Background: Craniocervical Dissections (CCD) are a crucial emergency state causing 20% of strokes in patients under the age of 45. Although DSA (digital substraction angiography) is regarded as the gold standard, noninvasive methods of CT, CTA and MRI, MRA are widely used for diagnosis.Aim: Our aim is to illustrate noninvasive imaging findings in CCD.Conclusion: Emphasizing on diagnostic pitfalls, limitations and mimicking diseases.

The purpose of this article was to review the anatomy of the cavernous sinus (CS), illustrate numerous lesions that can affect the CS, and emphasize the imaging characteristics for each lesion to further refine the differential diagnoses. The CS, notwithstanding its small size, contains a complicated and crucial network that consists of the carotid artery, the venous plexus, and cranial nerves. The wide-ranging types of pathologies that can involve the CS can be roughly classified as tumoral, congenital, infectious/inflammatory/granulomatous, and vascular. Conditions that affect the CS usually lead to symptoms that are similar to each other; thus, for diagnosis, imaging procedures are required. Radiological evaluations are also required to detect pre- and postoperative CS invasion. Magnetic resonance imaging, which can be supplemented with thin-section contrast-enhanced sequences, is the preferred imaging technique for evaluating the CS. For correct diagnosis of CS lesions and accurate evaluations of CS invasions, it is essential to carefully analyze the anatomical structures within the CS and to acquire precise knowledge about the imaging features of CS lesions, which may frequently overlap.

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To determine the utility of 18 F-DOPA PET/MRI versus cross-sectional MRI alone in glioma response assessment and identify whether the two techniques demonstrate different tumour features. Methods 18 F-DOPA PET/MRI studies from 40 patients were analysed. Quantitative PET parameters and conventional MRI features were recorded. Tumour volume was assessed on both PET and MRI. Using DSC-PWI, maps of CBF and CBV were Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporationobtained. Within VOIs of tumour features and normal-appearing white matter (NAWM) drawn on MRI, SUV max , CBF and CBV were recorded. Presence of residual active tumour was assessed by qualitative visual assessment. ROC analysis was performed univariately and on parameter combination to analyse ability to determine presence/absence of disease. Reference standard for presence of viable tissue was biopsy or clinical follow-up. ResultsMedian SUV max was 3.4 for low-grade glioma (LGG) and 3.3 for high-grade glioma (HGG). There was a significant correlation between PWI parameters and WHO grade (p<0.001), but no correlation with SUV max . Median 18 F-DOPA volume was 8216.88 mm 3 for HGG and 6284.94 mm 3 for LGG; MRI volume was 6316.57 mm 3 and 5931.55 mm 3 respectively. SUV max analysis distinguished enhancing and non-enhancing components from necrosis and NAWM and demonstrated active disease in non-enhancing regions. Visually, the modalities were concordant in 37 patients. Combining the multiparametric PET/MRI approach with all available data enhanced detection of the presence of tumour (AUC 0.99, p<0.01). ConclusionMRI and 18 F-DOPA are complementary modalities for assessment of tumour burden. Matching 18 F-DOPA and MRI in assessing residual tumour volume may better delineate the radiotherapy target volume.

Aim/Purpose Fibroblast activation protein-(FAP)-ligands, a novel class of tracers for PET/CT imaging, demonstrated promising results in previous studies in various malignancies compared to standard [18F]FDG PET/CT. 68Ga-labeled fibroblast activation protein inhibitor-([68Ga]Ga-DOTA-FAPI)-PET/CT impresses with sharp contrasts in terms of high tumor uptake and low background noise leading to clear delineation. [18F]FDG PET/CT has limited accuracy in bladder cancer due to high background signal. Therefore, we sought to evaluate the diagnostic potential of [68Ga]FAPI in patients with bladder cancer. Material and Methods This retrospective analysis consisted of 8 patients (median age 66), 7 of whom underwent both [68Ga]FAPI and [18F]FDG PET/CT scans with a median time interval of 5 days (range 1–20 days). Quantification of tracer uptake was determined with SUVmax and SUVmean. Furthermore, the tumor-to-background ratio (TBR) was derived by dividing the SUVmax of tumor lesions by the SUVmax of adipose tissue, skeletal muscle, and blood pool. Results Overall, 31 metastases were detected in five patients including lymph node metastases (n = 23), bone metastases (n = 4), lung metastases (n = 3), and a peritoneal metastasis (n = 1). In one patient, [68Ga]FAPI demonstrated significant uptake in the primary tumor located in the bladder wall. [68Ga]FAPI-PET/CT demonstrated significantly higher uptake compared to [18F]FDG PET/CT with higher mean SUVmax (8.2 vs. 4.6; p = 0.01). Furthermore, [68Ga]FAPI detected additional 30% (n = 9) lesions, missed by [18F]FDG. TBR demonstrated favorable uptake for [68Ga]FAPI in comparison to [18F]FDG. Significant differences were determined with regard to metastasis/blood pool ([68Ga]FAPI 5.3 vs [18F]FDG 1.9; p = 0.001). Conclusion [68Ga]FAPI-PET/CT is a promising diagnostic radioligand for patients with bladder cancer. This first described analysis of FAP-ligand in bladder cancer revealed superiority over [18F]FDG in a small patient cohort. Thus, this so far assumed potential has to be confirmed and extended by larger and prospective studies.

Background Gallium 68-tetraazacyclododecane-tetraacetic acid-octreotate ([68Ga]Ga-DOTA-TATE) is a selective somatostatin analogue ligand, which shows increased affinity for somatostatin receptor subtype (SSTR) 2 and has been used routinely for imaging neuroendocrine tumors with PET/CT. We investigated the utility of [68Ga]Ga-DOTA-TATE positron emission tomography/computed tomography (PET/CT) in patients with suspected pituitary pathology. We reviewed imaging for twenty consecutive patients (8 men, 12 women, mean age of 48.2, range 14–78) with suspected pituitary pathology who were referred for [68Ga]Ga-DOTA-TATE PET/CT. Results Nine patients presented with recurrent Cushing’s syndrome following surgical resection of pituitary adenomas due to recurrent Cushing’s disease (seven patients) and ectopic ACTH secreting tumor (2 patients). All seven patients with recurrent Cushing’s disease showed positive pituitary [68Ga]Ga-DOTA-TATE uptake while both cases of ectopic hormonal secretion had absented pituitary uptake. In 1 of these 2 patients, [68Ga]Ga-DOTA-TATE was able to localize the source of ectopic ACTH tumor. Six patients presented de novo with Cushing’s due to ectopic ACTH secretion; [68Ga]Ga-DOTA-TATE PET/CT was able to localize ectopic tumors in six of eight patients (3 lungs, 2 pancreases, 1 mid-gut) There was high uptake [68Ga]Ga-DOTA-TATE in 3 cases of recurrent central hyperthyroidism (SUVmax 6.6–14.3) and 2 cases of prolactinoma (SUVmax 5.5 and 11.3). Conclusion Absent [68Ga]Ga-DOTA-TATE activity in the pituitary fossa is useful in excluding pituitary disease in recurrent Cushing’s. Recurrent pituitary thyrotropinomas and prolactinomas showed moderate to high pituitary activity. In addition, in Cushing’s syndrome, [68Ga]Ga-DOTA-TATE is useful for detection of ectopic sources of ACTH production, especially where anatomic imaging is negative.

A 54-year-old man with multiple endocrine neoplasia type 1 had previous history of parathyroid surgery and left thyroid lobectomy 5 years earlier, and was referred for recurrent hypoglycemic episodes. 68Ga-DOTATATE PET/CT had showed multiple lesions in the right lung, liver, and pancreas. Biopsy from pancreas revealed low-grade neuroendocrine neoplasia. After 2 fractions of 177Lu-DOTATATE therapy, the size of lesions and its activity reduced on the 68Ga-DOTATATE scan and the hypoglycemic episodes manifested every day have scaled down to 1 time over 1-year follow-up. Herein, we report a case of malignant insulinoma successfully treated with radiolabeled somatostatin receptor therapy using 177Lu-DOTATATE.

Radiologic hyperperfusion does not match clinical hyperperfusion. Normal group responded to stenting with statistically significant changes of rMTT and dMTT. Hyperperfusion mostly occurred in the contralateral critically stenosed patients. The hyperperfused group, due to similar MTT of both hemispheres and ipsilateral internal carotid artery being the main feeder of both hemispheres, did not show significant changes in their rMTT and dMTT values after stenting. This shows that reduced hemodynamic reserve is the main reason behind the hyperperfusion after carotid stenting.