Search

Background: Identifying programmed death-ligand-1 (PD-L1) expression is crucial for optimizing treatment strategies involving immune checkpoint inhibitors. However, the role of intratumoral metabolic heterogeneity specifically derived from 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) images in predicting PD-L1 expression in patients with newly diagnosed non-small cell lung cancer (NSCLC) remains unexplored. Here, we investigated the association between FDG PET texture features and PD-L1 expression by retrospectively analyzing the data of patients newly diagnosed with NSCLC who underwent FDG PET/CT scans and PD-L1 immunohistochemical staining before treatment. Methods: Patients were categorized based on their tumor proportion scores (TPSs) into negative-, low-, and high-PD-L1 expression groups. We computed the maximum standardized uptake value and 31 texture features for the primary tumor from PET images and compared differences in parameters among the groups. Results: Of the 83 patients, 12, 45, and 26 were assigned to the negative-, low-, and high-PD-L1 expression groups, respectively. Six specific texture features (low gray-level run emphasis, short-run low gray-level emphasis, long-run high gray-level emphasis, low gray-level zone emphasis, high gray-level zone emphasis, and short-zone low gray-level emphasis) helped distinguish among all possible combinations. Conclusions: Our findings revealed that FDG PET texture features are potential imaging biomarkers for predicting PD-L1 expression in patients newly diagnosed with NSCLC. [ABSTRACT FROM AUTHOR]

Hybrid 201Tl SPECT/CCTA images revealed that the area where the RR pattern was seen was located in the distal left circumflex artery territory Coronary artery ectasia (CAE) is defined as a diffuse dilatation with a diameter of more than 1.5 times normal coronary artery and is a comparably rare cardiovascular disorder. The reverse redistribution (RR) pattern on SP 201 sp Tl single photon emission computed tomography (SPECT) may be defined as a normal or nearly normal perfusion in an early imaging (stress or rest acquisition after injection) and significantly smaller or less perfusion in a delayed rest imaging. The reverse redistribution pattern in the mid inferolateral wall was shown on 201Tl SPECT Graph: Figure 2 Coronary angiography images (A: right coronary artery, B: left coronary artery) and coronary computed tomography angiography (C). [Extracted from the article]

Purpose: To evaluate computed tomography (CT) findings of nonspecific interstitial pneumonia (NSIP) based on the current classification of idiopathic interstitial pneumonias (IIPs) and elucidate a characteristic of previously diagnosed NSIP excluded from the current classification. Materials and methods: The study included 74 patients with biopsy-proven NSIP (idiopathic NSIP [I-NSIP], 39 patients; NSIP associated with connective tissue disease [CTD-NSIP], 35 patients). Among patients who were compatible with the current classification of IIPs, 29 and 21 were categorized as having current I-NSIP and current CTD-NSIP, respectively. The remaining 24 patients were categorized as having previous I-NSIP or previous CTD-NSIP due to the primary pathologic diagnosis of cellular NSIP or associated findings of acute inflammatory changes. CT findings were evaluated and compared among the four groups. Results: Current I-NSIP was indicated by ground-glass attenuation and reticulation with traction bronchiectasis/bronchiolectasis in predominantly peribronchovascular areas of the lower lung zone. The previous I-NSIP group tended to show broader airspace consolidation than the current I-NSIP group (p = 0.068). The previous CTD-NSIP group showed significantly broader airspace consolidation than the current I-NSIP group (p = 0.035). Conclusion: Broad airspace consolidation is a characteristic of previously diagnosed CTD-NSIP excluded from the current classification of IIPs. [ABSTRACT FROM AUTHOR]

We prospectively investigated the feasibility of 3′-deoxy-3′-18F-fluorothymidine (FLT) positron emission tomography (PET) for the detection of gastric cancer, in comparison with 2-deoxy-2-18F-fluoro- d-glucose (FDG) PET, and determined the degree of correlation between the two radiotracers and proliferative activity as indicated by Ki-67 index. A total of 21 patients with newly diagnosed advanced gastric cancer were examined with FLT PET and FDG PET. Tumour lesions were identified as areas of focally increased uptake, exceeding that of surrounding normal tissue. For semiquantitative analysis, the maximal standardized uptake value (SUV) was calculated. For detection of advanced gastric cancer, the sensitivities of FLT PET and FDG PET were 95.2% and 95.0%, respectively. The mean (±SD) SUV for FLT (7.0 ± 3.3) was significantly lower than that for FDG (9.4 ± 6.3 p < 0.05). The mean FLT SUV and FDG SUV in nonintestinal tumours were higher than in intestinal tumours, although the difference was not statistically significant. The mean (±SD) FLT SUV in poorly differentiated tumours (8.5 ± 3.5) was significantly higher than that in well and moderately differentiated tumours (5.3 ± 2.1; p < 0.04). The mean FDG SUV in poorly differentiated tumours was higher than in well and moderately differentiated tumours, although the difference was not statistically significant. There was no significant correlation between Ki-67 index and either FLT SUV or FDG SUV. FLT PET showed as high a sensitivity as FDG PET for the detection of gastric cancer, although uptake of FLT in gastric cancer was significantly lower than that of FDG. [ABSTRACT FROM AUTHOR]

Primary hepatic neuroendocrine tumors (PHNETs) are extremely rare neoplasms. Herein, we report a case of a 70- year-old man with a hepatic mass. The non-contrast computed tomography (CT) image showed a low-density mass, and dynamic CT images indicated the enhancement of the mass in the arterial phase and early washout in the late phase. F-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and fused PET/CT images showed increased uptake in the hepatic mass. Whole-body 18F-FDG PET images showed no abnormal activity except for the liver lesion. Presence of an extrahepatic tumor was also ruled out by performing upper gastrointestinal endoscopy, total colonoscopy, and chest and abdominal CT. A posterior segmentectomy was performed, and histologic examination confirmed a neuroendocrine tumor (grade 1). The patient was followed up for about 2 years after the resection, and no extrahepatic lesions were radiologically found. Therefore, the patient was diagnosed with PHNET. To the best of our knowledge, no previous case of PHNET have been detected by 18F-FDG PET imaging. [ABSTRACT FROM AUTHOR]

We compared the effectiveness of 3-dimensional computed tomography pulmonary angiography (3D-CTPA) and thin-section multiplanar reconstruction (MPR) images obtained using contrast-enhanced multidetector row CT (MDCT), in the evaluation of pulmonary artery (PA) branches of the right upper lobe. We studied 127 patients suspected of having lung cancer of the right upper lobe who underwent contrast-enhanced MDCT scans and a right upper lobectomy. We compared the intraoperative findings of the PA branches of the right upper lobe obtained with 3D-CTPA and thin-section MPR images. In 125 (97.7%) patients, one or more PA branches arose from arteries other than the superior trunk. Among 10 (7.9%) patients, a PA branch arose from the middle lobe in one patient and from the superior segment of the lower lobe in the other 9 patients. According to the intraoperative findings, 97.2% and 99.7% of the PA branches were identified by 3D-CTPA and thin-section MPR images, respectively (p ＜ 0.03). The single branch missed by both imaging modalities was 1.0mm in dia. The 8 branches missed only by 3D-CTPA were ＜ 1.4mm in dia. Both the 3D-CTPA and thin-section MPR images provided precise preoperative information regarding PA branches of the right upper lobe. However, the thin-section MPR images appeared to contribute more to the evaluation of smaller PA branches.

We performed a retrospective study examining the prevalence and subtypes of pulmonary emphysema (PE) identified by computed tomography (CT) in females. We reviewed the records of 1,687 female subjects who had undergone CT. They were divided into the following 2 age groups:group A (＜50 years) and group B (≥50 years). PE was diagnosed by the presence of low-attenuation areas using visual assessment (grades 0-3) on CT images. Two subtypes of PE were observed:centrilobular emphysema (CLE) and paraseptal emphysema (PSE). PE was divided into the following 3 categories:I (CLE or CLE-predominant);II (CLE and PSE of equal extent);and III (PSE or PSE-predominant). PE was found in 64 of 274 smokers (23.3%) and 54 of 1,413 non-smokers (3.8%). In smoking subjects, when grades 1 and 2 were grouped together as mild PE, the mean age for CT grade 3 (severe PE) was significantly higher than that for mild PE. In group A, category III predominated, whereas category I was more prevalent in group B, in both smoking and non-smoking subjects. A high incidence of PE was found in smoking subjects as compared with non-smoking subjects. PSE predominated in younger subjects, whereas CLE predominated in older subjects.

In recent years, due to the advanced computerization of medical institutions, systems such as radiology information system (RIS) and reporting have been used extensively also at radiology departments. However, the introduction of these systems will need a great amount of money, and the systems are not yet introduced in our hospital. On the contrary, thanks to the sophistication and price reduction of personal computers (PCs), there is now found a rapid expansion of end user computing (EUC) in which users of a system actively build and manage the system of their duties. Under these circumstances, in order to assist the duties at low costs, we worked the computerization of duties done at our Radiology Department by using the EUC. Specifically, we used software of general-purpose database to build the system with functions dealing with records on implementing medical examinations and treatments, examination booking and diagnostic imaging report. This system which has been developed according to details of conventional duties and requests from medical personnel makes it possible to alleviate the duties which were done manually.