Abdominal Radiology最新文献

Purpose: Our primary purpose was to understand the correlation between pancreas T1-weighted signal intensity ratio (SIR) and T1 relaxation time in children. We also sought to characterize differences in T1 SIR between children without and with pancreatitis.

Methods: Retrospective study of patients < 18-years-old. SIR-pancreas:spleen (SIR-PS) and SIR-pancreas:paraspinal muscle (SIR-PM) were generated from T1-weighted gradient recalled echo images. Subdivided by field strength, T1 SIR was correlated (Spearman's) with T1 relaxation time.

Results: 220 participants were included, 144 imaged at 1.5T (mean: 11.4 ± 4.2 years) and 76 imaged at 3T (mean: 10.9 ± 4.5 years). At 1.5T, SIR-PS (rho=-0.62, 95% CI: -0.71 to -0.51, p < 0.0001) and SIR-PM (rho=-0.57, 95% CI: -0.67 to -0.45, p < 0.0001) moderately negatively correlated with T1 relaxation time. At 3T, correlations between T1 SIR and T1 relaxation time were moderate (rho=-0.40 to -0.43, p ≤ 0.0003). SIR-PS was significantly different between patient groups at 1.5T (p < 0.0001) with pairwise differences between: normal vs. acute on chronic pancreatitis (1.52 vs. 1.13; p < 0.0001). SIR-PM was also significantly different between groups at 1.5T (p < 0.0001) with differences between: normal vs. acute pancreatitis (1.65 vs. 1.40; p = 0.0006), normal vs. acute on chronic pancreatitis (1.65 vs. 1.18; p < 0.0001), and normal vs. chronic pancreatitis (1.65 vs. 1.52; p = 0.0066). A SIR-PS cut-off of ≤ 1.31 had 44% sensitivity and 95% specificity and SIR-PM cut-off of ≤ 1.53 had 69% sensitivity and 70% specificity for pancreatitis. At 3T, SIR-PS was significantly different between groups (p = 0.033) but without significant pairwise differences.

Conclusion: At 1.5T pancreas T1 SIR moderately to strongly correlates with estimated T1 relaxation time and is significantly lower in children with pancreatitis.

Several pseudolesions mimicking malignancy have been reported in cirrhotic and non-cirrhotic livers. Pericholecystic regeneration is among those pseudolesions and can occasionally mimic malignancy. Herein we present a case series comprised of 10 cirrhotic patients (majority due to alcoholic liver disease [ALD] or metabolic dysfunction associated steatotic liver disease [MASLD]) with pericholecystic observations initially categorized as highly suspicious for HCC (LR-4 and LR-5) due to their suspicious enhancement pattern which were later proven to be benign based on biopsy, transplantation or imaging criteria (stability of size and morphology on serial CT or MRI for > 2 years). These observations ranged 2-6.3 cm in size, were multiple in most patients and universally resulted in indentations of gallbladder. Arterial phase hyperenhancement and washout, features usually attributed to hepatocellular carcinoma (HCC), were seen in most patients. However, ancillary features of malignancy such as diffusion restriction, increased T2 signal, and hypointensity on hepatobiliary phase MRI were not present. Pericholecystic observations, in particular in the setting of ALD and MASLD, should be carefully assessed and possibility of pseudolesion should be considered especially when the observations are multiple, cause indentation of gallbladder, and lack ancillary features of malignancy.

Purpose: To describe the gadoxetic acid-enhanced magnetic resonance imaging (MRI) features and follow-up changes of hepatic focal nodular hyperplasia (FNH)-like lesions induced by chemotherapy in patients with colorectal cancer (CRC) and the differential diagnosis of FNH-like lesions and liver metastases.

Methods: We retrospectively analyzed the data of patients with CRC who received chemotherapy and gadoxetic-enhanced MRI at our hospital. Based on imaging features and pathological findings, the patients were classified into two groups: FNH-like lesions and liver metastases. Two abdominal radiologists reviewed and compared the signal intensities of all images in each phase for both groups. The characteristics of the FNH-like lesions in the hepatobiliary phase were evaluated, and changes in size of lesions were monitored.

Results: Thirty patients with 82 FNH-like lesions and 30 with 49 liver metastases following chemotherapy were included in the study. All MRI findings were statistically significantly different between the two groups (p < 0.05). In FNH-like lesions, three enhancement patterns were observed in the hepatobiliary phase: hyperintense/isointense (18.3%), heterogeneous hyperintense (8.5%), and ring-like enhancement (73.2%). The median time from completion of chemotherapy to development of FNH-like lesions was 31 months. During 4-87 months of follow-up, 27 patients with 73 lesions showed the following outcomes: 41 lesions (56.16%) showed stability, 21 lesions (28.77%) growth, and 11 lesions (15.07%) reduction or disappearance.

Conclusion: Gadoxetic acid-enhanced MRI can distinguish between chemotherapy-induced FNH-like lesions and liver metastases in patients with CRC. The FNH-like lesions exhibited three enhancement patterns in the hepatobiliary phase, and the changes varied during follow-up.

Purpose: ChatGPT has recently been the subject of many studies, and its responses to medical questions have been successful. We examined ChatGPT-4's evaluation of structured ⁶⁸Ga prostate-specific membrane antigen (PSMA) PET/CT reports of newly diagnosed prostate cancer patients.

Methods: ⁶⁸Ga PSMA PET/CT reports of 164 patients were entered to ChatGPT-4. ChatGPT-4 was asked to respond the following questions according to the PET/CT reports: 1-Has the cancer in the prostate extended to organs adjacent to the prostate? 2-Has the cancer in the prostate spread to neighboring lymph nodes? 3-Has the cancer in the prostate spread to lymph nodes in distant areas? 4-Has the cancer in the prostate spread to the bones? 5-Has the cancer in the prostate spread to other organs? ChatGPT-4's responses were scored on a Likert-type scale for clarity and accuracy.

Results: The mean scores for clarity were 4.93 ± 0.32, 4.95 ± 0.25, 4.96 ± 0.19, 4.99 ± 0.11, and 4.96 ± 0.30, respectively. The mean scores for accuracy were 4.87 ∓ 0.61, 4.87 ∓ 0.62, 4.79 ± 0.83, 4.96 ± 0.25, and 4.93 ± 0.45, respectively. Patients with distant lymphatic metastases had a lower mean accuracy score than those without (4.28 ± 1.45 vs. 4.94 ± 0.39; p < 0.001). ChatGPT-4's responses in 13 patients (8%) had the potential for harmful information.

Conclusion: ChatGPT-4 successfully interprets structured ⁶⁸Ga PSMA PET/CT reports of reports of newly diagnosed prostate cancer patients. However, it is unlikely that ChatGPT-4 evaluations will replace physicians' evaluations today, especially since it can produce fabricated information.

Objectives: To develop an end-to-end radiomics-based pipeline for the prediction of International Society of Urological Pathology grade group (ISUP GG) in prostate cancer (PCa).

Methods: This retrospective study includes 356 patients (241 in training set and 115 in independent test set) with histopathologically confirmed PCa who underwent [¹⁸F]PSMA-1007 PET/CT scan. Patients were classified into two groups according to their ISUP GG (1-3 vs. 4-5). Radiomics features were extracted from the whole, automatically segmented prostate on PET/CT images, 30 models were constructed by combining 6 feature selection algorithms and 5 machine learning classifiers. The clinical model incorporated age, total prostate-specific antigen (tPSA), maximum standardized uptake value (SUVmax), and prostate volume. The predictive performance of the models was evaluated using the area under the receiver operating characteristic curve (AUC), balanced accuracy (bAcc), and decision curve analysis (DCA).

Results: The best-performing radiomics model significantly outperformed clinical model (AUC 0.879 ± 0.041 vs. 0.799 ± 0.051, bAcc 0.745 ± 0.074 vs. 0.629 ± 0.045). On an external independent test set, best-performing radiomics model perform better than clinical model, with an AUC of 0.861 vs. 0.750, p = 0.002 (Delong), and bAcc of 0.764 vs. 0.582, p = 0.043 (McNemar). The learning curve, calibration curve and DCA demonstrated goodness-of-fit and improved benefits in clinical practice.

Conclusion: The end-to-end radiomics-based pipeline is an effective non-invasive tool to predict ISUP GG in PCa.

Objectives: This study aimed to identify the incidence of adrenal hemorrhage (AH) after OLT and to summarize the ultrasound (US) and contrast-enhanced ultrasound (CEUS) characteristics.

Methods: Patients with adrenal lesions after OLT at our hospital were retrospectively reviewed between January 2010 and November 2023. The reference diagnosis was defined on the basis of surgical data, computed tomography scans, and magnetic resonance imaging with at least 12 months of follow-up. The incidence of AH and the US and CEUS characteristics after OLT were analyzed and compared with those of adrenal metastases.

Results: A total of 23 patients (1.2%) with AH and 7 patients (0.35%) with suprarenal metastases were assessed. Compared with metastases, hematomas had more inhomogeneous echotextures (57% vs. 0.00%, P = 0.010), hypoechoic or mixed-echoic patterns (96% vs. 71%, P = 0.022), and anechoic areas (52% vs. 0.00%, P = 0.024), and their echotextures varied more over time (65% vs. 0.14%, P = 0.031). CEUS was performed on 12 patients with AH and 2 patients with metastases. A "jet-like" contrast superflux was observed in one actively bleeding hematoma, whereas no enhancement was observed in any static hematoma (100%). However, adrenal metastases had a contrast-enhanced appearance in the early arterial phase, followed by fast washout in the late phase (100%), and the difference was statistically significant (P < 0.001).

Conclusion: The sonographic characteristics of AH after OLT vary over time. CEUS is recommended when adrenal lesions are detected, as CEUS can differentiate AH from metastases.

Background: The Liver Imaging Reporting and Data System (LI-RADS) does not consider factors extrinsic to the observation of interest, such as concurrent LR-5 observations.

Purpose: To evaluate whether the presence of a concurrent LR-5 observation is associated with a difference in the probability that LR-3 or LR-4 observations represent hepatocellular carcinoma (HCC) through an individual participant data (IPD) meta-analysis.

Methods: Multiple databases were searched from 1/2014 to 2/2023 for studies evaluating the diagnostic accuracy of CT/MRI for HCC using LI-RADS v2014/2017/2018. The search strategy, study selection, and data collection process can be found at https://osf.io/rpg8x . Using a generalized linear mixed model (GLMM), IPD were pooled across studies and modeled simultaneously with a one-stage meta-analysis approach to estimate positive predictive value (PPV) of LR-3 and LR-4 observations without and with concurrent LR-5 for the diagnosis of HCC. Risk of bias was assessed using a composite reference standard and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2).

Results: Twenty-nine studies comprising 2591 observations in 1456 patients (mean age 59 years, 1083 [74%] male) were included. 587/1960 (29.9%) LR-3 observations in 1009 patients had concurrent LR-5. The PPV for LR-3 observations with concurrent LR-5 was not significantly different from the PPV without LR-5 (45.4% vs 37.1%, p = 0.63). 264/631 (41.8%) LR-4 observations in 447 patients had concurrent LR-5. The PPV for LR-4 observations with concurrent LR-5 was not significantly different from LR-4 observations without concurrent LR-5 (88.6% vs 69.5%, p = 0.08). A sensitivity analysis for low-risk of bias studies (n = 9) did not differ from the primary analysis.

Conclusion: The presence of concurrent LR-5 was not significantly associated with differences in PPV for HCC in LR-3 or LR-4 observations, supporting the current LI-RADS paradigm, wherein the presence of synchronous LR-5 may not alter the categorization of LR-3 and LR-4 observations.

The rising prevalence of pancreatic cystic lesions (PCLs), particularly intraductal papillary neoplasms (IPMNs), has been attributed to increased utilization of advanced imaging techniques. Incidental detection of PCLs is frequent in abdominal CT and MRI scans, with IPMNs representing a significant portion of these lesions. Surveillance of IPMNs is recommended due to their malignant potential; however, their overlapping imaging features with benign entities can lead to misdiagnosis, overtreatment, and overutilization of healthcare resources. This paper aims to highlight and differentiate lesions often mistaken for IPMNs, providing insight into their imaging characteristics, diagnostic challenges, and distinctive features while highlighting the incidence of wrong diagnosis for these lesions. These lesions include serous cystadenomas, cystic pancreatic neuroendocrine tumors, mucinous cystic neoplasms, lymphoepithelial cysts, duodenal diverticula, pancreatic schwannomas, chronic pancreatitis, retention cysts, intrapancreatic accessory spleens, pancreatic lipomas, choledochal cysts, and others. Utilizing various imaging modalities, including contrast-enhanced CT, MRI, and EUS, alongside histological and molecular analyses, can aid in accurate diagnosis and appropriate management. Understanding these mimicry scenarios is crucial to avoid unnecessary surveillance, interventions, and the burden they place on both patients and healthcare systems. Improved recognition of these lesions can lead to better patient outcomes and resource allocation.