Intravenous Administration Of Contrast Material Research Articles

Non-invasive quantification of age-related changes in the vertebral endplate in rats using in vivo DCE-MRI

BackgroundSmall animal models that can mimic degenerative disc disease (DDD) are commonly used to examine DDD progression. However, assessments such as histological studies and macroscopic measurements do not allow for longitudinal studies because they can only be completed after the animal is sacrificed. Dynamic contrast-enhanced MRI (DCE-MRI) may provide a reliable, non-invasive in vivo method for detecting the progression.MethodsThe present study investigated the progression of changes in lumbar discs and the effect of endplate conditions on diffusion into the lumbar discs of aging sand rats after intravenous administration of gadolinium-containing contrast medium through the tail vein. Contrast enhancement was measured in the lumbar intervertebral discs on each image. The results were compared with those from conventional histological characterizations.ResultsT2-weighted images revealed that with aging, the shape of L3–L4, L4–L5, L5–L6, and L6–S1 nucleus pulposus (NP) became irregular, while the mean areas, signal intensities, and T2 values of the NP were significantly decreased. Each of the observed disc changes demonstrated a progressive increase in phase during 2-min scout scans. Post-contrast MRI showed impaired endplate nutritional diffusion to the disc with aging, enhancement was significantly greater in young animals than in old animals. Endplate calcification or sclerosis was histologically confirmed; histologic score was correlated with the age. We found the histological score of the endplate negatively corresponded to the DCE-MRI results.ConclusionsDCE-MRI studies offer a non-invasive in vivo method for investigating the progress of diffusion into the discs and the functional conditions of the endplate. We conclude that quantitative DCE-MRI can identify the severity of disc degeneration and efficiently reflect the progression of vertebral endplate changes in the aging sand rat lumbar spine via the NP contrast enhancement patterns.

Acute kidney injury in patients with nephrotic syndrome undergoing contrast-enhanced CT for suspected venous thromboembolism: a propensity score-matched retrospective cohort study.

To determine whether intravenous iodinated contrast material administration increases the risk of acute kidney injury (AKI) in patients with nephrotic syndrome undergoing contrast-enhanced CT. Patients with nephrotic syndrome undergoing contrast-enhanced CT were retrospectively identified (n = 701). Control group consisted of patients with nephrotic syndrome receiving non-contrast CT (n = 1053). Two different 1:1 propensity score matching models using three or 10 variables were developed for each estimated glomerular filtration (eGFR) subgroup. Incidence of post-CT AKI for the two groups was assessed and compared by standard AKI criteria and Acute Kidney Injury Network (AKIN) criteria. After matching with three variables, the AKI incidence in the contrast-enhanced CT and non-contrast CT groups was 2.7% vs 2.5% (standard AKI criteria) and 4.2% vs. 6.7% (AKIN criteria) (p = 1.00 and 0.05), respectively. After matching with 10 variables, AKI incidences were 3.1% vs. 2.6% (standard AKI criteria) and 4.1% vs. 7.4% (AKIN criteria) (p = 0.72 and 0.03), respectively. AKI incidences of each eGFR subgroup in the contrast-enhanced CT group were not higher than in the non-contrast CT group (lowest p = 0.46). Intravenous contrast material administration during CT was not found to be a risk factor for AKI in this large cohort of patients with nephrotic syndrome. • AKI incidence of contrast-enhanced CT and non-contrast CT had no difference. • AKI incidences of eGFR subgroup in contrast-enhanced CT were not increased. • Studies without a non-contrast CT control group may overestimate CIN incidence.

Training requirements for the administration of intravenous contrast media by radiographers: Radiologists’ perspective

Background. The administration of intravenous contrast media (IVCM) is one of the key areas currently under investigation for inclusion in the South African (SA) radiographers’ scope of practice. However, for the radiographers to legally administer IVCM, training guidelines must first be identified, developed and accredited by the Health Professions Council of SA. Objective. To investigate the radiologists’ perspective of the knowledge, skills and medicolegal training required of radiographers for the administration of IVCM to provide input for the development of national training guidelines. Methods. A quantitative, cross-sectional research study using an online survey, administered by SurveyMonkey, was conducted. The target population included all radiologists residing and practising in the province of KwaZulu-Natal, SA. Results. Fifty-nine participants (60.8%) completed the online survey. Twelve were excluded owing to incomplete surveys, resulting in a final response rate of 48.5% ( n =47). The study revealed that various theoretical, clinical/practical and medicolegal study units should be included in the training, i.e. the study of the pharmacology of contrast media, practical training on cardiopulmonary resuscitation and basic life support, as well as the rights and responsibilities of a healthcare professional. In addition, both theory and practical/clinical assessments need to be included. Conclusion. Key data have been provided for the development of national training guidelines for radiographers to administer IVCM, based on scientific evidence that is relevant to the SA context. The study may be of value to other related health professions where scopes of practice are expanded through transforming the education and training curricula.

Implant-specific follow-up imaging of treated intracranial aneurysms: TOF-MRA vs. metal artifact reduced intravenous flat panel computed tomography angiography (FPCTA)

To compare the diagnostic quality of time-of-flight magnetic resonance angiography (TOF-MRA) and metal-artefact-reduction (MAR) flat-panel-detector computed tomography angiography (FPCTA) and to determine the imaging technique best suited for evaluation endovascular and surgically treated aneurysms. The image quality of TOF-MRA and MAR-FPCTA of 44 intracranial implants (coiling: n=20; clipping: n=15; coiling + stenting: n=9) in a patient cohort of 25 was evaluated by two independent readers. Images obtained using MAR-FPCTA (20 second scan time, 496 projections, intravenous contrast medium administration; Artis Zee, Siemens Healthcare, Forchheim) were compared with TOF-MRA-images (1.5 or 3 T). Nominal data were analysed using McNemar's chi-square test and ordinal variables using the Wilcoxon rank test. Compared to TOF-MRA, MAR-FPCTA was significantly better suited to detect aneurysm remnants and to evaluate parent vessels after clipping (p<0.01). For coil packages >160 mm3, TOF-MRA provided significantly better assessment than MAR-FPCTA (p<0.01). For small coil packages (<160 mm3), no significant difference between TOF-MRA and MAR-FPCTA (p=0.232) was observed. For different clip sizes (cut-off 492 mm3) likewise no significant differences were found. The interobserver comparison showed high interrater agreement. MAR-FPCTA is significantly better suited for follow-up examinations of clipped aneurysms, whereas for larger coil packages TOF-MRA is preferable. Smaller coil packages can be analysed using MAR-FPCTA or TOF-MRA.

Is Intravenous Administration of Iodixanol Associated with Increased Risk of Acute Kidney Injury, Dialysis, or Mortality? A Propensity Score-adjusted Study.

Purpose To compare the rates of acute kidney injury (AKI), emergent dialysis, and short-term mortality between patients who underwent intravenous administration of the iso-osmolar contrast material (IOCM) iodixanol 320 and patients who underwent a noncontrast computed tomography (CT) examination. Materials and Methods Study design and implementation were overseen by an institutional review board and conformed to HIPAA guidelines on patient data integrity. All patients who underwent an iodixanol-enhanced (IOCM group) or a noncontrast (noncontrast group) CT examination from January 2003 to December 2014 were identified. Patients were subdivided into subgroups of those with stage 1-2 chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR], ≥ 60 mL/min/1.73 m2), those with stage 3 CKD (eGFR, 30-59 mL/min/1.73 m2), and those with stage 4-5 CKD (eGFR < 30 mL/min/1.73 m2) and separately underwent propensity score stratification and matching. Rates of AKI, emergent dialysis, and mortality were compared between IOCM and noncontrast groups. Additional analyses incorporating intravenous fluid administration, including additional CT studies at other sites within a single institution, and a paired analysis of patients who underwent both IOCM and noncontrast CT studies during the study time frame, were also performed. Results A total of 5758 patients (1538 with stage 1-2 CKD, 2899 with stage 3 CKD, and 1321 with stage 4-5 CKD) were included in the study. After propensity score adjustment, rates of AKI, dialysis, and mortality were not significantly higher in the IOCM group compared with the noncontrast group for all CKD subgroups (AKI odds ratios [ORs], 0.74-0.91, P = .16-0.69; dialysis ORs, 0.74-2.00, P = .42-.76; mortality ORs, 0.98-1.24, P = .39-.88). Sensitivity analyses yielded similar results. Conclusion Among patients at the highest perceived risk of postcontrast AKI, intravenous administration of iodixanol for contrast material enhanced CT was not an independent risk factor for AKI, dialysis, or mortality. © RSNA, 2017 Online supplemental material is available for this article.

CT Angiography in the Emergency Department: Maximizing Contrast Enhancement and Image Quality While Minimizing Radiation Dose and Contrast Material Volume: Vascular/Interventional Radiology.

CT angiographic image quality and radiation dose can be optimized for each patient by applying knowledge of the principles of intravenous contrast material flow and the factors that influence contrast enhancement.

Remote Ischemic Conditioning and Renal Protection.

Over the course of the last 2 decades, the concept of remote ischemic conditioning (RIC) has attracted considerable research interest, because RIC, in most of its embodiments offers an inexpensive way of protecting tissues against ischemic damage inflicted by a number of medical conditions or procedures. Acute kidney injury (AKI) is a common side effect in the context of various medical procedures, and RIC has been suggested as a means of reducing its incidence. Outcomes regarding kidney function have been reported in numerous studies that evaluated the effects of RIC in a variety of settings (eg, cardiac surgery, interventions requiring intravenous administration of contrast media). Although several individual studies have implied a beneficial effect of RIC in preserving kidney function, 3 recently published randomized controlled trials evaluating more than 1000 patients each (Effect of Remote Ischemic Preconditioning in the Cardiac Surgery, Remote Ischaemic Preconditioning for Heart Surgery, and ERICCA) were negative. However, AKI or any other index of renal function was not a stand-alone primary end point in any of these trials. On the other hand, a range of meta-analyses (each including thousands of participants) have reported mixed results, with the most recent among them showing benefit from RIC, pinpointing at the same time a number of shortcomings in published studies, adversely affecting the quality of available data. The present review provides a critical appraisal of the current state of this field of research. It is the opinion of the authors of this review that there is a clear need for a common clinical trial framework for ischemic conditioning studies. If the current babel of definitions, procedures, outcomes, and goals persists, it is most likely that soon ischemic conditioning will be "yesterday's news" with no definitive conclusions having been reached in terms of its real clinical utility.

Effect of Intravenous Administration of Contrast Media on Serum Creatinine Levels in Neonates.

Purpose To assess the effect of intravenous contrast media on renal function in neonates. Materials and Methods Institutional review board approval was obtained with waiver of consent. Electronic health records from January 2011 to April 2013 were reviewed retrospectively. Measures of renal function were obtained in inpatient neonates who underwent magnetic resonance (MR) imaging or computed tomography (CT) and for whom serum creatinine (Cr) levels were obtained within 72 hours before imaging and at least one time after imaging (>1 day after administration of contrast material). A total of 140 neonates who received contrast material (59 who underwent CT with iohexol or iodixanol and 81 who underwent MR imaging with gadopentetate dimeglumine) were identified. These neonates were frequency matched according to sex, gestational and postnatal age, and preimaging serum Cr levels with neonates who underwent unenhanced MR imaging or CT. Cr levels and glomerular filtration rates (GFRs) were grouped according to when they were obtained (before imaging, 1-2 days after imaging, 3-5 days after imaging, 6-9 days after imaging, 10-45 days after imaging, and more than 45 days after imaging). Serum Cr levels and GFRs for each time period were compared between groups by using hierarchic regressions or χ2 or Fisher exact tests and with repeated-measures analysis of variance to compare groups on the rate of change in serum Cr levels and GFRs from before to after imaging. Results Cr levels decreased and GFRs increased in both groups from before to after imaging (CT group, P ≤ .01; MR imaging group, P ≤ .01). The neonates who underwent contrast material-enhanced imaging and the neonates who underwent unenhanced imaging showed similar serum Cr levels at all examined time periods. Groups also did not differ in the proportion of neonates with serum Cr levels higher than the reference range (>0.4 mg/dL) at any time point (iodine- [P > .12] or gadolinium-based [P > .13] contrast material). Similar findings were observed for GFRs. None of the neonates developed nephrogenic systemic fibrosis. Conclusion In the absence of known renal failure, neonates receiving standard inpatient care do not appear to be at increased risk for developing renal toxicity due to administration of intravenous iodine- and gadolinium-based contrast material. © RSNA, 2017.

Breast fat volume measurement using wide-bore 3 T MRI: comparison of traditional mammographic density evaluation with MRI density measurements using automatic segmentation

To compare magnetic resonance imaging (MRI)-derived breast density measurements using automatic segmentation algorithms with radiologist estimations using the Breast Imaging Reporting and Data Systems (BI-RADS) density classification. Forty women undergoing mammography and dynamic breast MRI as part of their clinical management were recruited. Fat-water separated MRI images derived from a two-point Dixon technique, phase-sensitive reconstruction, and atlas-based segmentation were obtained before and after intravenous contrast medium administration. Breast density was assessed using software from Advanced MR Analytics (AMRA), Linköping, Sweden, with results compared to the widely used four-quartile quantitative BI-RADS scale. The proportion of glandular tissue in the breast on MRI was derived from the AMRA sequence. The mean unenhanced breast density was 0.31±0.22 (mean±SD; left) and 0.29±0.21 (right). Mean breast density on post-contrast images was 0.32±0.19 (left) and 0.32±0.2 (right). There was "almost perfect" correlation between pre- and post-contrast breast density quantification: Spearman's correlation rho=0.98 (95% confidence intervals [CI]: 0.97-0.99; left) and rho=0.99 (95% CI: 0.98-0.99; right). The 95% limits of agreement were -0.11-0.08 (left) and -0.08-0.03 (right). Interobserver reliability for BI-RADS was "substantial": weighted Kappa k=0.8 (95% CI: 0.74-0.87). The Spearman correlation coefficient between BI-RADS and MRI breast density was rho=0.73 (95% CI: 0.60-0.82; left) and rho=0.75 (95% CI: 0.63-0.83; right) which was also "substantial". The AMRA sequence provides a fully automated, reproducible, objective assessment of fibroglandular breast tissue proportion that correlates well with mammographic assessment of breast density with the added advantage of avoidance of ionising radiation.

Erratum to: Post-contrast acute kidney injury in intensive care unit patients: a propensity score-adjusted study.

To examine the association of intravenous iodinated contrast material administration with the subsequent development of post-contrast AKI (PC-AKI), emergent dialysis, and short-term mortality using a propensity score-adjusted analysis of a cohort of intensive care unit (ICU) patients who underwent CT examination. All ICU patients at our institution who received a contrast-enhanced (contrast group) or unenhanced (noncontrast group) CT scan from January 2006 to December 2014 were identified. Patients were subdivided into pre-CT eGFR > 45 and eGFR ≤ 45 subsets and separately underwent propensity score analysis. Rates of KDIGO-defined AKI, dialysis, and mortality were compared between contrast and noncontrast groups. Separate analyses of eGFR ≥ 60, 30–59, and 45 subset. Significantly higher rates of dialysis (6.7 vs. 2.5%, OR 2.72 (1.14–6.46), p = .0240) were observed in the contrast versus noncontrast group in the matched eGFR ≤ 45 subset. Intravenous contrast material administration was not associated with an increased risk of AKI, emergent dialysis, and short-term mortality in ICU patients with pre-CT eGFR > 45. An increased risk of dialysis was observed in patients with pre-CT eGFR ≤ 45.

Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and Complications.

Heterotopic pancreas is a congenital anomaly in which pancreatic tissue is anatomically separate from the main gland. The most common locations of this displacement include the upper gastrointestinal tract-specifically, the stomach, duodenum, and proximal jejunum. Less common sites are the esophagus, ileum, Meckel diverticulum, biliary tree, mesentery, and spleen. Uncomplicated heterotopic pancreas is typically asymptomatic, with the lesion being discovered incidentally during an unrelated surgery, during an imaging examination, or at autopsy. The most common computed tomographic appearance of heterotopic pancreas is that of a small oval intramural mass with microlobulated margins and an endoluminal growth pattern. The attenuation and enhancement characteristics of these lesions parallel their histologic composition. Acinus-dominant lesions demonstrate avid homogeneous enhancement after intravenous contrast material administration, whereas duct-dominant lesions are hypovascular and heterogeneous. At magnetic resonance imaging, the heterotopic pancreas is isointense to the orthotopic pancreas, with characteristic T1 hyperintensity and early avid enhancement after intravenous gadolinium-based contrast material administration. Heterotopic pancreatic tissue has a rudimentary ductal system in which an orifice is sometimes visible at imaging as a central umbilication of the lesion. Complications of heterotopic pancreas include pancreatitis, pseudocyst formation, malignant degeneration, gastrointestinal bleeding, bowel obstruction, and intussusception. Certain complications may be erroneously diagnosed as malignancy. Paraduodenal pancreatitis is thought to be due to cystic degeneration of heterotopic pancreatic tissue in the medial wall of the duodenum. Recognizing the characteristic imaging features of heterotopic pancreas aids in differentiating it from cancer and thus in avoiding unnecessary surgery. © RSNA, 2017.

Post-contrast acute kidney injury in intensive care unit patients: a propensity score-adjusted study.

To examine the association of intravenous iodinated contrast material administration with the subsequent development of post-contrast AKI (PC-AKI), emergent dialysis, and short-term mortality using a propensity score-adjusted analysis of a cohort of intensive care unit (ICU) patients who underwent CT examination. All ICU patients at our institution who received a contrast-enhanced (contrast group) or unenhanced (noncontrast group) CT scan from January 2006 to December 2014 were identified. Patients were subdivided into pre-CT eGFR>45 and eGFR≤45 subsets and separately underwent propensity score analysis. Rates of KDIGO-defined AKI, dialysis, and mortality were compared between contrast and noncontrast groups. Separate analyses of eGFR≥60, 30-59, and <30 subsets were also performed. A total of 6877 ICU patients (4351 contrast, 2526 noncontrast) were included in the study. Following propensity score adjustment, the rates of AKI (31 vs. 34%, OR .88 (95%CI .75-1.05), p=.15), dialysis (2.0 vs. 1.7%, OR 1.20 (.66-2.17), p=.55), and mortality (12 vs. 14%, OR .87 (.69-1.10), p=.23) were not significantly higher in the contrast versus noncontrast group in the matched eGFR>45 subset. Significantly higher rates of dialysis (6.7 vs. 2.5%, OR 2.72 (1.14-6.46), p=.0240) were observed in the contrast versus noncontrast group in the matched eGFR≤45 subset. Intravenous contrast material administration was not associated with an increased risk of AKI, emergent dialysis, and short-term mortality in ICU patients with pre-CT eGFR>45. An increased risk of dialysis was observed in patients with pre-CT eGFR≤45.

Risk of Acute Kidney Injury After Intravenous Contrast Media Administration

The study objective was to determine whether intravenous contrast administration for computed tomography (CT) is independently associated with increased risk for acute kidney injury and adverse clinical outcomes. This single-center retrospective cohort analysis was performed in a large, urban, academic emergency department with an average census of 62,179 visits per year; 17,934 ED visits for patients who underwent contrast-enhanced, unenhanced, or no CT during a 5-year period (2009 to 2014) were included. The intervention was CT scan with or without intravenous contrast administration. The primary outcome was incidence of acute kidney injury. Secondary outcomes included new chronic kidney disease, dialysis, and renal transplantation at 6 months. Logistic regression modeling and between-groups odds ratios with and without propensity-score matching were used to test for an independent association between contrast administration and primary and secondary outcomes. Treatment decisions, including administration of contrast and intravenous fluids, were examined. Rates of acute kidney injury were similar among all groups. Contrast administration was not associated with increased incidence of acute kidney injury (contrast-induced nephropathy criteria odds ratio=0.96, 95% confidence interval 0.85 to 1.08; and Acute Kidney Injury Network/Kidney Disease Improving Global Outcomes criteria odds ratio=1.00, 95% confidence interval 0.87 to 1.16). This was true in all subgroup analyses regardless of baseline renal function and whether comparisons were made directly or after propensity matching. Contrast administration was not associated with increased incidence of chronic kidney disease, dialysis, or renal transplant at 6 months. Clinicians were less likely to prescribe contrast to patients with decreased renal function and more likely to prescribe intravenous fluids if contrast was administered. In the largest well-controlled study of acute kidney injury following contrast administration in the ED to date,intravenous contrast was not associated with an increased frequency of acute kidney injury.

Sigmoid Diverticulitis Mimicking Acute Appendicitis in Right-Sided Descending and Sigmoid Colon: A Case Report

Introduction: Acute abdominal pain in the lower-right quadrant can be misdiagnosed as acute appendicitis and may be caused by anatomic variations of the intra-abdominal organs in rare cases. Anatomical variations in the position and morphology of the sigmoid colon should be considered by clinicians and radiologists to avoid misdiagnosis and unnecessary surgical procedures.Case Report: A 54-year-old man was admitted to our emergency department complaining of abdominal pain in the lowerright quadrant, nausea, vomiting, and fever for 2 days. Physical examination revealed local rebound tenderness on the lowerright quadrant and a temperature of 38°C. Abdominal ultrasound showed that the intestinal loops were thickened and the surrounding mesenteric tissue was edematous in the right abdominal quadrant. Abdominal computed tomography was performed after a bolus administration of intravenous contrast material, and sigmoid colon position anomalies and diverticulitis were observed. The patient was treated medically, and diverticulosis was confirmed by colonoscopy. Conclusion: Clinical evaluation and ordered appropriate imaging methods by the emergency specialist is important in patients with abdominal pain on the lower-right quadrant who are admitted to the emergency department. Thus, rare anatomical variations mimicking acute appendicitis can be diagnosed accurately, and patients can be protected from undergoing unnecessary surgeries

Selection of peripheral intravenous catheters with 24-gauge side-holes versus those with 22-gauge end-hole for MDCT: A prospective randomized study

PurposeTo compare the 24-gauge side-holes catheter and conventional 22-gauge end-hole catheter in terms of safety, injection pressure, and contrast enhancement on multi-detector computed tomography (MDCT). Materials & methodsIn a randomized single-center study, 180 patients were randomized to either the 24-gauge side-holes catheter or the 22-gauge end-hole catheter groups. The primary endpoint was safety during intravenous administration of contrast material for MDCT, using a non-inferiority analysis (lower limit 95% CI greater than −10% non-inferiority margin for the group difference). The secondary endpoints were injection pressure and contrast enhancement. ResultsA total of 174 patients were analyzed for safety during intravenous contrast material administration for MDCT. The overall extravasation rate was 1.1% (2/174 patients); 1 (1.2%) minor episode occurred in the 24-gauge side-holes catheter group and 1 (1.1%) in the 22-gauge end-hole catheter group (difference: 0.1%, 95% CI: −3.17% to 3.28%, non-inferiority P=1). The mean maximum pressure was higher with the 24-gauge side-holes catheter than with the 22-gauge end-hole catheter (8.16±0.95kg/cm2 vs. 4.79±0.63kg/cm2, P<0.001). The mean contrast enhancement of the abdominal aorta, celiac artery, superior mesenteric artery, and pancreatic parenchyma in the two groups were not significantly different. ConclusionIn conclusion, our study showed that the 24-gauge side-holes catheter is safe and suitable for delivering iodine with a concentration of 300mg/mL at a flow-rate of 3mL/s, and it may contribute to the care of some patients, such as patients who have fragile and small veins. (Trial registration: UMIN000023727)

Case 236: Middle Interhemispheric Variant of Holoprosencephaly.

History A 13-year-old girl presented for evaluation and further management of spastic diplegia cerebral palsy. Absence of the corpus callosum was noted at screening prenatal head ultrasonography. She was born at full term via spontaneous vaginal delivery. Physical examination revealed decreased axial muscle tone and increased muscle tone in her extremities; the latter was more severe. She was nonambulatory. No midline craniofacial anomaly was seen. She had dysarthria but was able to speak in full sentences. She was in sixth grade with an individualized education program. She had mild behavioral problems, such as "acting out" in school. Brain magnetic resonance (MR) imaging, including three-dimensional T1- and T2-weighted sequences, was performed without intravenous administration of contrast material to evaluate the brain.

MRI of nasopharyngeal adenoid hypertrophy.

Nasopharyngeal adenoid hypertrophy (NAH) is a typical benign lesion. Due to involution, nasopharyngeal lymphatic tissue usually is not found in adults beyond the 30th to 40th year of life. However, occasionally NAH has been recognized after the 50th or 60th year. The aim of this study is to identify the frequency of NAH and to analyze its MRI findings in different age groups. From 2007 to 2011, 6693 MR investigations of the head were performed at our institution. MRI was obtained with a 1.5 T MRI device. NAH was identified in 18.0% of the patients. The frequency of NAH varied from 60.3% to 1.0% in the different age groups. The mean size of NAH was 23.2 ± 4.5 mm in cranio-caudal, 31.1 ± 5.2 mm in left-right, and 14.2 ± 4.1 mm in the anterior-posterior direction. The left-right and cranio-caudal sizes of NAH were largest in the 0-9 age group and decreased with age. On T1-w images most lesions (95.4%) were hypointense in comparison to the adjacent musculature. On T2-w fat-saturated images 82.4% of the lesions were hyperintense. After intravenous administration of contrast medium most lesions showed a slight enhancement (58.6%). Moderate enhancement was seen in 32.4% and a marked enhancement was identified in 9.0%. In the 0-9 age group most lesions showed a slight enhancement. Cysts within NAH were identified in 433 cases (35.9%). The frequency of cysts increased continuously with age, namely from 10.9% to 65.2%.

Contemporary management of isolated chronic infrarenal abdominal aortic dissections

The purpose of this study was to report the presentation, treatment, and follow-up of isolated infrarenal aortic dissections. A review of 37 patients with isolated infrarenal aortic dissections was performed. Computed tomography scans with intravenous administration of contrast material were examined for all patients; catheter-based angiography, magnetic resonance angiography, and duplex ultrasound were used selectively. In dissections associated with the development of abdominal aortic aneurysm (AAA), the aneurysm growth rate was determined by measuring the change in maximum aneurysm diameter over time and dividing that by the duration of observation. The majority of infrarenal abdominal aortic dissection patients were male (67.6%). Hypertension (77.1%) and hyperlipidemia (77.1%) were the most common comorbidities among these patients. Aortic atherosclerosis was present in the majority of patients (60.0%); 67.6% of dissections were discovered incidentally and were asymptomatic. The mean dissection length was 5.84± 4.23cm. Concomitant AAAs were present in 48.6% of cases with an average maximum diameter of 4.38± 1.41cm. The aneurysm growth rate was 1.2mm/y. Aneurysms were significantly larger in men than in women (4.87± 1.31 vs 3.12± 0.67cm; P= .001). Endovascular intervention was performed on 14 (37.8%) patients, open surgery was performed on 1 (2.7%) patient, and surveillance with conservative medical treatment was used for 22 (59.5%) patients. Ten patients were treated successfully with endovascular repair for progressive aneurysm expansion. At the time of intervention, the mean AAA diameter was 5.04± 1.39cm. The mean growth rate for aneurysms that were intervened on was 2.3mm/y. The mean diameter of AAAs that were not intervened on was 3.56± 1.04cm. Type II endoleaks were observed in three (30%) patients who underwent endovascular repair. None of these were associated with aneurysm growth and none required reintervention. The mortality rate for endovascular intervention was 0%. The only open surgical repair performed was on a patient with a ruptured AAA, which the patient did not survive. Angioplasty with stent or stent graft placement was performed in four patients for the treatment of symptomatic arterial insufficiency resulting from aortic dissection. No patients experienced restenosis, and no reinterventions were performed. Isolated infrarenal aortic dissection is an uncommon vascular disease that is related to hypertension, hyperlipidemia, and atherosclerosis and may be associated with infrarenal AAA formation. The presence of dissection does not appear to increase the risk of complication or mortality for repair of concomitant aneurysm or for treatment of stenosis.

The many shades of enhancement: timing of post-gadolinium images strongly influences the scoring of juvenile idiopathic arthritis wrist involvement on MRI.

Potential long-term side effects of treatment for juvenile idiopathic arthritis are concerning. This has necessitated accurate tools, such as MRI, to monitor treatment response and allow for personalized therapy. To examine the extent to which timing of post-contrast MR images influences the scoring of inflammatory change in the wrist in children with juvenile idiopathic arthritis. We studied two sets of post-contrast 3-D gradient echo MRI series of the wrist in 34 children with juvenile idiopathic arthritis. These images were obtained immediately after administration of intravenous contrast material and again after approximately 10min. The dataset was drawn from a prospective multicenter project conducted 2006-2010. We assessed five wrist locations for synovial enhancement, effusion and overall inflammation. Examinations were scored by one radiologist in two sessions - the first was based on the early post-contrast images, and the later session, for which the previous findings were masked, was based on the later post-contrast images. Fifty-two of the 170 locations (30.6%) received a higher synovial enhancement score based on the late post-contrast images as compared to the early images. Sixty of the 170 (35%) locations received a higher total inflammation score. The mean scores of synovial enhancement and total inflammation were significantly higher when based on the late post-contrast images as compared to the early post-contrast images. An MRI-based scoring system for the presence and degree of synovitis should be based on a standardized MR-protocol with a fixed interval between intravenous contrast injection and post-contrast images.

Diagnostic value of computed tomography colonography (CTC) after incomplete optical colonoscopy

IntroductionThis study evaluated the role of computed tomography colonography (CTC) in patients who previously underwent incomplete optical colonoscopy (OC). We analyzed the impact of colonic lesions in intestinal segments not studied by OC and extracolonic findings in these patients. MethodsBetween January 2014 and May 2015, 61 patients with a history of abdominal pain and incomplete OC examination were studied by CTC. CTCs were performed by 320-row CT scan in both the supine and the prone position, without intravenous administration of contrast medium. In all patients both colonic findings and extracolonic findings were evaluated. ResultsAmong the study group, 24 CTC examinations were negative for both colonic and extracolonic findings while 6 examinations revealed the presence of both colonic and extracolonic findings. In 24 patients CTC depicted colonic anomalies without extracolonic ones, while in 7 patients it showed extracolonic findings without colonic ones. DiscussionCTC is a noninvasive imaging technique with the advantages of high diagnostic performance, rapid data acquisition, minimal patient discomfort, lack of need for sedation, and virtually no recovery time. CTC accurately allows the evaluation of the nonvisualized part of the colon after incomplete OC and has the distinct advantage to detect clinically important extracolonic findings in patients with incomplete OC potentially explaining the patient's symptoms and conditioning their therapeutic management. ConclusionCTC accurately allows the assessment of both colonic and extracolonic pathologies representing a useful diagnostic tool in patients for whom complete OC is not achievable.