•Photon Counting (PC) detectors enable high quality computed tomography imaging with significantly reduced Xray dose.•High Resolution images are available in daily routine without increasing the dose ...applied to the patient.•PC detectors offer multi energy data in every scan and thus allow spectral material separation for better diagnostic and patient health.
Photon counting detectors in Computed Tomography overcome several drawbacks of classical detectors used in Computed Tomography.
Classical detectors measure X-rays by converting them into visible light during the initial absorption inside a pixel (individual scintillator cube which is separated mechanically from neighboring pixels) and then collecting the emitted visible light per pixel with a photo diode. High resolution imaging with scintillator-based detector experiences a limit due to the dose usage capabilities, low dose applications suffer from classical electronic noise and true material separation inside the scan object can only be performed, if the data acquisition was selected prior the scan examination (dual energy protocols).
Photon counting detectors made of a semiconductor crystal which allows the detection of the incoming photons individually using a direct conversion process. The spatial resolution is defined electrically and only limited by the charge distribution inside the semiconductor. This enables sharper images without the dose penalty of interpixel gaps or post patient collimation. The contrast to noise ratio is increased by detecting each photon individually with respect to its energy. This additional energy information can be used during any diagnostic procedure to gain further detailed insights into the morphology and functionality of the scanned object. And finally, no classical noise is deteriorating the signal as the digitization of the signal is done during the initial detection.
Photon counting detectors lead the way to higher contrasts, higher resolution, and lower doses which may help elevating the potential of computed tomography. Upcoming studies will evaluate the true potential of this technology and point to the variety of clinical fields which may profit from this imaging modality to make all humans lives healthier.
Many people restrict their palatable food intake. In animal models, time-limiting access to palatable foods increases their intake while decreasing intake of less preferred alternatives; negative ...emotional withdrawal-like behavior is sometimes reported. In drug addiction models, intermittent extended access drives greater changes in use than brief access. When it comes to palatable food, the impact of briefer vs. longer access durations within intermittent access conditions remains unclear. Here, we provided male rats with chow or with weekday access to a preferred, sucrose-rich diet (PREF) (2, 4, or 8 h daily) with chow otherwise available. Despite normal energy intake, all restricted access conditions increased weight gain by 6 weeks and shifted diet acceptance within 1 week. They increased daily and 2-h intake of PREF with individual vulnerability and decreased chow intake. Rats with the briefest access had the greatest binge-like (2-h) intake, did not lose weight on weekends despite undereating chow, and were fattier by 12 weeks. Extended access rats (8 h) showed the greatest daily intake of preferred food and corresponding undereating of chow, slower weight gain when PREF was unavailable, and more variable daily energy intake from week to week. Increased fasting glucose was seen in 2-h and 8-h access rats. During acute withdrawal from PREF to chow diet, restricted access rats showed increased locomotor activity. Thus, intermittent access broadly promoted weight gain, fasting hyperglycemia and psychomotor arousal during early withdrawal. More restricted access promoted greater binge-like intake and fat accumulation, whereas longer access promoted evidence of greater food reward tolerance.
Abstract Background Palatable food access promotes obesity leading some to diet. Here, we modeled the roles of duration, intermittency and choice of access in bingeing, escalation of daily intake, ...and underacceptance of alternatives. Method Female rats with (“Choice”) or without continuous chow access, received chow or continuous (Chocolate), intermittent (MWF) long (24 h, Int-Long), or intermittent short (30 min, Int-Short) access to a sucrose-rich, chocolate-flavored diet (CHOC). Results Int-Long rats showed cycling body weight; they overate CHOC, had increased feed efficiency on access days and underate chow and lost weight on non-access days, the latter correlating with their reduced brown fat. Int-Short rats had the greatest 30-min intake upon CHOC access, but did not underaccept chow or weight cycle. Individual vulnerability for intermittent access-induced feeding adaptations was seen. Continuous access rats gained fat disproportionate, but in direct relation, to their normalized energy intake and persistently underaccepted chow despite abstinence and return to normal weight. Abstinence reduced the binge-like CHOC intake of Int-Short rats and increased that of continuous access rats, but not to levels associated with intermittent access history. Choice increased daily CHOC intake under Continuous access and binge-like intake under Int-Short access. Conclusions Intermittency and duration of past access to palatable food have dissociable, individually-vulnerable influences on its intake and that of alternatives. With extended access, daily intake reflects the palatability of available food, rather than metabolic need. Ongoing restrictedness of access or a history of intermittency each drive binge-like intake. Aspects of palatable food availability, similar and different to drug availability, promote disordered eating.
Introduction
The col-cap concept encouraged neurologists to inject a large group of muscles in the treatment of cervical dystonia. This includes deep muscles such as the obliquus capitis inferior or ...the semispinalis capitis, and muscles close to vascular or neurological structures such as scalene muscles. Our aim was to determine the accuracy of injections in cervical muscles using ultrasonography (US) or palpation of anatomical landmarks.
Methods
A mix of paint, gelatin and iodized contrast agent was injected in nine pairs of cervical muscles of human cadavers, according to two injection techniques: US-guided and non-guided. The dye was localized on 1 cm-thick, frozen slices.
Results
A total of 102 muscles was injected in the US-guided group (
n
= 8). The global accuracy was 88.2%. The lowest accuracy was in the OCI (41.7%); trying to avoid the vertebral artery, injections were too medial. A total of 54 muscles was injected in the non-guided group (
n
= 3). The global accuracy was 48.0%; moreover, some dye was found in four blood vessels. The embalming process produced texture changes, making difficult the palpation of bony landmarks.
Conclusions
Our results indicate that US-guided injections are more accurate than non-guided injections in most cervical muscles.
Abstract Satiety signals arising from the gastrointestinal (GI) tract and related digestive organs during food ingestion and digestion are conveyed by vagal sensory afferents to the hindbrain nucleus ...of the solitary tract (NST). Two intermingled but chemically distinct NST neuronal populations have been implicated in meal size control: noradrenergic (NA) neurons that comprise the A2 cell group, and glucagon-like peptide-1 (GLP-1)-positive neurons. Previous results indicate that A2 neurons are activated in a meal size-dependent manner in rats that have been acclimated/entrained to a feeding schedule in order to increase meal size, whereas feeding under the same conditions does not activate GLP-1 neurons. The present study was designed to test the hypothesis that both A2 and GLP-1 neuronal populations are recruited in non-entrained rats after voluntary first-time intake of an unrestricted, satiating volume of liquid Ensure. DBH-positive A2 neurons within the caudal visceral NST were progressively recruited to express cFos in rats that consumed progressively larger volumes of Ensure. Among these DBH-positive neurons, the prolactin-releasing peptide (PrRP)-positive subset was more sensitive to feeding-induced activation than the PrRP-negative subset. Notably, significant activation of GLP-1-positive neurons occurred only in rats that consumed the largest volumes of Ensure, corresponding to nearly 5% of their BW. We interpret these results as evidence that progressive recruitment of NA neurons within the caudal NST, especially the most caudally-situated PrRP-positive subset, effectively “tracks” the magnitude of GI satiety signals and other meal-related sensory feedback. Conversely, GLP-1 neurons may only be recruited in response to the homeostatic challenge of consuming a very large, unanticipated meal.
Published research supports a role for central glucagon-like peptide 1 (GLP-1) signaling in suppressing food intake in rodent species. However, it is unclear whether GLP-1 neurons track food intake ...and contribute to satiety, and/or whether GLP-1 signaling contributes to stress-induced hypophagia. To examine whether GLP-1 neurons track intake volume, rats were trained to consume liquid diet (LD) for 1 h daily until baseline intake stabilized. On test day, schedule-fed rats consumed unrestricted or limited volumes of LD or unrestricted volumes of diluted (calorically matched to LD) or undiluted Ensure. Rats were perfused after the test meal, and brains processed for immunolocalization of cFos and GLP-1. The large majority of GLP-1 neurons expressed cFos in rats that consumed satiating volumes, regardless of diet type, with GLP-1 activation proportional to intake volume. Since GLP-1 signaling may limit intake only when such large proportions of GLP-1 neurons are activated, a second experiment examined the effect of central GLP-1 receptor (R) antagonism on 2 h intake in schedule-fed rats. Compared with baseline, intracerebroventricular vehicle (saline) suppressed Ensure intake by ∼11%. Conversely, intracerebroventricular injection of vehicle containing GLP-1R antagonist increased intake by ∼14% compared with baseline, partly due to larger second meals. We conclude that GLP-1 neural activation effectively tracks liquid diet intake, that intracerebroventricular injection suppresses intake, and that central GLP-1 signaling contributes to this hypophagic effect. GLP-1 signaling also may contribute to satiety after large volumes have been consumed, but this potential role is difficult to separate from a role in the hypophagic response to intracerebroventricular injection.
Aim
Anastomotic leakage is a major complication after right hemicolectomy leading to increased morbidity, mortality, length of stay and hospital costs. Previous studies have shown that the type of ...anastomosis (handsewn or stapled) is a major risk factor for anastomotic leakage. The purpose of this study was to evaluate the clinical impact of anastomotic leakage depending on the type of anastomotic technique (handsewn vs stapled).
Method
This was an observational, retrospective, cross‐sectional study. Data were collected at two major hospitals in Spain from January 2010 to December 2016. Patients had elective right colectomy for cancer with handsewn or stapled ileocolic anastomosis. The main outcome was the grading of postoperative treatments needed to manage anastomotic leakage according to two major classification systems. The other outcomes were demographics, time of hospitalization and death rate.
Results
Patients (n = 961) underwent elective surgery for neoplasia of the right colon. Anastomotic leakage was diagnosed in 116 patients (12.07%). Patients with handsewn anastomosis had more Type IIIA surgical complications and received milder treatments than patients with stapled anastomosis (SA) who had more Type IIIB complications and more re‐laparotomies (P = 0.004). The clinical impact of anastomotic leakage was significantly more severe (Grade C) in patients with SA than in patients with a handsewn anastomosis (P = 0.007). No differences were found for hospital stay of patients with anastomotic leakage depending on the type of anastomosis (P = 0.275). Death due to anastomotic leakage was similar in both groups.
Conclusions
The clinical impact of anastomotic leakage in patients with handsewn anastomosis is lower than in patients with SA.
PDF
