Since its introduction in the 1970s, computed tomography(CT) has revolutionized diagnostic decision-making. One of the major concerns associated with the widespread use of CT is the associated ...increased radiation exposure incurred by patients. The link between ionizing radiation and the subsequent development of neoplasia has been largely based on extrapolating data from studies of survivors of the atomic bombs dropped in Japan in 1945 and on assessments of the increased relative risk of neoplasia in those occupationally exposed to radiation within the nuclear industry. However, the association between exposure to low-dose radiation from diagnostic imaging examinations and oncogenesis remains unclear. With improved technology, significant advances have already been achieved with regards to radiation dose reduction. There are several dose optimization strategies available that may be readily employed including omitting unnecessary images at the ends of acquired series, minimizing the number of phases acquired, and the use of automated exposure control as opposed to fixed tube current techniques. In addition, new image reconstruction techniques that reduce radiation dose have been developed in recent years with promising results. These techniques use iterative reconstruction algorithms to attain diagnostic quality images with reduced image noise at lower radiation doses.
Surgical resection for gastric adenocarcinoma is associated with significant post-operative morbidity and mortality. The aim of this study was to assess the prognostic significance of sarcopenia in ...patients undergoing resection for gastric adenocarcinoma with respect to post-operative morbidity and survival.
A retrospective analysis was conducted on a cohort of consecutive patients who underwent surgical resection for gastric adenocarcinoma between 2008 and 2014. Patient demographics, radiological parameters, and pathological data were collected. OsiriX software (Pixmeo) was used to measure skeletal muscle area, which was normalized for height to calculate skeletal muscle index.
A total of 56 patients (41 male, 15 female; mean age, 68.4 ± 11.9 years) met the inclusion criteria. Of these, 36% (20 of 56) of the patients were sarcopenic pre-operatively. Both sarcopenic and non-sarcopenic patient groups were equally matched with the exception of weight and body mass index (P=0.036 and 0.001, respectively). Sarcopenia was associated with a decreased overall survival (log-rank P=0.003) and was an adverse prognostic predictor of overall survival in multivariate analysis (hazard ratio, 10.915; P=0.001). Sarcopenia was a predictor of serious in-hospital complications in multivariate analysis (odds ratio, 3.508; P=0.042).
In patients undergoing curative resection for gastric cancer, there was a statistically significant association between sarcopenia and both decreased overall survival and serious post-operative complications. The measurement and reporting of skeletal muscle index on pre-operative computed tomography should be considered.
Objectives
Performance of a modified abdominopelvic CT protocol reconstructed using full iterative reconstruction (IR) was assessed for imaging patients presenting with acute abdominal symptoms.
...Materials and methods
Fifty-seven patients (17 male, 40 female; mean age of 56.5 ± 8 years) were prospectively studied. Low-dose (LD) and conventional-dose (CD) CTs were contemporaneously acquired between November 2015 and March 2016. The LD and CD protocols imparted radiation exposures approximating 10–20% and 80–90% those of routine abdominopelvic CT, respectively. The LD images were reconstructed with model-based iterative reconstruction (MBIR), and CD images with hybrid IR (40% adaptive statistical iterative reconstruction (ASIR)). Image quality was assessed quantitatively and qualitatively. Independent clinical interpretations were performed with a 6-week delay between reviews.
Results
A 74.7% mean radiation dose reduction was achieved: LD effective dose (ED) 2.38 ± 1.78 mSv (size-specific dose estimate (SSDE) 3.77 ± 1.97 mGy); CD ED 7.04 ± 4.89 mSv (SSDE 10.74 ± 5.5 mGy). LD-MBIR images had significantly lower objective and subjective image noise compared with CD-ASIR (
p
< 0.0001). Noise reduction for LD-MBIR studies was greater for patients with BMI < 25 kg/m
2
than those with BMI ≥ 25 kg/m
2
(5.36 ± 3.2 Hounsfield units (HU) vs. 4.05 ± 3.1 HU,
p
< 0.0001). CD-ASIR studies had significantly better contrast resolution, and diagnostic acceptability (
p
< 0.0001 for all). LD-MBIR studies had significantly lower streak artifact (
p
< 0.0001). There was no difference in sensitivity for primary findings between the low-dose and conventional protocols with the exception of one case of enteritis.
Conclusions
Low-dose abdominopelvic CT performed with MBIR is a feasible radiation dose reduction strategy for imaging patients presenting with acute abdominal pain.
Cystic fibrosis(CF)is the most common autosomal recessive disease of the Caucasian population worldwide,with respiratory disease remaining the most relevant source of morbidity and mortality.Computed ...tomography(CT)is frequently used for monitoring disease complications and progression.Over the last fifteen years there has been a six-fold increase in the use of CT,which has lead to a growing concern in relation to cumulative radiation exposure.The challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality,but fulfil the requirements of a diagnostic quality CT.Dose-optimisation,particularly in CT,is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 m Sv,a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic Radiation.This review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.
AIM:To quantify cumulative effective dose of intensive care unit(ICU)patients attributable to diagnostic imaging.METHODS:This was a prospective,interdisciplinary study conducted in the ICU of a large ...tertiary referral and level 1 trauma center.Demographic and clinical data including age,gender,date of ICU admission,primary reason for ICU admission,APACHE Ⅱ score,length of stay,number of days intubated,date of death or discharge,and re-admission data was collected on all patients admitted over a 1-year period.The overall radiation exposure was quantified by the cumulative effective radiation dose(CED)in millisieverts(mS v)and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board.Pediatric patients were selected for subgroupanalysis.RESULTS:A total of 2737 studies were performedin 421 patients.The total CED was 1704 m Sv with a median CED of 1.5 mS v(IQR 0.04-6.6 mS v).Total CED in pediatric patients was 74.6 mS v with a median CED of 0.07 mS v(IQR 0.01-4.7 mS v).Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED.Computed tomography(CT)accounted for 16% of all studies performed and contributed 97% of total CED.Trauma patients received a statistically significant higher dose median CED 7.7 mS v(IQR 3.5-13.8 mS v) than medical median CED 1.4 m Sv(IQR 0.05-5.4 m Sv) and surgical median CED 1.6 mS v(IQR 0.04-7.5 mS v) patients.Length of stay in ICU OR = 1.12(95%CI:1.079-1.157) was identified as an independent predictor of receiving a CED greater than 15 mS v.CONCLUSION:Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs.CED should be minimized where feasible,especially in young patients.
Haematuria: An Imaging Guide Moloney, Fiachra; Murphy, Kevin P; Twomey, Maria ...
Advances in Urology,
01/2014, Letnik:
2014
Journal Article
Recenzirano
Odprti dostop
This paper discusses the current status of imaging in the investigation of patients with haematuria. The physician must rationalize imaging so that serious causes such as malignancy are promptly ...diagnosed while at the same time not exposing patients to unnecessary investigations. There is currently no universal agreement about the optimal imaging work up of haematuria. The choice of modality to image the urinary tract will depend on individual patient factors such as age, the presence of risk factors for malignancy, renal function, a history of calculus disease and pregnancy, and other factors, such as local policy and practice, cost effectiveness and availability of resources. The role of all modalities, including conventional radiography, intravenous urography/excretory urography, ultrasonography, retrograde pyelography, multidetector computed tomography urography (MDCTU), and magnetic resonance urography, is discussed. This paper highlights the pivotal role of MDCTU in the imaging of the patient with haematuria and discusses issues specific to this modality including protocol design, imaging of the urothelium, and radiation dose. Examination protocols should be tailored to the patient while all the while optimizing radiation dose.
AIM To assess the effect of neutral(NC) and positive(PC) oral contrast use on patient dose in low-dose abdominal computed tomography(CT).METHODS Low-dose clinically indicated CTs were performed on 79 ...Crohn’s patients(35 = PC, 1 L 2% gastrografin; 44 = NC, 1.5 L polyethylene glycol). Scanner settings for both acquisitions were identical apart from 25 s difference in intravenous contrast timing. Body mass index(BMI), scan-ranges, dose-length product and size-specific dose estimated were recorded. Data was reconstructed with pure model-based iterative reconstruction. Image quality was objectively and subjectively analysed. Data analysis was performed with Statistical Package for Social Scientists.RESULTS Higher doses were seen in neutral contrast CTs(107.60 ± 78.7 m Gy.cm, 2.47 ± 1.21 m Gy vs 85.65 ± 58.2 m Gy.cm, 2.18 ± 0.96 m Gy). The differencehad both NC and PC investigations. Image-quality assessment yielded 6952 datapoints. NC image quality was significantly superior(P < 0.001)(objective noise, objective signal to noise ratio, subjective spatial resolution, subjective contrast resolution, diagnostic acceptability) at all levels. NC bowel distension was significantly(P < 0.001) superior.CONCLUSION The use of polyethylene glycol as a neutral OC agent leads to higher radiation doses than standard positive contrast studies, in low dose abdominal CT imaging. This is possibly related to the osmotic effect of the agent resulting in larger intraluminal fluid volumes and resultant increased overall beam attenuation.
Castleman disease (CD) is a rare benign lymphoproliferative disorder, the etiology of which is unclear. Clinically it may manifest as localized disease (unicentric) or disseminated disease ...(multicentric). CD occurs in the thorax in 70% of cases, abdomen and pelvis in 15%, and in the neck in 10–15% of cases. We present a case of a pleural mass located posteriorly in a paraspinal location, which was discovered incidentally in a 50-year-old man and was subsequently resected followed by an unexpected diagnosis of Castleman disease on histological examination. In this report, we review the clinical and histological findings in a rare presentation of Castleman disease and discuss the findings in this case as part of an overall review of the typical radiological findings seen in Castleman disease.
Roifman syndrome is a rare autosomal recessive inherited syndromic immunodeficiency. We wish to add to the available literature by reporting two brothers with clinical, radiological and immunological ...features of Roifman syndrome, confirmed on whole exome sequencing. We report an excellent response to subcutaneous immunoglobulin therapy in both brothers, reducing infection burden and hospital admissions. New radiological features are also described here which may assist in the diagnosis of other patients.
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