Role of F-18 FDG PET-CT in neuropsychiatric systemic lupus erythematosus.

BACKGROUND: Neuropsychiatric systemic lupus erythematosus (NPSLE) is a major contributor to morbidity and mortality in systemic lupus erythematosus (SLE) patients. To date no single clinical, laboratory or imaging test has proven accurate for NPSLE diagnosis which is a testament to the intricate and multifactorial pathophysiological mechanisms suspected to exist. Functional imaging with FDG PET-CT has shown promise in NPSLE diagnosis, detecting abnormalities prior to changes evident on anatomical imaging. Research indicates that NPSLE may be more aggressive in people of African descent with higher mortality rates, making rapid and correct diagnosis even more important in the African context. METHODS: In this narrative review, we provide a thorough appraisal of the current literature on the role of FDG PET-CT in NPSLE. Large, well-known databases were searched using appropriate search terms. Manual searches of references of retrieved literature were also included. FINDINGS: A total of 73 article abstracts were assessed, yielding 26 papers that were directly relevant to the topic of FDG PET-CT in NPSLE. Results suggest that FDG PET-CT is a sensitive imaging test for NPSLE diagnosis and may play a role in assessing treatment response. It is complementary to routine anatomical imaging, particularly in diffuse manifestations of the disease. Newer quantitative analyses are commonly used for interpretation and can detect even subtle abnormalities, missed on visual inspection. Findings of group-wise analyses of FDG PET-CT scans in NPSLE patients are important in furthering our understanding of the complicated pathophysiological mechanisms involved. Limitations of FDG PET-CT include its lack of specificity, high cost and poor access. CONCLUSION: FDG PET-CT is a sensitive test for NPSLE diagnosis but is hampered by lack of specificity. It is a valuable tool for clinicians managing SLE patients, particularly when anatomical imaging is negative. Its exact application will depend on the local context and clinical scenario.

Artificial intelligence (AI)-assisted chest computer tomography (CT) insights: a study on intensive care unit (ICU) admittance trends in 78 coronavirus disease 2019 (COVID-19) patients.

Background: The global coronavirus disease 2019 (COVID-19) pandemic has posed substantial challenges for healthcare systems, notably the increased demand for chest computed tomography (CT) scans, which lack automated analysis. Our study addresses this by utilizing artificial intelligence-supported automated computer analysis to investigate lung involvement distribution and extent in COVID-19 patients. Additionally, we explore the association between lung involvement and intensive care unit (ICU) admission, while also comparing computer analysis performance with expert radiologists' assessments. Methods: A total of 81 patients from an open-source COVID database with confirmed COVID-19 infection were included in the study. Three patients were excluded. Lung involvement was assessed in 78 patients using CT scans, and the extent of infiltration and collapse was quantified across various lung lobes and regions. The associations between lung involvement and ICU admission were analysed. Additionally, the computer analysis of COVID-19 involvement was compared against a human rating provided by radiological experts. Results: The results showed a higher degree of infiltration and collapse in the lower lobes compared to the upper lobes (P<0.05). No significant difference was detected in the COVID-19-related involvement of the left and right lower lobes. The right middle lobe demonstrated lower involvement compared to the right lower lobes (P<0.05). When examining the regions, significantly more COVID-19 involvement was found when comparing the posterior vs. the anterior halves and the lower vs. the upper half of the lungs. Patients, who required ICU admission during their treatment exhibited significantly higher COVID-19 involvement in their lung parenchyma according to computer analysis, compared to patients who remained in general wards. Patients with more than 40% COVID-19 involvement were almost exclusively treated in intensive care. A high correlation was observed between computer detection of COVID-19 affections and the rating by radiological experts. Conclusions: The findings suggest that the extent of lung involvement, particularly in the lower lobes, dorsal lungs, and lower half of the lungs, may be associated with the need for ICU admission in patients with COVID-19. Computer analysis showed a high correlation with expert rating, highlighting its potential utility in clinical settings for assessing lung involvement. This information may help guide clinical decision-making and resource allocation during ongoing or future pandemics. Further studies with larger sample sizes are warranted to validate these findings.

Study on the effect of Al18F-PSMA-BCH scan on early diagnosis and treatment decision of prostate cancer of biochemical recurrence / 中国医学装备

Objective:To explore the effect of the labeled positron emission tomography/computed tomography(PET/CT)scan with Al18F-PSMA-BCH(Beijing Cancer Hospital)on early diagnosis and treatment decision of prostate cancer of biochemical recurrence.Methods:A total of 80 patients who underwent radical prostatectomy(RP)for prostate cancer(PCa)in the Kashgar First People's Hospital from August 2021 to June 2022 were retrospectively analyzed.According to the presence of biochemical recurrence(BCR),they were divided into biochemical recurrence group(n=29)and non-biochemical recurrence group(n=51).All patients were scanned with Al18F-PSMA-BCH PET/CT markers.The detection situations of the labeled scan with Al18F-PSMA-BCH on clinically local recurrence or metastasis of patients with BCR were analyzed.The correlations between the maximum standardized uptake value(SUVmax)of recurrence and metastasis,the serum prostate specific antigen(PSA)and Gleason scores were compared.The detection efficiency of SUVmax on BCR patients with different risk levels under labeled scan with Al18F-PSMA-BCH was analyzed.According to the preoperative PSA,Gleason score of obtaining from postoperative pathological results and clinical stage,80 patients were divided into low-risk grade,medium risk grade and high risk grade.Results:Under the labeled scan with Al18F-PSMA-BCH PET/CT,23 patients in biochemical recurrence group occurred clinical recurrence and metastasis(79.31%),of which 14 cases existed various degrees of lymph node metastasis(60.87%),including simple pelvic lymph node metastasis in 8 cases(34.78%),simple retroperitoneal lymph node metastasis in 2 cases(8.70%),pelvic with retroperitoneal lymph node metastasis in 3 cases(13.04%)and 1 case of supraseptal lymph node metastasis(4.35%).There were 4 cases of recurrence in prostatectomy area(17.39%),1 case of visceral metastasis(4.35%)(brain),and 15 cases with various degrees of bone metastasis(65.22%).For PCa patients with BCR after RP,the area under curve(AUC)of the receiver operating characteristic(ROC)curve of the labeled scan with Al18F-PSMA-BCH PET/CT was 0.897(95% CI:0.808-0.953,P<0.001)in detecting patients with clinical local recurrence or metastasis,and the sensitivity and specificity of that were respectively 79.3% and 100.00%.The SUVmax of patients with bone metastasis was(14.82±24.32),which was positively correlated with PSA level and Gleason score(r=0.442,0.372,P<0.001),respectively.The SUVmax of patients with recurrence in operation area was(24.38±26.54),which was positively correlated with PSA level and Gleason score(r=0.423,0.338,P<0.05),respectively.The SUVmax of patients with pelvic lymph node metastasis was(45.34±47.04),which was positively correlated with PSA level and Gleason score(r=0.423,0.316,P<0.05),respectively.At the same time,in these patients with BCR,the detection rate(100%)of recurrence or metastasis in patients with Gleason score≥8 was significantly higher than that in patients with Gleason score≤7(11/17,64.71%),and the difference was statistically significant(x2=6.502,P<0.05).There were significant differences in the detection rates among patients with 0.2 ng/ml≤PSA<0.5 ng/ml(6/10),patients with 0.5 ng/ml≤PSA<1 ng/ml(6/8),patients with 1 ng/ml≤PSA<2 ng/ml(12/12)and patients with PSA≥2 ng/ml(9/9)(x2=9.041,P<0.05).The AUC values of SUVmax for recurrence or metastasis in patients with low,medium and high-risk BCR were 0.708(95% CI:0.543-0.840,P＞0.05),0.780(95% CI:0.621-0.895,P<0.05)and 0.914(95% CI:0.781-0.979,P<0.001),respectively.The diagnostic efficiency of Al18F-PSMA-BCH on local recurrence and metastasis of patients with high-risk BCR was significantly better than that of patients with low-risk BCR(x2=8.986,P<0.05).In the 23 patients who underwent labeled scan with Al18F-PSMA-BCH,15 patients(65.22%)received the added treatment of local radiotherapy,systemic chemotherapy,endocrine therapy or pelvic lymph node dissection on the basis of the original treatment plan,which changed the treatment strategies.Conclusion:The labeled scan with Al18F-PSMA-BCH has higher early diagnostic value for BCR of patients with PCa,which will have a certain influence on the treatment strategy of patients.

Multicenter quantitative 18F-fluorodeoxyglucose positron emission tomography performance harmonization: use of hottest voxels towards more robust quantification.

Background: Harmonization methods reduce variability between different make and models of positron emission tomography (PET) scanners. The study aims to explore harmonization strategies that lead to comparable and robust quantitative metrics in a multicenter setting. Methods: NEMA IEC Phantom data acquisition was performed for low and high spheres-to-background ratios (SBR4:1 and 10:1) on six PET/CT (computed tomography) scanners. Different reconstruction sets, including the number of sub-iterations, number of subsets, and full width at half maximum (FWHM) for each scanner, were evaluated towards optimized and harmonized reconstruction settings. Recovery coefficients (RCs) of four quantitative metrics, including standardized uptake value (SUV)max, SUVISO-50 (SUVmean in 50% isocontour), SUVpeak, and mean uptake of 10 highest concentration voxels were evaluated as RCmax, RCISO-50, RCpeak, and RC10V, representing percent difference relative to the static ground truth case as functions of sphere sizes. A set of image reconstruction parameters was proposed for harmonized reconstruction to minimize variability between scanners. The root mean square error (RMSE), curvature, and reproducibility were examined. The proposed reconstruction protocols for harmonization and standard clinical reconstruction settings were compared to each other across all scanners. Results: A significant difference (P value <0.0001) was observed in the aforementioned quantitative metrics between SBR10 and SBR4. Reconstruction parameter sets with the smallest RMSE and RC values within 10% bias were identified as the best candidate for harmonization. The coefficient of variation of the mean value of RCs (CVMRC) shows a remarkable reduction of about 28%, 26%, 32%, and 19% in harmonized reconstruction settings for MRCmax, MRCISO-50, MRCpeak, and MRC10V, respectively. CVMRC for MRC10V in the harmonized reconstruction setting was 5.9% in SBR4, while the smallest value in SBR10 belongs to MRCpeak, with a value of 5.8%. The reproducibility of RC is improved by deriving the value from ten hottest voxels and is equally reproducible with RCpeak. Compared to RCmax and RCISO-50, the variability is reduced by 18% and 22% if ten voxels are pooled. Conclusions: Harmonizing PET/CT systems with and without point spread function/time of flight (PSF/TOF) using various vendor-developed image reconstruction algorithms improves the quantification reproducibility. RC10V, likewise RCpeak, is superior to the rest of the quantitative indices in terms of accuracy and reproducibility and helpful in quantifying lesion volume below 1 mL.

Differential diagnostic performance of PET/CT in adult-onset still's disease and lymphoma: a retrospective pilot study.

Background: Adult-onset still's disease (AOSD) and lymphoma are the common causes of fever of unknown origin (FUO) and show some similar clinical symptoms. This study aimed to establish a reliable and easy-to-used scoring model based on clinical information, laboratory characteristics and 18F-fluorodeoxyglucose positron emission tomography/computer tomography (18F-FDG PET/CT) images for the differential diagnosis of these two diseases. Methods: A development cohort including 70 AOSD and 37 lymphoma patients was used to establish a scoring model based on the features of PET/CT images. The scoring model was then validated in a validation cohort of 15 AOSD and 12 lymphoma patients. The features of involved bone marrow, spleen, lymph nodes, and other organs or tissues displayed on PET/CT images were compared. Multiple logistics regression and decision tree analysis were used to establish the scoring model. Results: Four features that could significantly differentiate these two diseases were selected to establish a scoring model discriminating AOSD from lymphoma, including (I) white blood cell (WBC) count ≤10×109/L (1 point); (II) ferritin ≤ upper limit of normal (ULN) (1 point); (III) no abnormal bone marrow metabolism (1 point); (IV) total lesion glycolysistotal (TLGtotal) >9.0 (1 point). After decision tree analysis, it showed that a score ≤1 indicates AOSD. A score ≥3 strongly suggested lymphoma, with a sensitivity of 81.1% and specificity of 90.0% in the development cohort, and a sensitivity of 58.3% and specificity of 100% in the validation cohort. Conclusions: Our scoring model showed good diagnosis performance in distinguishing AOSD from lymphoma.

Extramedullary Hematopoiesis Visualized on FDG-PET/CT in a Patient with Beta-Thalassemia.

Beta-thalassemia is an inherited blood disorder caused by reduced or absent synthesis of the beta chains of hemoglobin, resulting in decreased hemoglobin production. Symptoms depend on the type of beta-thalassemia ranging from no symptoms to severe illness. Ineffective erythropoiesis leads to a sequence of events responsible for bone marrow expansion, anemia, hemolysis, splenomegaly, increased iron absorption, and sometimes extramedullary hematopoiesis (EMH). We report an interesting case with EMH visualized on FDG-PET/CT and where FDG-PET/CT has also found the focus of a severe infection in a patient with beta-thalassemia.

A Review of Nuclear Medicine Approaches in the Diagnosis and the Treatment of Gynecological Malignancies.

Nuclear medicine is defined as the diagnosis and the treatment of disease using radiolabeled compounds known as radiopharmaceuticals. Single-photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/computer tomography (PET/CT) based radiopharmaceuticals have proven reliable in diagnostic imaging in nuclear medicine and cancer treatment. One of the most critical cancers that also relies on an early diagnosis is gynecological cancer. Given that approximately 25% of all cancers in developing countries are a subset of gynecological cancer, investigating this cancer subtype is of significant clinical worth, particularly in light of its high rate of mortality. With accurate identification of high grade distant abdominal endometrial cancer as well as extra abdominal metastases, 18F-Fluorodeoxyglucose ([18F]FDG) PET/CT imaging is considered a valuable step forward in the investigation of gynecological cancer. Considering these factors, [18F]FDG PET/CT imaging can assist in making management of patient therapy more feasible. In this literature review, we will provide a short overview of the role of nuclear medicine in the diagnosis of obstetric and gynecological cancers.

Utility of Fluorine18 Fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography in Metabolic Characterization of Solid Renal Mass Lesion and Localization of Extra Renal Lesions in the Body - A Prospective Study from the Tertiary Care Center in South India.

Purpose of the Study: Renal mass lesions in majority of the cases are due to malignant etiology and about one-third of them are reported with metastatic lesions at the time of presentation. Thus proper investigational workup is needed for staging and thereby treatment planning. The current fluorine18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F18-FDG PET/CT) study was designed to characterize renal mass lesions metabolically and identifying other metabolically active lesions in the body suggesting metastatic disease. Materials and Methods: A total of 24 patients (males - 18 and females - 6) with a mean age of 53.8 ± 12.3 years were recruited in this study for dual time-point PET/CT scan. All patients with renal mass lesions underwent contrast-enhanced CT prior to PET/CT. Metabolic parameters such as maximum standardized uptake value (max.SUV) with a cut off ≥2.5 and retention index (RI) of ≥10% were used to label the lesion as malignant and remaining less than cutoff as benign. The final diagnosis of lesion on imaging was confirmed with a histopathological examination (HPE). Results: Using max.SUV cut off value, 17/24 renal mass lesions were characterized as malignant and remaining 7/24 renal lesions of benign etiology. PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 80%, 75%, 94.1%, 42.8%, and 79.1%, respectively, by considering HPE as a gold standard. Nine patients were diagnosed with distant site involvement suggestive of metastases. Conclusion: F18-FDG PET/CT can efficiently characterize solid renal mass lesion as benign and malignant using metabolic parameters such as max.SUV and RI. In addition, whole-body survey identified distant site involvement in 25% of the patients, thus contributing change in management.

Normal Variants, Pitfalls, and Artifacts in Ga-68 Prostate Specific Membrane Antigen (PSMA) PET/CT Imaging.

The advent of gallium 68 prostate specific membrane antigen (PSMA) PET imaging has revolutionized the diagnosis and treatment of prostate cancer. PSMA is a transmembrane glycoprotein that is overexpressed in prostate cancer and yields images with high tumor-to-background contrast. Effective "one-stop-shop" imaging of the prostate, lymph nodes, soft tissue, and bone is achieved with PSMA PET. Compared to conventional imaging, PSMA PET provides superior sensitivity and specificity and plays a pivotal role in staging high-risk prostate cancer as well as in biochemical recurrence by identifying oligometastatic disease. PSMA PET furthermore assists in the selection of patients with metastatic castrate resistant prostate cancer for possible treatment (e.g., labeled with a beta emitter lutetium 177) by using a theranostic approach. The term "prostate specific" is a misnomer as PSMA is also present in other malignant and benign conditions since it acts as a folate hydrolase. To avoid pitfalls and false-positives, a sound knowledge of the normal biodistribution of PSMA as well as other potential causes for false-positive uptake is imperative. This review will describe the expected patterns of distribution of Ga 68 PSMA PET imaging and the common pitfalls noted in published literature since the topic is still evolving.

Normal Variants, Pitfalls and Artifacts in Ga-68 DOTATATE PET/CT Imaging.

Indium 111 DTPA Octreotide (Octreoscan) has been the pillar of Somatostatin receptor (SSTRs) imaging in nuclear medicine for over three decades. The advent of PET/CT brought new analogs of somatostatin that have higher affinity and improved resolution due to their labeling to Gallium 68 for positron imaging. The most used analogs include DOTATATE, DOTATOC and DOTANOC. However, Gallium 68-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE) is probably the most common non-FDG (fluoro-2-deoxy glucose) PET tracer alongside PSMA (prostate specific membrane antigen). In contrast to F18-labeled FDG, it does not require proximity to a cyclotron due to the availability of the Ga68 generator. DOTATATE is a somatostatin analog which allows whole body imaging of somatostatin receptors on cell surfaces. 68Ga-DOTA compounds provide the imaging standard for well-differentiated (Grade 1 and low grade 2) neuro-endocrine tumors (NETs) and is utilized in the staging and characterization and restaging of patients with NETs. 68Ga DOTATATE has a complementary role with 18F-FDG where tumors may exhibit varying degrees of differentiation. It furthermore has application as a prelude to therapy in selecting patients for peptide receptor radionuclide therapy using a theranostic approach. A sound knowledge of the normal biodistribution of the radiotracer is imperative for optimal patient outcome and to avoid potential false positives such as inflammation, normal pancreatic uncinate process uptake and osteoblastic activity. In this review, we will describe the normal appearances of the 68Ga DOTATATE and the potential pitfalls with the support of images to aid in improving interpretation of this crucial innovative tool in the management of individuals with tumors expressing SSTRs.

[Clinical analysis of 554 patients with colorectal diverticulosis].

Objective: Most patients with asymptomatic colorectal diverticulosis are easily overlooked. However, some of diverticulosis become diverticulitis, bleeding and even perforation, which cause extensive harm to patients. The purpose of this study is to analyze the incidence, clinical features, diagnosis and treatment of colorectal diverticulosis in order to improve the clinical understanding of diverticulosis and its related complications. Methods: A descriptive cohort study was carried out. Clinical data of 554 patients with colorectal diverticulosis confirmed by CT, colonoscopy, digestive tract radiography or operation in Peking University First Hospital from January 2009 to June 2019 were retrospectively analyzed. Patients with malignant tumors, autoimmune diseases, long term use of immunosuppressive drugs, chronic liver diseases and renal diseases, and mental disorders were excluded. The analysis parameters included gender, onset age, clinical symptoms, location of diverticulitis, treatment and prognosis. According to the criteria established by the World Society of Emergency Surgery (WSES), acute diverticulitis was divided into 5 stages based on the extension of the infectious process. Stage 0 was simple diverticulitis and stage 1-4 was complicated diverticulitis. Results: Among the 554 patients with colorectal diverticulosis, 358 (64.6%) were males, the median onset age was 63 years; 191 patients (34.5%) had various digestive symptoms, of whom 113 (20.4%) had chronic constipation and abdominal distension, 78 (14.1%) had chronic diarrhea and abdominal pain; the other 363 patients had no obvious abdominal symptoms. Four hundred and six patients were found by colonoscopy and 465 patients were found by CT. Twenty-five patients were diagnosed by lower gastrointestinal tract radiography and 3 were confirmed during operation. There were 339 patients with multiple diverticula (61.2%) and 215 patients with single diverticulum (38.8%). 76.5% (424/554) of diverticula were located in colon, 37.0% (205/554) in ascending colon, 21.3% (118/554) in multiple sites, and 2.2% (12/554) in rectum. The median diameter of diverticulum was 7 mm, and 78 cases (14.1%) was ≥30 mm. Forty-nine patients (8.8%) developed acute diverticulitis, including 13 patients with simple diverticulitis and 36 patients with complicated diverticulitis. Among 36 patients with complicated diverticulitis, 29 (80.6%) were males, 27 (75.0%) had recurrent abdominal pain and fever before onset; diverticula of 25 cases were located in sigmoid colon; 11 cases in ascending colon. Nine cases developed sigmoid colon perforation and 8 cases developed vesicocolonic fistula, and these 17 patients underwent surgical treatment. The other 19 cases with complicated diverticulitis developed gastrointestinal bleeding, of whom 18 cases were male, 11 cases were located in ascending colon; 13 cases were healed after conservative treatment, 4 cases received endoscopic hemostatic intervention, and 2 cases underwent surgery. Conclusions: Colorectal diverticulosis is more common in male patients, and CT and colonoscopy are main diagnostic methods. The symptoms of complicated colonic diverticulitis are related to the location of diverticulum. In addition to symptomatic treatment, surgical procedures are the most important treatments.

Clinical analysis of 554 patients with colorectal diverticulosis / 中华胃肠外科杂志

Objective: Most patients with asymptomatic colorectal diverticulosis are easily overlooked. However, some of diverticulosis become diverticulitis, bleeding and even perforation, which cause extensive harm to patients. The purpose of this study is to analyze the incidence, clinical features, diagnosis and treatment of colorectal diverticulosis in order to improve the clinical understanding of diverticulosis and its related complications. Methods: A descriptive cohort study was carried out. Clinical data of 554 patients with colorectal diverticulosis confirmed by CT, colonoscopy, digestive tract radiography or operation in Peking University First Hospital from January 2009 to June 2019 were retrospectively analyzed. Patients with malignant tumors, autoimmune diseases, long term use of immunosuppressive drugs, chronic liver diseases and renal diseases, and mental disorders were excluded. The analysis parameters included gender, onset age, clinical symptoms, location of diverticulitis, treatment and prognosis. According to the criteria established by the World Society of Emergency Surgery (WSES), acute diverticulitis was divided into 5 stages based on the extension of the infectious process. Stage 0 was simple diverticulitis and stage 1-4 was complicated diverticulitis. Results: Among the 554 patients with colorectal diverticulosis, 358 (64.6%) were males, the median onset age was 63 years; 191 patients (34.5%) had various digestive symptoms, of whom 113 (20.4%) had chronic constipation and abdominal distension, 78 (14.1%) had chronic diarrhea and abdominal pain; the other 363 patients had no obvious abdominal symptoms. Four hundred and six patients were found by colonoscopy and 465 patients were found by CT. Twenty-five patients were diagnosed by lower gastrointestinal tract radiography and 3 were confirmed during operation. There were 339 patients with multiple diverticula (61.2%) and 215 patients with single diverticulum (38.8%). 76.5% (424/554) of diverticula were located in colon, 37.0% (205/554) in ascending colon, 21.3% (118/554) in multiple sites, and 2.2% (12/554) in rectum. The median diameter of diverticulum was 7 mm, and 78 cases (14.1%) was ≥30 mm. Forty-nine patients (8.8%) developed acute diverticulitis, including 13 patients with simple diverticulitis and 36 patients with complicated diverticulitis. Among 36 patients with complicated diverticulitis, 29 (80.6%) were males, 27 (75.0%) had recurrent abdominal pain and fever before onset; diverticula of 25 cases were located in sigmoid colon; 11 cases in ascending colon. Nine cases developed sigmoid colon perforation and 8 cases developed vesicocolonic fistula, and these 17 patients underwent surgical treatment. The other 19 cases with complicated diverticulitis developed gastrointestinal bleeding, of whom 18 cases were male, 11 cases were located in ascending colon; 13 cases were healed after conservative treatment, 4 cases received endoscopic hemostatic intervention, and 2 cases underwent surgery. Conclusions: Colorectal diverticulosis is more common in male patients, and CT and colonoscopy are main diagnostic methods. The symptoms of complicated colonic diverticulitis are related to the location of diverticulum. In addition to symptomatic treatment, surgical procedures are the most important treatments.

Auto-segmentations by convolutional neural network in cervical and anorectal cancer with clinical structure sets as the ground truth.

BACKGROUND: It is time-consuming for oncologists to delineate volumes for radiotherapy treatment in computer tomography (CT) images. Automatic delineation based on image processing exists, but with varied accuracy and moderate time savings. Using convolutional neural network (CNN), delineations of volumes are faster and more accurate. We have used CTs with the annotated structure sets to train and evaluate a CNN. MATERIAL AND METHODS: The CNN is a standard segmentation network modified to minimize memory usage. We used CTs and structure sets from 75 cervical cancers and 191 anorectal cancers receiving radiation therapy at Skåne University Hospital 2014-2018. Five structures were investigated: left/right femoral heads, bladder, bowel bag, and clinical target volume of lymph nodes (CTVNs). Dice score and mean surface distance (MSD) (mm) evaluated accuracy, and one oncologist qualitatively evaluated auto-segmentations. RESULTS: Median Dice/MSD scores for anorectal cancer: 0.91-0.92/1.93-1.86 femoral heads, 0.94/2.07 bladder, and 0.83/6.80 bowel bag. Median Dice scores for cervical cancer were 0.93-0.94/1.42-1.49 femoral heads, 0.84/3.51 bladder, 0.88/5.80 bowel bag, and 0.82/3.89 CTVNs. With qualitative evaluation, performance on femoral heads and bladder auto-segmentations was mostly excellent, but CTVN auto-segmentations were not acceptable to a larger extent. DISCUSSION: It is possible to train a CNN with high overlap using structure sets as ground truth. Manually delineated pelvic volumes from structure sets do not always strictly follow volume boundaries and are sometimes inaccurately defined, which leads to similar inaccuracies in the CNN output. More data that is consistently annotated is needed to achieve higher CNN accuracy and to enable future clinical implementation.

Intricacies of Radiographic Assessment in Testicular Germ Cell Tumors.

Testicular germ cell tumors (GCTs) are malignancies with a unique biology, pathology, clinical appearance, and excellent outcomes. A correct radiographic assessment of GCTs is extremely important for the clinical management in several typical scenarios. Advancements in the field of diagnostic medicine bring an increasing number of sophisticated imaging methods to increase the performance of imaging studies. The conventional computed tomography (CT) remains the mainstay of diagnostic imaging in the management of GCTs. While certain improvements in the sensitivity and specificity are suggested with magnetic resonance (MR) imaging with lymphotrophic nanoparticles in evaluating retroperitoneal lymph nodes during the staging procedure, further exploration in larger prospective studies is needed. A common diagnostic dilemma is assessing the post-chemotherapy residual disease in GCTs. Several studies have consistently shown advantages in the utility of positron emission tomography (PET) scanning in post-chemotherapy residual retroperitoneal lymph nodes in patients with seminoma, but not with non-seminoma. Recommendations suggest that seminoma patients with a residual disease in the retroperitoneum larger than 3 cm should be subjected for PET scanning with 18-fluorodeoxyglucose. Relatively high sensitivity, specificity and a negative predictive value (80-95%) may guide clinical decision to spare these patients of high morbidity of an unnecessary surgery. However, a positive predictive value of around 50% renders PET scanning difficult to interpret in the case of positive finding. These patients often require extremely difficult surgical procedures with the high risk of post-operative morbidity. Therefore, seminoma patients with PET positive residual masses larger than 3 cm still remain a serious challenge in the decision making of nuclear medicine specialist, oncologists, and urologic surgeons. In this article, we aim to summarize data on controversial dilemmas in staging procedures, active surveillance, and post-chemotherapy assessment of GCTs based on the available published literature.

Characteristics of chronic alcohol-related brain damage from 18F-FDG PET-CT findings / 中华神经医学杂志

Objective To analyze the characteristics of alcohol-related brain damage according to 18F-fluorodeoxy-glucose (18F-FDG) position emission tomography-computer tomography (PET-CT).Methods Excessive alcohol consumption patients accepted 18F-FDG PET-CT in our hospital from August 2016 to November 2018 were chosen as excessive alcohol consumption group and non-drinking patients accepted 18F-FDG PET-CT in our hospital at the same time were chosen as non-drinking group according to 1:4 ratio.The 18F-FDG PET-CT imaging data were analyzed;the characteristics of abnormal changed rate of CT sequences after stratification by age and the relations of alcohol consumption with abnormal CT sequences and PET sequences were compared between the two groups.Results A total of 52 patients with excessive alcohol consumption and 200 non-drinking patients were chosen.Among patients aged 45-59 years,the abnormal changed rate of CT sequences in the excessive alcohol consumption group was significantly higher than that in the non-drinking group (P＜0.05).In the CT sequences,33 patients in the 2 groups presented abnormalities,mainly including cerebral atrophy and lacunar infarction.In the PET sequences,62 patients in the two groups presented abnormalities,mainly manifesting as reduced metabolism level of bilateral frontal and parietal lobes.Among the 52 patients from excessive alcohol consumption group,those with abnormal CT sequences were older,had longer drinking history and had higher total drinking amount than those with normal CT sequences,and the differences were statistically significant (P＜0.05).As compared with those in patients with normal PET sequences,those with abnormal PET sequences had higher weekly and total alcohol consumption,and longer drinking history,and the differences were statistically significant (P＜0.05).Conclusion Excessive alcohol consumption is an important risk factor for structural damages in middle-aged men,which can cause a decrease of glucose metabolism level in the frontal and parietal lobes.

Penile Metastasis from Prostate Cancer Presenting as Malignant Priapism Detected Using Gallium-68 Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography.

Gallium-68 prostate-specific membrane antigen positron emission tomography/computed tomography (Ga-68 PSMA PET/CT) is a promising diagnostic tool for patients with prostate cancer. Penile metastasis from prostate cancer is a rare phenomenon that infrequently manifests as malignant priapism. We present a case of 79-year-old patient diagnosed as a case of adenocarcinoma prostate presenting with penile metastases imaged using Ga-68 PSMA PET/CT.

Detection of Primary Malignancy and Metastases with FDG PET/CT in Patients with Cholangiocarcinomas: Lesion-based Comparison with Contrast Enhanced CT.

The current National Comprehensive Cancer Network (NCCN) Guidelines consider the role of 2-deoxy-2-(18)F-fluoro-d-glucose positron emission tomography/computer tomography (FDG PET/CT) in the evaluation of cholangiocarcinoma (CCA) as "uncertain," and have recommended contrast enhanced computed tomography (CECT) but not FDG PET/CT as a routine imaging test for CCA workup. We set out to compare the diagnostic performance of FDG PET/CT and CECT in patients with CCA. The retrospective study included patients with CCA who underwent FDG PET/CT and CECT within 2-month interval between 2011 and 2013 in our hospital. Lesion-based comparison was conducted. Final diagnoses were made based on the composite clinical and imaging data with minimal 6-month follow-up. A total of 18 patients with 28-paired tests were included. There is a total of 142 true malignant lesions as revealed by the 6-paired pre-treatment and 22-paired post-treatment tests. On a lesion-based analysis, the sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs), and accuracies of PET/CT and CECT for detection of CCA were 96.5%, 55.5%, 97.2%, 50.0%, 94.1% and 62.2%, 66.7%, 96.7%, 10.0%, 62.5%, respectively. FDG PET/CT detected more intrahepatic malignant and extrahepatic metastases; and had significant higher sensitivity, NPV, and accuracy than CECT, while similar in specificity and PPV. No true positive lesion detected on CECT that was missed on PET/CT, and none of the false negative lesions on PET/CT were detected on CECT. Six patients had paired pretreatment tests, and FDG PET/CT results changed planned management in three patients. Our data suggest that FDG PET/CT detect more primary and metastatic lesions and lead to considerable changes in treatment plan in comparison with CECT.

PET/CT in Head-neck Malignancies: The Implications for Personalized Clinical Practice.

PET/CT has been shown to help localize head and neck cancers and provide more accurate staging, post-treatment assessment, and restaging than standard imaging. PET/CT detects synchronous and metachronous cancers and sequelae of therapy and provides prognostic information for each patient. Information provided by PET/CT allows for more individualized therapeutic and surveillance plans for patients with head and neck squamous cell carcinoma.

Value of 18F-FDG PET/CT for diagnosis of lymphatic metastasis in patients with non-small cell lung cancer / 局解手术学杂志

Objective To assess the value of fuorine-18-fluom deoxy glucose positron emission tomography /computer tomography (18F-FDG PET/CT) in diagnosis of lymph node metastasis in the cases with non-small cell lung cancer ( NSCLC) .Methods From March 2012 to March 2015,167 patients underwent 18F-FDG PET/CT and contrast enhanced CT inspection within 10 days prior to the surgery and were pathologically diagnosed as non-small cell lung cancer(NSCLC) after surgery.With regard to estimation of the lymphatic metastasis,we com-pared the sensitivity,specificity,accuracy,positive and negative predictive value ,and Youden index between the PET/CT and contrast en-hanced CT.Results There were 731 lymph node stations from the 167 patients.Referred to the final pathological results ,PET/CT has screened 143 lymph node stations in true positive set ,26 lymph node stations in false positive set ,61 lymph node stations in false negative set , and 501 lymph node stations in true negative set .Furthermore,the sensitivity,specificity,the positive and negative forecast values ,and Youden index of PET/CT and CT was 70.10%vs.54.19%(P<0.05),95.07%vs.92.23%(P<0.05),88.10%vs.81.67%(P<0.05),84.62%vs.72.85%(P<0.05),89.15%vs.81.67%(P<0.05) and 0.65 vs.0.46 (P<0.05),respectively.Conclusion It is more effective to to precisely validate lymphatic metastasis of NSCLC by using PET /CT than using contrast enhanced CT inspection .Additionally,PET/CT can provide more information for the preoperative diagnosis , staging and the follow-up treatment of lung cancer .