: All 3 imaging methods showed good accuracy in detecting the presence of gastrointestinal bleeding. The addition of SPECT or SPECT/CT made the anatomical position of the uptake clear and contributed to the localization of the site of gastrointestinal bleeding. Planar + SPECT/CT imaging therefore showed the highest diagnostic ability for detecting the site of gastrointestinal bleeding.

Diagnostic Performance of Arterial Spin Labeling for Grading Nonenhancing Astrocytic Tumors.

PURPOSE: We evaluated the utility of arterial spin labeling (ASL) imaging of tumor blood flow (TBF) for grading non-enhancing astrocytic tumors. MATERIALS AND METHODS: Thirteen non-enhancing astrocytomas were divided into high-grade (n = 7) and low-grade (n = 6) groups. Both ASL and conventional sequences were acquired using the same magnetic resonance machine. Intratumoral absolute maximum TBF (TBFmax), absolute mean TBF (TBFmean), and corresponding values normalized to cerebral blood flow (TBFmax and TBFmean ratios) were measured. The Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis were used to assess the accuracy of TBF variables for tumor grading. RESULTS: Compared with low-grade astrocytoma, high-grade astrocytoma exhibited significantly greater absolute TBFmax (90.93 ± 24.96 vs 46.94 ± 20.97 ml/100 g/min, P < 0.001), TBFmean (58.75 ± 19.89 vs 31.16 ± 17.63 ml/100 g/min, P < 0.001), TBFmax ratio (3.34 ± 1.22 vs 1.35 ± 0.5, P < 0.001), and TBFmean ratio (2.15 ± 0.94 vs 0.88 ± 0.41, P < 0.001). The TBFmax ratio yielded the highest diagnostic accuracy (sensitivity 100%, specificity 86.3%), while absolute TBFmean yielded the lowest accuracy (sensitivity 85.7%, specificity 70.1%) by ROC analysis. CONCLUSION: Parameters from ASL perfusion imaging, particularly TBFmax ratio, may be useful for distinguishing high-grade from low-grade astrocytoma in cases with equivocal conventional MRI findings.

The utility of the combination of a SPECT study with [123I]-FP-CIT of dopamine transporters and [123I]-MIBG myocardial scintigraphy in differentiating Parkinson disease from other degenerative parkinsonian syndromes.

OBJECTIVE: Molecular imaging of nigrostriatal dopamine transporters (DAT) and sympathetic cardiac innervation with single-photon emission computed tomography (SPECT) are useful tools for differentiating idiopathic Parkinson disease (PD) from other degenerative parkinsonian syndromes (non-PD). Nevertheless, these modalities are often insufficient for achieving a definite diagnosis. The aims of this study were to evaluate the diagnostic accuracy of the combination of these tools. MATERIALS AND METHODS: The SPECT radiotracers [I]-N-ω-fluoropropyl-2ß-carbomethoxy-3ß-(4-iodophenyl)-nortropane (FP-CIT) and meta-[I]-iodobenzylguanidine (MIBG) were used to research presynaptic dopaminergic projections (DAT SPECT) and myocardial adrenergic innervation (MIBG scintigraphy), respectively. PD patients (n=15; age: 61.5±13.6 years) and non-PD patients (n=19; age: 62.6±14.2 years) who underwent both tests were enrolled in this study. Receiver-operating characteristic analyses were used to set the cutoff values of the specific binding ratio in DAT SPECT and the heart to mediastinum ratio in delayed scan in MIBG scintigraphy for differentiating PD from non-PD. We calculated the sensitivity, specificity, and test accuracy of the individual methods and also the combination of these two modalities. RESULTS: When DAT SPECT and MIBG scintigraphy were used individually, they showed mild accuracy in differentiating PD from non-PD (DAT, 67.6%; MIBG, 67.6%). The combination of the two approaches using cutoff values of less than 3.24 for the specific binding ratio and less than 2.745 for the delayed heart to mediastinum ratio enabled more accurate differentiation between PD and non-PD. The accuracy of these indices in distinguishing PD from non-PD was 79.4%. CONCLUSION: These results suggested that the combination of DAT SPECT and MIBG scintigraphy may improve the diagnostic accuracy in differentiating PD from non-PD.

The physiological accumulation of FDG in the muscles in relation to the side of intravenous administration.

PURPOSE: The purpose of the study was to evaluate the physiological accumulation of 18F-FDG in the muscles in relation to the side of intravenous administration. MATERIALS AND METHODS: We retrospectively investigated 3,118 18F-FDG-PET/CT examinations. We evaluated the physiological accumulation of FDG in the muscles of the shoulder and arm relative to its dependence on the side of intravenous administration. RESULTS: Six hundred six of the 3,118 examinations (19.4%) showed physiological accumulation of FDG in the teres minor muscle. Accumulation was seen on the side of administration in 486 examinations (80.2%), contralateral to the side of administration in 56 examinations (9.2%), and bilaterally in 64 examinations (10.6%). Five hundred seventy-seven of the 3,118 examinations (18.5%) showed accumulation of FDG in the muscles between the radioulna near the elbow. Accumulation was observed on the side of administration in 432 examinations (74.9%), contralateral to the side of the administration in 71 examinations (12.3%), and bilaterally in 74 examinations (12.8%). CONCLUSION: The present study finds that not only accumulation in the teres minor muscles but also accumulation in the muscles between the radioulna near the elbow occurs significantly more frequently on the side of intravenous administration compared to the contralateral side.

Comparison of Brain Tumor Contrast-enhancement on T1-CUBE and 3D-SPGR Images.

PURPOSE: T1-Cube (GE HealthCare) is a relatively new 3-dimensional (3D) fast spin-echo (FSE)-based magnetic resonance (MR) imaging sequence that uses a variable flip angle to acquire gap-free volume scans. We compared the gadolinium enhancement characteristics of a heterogeneous population of brain tumors imaged by T1-Cube and then 3D fast spoiled gradient recall acquisition in steady state (3D FSPGR) 3-tesla MR imaging to identify the superior modality for specific diagnostic purposes. METHODS: We examined 61 lesions from 32 patients using the 2 sequences after administration of gadopentetic acid (Gd-DTPA; 0.1 mmol/kg). Two neuroradiologists independently measured each lesion twice using a region-of-interest (ROI) method. We measured the contrast-to-noise ratio (CNR), the difference in signal intensity (SI) between the tumor and normal white matter relative to the standard deviation (SD) of the SI within the lesion, for both post-contrast 3D FSPGR and post-contrast T1-Cube images of the same tumor and compared modality-specific CNRs for all tumors and in subgroups defined by tumor size, enhancement ratio, and histopathology. RESULTS: The mean CNR was significantly higher on T1-Cube images than 3D FSPGR images for the total tumor population (1.85 ± 0.97 versus 1.12 ± 1.05, P < 0.01) and the histologic types, i.e., metastasis (P < 0.01) and lymphoma (P < 0.05). The difference in CNR was even larger for smaller tumors in the metastatic group (4.95 to 23.5 mm(2)) (P < 0.01). In contrast, mean CNRs did not differ between modalities for high grade glioma and meningioma. CONCLUSIONS: Gadolinium enhancement of brain tumors was generally higher when imaged by T1-Cube than 3D FSPGR, and T1-Cube with Gd enhancement may be superior to 3D FSPGR for detecting smaller metastatic tumors.

Primary progressive apraxia of speech (AOS) in a patient with Pick's disease with Pick bodies: a neuropsychological and anatomical study and review of literatures.

A 56-year-old right-handed man suffered from progressive apraxia of speech (AOS), characterized by agrammatism and buccofacial apraxia. He also became mute at the later stages of the disease progression. At autopsy, the left precentral gyrus, pars opercularis, and hippocampus showed severe atrophy. Pick bodies and Pick cells were observed. In this report, we also review previous case reports of AOS. Pick's disease is among the most commonly associated of the major diseases. Brain lesions associated with AOS may be found in regions such as the precentral gyrus and the pars opercularis in the left hemisphere.

Selective nuclear shrinkage of oligodendrocytes lacking glial cytoplasmic inclusions in multiple system atrophy: a 3-dimensional volumetric study.

Glial cytoplasmic inclusions (GCIs) are a pathologic hallmark of multiple system atrophy (MSA), but their pathogenetic roles need to be clarified. To determine possible roles of GCIs in individual cells, serial optical sections obtained by confocal microscopy were reconstructed to yield 3-dimensional (3D) images of the nuclei to quantify nuclear volume. Oligodendroglial nuclear volumes were determined in the pons of 6 MSA and 7 control patients. The nuclear volumes were significantly smaller in the MSA group as a whole (135.81 +/- 60.83 microm, mean +/- SD; n = 404) than in the control group (188.05 +/- 55.71 microm; n = 308; p < 0.001). This difference was due to a significantly smaller nuclear volume of oligodendrocytes without GCIs (GCI group, 91.26 +/- 23.77 microm; n = 210) compared with the control group (p < 0.001) and compared with the oligodendrocytes with GCIs (GCI group, 184.03 +/- 51.18 microm; n = 194; p < 0.001); the difference between the latter GCI and control groups was not significant (p > 0.05). This selective decrease in nuclear volume restricted to the GCI group cannot be explained if nuclear shrinkage was accelerated in the presence of GCIs. Conversely, GCI formation might be linked, either directly or indirectly, to a mechanism that counteracts rather than accelerates nuclear shrinkage. This novel 3-dimensional strategy provides pivotal data that link GCI formation and degeneration in MSA.