Role of N-13 ammonia PET/CT in diagnosing pancreatic necrosis in patients with acute pancreatitis as compared to contrast enhanced CT – Results of a pilot study

Pancreatology ◽  
2014 ◽  
Vol 14 (3) ◽  
pp. 154-158 ◽  
Author(s):  
Raghava Kashyap ◽  
Bhagwant Rai Mittal ◽  
Abdul Khaliq ◽  
Manish Manrai ◽  
Sreekanth Appasani ◽  
...  
Author(s):  
Raluca-Ioana Dascălu ◽  
Dan Nicolae Păduraru ◽  
Alexandra Bolocan ◽  
Daniel Ion ◽  
Octavian Andronic

Background: Gastric cancer is one of the most common and leading causes of cancer death worldwide, with an increasing risk and prevalence. Although the usage of 18-FDG PET-CT in gastric cancer evaluation remains a matter of debate and is not consistently recommended by international guidelines, our descriptive review aims to highlight its actual role in the diagnostic accuracy, staging, therapeutic management, and relapse monitoring of this malignancy. Methods: The current research was conducted using scholarly databases including PubMed, Scopus, and Google Scholar by searching useful science journals, references, and abstracts on the topic. The keywords used were “gastric cancer” AND “PET-CT”. Results: 18-FDG PET-CT remains a promising method with increasing clinical utility not only across a wide variety of malignancies, but also among gastric cancer patients. Conclusions: We are certain that with further improvements, this technique could improve the diagnosis and evaluation of gastric cancer, and make it more approachable and accurate. Keywords gastric cancer (GC), PET-CT, 18-FDG PET-CT, 18F-FDG uptake, ceCT (contrast-enhanced CT)


Author(s):  
Aimee R Hayes ◽  
Alexander Crawford ◽  
Khulood Al Riyami ◽  
Christine Tang ◽  
Jamshed Bomanji ◽  
...  

Abstract Context Metastatic medullary thyroid cancer (MTC) is a rare malignancy with minimal treatment options. Many, but not all, MTCs express somatostatin receptors. Objective Our aim was to explore the role of 68Ga-DOTA-somatostatin analogue (SSA) PET/CT in patients with metastatic MTC, and to determine their eligibility for peptide receptor radionuclide therapy (PRRT). Methods We retrospectively identified patients with metastatic MTC who had 68Ga-DOTA-SSA PET/CT at five centers. We collected characteristics on contrast-enhanced CT, 68Ga-DOTA-SSA and 18F-FDG PET/CT. The efficacy of PRRT was explored in a subgroup of patients. Kaplan-Meier analysis was used to estimate time to treatment failure (TTF) and overall survival (OS). Results Seventy-one patients were included (10 local recurrence, 61 distant disease). Of the patients with distant disease, 16 (26%) had ≥50% of disease sites with tracer avidity greater than background liver, including 10 (10/61, 16%) with >90%. In 19 patients with contemporaneous contrast-enhanced CT, no disease regions were independently identified on 68Ga-DOTA-SSA PET/CT. Thirty-five patients had an 18F-FDG PET/CT, with 18F-FDG positive/ 68Ga-DOTA-SSA negative metastases identified in 15 (43%). Twenty-one patients had PRRT with a median TTF of 14 months (95%CI 8-25) and a median OS of 63 months (95%CI 21–not reached). Of the entire cohort, the median OS was 323 months (95%CI 152-not reached). Predictors of poorer overall survival included a short calcitonin doubling-time (≤24 months), strong 18F-FDG avidity and age ≥60 years. Conclusions The prevalence of high tumour avidity on 68Ga-DOTA-SSA PET/CT is low in the setting of metastatic MTC; nevertheless, PRRT may still be a viable treatment option in select patients.


Author(s):  
Monica Maher Amin Nawar ◽  
Sameh Abdel Aziz Zaky Hanna ◽  
Shereen Sadik El-Sawy ◽  
Sally Yehia Shokralla

Abstract Background The term adrenal incidentaloma (AI), by definition, is an adrenal mass that is unexpectedly detected through an imaging procedure performed for reasons unrelated to adrenal dysfunction or suspected dysfunction. Despite their frequent appearance, the challenge remains in recognizing and treating the small percentage of AI that poses a significant risk, either because of their hormonal activity or because of their malignant histology. The aim of this study is to study the role of MRI, specifically chemical shift imaging (CSI), against various MDCT scans (non-enhanced, enhanced, and delayed) in the characterization of incidentally discovered adrenal masses to offer a way for the patients to avoid unnecessary time and money-wasting imaging modalities used to reach a diagnosis of their incidentally discovered adrenal lesions. We examined a total number of 20 patients with total of 22 adrenal lesions. The mean age was 51.1 ± 15.27. Results In our study, we found that among CT parameters, APW and RPW showed the highest sensitivity and specificity for detection of lipid-rich adenomas. CSI has also proven to be the best MR technique. However, there is no statistically significant difference in the diagnostic capability of CSI versus the CT washout technique. Both modalities could be conducted, according to specific patient preferences and/or limitations, with comparable highly accurate outcomes. Conclusion This study demonstrates that a similar diagnostic outcome is obtained from contrast-enhanced CT (CECT) and MRI with CSI of adrenal lesions.


2016 ◽  
Author(s):  
S. Dash ◽  
A. Goel ◽  
S. Sogani

Purpose: To evaluate the role of 18F-FDG PET with contrast enhanced CT (PET-CECT) in early detection of recurrence in follow up patients of carcinoma cervix. Methods: Patients with histopathologically proven carcinoma cervix who underwent chemotherapy, radiotherapy and/or surgery and on follow up were recruited in the study. Fifty-two patients underwent 18F-FDG PET-CECT for detection of recurrence. The median age was 51.5 (average = 53.4) years. PET-CECT studies were evaluated and analyzed separately by an experienced nuclear medicine physician and a radiologist independently. The physicians were blinded for the patient history. PET-CECT results were validated with histopathological correlation, conventional radiologic imaging/follow up PET-CECT study and clinical follow up. Results: Out of 52 patients, 34 patients were reported as positive for recurrence, 17 of these were having active local recurrence and 31 patients had regional lymph nodal metastases, 14 patients had distant metastases (out of them 6 patients had distant lymph node metastases, 6 had pulmonary metastases, 4 had skeletal metastases and two had liver metastases). Remaining 18 patients were reported as negative for recurrence. The lung was the most common site for distant metastasis. Patient were then further evaluated based on histopathological correlation, conventional radiologic imaging and follow up PET-CECT scan and five were found to be false positive and one patient was identified as false negative. The sensitivity, specificity, positive and negative predictive value were derived to be 96.7%, 77.3%, 85.3% and 94.4%, respectively. Accuracy was calculated to be 88.5%. Conclusions: 18F-FDG PET-CECT is a very useful non-invasive modality for the early detection of recurrence and metastatic workup in patients with carcinoma cervix with a very high sensitivity and negative predictive value. It is also useful in targeting biopsy sites in suspected cases of recurrence.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii93-ii93
Author(s):  
Kate Connor ◽  
Emer Conroy ◽  
Kieron White ◽  
Liam Shiels ◽  
William Gallagher ◽  
...  

Abstract Despite magnetic resonance imaging (MRI) being the gold-standard imaging modality in the glioblastoma (GBM) setting, the availability of rodent MRI scanners is relatively limited. CT is a clinically relevant alternative which is more widely available in the pre-clinic. To study the utility of contrast-enhanced (CE)-CT in GBM xenograft modelling, we optimized CT protocols on two instruments (IVIS-SPECTRUM-CT;TRIUMPH-PET/CT) with/without delivery of contrast. As radiomics analysis may facilitate earlier detection of tumors by CT alone, allowing for deeper analyses of tumor characteristics, we established a radiomic pipeline for extraction and selection of tumor specific CT-derived radiomic features (inc. first order statistics/texture features). U87R-Luc2 GBM cells were implanted orthotopically into NOD/SCID mice (n=25) and tumor growth monitored via weekly BLI. Concurrently mice underwent four rounds of CE-CT (IV iomeprol/iopamidol; 50kV-scan). N=45 CE-CT images were semi-automatically delineated and radiomic features were extracted (Pyradiomics 2.2.0) at each imaging timepoint. Differences between normal and tumor tissue were analyzed using recursive selection. Using either CT instrument/contrast, tumors > 0.4cm3 were not detectable until week-9 post-implantation. Radiomic analysis identified three features (waveletHHH_firstorder_Median, original_glcm_Correlation and waveletLHL_firstorder_Median) at week-3 and -6 which may be early indicators of tumor presence. These features are now being assessed in CE-CT scans collected pre- and post-temozolomide treatment in a syngeneic model of mesenchymal GBM. Nevertheless, BLI is significantly more sensitive than CE-CT (either visually or using radiomic-enhanced CT feature extraction) with luciferase-positive tumors detectable at week-1. In conclusion, U87R-Luc2 tumors > 0.4cm3 are only detectable by Week-8 using CE-CT and either CT instrument studied. Nevertheless, radiomic analysis has defined features which may allow for earlier tumor detection at Week-3, thus expanding the utility of CT in the preclinical setting. Overall, this work supports the discovery of putative prognostic pre-clinical CT-derived radiomic signatures which may ultimately be assessed as early disease markers in patient datasets.


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