The Prevalence of Wrist Ganglia in an Asymptomatic Population: Magnetic Resonance Evaluation

Magnetic resonance imaging (MRI) was performed on the wrists of 103 asymptomatic volunteers. The images were evaluated independently by two musculoskeletal radiologists and one orthopaedic surgeon. Wrist ganglia were identified in 53 out of the 103 wrists. The average long and short axes measurements were 8 mm (range 3–22) and 3 mm (range 2–10), respectively. Seventy per cent of the ganglia originated from the palmar capsule in the region of the interval between the radioscaphocapitate ligament and the long radiolunate ligament. Fourteen per cent of the ganglia were dorsal and originated from the dorsal, distal fibres of the scapholunate ligament. Two ganglia had surrounding soft tissue oedema and one had an associated intraosseous component. Unlike previous surgical and pathological series, our study showed that palmar wrist ganglia are more common than dorsal wrist ganglia. The vast majority of these asymptomatic ganglia occur without associated ligamentous disruption, soft tissue oedema or intraosseous communication.

Computed tomography in diagnosis and staging of the retroperitoneal tumors

The main role of retroperitoneal tumor diagnosis is the imaging examination. Diagnostic imaging is essential for describing and predicting lesion integrity limits adjacent organs.

Methods. The results are based on a sample of 53 patients admitted in the Urology Clinic and investigated during the period 1 January 2005 - 31 December 2014. Results. CT scan for retroperitoneal tumor: vascular tumors are diagnosed in 100% of cases, while endocrine tumors and lymphomas values are between 50-66.67% in terms of a positive diagnosis. In 54.71% of cases studied was identified retroperitoneal tumor invasion into adjacent structures (29 patients), and for 12 cases (22.64%) CT scan was not conclusive enough. CT scan investigation to identify metastasis has statistical significance (p <0.01) according to the different types of retroperitoneal tumors, there were on average 35% for highlighting values of peritumoral lymph nodes and 13% for metastases. The relationship between retroperitoneal tumor size detected by CT (coefficient R =0.736) than those found intraoperative CT examination reveals that tends to underestimate the retroperitoneal tumor size.

Conclusions. Imaging diagnosis is mainframe of positive diagnosis for retroperitoneal tumors. CT scanning bring data not only on tumor location, but also about the nature of injuries (cystic or solid), presence or absence of necrosis, invasion of adjacent structures and abdominal metastases.

Radiation doses in chest, abdomen and pelvis CT procedures

Computed tomography (CT) scanning is recognised as a high-radiation dose modality and estimated to be 17 % of the radiological procedure and responsible for 70 % of medical radiation exposure. Although diagnostic X rays provide great benefits, their use involves some risk for developing cancer. The objectives of this study are to estimate radiation doses during chest, abdomen and pelvis CT. A total of 51 patients were examined for the evaluation of metastasis of a diagnosed primary tumour during 4 months. A calibrated CT machine from Siemens 64 slice was used. The mean age was 48.0 ± 18.6 y. The mean patient weight was 73.8 ± 16.1 kg. The mean dose-length product was 1493.8 ± 392.1 mGy cm, Volume CT dose index (CTDI vol) was 22.94 ± 5.64 mGy and the mean effective dose was 22.4 ± 5.9 mSv per procedure. The radiation dose per procedure was higher as compared with previous studies. Therefore, the optimisation of patient's radiation doses is required in order to reduce the radiation risk.

Clinico-Radiologic Profile of Spinal Cord Multiple Sclerosis in Adults

MRI is extremely useful for the assessment of initial disease burden and to identify the dissemination of the multiple sclerosis (MS) in time and space. Though MRI of the spinal cord is not used to establish the diagnosis of MS, spinal cord is frequently involved in this disease and there has been increasing emphasis of the spinal imaging in making clinical decision in the management of MS. We undertook a retrospective study of patients with diagnosed MS: 1) to identify radiologic pattern of spinal cord involvement in MS and 2) to correlate radiologic findings with clinical presentation. We reviewed radiologic records from 2004 to 2009 of patients with abnormal T2 signal intensity of the spinal cord with radiologic concern of demyelinating disease. Patients in this cohort who met the Revised McDonald MS Diagnostic Criteria were included in this study. 166 patients were included in the study. There was preference for cervical spinal cord particularly posterior aspect of the spinal cord. Enhancement of the lesions was rare (4.1%). Mean lesion length was 18.2 mm. The average number of lesions per patient was 2.04. Sensory symptoms were predominating and most of the patients had relapsing-remitting course. Patients with sensory symptoms, bladder and bowel involvement and motor symptoms had almost equally distributed lesions among anterior, posterior and central spinal cord. However, all of the patients presented with posterior column signs and gait abnormality had involvement of the posterior spinal cord. Radiologic manifestation of spinal cord MS is extremely variable and can involve the entire length of the spinal cord. Clinical symptoms may or may not be associated with radiologic presentation of the lesions.

Impact of FDG-PET scan on follow-up care in nonmetastatic breast cancer

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Background: Fluorine-18-FDG positron emission tomography (FDG-PET) role in the follow up care of non-metastatic breast cancer is not defined. Methods: We retrospectively analyzed 177 patients with stage I-III breast cancer between November 2004 and June 2006. IRB approval was obtained for this study. Patients were divided into two groups. Group A consisted of patients who had one or more FDG-PET scans as part of their clinical follow up (N=68), and Group B consisted of patients who did not (N=109). Clinical, radiological and pathology data were obtained from patients’ records. Results: Median follow-up is 35 months. Mean age 53 years for group A and 57 years for group B. Group A patients were more likely to have had higher stages (29% stage I, 53% stage II, and 18% stage III) compared with group B (64 % stage I, 31% stage II and 4% stage III). The two groups did not differ significantly in ER+ status (69% vs. 78% p=0.21), or Her2neu status (19% vs. 17%; p=0.6). Group A patients had more clinic visits (18 vs. 11; p=0.009), their tumor marker was checked more often (13 vs. 9 times; p=0.0001), had more radiological studies (10 studies vs. 5; p=0.0001), and had more biopsies (0.88 vs. 0.48 biopsy per patient; p=0.05). These differences were significant even after controlling for stage and chemotherapy. 9/68 patients in group A had tumor recurrence compared to 1/109 in group B (p=0.0003). PET scan indications were as follows: 29 (43%) for asymptomatic follow up evaluation [2 recurred]; 18 (26%) concerning symptoms [0 recurred]; 10 (15%) elevated tumor marker [2 recurred]; 7 (10%) other abnormal imaging studies [1 recurred]; 4 (6%) metastatic workup. Conclusions: While FDG-PET might aid in detecting recurrence in some patients with non-metastatic breast cancer, its use was associated with more clinic visits, blood tests, biopsies, and radiological tests.

No significant financial relationships to disclose.

Positron emission tomography analysis of [11C]KW-6002 binding to human and rat adenosine A2A receptors in the brain

Adenosine A(2A) receptors are found on striatal neurones projecting to the external pallidum. KW-6002 (istradefylline) is a potent and selective antagonist for the adenosine A(2A) receptors in the CNS and acts to inhibit the excessive activity of this pathway in the MPTP marmoset model of PD, thus relieving parkinsonism. The objectives of this study were to investigate the regional binding of the novel positron emission tomography tracer [(11)C]KW-6002 in the healthy human brain and the rat brain, along with receptor occupancy by cold KW-6002 at varying doses in human. The highest [(11)C]KW-6002 uptake in the rat brain was seen in striatum and lower levels in cortex and cerebellum. Brain [(11)C]KW-6002 uptake was well characterized in humans by a two-tissue compartmental model with a blood volume term, and the ED(50) of cold KW-6002 was 0.5 mg in the striatum. Over 90% receptor occupancy was achieved with daily oral doses of greater than 5 mg. In humans, blockable binding was present in all gray matter structures including the cerebellum, which has not been reported to express A(2A) receptors. MRS 1745, an A(2B) receptor selective antagonist, had no effect on the cerebellar binding of [(11)C]KW-6002 in rats, suggesting that this blockable signal is unlikely to result from an affinity for adenosine A(2B) receptors.

A feasibility study of [11C]choline for the molecular imaging of human breast cancer in vivo using positron emission tomography (PET)

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Background: [11C]Choline is a novel PET radiotracer. Preclinical studies suggest that it may be promising in breast cancer. [11C]Choline has been recently evaluated as a screening agent in prostate cancer, but no studies have yet investigated its potential in breast cancer. We report a pilot study evaluating the utility and reproducibility of [11C]Choline-PET in breast cancer. Methods: Dynamic imaging was performed on an ECAT962 HR+ PET scanner for 65 min after intravenous injection with 190–369 MBq [11C]choline. Patients with locally advanced and metastatic breast cancer were eligible. All histological subtypes were included (ductal, lobular, and inflammatory). Arterial blood samples were taken continuously for 10 min, with 8 discrete samples up to 60 min to measure [11C]choline and metabolites. Tissue uptake was determined by standardised uptake value at 60 min (SUV, dose and BSA corrected) and Ki (irreversible trapping) calculated using Patlak (corrected for [11C]choline metabolites in plasma) and modified Patlak analysis (corrected for plasma + tissue metabolites). Reproduciblilty scans were performed 2–17 days later in the absence of treatment. Results: Tumour [11C]choline uptake was observed in 10 out of 11 patients (12 out of 13 distinct lesions). There was a significant difference between tumour and normal tissue (breast/lung) in [11C]choline uptake for Ki (p<0.0001) and SUV (p<0.0001). Tissue uptake was of the order lung ≤ normal breast < tumour < liver ≤ spleen. [11C]choline was rapidly metabolised, at 60 min the mean ± S.E. plasma radioactivity due to [11C]choline was 16.4 ± 2.9%. [11C]Choline uptake was found to be reproducible for Ki (modified Patlak: r=0.93, p<0.0001, Patlak: r=0.85, p=0.002) and SUV (r=0.94, p<0.0001) - measured in 8 patients (median of 2 days after the 1st scan). Tumour Patlak Ki was 13.2% > Ki calculated using modified Patlak analysis. Conclusions: [11C]Choline-PET imaging of breast cancer is promising and warrants further evaluation. Tumour [11C]Choline uptake measured by Ki and SUV is reproducible. We plan to study the relationship between choline uptake measured by PET and immunoassays of tumour samples. Functional imaging could have a vital role to determine the efficacy of target-specific agents.

No significant financial relationships to disclose.

Glucose metabolism in brain tumours can be estimated using [18F]2-fluorodeoxyglucose positron emission tomography and a population-derived input function scaled using a single arterialised venous blood sample

The aim of this study was to assess simplified methods for deriving input functions for estimating glucose metabolism using 18F-FDG-PET. Nine glioma patients underwent paired 18F-FDG-PET scans as part of a phase II study and the data used to estimate the metabolic rate of glucose (MRGlu) using a population-derived input function (arterial data from 14 scans) scaled using a single arterial blood sample taken at 20 min. Paired studies were performed in four further glioma patients with stable disease at least four months following radiotherapy to determine whether scaling the population-derived input function using a 20-min arterialised venous or venous sample further simplified the method. The heated hand method was used to obtain arterialised venous blood that approximated arterial blood. In the 9 phase II glioma patients, there was a good, statistically significant correlation between the MRGlu values estimated using the individual arterial input functions and the single arterial sample scaled population-derived input functions (r(2)=0.88, p<0.001, n=36). Blood samples collected during three scans on two of the stable disease patients showed no significant difference between the arterialised venous and arterial plasma concentrations of 18F (p>0.1, n=15) when the degree of arterialisation of the blood was monitored and maintained using a thermocouple. A significant difference was found between the plasma arterial and venous levels of 18F. There was an excellent correlation between MRGlu estimated using an arterial input function and a population-derived input function scaled using a single arterialised venous blood sample (r(2)=0.98, n=12). The method was reproducible with less than 4.4% variation between repeat tumour scans. Therefore, a population-derived input function scaled using a single arterialised venous blood sample at 20 min can be used for estimating MRGlu using 18F-FDG PET in glioma patients.

In vivo evaluation of [18F]fluoroetanidazole as a new marker for imaging tumour hypoxia with positron emission tomography

Development of hypoxia-targeted therapies has stimulated the search for clinically applicable noninvasive markers of tumour hypoxia. Here, we describe the validation of [¹⁸F]fluoroetanidazole ([¹⁸F]FETA) as a tumour hypoxia marker by positron emission tomography (PET). Cellular transport and retention of [¹⁸F]FETA were determined in vitro under air vs nitrogen. Biodistribution and metabolism of the radiotracer were determined in mice bearing MCF-7, RIF-1, EMT6, HT1080/26.6, and HT1080/1-3C xenografts. Dynamic PET imaging was performed on a dedicated small animal scanner. [¹⁸F]FETA, with an octanol–water partition coefficient of 0.16±0.01, was selectively retained by RIF-1 cells under hypoxia compared to air (3.4- to 4.3-fold at 60–120 min). The radiotracer was stable in the plasma and distributed well to all the tissues studied. The 60-min tumour/muscle ratios positively correlated with the percentage of pO₂ values <5 mmHg (r=0.805, P=0.027) and carbogen breathing decreased [¹⁸F]FETA-derived radioactivity levels (P=0.028). In contrast, nitroreductase activity did not influence accumulation. Tumours were sufficiently visualised by PET imaging within 30–60 min. Higher fractional retention of [¹⁸F]FETA in HT1080/1-3C vs HT1080/26.6 tumours determined by dynamic PET imaging (P=0.05) reflected higher percentage of pO₂ values <1 mmHg (P=0.023), lower vessel density (P=0.026), and higher radiobiological hypoxic fraction (P=0.008) of the HT1080/1-3C tumours. In conclusion, [¹⁸F]FETA shows hypoxia-dependent tumour retention and is, thus, a promising PET marker that warrants clinical evaluation.