Intravenous Contrast Injection Research Articles

Impact of gadolinium-based contrast agent in the assessment of Crohn's disease activity: Is contrast agent injection necessary?

To determine whether magnetic resonance enterography (MRE) performed without intravenous contrast injection is diagnostically noninferior to conventional contrast-enhanced MRE (CE-MRE) in patients with Crohn's disease (CD). This was an Institutional Review Board (IRB)-approved retrospective study. Ninety-six patients (52 male and 44 female; 47.18 years ± 13.6) with a diagnosis of CD underwent MRE at 1.5T including T2 -weighted single-shot turbo-spin-echo, T2 -weighted spectral fat presaturation with inversion recovery (SPAIR), T1 -weighted balanced fast-field-echo MR sequences, and CE-MRE consisting in T1 -weighted breath-hold THRIVE 3D MRI sequences after administration of gadobenate dimeglumine (0.2 mL/kg of body weight). Unenhanced MRE, CE-MRE, and unenhanced MRE plus CE-MRE were reviewed in separate sessions with blinding by two readers in consensus, and subsequently by two other readers independently considering a subgroup of 20 patients. Crohn's Disease Endoscopic Index of Severity (CDEIS) and/or histologic analysis of the surgical specimen were considered as reference standards for the assessment of inflammatory activity. Patients revealed prevalently active (n = 55 patients) or quiescent CD (n = 41 patients). The agreement between unenhanced MRE vs. CE-MRE in interpreting active bowel inflammation was 96% (123/128 bowel segments; one-sided 95% confidence interval [CI], >94.4%). Unenhanced MRE vs. CE-MRE vs. unenhanced MRE plus CE-MRE revealed a diagnostic accuracy of 93% [90/96] vs. 92% [88/96] vs. 97% [93/96] (P > 0.05) in the diagnosis of active CD. Interreader agreement was very good for all variables (κ value = 0.8-0.9) except for the measurement of the length of disease (κ value = 0.45). Unenhanced MRE was noninferior to CE-MRE in diagnosing active inflammation in patients with CD.

Contrast‐enhanced spectral mammography (CESM) and contrast enhanced MRI (CEMRI): Patient preferences and tolerance

Contrast-enhanced spectral mammography (CESM) may have similar diagnostic performance to Contrast-enhanced MRI (CEMRI) in the diagnosis and staging of breast cancer. To date, research has focused exclusively on diagnostic performance when comparing these two techniques. Patient experience is also an important factor when comparing and deciding on which of these modalities is preferable. The aim of this study is to compare patient experience of CESM against CEMRI during preoperative breast cancer staging. Forty-nine participants who underwent both CESM and CEMRI, as part of a larger trial, completed a Likert questionnaire about their preference for each modality according to the following criteria: comfort of breast compression, comfort of intravenous (IV) contrast injection, anxiety and overall preference. Participants also reported reasons for preferring one modality to the other. Quantitative data were analysed using a Wilcoxon sign-rank test and chi-squared test. Qualitative data are reported descriptively. A significantly higher overall preference towards CESM was demonstrated (n = 49, P < 0.001), with faster procedure time, greater comfort and lower noise level cited as the commonest reasons. Participants also reported significantly lower rates of anxiety during CESM compared with CEMRI (n = 36, P = 0.009). A significantly higher rate of comfort was reported during CEMRI for measures of breast compression (n = 49, P = 0.001) and the sensation of IV contrast injection (n = 49, P = 0.003). Our data suggest that overall, patients prefer the experience of CESM to CEMRI, adding support for the role of CESM as a possible alternative to CEMRI for breast cancer staging.

4DCT Simulation With Synchronized Contrast Injection in Liver SBRT Patients.

Delivering stereotactic body radiotherapy for liver metastases remains a challenge because of respiratory motion and poor visibility without intravenous contrast. The purpose of this article is to describe a novel and simple computed tomography (CT) simulation process of integrating timed intravenous contrast that could overcome the uncertainty of target delineation. The simulation involves two 4-dimensional CT (4DCT) scans. The first scan only encompasses the immediate region of the tumor and surrounding tissue, which reduces the 4DCT scan time so that it can be optimally timed with intravenous contrast injection. The second 4DCT scan covers a larger volume and is used as the primary CT data set for dose calculation, as well as patient setup verification on the treatment unit. The combination of the two 4DCT scans allows us to optimally visualize liver metastases over all phases of the breathing cycle while simultaneously acquiring a long enough 4DCT data set that is suitable for planning and patient setup verification. This simulation technique allows for a better target definition when treating liver metastases, without being invasive.

Spontaneous non-aortic retroperitoneal hemorrhage: etiology, imaging characterization and impact of MDCT on management. A multicentric study.

The purpose of this multicentric study is to assess the usefulness of multiphasic Computed tomography in the identification of spontaneous non-traumatic retroperitoneal hematoma (SRH) and its management, with references to the role of interventional radiology. From January 2011 to June 2014, 27 patients with SRH were selected. Patients with aortic, traumatic, or iatrogenic source of bleeding were excluded. All the patients were studied with multiphasic MDCT after injection of intravenous contrast. Digital Subtraction angiography and percutaneous embolization treatment were performed. CT identified SRH in all cases (100%), showing the source of bleeding in 11 cases (40%) and pointing out the source of bleeding in 15 cases (55%). In one case (5%), the bleeding origin was recognized only at surgery as adrenal source. CT has identified a contrast medium extravasation in the arterial phase in 17 patients (63%), treated successfully by percutaneous embolization in 13 and by open-surgery in two cases. Two patients died before undergoing intervention and surgery, respectively. Ten patients (37%) were non-operatively treated successfully with clinical, laboratory, and imaging follow-up. Multiphasic CT is the gold standard for the identification of a SRH. Recognition of CT signs of active bleeding is the crucial feature influencing the timing of therapeutic treatment. Urgent embolization should be performed in cases of arterial bleeding or contained vascular injuries supplying the retroperitoneal hematoma. Surgery is to be addressed in cases of actively bleeding hematomas associated with complication. Finally, an initial more conservative approach can be adopted in patients without signs of contrast extravasation or low-flow active bleeding. Technical skill, expertise, and recognition of CT signs of arterial active bleeding are critical features influencing patients management.

Erratum to: Isolated Calyx Mistaken for a Cyst: Inappropriately Performed Catheter-Directed Sclerotherapy and Safe Removal of the Catheter After Selective Embolization

We present a case of isolated calyx that was mistaken for a large cyst. A 47-year-old woman was referred for sclerotherapy of a large cystic lesion on her left kidney. Computed tomography (CT) and ultrasound showed that the cystic lesion was a large cyst. We noticed that the cystic lesion was not a typical simple cyst, even after two sessions of catheter-mediated sclerotherapy. Isolated calyx was presumed by medical history review and was confirmed by aspirated fluid analysis and far delayed-phase CT after intravenous contrast injection. We performed meticulous selective arterial embolization for an isolated calyx and inserted a catheter that could be removed without complication.

Poster — Thur Eve — 16: 4DCT simulation with synchronized contrast injection of liver SBRT patients

Stereotactic body radiation therapy (SBRT) has recently emerged as a valid option for treating liver metastases. SBRT delivers highly conformai dose over a small number of fractions. As such it is particularly sensitive to the accuracy of target volume delineation by the radiation oncologist. However, contouring liver metastases remains challenging for the following reasons. First, the liver usually undergoes significant motion due to respiration. Second, liver metastases are often nearly indistinguishable from the surrounding tissue when using computed tomography (CT) for imaging making it difficult to identify and delineate them. Both problems can be overcome by using four dimensional CT (4DCT) synchronized with intravenous contrast injection. We describe a novel CT simulation process which involves two 4DCT scans. The first scan captures the tumor and immediately surrounding tissue which in turn reduces the 4DCT scan time so that it can be optimally timed with intravenous contrast injection. The second 4DCT scan covers a larger volume and is used as the primary CT dataset for dose calculation, as well as patient setup verification on the treatment unit. The combination of two 4DCT scans, short and long, allows visualization of the liver metastases over all phases of breathing cycle while simultaneously acquiring long enough 4DCT dataset suitable for planning and patient setup verification.

O-001 A Novel Metal Artefact Removal Software for C-arm CT; A Novel Imaging Modality to Analyze Aneurysms Treated with Stent Assisted Coil Embolization

PurposeStent assisted coil embolization recently became a common treatment strategy for the wide neck aneurysms. Normal digital subtraction angiography (DSA), however, does not allow visualization of the deployed stents. With...

SP0209 Technical Validity of MRI for Evaluating Joint Damage and Inflammation in Rheumatoid Arthritis

Magnetic resonance imaging (MRI) allows quantitative (volume or, for synovitis, early contrast enhancement after intravenous contrast injection) as well as less detailed (qualitative: presence/absence; semiquantitative: scoring) evaluation of synovitis, bone...

Imaging and Target Volume Delineation in Glioma

Here we review current practices in target volume delineation for radical radiotherapy planning for gliomas. Current radiotherapy planning margins for glioma are informed by historic data of recurrence patterns using radiological imaging or post-mortem studies. Radiotherapy planning for World Health Organization grade II–IV gliomas currently relies predominantly on T1-weighted contrast-enhanced magnetic resonance imaging (MRI) and T2/fluid-attenuated inversion recovery sequences to identify the gross tumour volume (GTV). Isotropic margins are added empirically for each tumour type, usually without any patient-specific individualisation. We discuss novel imaging techniques that have the potential to influence radiotherapy planning, by improving definition of the tumour extent and its routes of invasion, thus modifying the GTV and allowing anisotropic expansion to a clinical target volume better reflecting areas at risk of recurrence. Identifying the relationships of tumour boundaries to important white matter pathways and eloquent areas of cerebral cortex could lead to reduced normal tissue complications. Novel magnetic resonance approaches to identify tumour extent and invasion include: (i) diffusion-weighted magnetic resonance metrics; (ii) diffusion tensor imaging; and (iii) positron emission tomography, using radiolabelled amino acids methyl-11C-L-methionine and 18F-fluoroethyltyrosine. Novel imaging techniques may also have a role together with clinical characteristics and molecular genetic markers in predicting response to therapy. Most significant among these techniques is dynamic contrast-enhanced MRI, which uses dynamic acquisition of images after injection of intravenous contrast. A number of studies have identified changes in diffusion and microvascular characteristics occurring during the early stages of radiotherapy as powerful predictive biomarkers of outcome.

Isolated Calyx Mistaken for a Cyst: Inappropriately Performed Catheter-Directed Sclerotherapy and Safe Removal of the Catheter After Selective Embolization

We present a case of isolated calyx that was mistaken for a large cyst. A 47-year-old woman was referred for sclerotherapy of a large cystic lesion on her left kidney. Computed tomography (CT) and ultrasound showed that the cystic lesion was a large cyst. We noticed that the cystic lesion was not a typical simple cyst, even after two sessions of catheter-mediated sclerotherapy. Isolated calyx was presumed by medical history review and was confirmed by aspirated fluid analysis and far delayed-phase CT after intravenous contrast injection. We performed meticulous selective arterial embolization for an isolated calyx and inserted a catheter that could be removed without complication.

Bile duct evaluation of potential living liver donors with Gd-EOB-DTPA enhanced MR cholangiography: Single-dose, double dose or half-dose contrast enhanced imaging

IntroductionDetailed knowledge of the biliary anatomy is essential to avoid complications in living donor liver transplantation. The aim of this study was to determine the optimal dosage of Gd-EOB-DTPA for contrast-enhanced magnetic resonance cholangiography (ce-MRC) with reference to contrast-enhanced CT cholangiography (ce-CTC). Materials and methods30 potential living liver donors (PLLD) underwent both ce-CTC and ce-MRC. Ten candidates each received single, double or half-dose Gd-EOB-DTPA. Ce-MRC images with and without inversion recovery pulses (T1w±IR) were acquired 20–30min after intravenous contrast injection. Image data was quantitatively and qualitatively reviewed by two radiologists based on a on a 5-point scale. Data sets were compared using a Mann–Whitney-U-test or Wilcoxon-rank-sum-test. Kappa values were also calculated. ResultsAll image series provided sufficient diagnostic information both showing normal biliary anatomy and variant bile ducts. Ce-CTC showed statistically significant better results compared to all ce-MRC data sets. T1w MRC with single dose Gd-EOB-DTPA proved to be superior to half and double dose in subjective and objective evaluation without a statistically significant difference. ConclusionsCe-MRC is at any dosage inferior to ce-CTC. As far as preoperative planning of bile duct surgery is focused on the central biliary anatomy, ce-MRC can replace harmful ce-CTC strategies, anyway. Best results were seen with single dose GD-EOB-DTPA on T1w MRC+IR.

Color-coded perfusion analysis of CEUS for pre-interventional diagnosis of microvascularisation in cases of vascular malformations.

Aim of our pilot study was the application of a contrast-enhanced color-coded ultrasound perfusion analysis in patients with vascular malformations to quantify microcirculatory alterations. 28 patients (16 female, 12 male, mean age 24.9 years) with high flow (n = 6) or slow-flow (n = 22) malformations were analyzed before intervention. An experienced examiner performed a color-coded Doppler sonography (CCDS) and a Power Doppler as well as a contrast-enhanced ultrasound after intravenous bolus injection of 1 - 2.4 ml of a second-generation ultrasound contrast medium (SonoVue®, Bracco, Milan). The contrast-enhanced examination was documented as a cine sequence over 60 s. The quantitative analysis based on color-coded contrast-enhanced ultrasound (CEUS) images included percentage peak enhancement (%peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT). No side effects occurred after intravenous contrast injection. The mean %peak in arteriovenous malformations was almost twice as high as in slow-flow-malformations. The area under the curve was 4 times higher in arteriovenous malformations compared to the mean value of other malformations. The mean transit time was 1.4 times higher in high-flow-malformations compared to slow-flow-malformations. There was no difference regarding the time to peak between the different malformation types. The comparison between all vascular malformation and surrounding tissue showed statistically significant differences for all analyzed data (%peak, TTP, AUC, MTT; p < 0.01). High-flow and slow-flow vascular malformations had statistically significant differences in %peak (p < 0.01), AUC analysis (p < 0.01), and MTT (p < 0.05). Color-coded perfusion analysis of CEUS seems to be a promising technique for the dynamic assessment of microvasculature in vascular malformations.

Use of low-dose CT KUB: is it becoming the easy way out?

In 1995, Smith and colleagues first proposed the use of low-dose CT KUB for the diagnosis of ureteric colic [1]. Since then, popularity of this imaging modality has increased due to a number of reasons: a sensitivity of 94 to 97%, a specificity of 96 to 99%, lack of intravenous contrast injection and speed of examination. The UK College of Emergency Medicine considers CT KUB as best practice for radiological investigation of renal colic. A review of the literature suggests that the true positive rate (number of patients diagnosed with an obstructing or symptom causing calculus) should be between 47.5 and 67% and alternative diagnoses should be confirmed in approximately 10% of patients imaged [2].

Dynamic pulmonary computed tomography angiography: a new standard for evaluation of combined airway and vascular abnormalities in infants

Airway abnormalities are frequently associated with congenital heart disease in infants and children. Respiratory distress in these children frequently requires prolonged respiratory support. Wide-detector dynamic pulmonary computed tomography angiography (DP-CTA) is a non-invasive technique that completely evaluates vascular and airway abnormalities during a single breathe. Our purpose was to evaluate the efficacy of DP-CTA to provide unique actionable information for patient care in newborns and infants with congenital heart disease and persistent respiratory distress. 23 infants with congenital heart disease and persistent respiratory distress underwent DP-CTA. All were intubated at the time of the examinations. The most common cardiac anomalies were tetralogy of Fallot (6) and hypoplastic left heart syndrome variants (5). The most common cardiac surgeries prior to DP-CTA were Norwood (4) and hybrid (3) procedures. The protocol for DP-CTA for intubated infants is four gantry rotations in 1.4 s after intravenous contrast injection. 3D and multiplanar reconstruction with cine loops were created for combined cardiopulmonary imaging. Tracheobronchomalacia was present in 17 children. Lobar bronchomalacia was identified in six children. Branch pulmonary artery stenosis was the most common vascular finding (10 children). Medical management was changed or a surgical procedure performed based on the information resulting from DP-CTA in 16 of the 23 patients (70 %). DP-CTA is non-invasive, fast and provides unique information for the management of infants with congenital heart disease and persistent respiratory distress. DP-CTA is uniquely suited for comprehensive and simultaneous evaluation of airway and vascular abnormalities in infants.

The use of central venous catheters for pump injection of intravenous contrast during CT examination. Are we safe?

Background: There are currently no guidelines for pump injection of intravenous contrast via a central venous catheter (CVC). Radiologists are often asked about line compatibility, safe flow rates or to connect the line to the pump device. Our aim was to assess trainees knowledge of which CVC lines (PICC, Central, Hickman and Ports) were safe to use for pump injection of contrast. Is there a need for local guidelines and teaching aseptic technique?

Incidence and severity of acute adverse reactions to intravenous iodinated contrast media: 8-year experience in King Chulalongkorn Memorial Hospital

Background: Increasing numbers of acute adverse reactions to contrast media are being seen. Institutional information about incidence and severity of acute adverse reactions to contrast media is essential to inform radiologists of the both common and life-threatening acute adverse reactions encountered. Objectives: We determined the overall, type-specific and severity of acute adverse reactions to intravenous iodinated contrast media at King Chulalongkorn Memorial hospital between January 2002 and December 2009. Methods: This retrospective study reviewed 663 report forms for acute adverse reactions to contrast media among 74,010 intravenous iodinated contrast injections using five types of contrast media including meglumine/sodium ioxitalamate, iohexol, iopamidol, iopromide, and iobitridol. Results: The overall incidence of acute adverse reactions to iodinated contrast media was about 0.9%. Of these 0.8% were minor, and 0.1% were major reactions. The majority of minor reactions were urticaria and the majority of major reactions were facial edema. One contrast-related death was reported. Incidence of acute adverse reactions to nonionic contrast media was 0.58%, and was 4.29 % in the ionic group. The type-specific incidence of acute adverse reactions was 4.29% for meglumine/sodium ioxitalamate, 0.82% for iohexol, 0.29% for iopamidol, 0.65% for iopromide, and 0.25% for iobitridol. Conclusion: Acute adverse reactions to intravenous iodinated contrast media account for less than one percent of injections. The incidence is higher in the ionic contrast media group. The majority of reactions are mild. However, severe reactions can still be encountered and death related to contrast media exist. Keywords: Acute adverse reactions, contrast media, intravenous, iodinated, incidence, severity

C-Arm CT Measurement of Cerebral Blood Volume and Cerebral Blood Flow Using a Novel High-Speed Acquisition and a Single Intravenous Contrast Injection

Assessment of perfusion parameters is important in the selection of patients who are most likely to benefit from revascularization after an acute ischemic stroke. The aim of this study was to evaluate the feasibility of measuring cerebral perfusion parameters with the use of a novel high-speed C-arm CT acquisition in conjunction with a single intravenous injection of contrast. Seven canines had experimentally induced focal ischemic regions confirmed by CT perfusion imaging. Four hours after ischemic injury creation, each subject underwent cerebral perfusion measurements with the use of standard perfusion CT, immediately followed by the use of C-arm CT. Cerebral blood flow and cerebral blood volume maps measured by C-arm CT were quantitatively and qualitatively compared with those measured by perfusion CT for 6 of the 7 canine subjects. Results from independent observer evaluations of perfusion CT and C-arm perfusion maps show strong agreement between observers for identification of ischemic lesion location. Significant percentage agreement between observers for lesion detection and identification of perfusion mismatch between CBV and CBF maps indicate that the maps for both perfusion CT and C-arm are easy to interpret. Quantitative region of interest-based evaluation showed a strong correlation between the perfusion CT and C-arm CBV and CBF maps (R(2) = 0.68 and 0.85). C-arm measurements for both CBV and CBF were consistently overestimated when compared with perfusion CT. Qualitative and quantitative measurements of CBF and CBV with the use of a C-arm CT acquisition and a single intravenous injection of contrast agent are feasible. Future improvements in flat detector technology and software algorithms probably will enable more accurate quantitative perfusion measurements with the use of C-arm CT.

Lost and Found Unusual Location of a Urinary Tract Calculus = فقد ثم تم العثور عليه موقع غير عادي لحصوة في المجرى البولي

A 41-year-old male patient presented to the Emergency Department (ED) of Sultan Qaboos University Hospital (SQUH) complaining of left flank pain of one day’s duration which was colicky and increasing in intensity. There was no history of fever, nausea or vomiting or other significant medical history; however, a similar episode had occurred previously. The patient’s vital signs were stable and he was afebrile. Physical examination of the abdomen was non-contributory; routine microscopic urinalysis was normal. In view of the suspicion of left renal colic, he was referred for a non-contrast enhanced computed tomography (NCCT) scan, the gold standard at SQUH to assess urinary tract calculi in patients presenting with renal colic. The scan showed significant left perinephric fat stranding and mild left hydroureteronephrosis and evidence of periureteric fat stranding around the left ureter. No calculi could be identified in the left kidney or the left ureter. There was a direct inguinal hernia on the right side which contained part of the urinary bladder and a small radio-opaque calculus. These findings suggested the recent passage of a left ureteric stone into the bladder and the migration of this stone into the herniated part of the urinary bladder. It is also possible that the patient had passed out the ureteric stone via the urethra, and that the stone in the herniated bladder was an incidental finding. Clinically, the pain decreased over the period of observation in the ED, and the patient was discharged. At Urology Clinic follow-ups, there was no recurrence of pain, and the patient was managed conservatively. Inguinal hernias can be direct or indirect; the Hesselbach triangle is usually the site for direct inguinal hernias. On CT, the direct inguinal hernia lies medial to the inferior epigastric artery.1 A total of 1–3% of all inguinal hernias involve the bladder;2 in obese men aged 50–70 years, the incidence may reach 10%.3 Inguinal hernias generally occur on the right side.2 Urinary bladder hernias are mostly diagnosed incidentally during hernia surgeries,4 or during imaging.2 The herniated parts of the urinary bladder can contain tumors or calculi.2,5 These may migrate from upper tracts or form de novo in the hernia due to stasis. CT is the best modality for the diagnosis and evaluation of inguinoscrotal urinary bladder herniation after injection of intravenous contrast. The post-processing of the CT using 3D reconstructions can demonstrate the contents of the hernia and its relationships.6 Our patient’s calculus, could possibly have passed from the left ureter. However, it is possible that it may instead have travelled to the herniated component of the urinary bladder and been overlooked, especially as the herniated part of the bladder was small and did not significantly distort the urinary bladder in the pelvis. Therefore, we suggest that the protocol for the routine NCCT of the kidney, ureter and bladder for urolithiasis should extend below the pubic symphysis so as not to miss posterior urethral calculi or calculi in unusual areas.

039 PREVALENCE AND EXTENT OF INFARCT AND MICROVASCULAR OBSTRUCTION FOLLOWING A RANGE OF REPERFUSION TECHNIQUES IN ST-ELEVATION MYOCARDIAL INFARCTION (STEMI): Table 1

Introduction Cardiac MRI (CMR) provides unique characterisation of myocardial injury post acute STEMI. It is the gold standard for non-invasive measurement of Infarct Size (IS) and tissue perfusion during STEMI. Microvascular obstruction (MVO) describes suboptimal tissue perfusion despite restoration of flow in the infarct-related artery (IRA). IS and MVO are independent predictors of adverse remodelling and prognosis post STEMI. MVO is generally assumed to be related primarily to reperfusion. CMR extent of IS and MVO decreases after 48 h post STEMI. There is a dearth of data on the prevalence and extent of MVO in clinical practice using different reperfusion methods, in particular in those without reperfusion. We hypothesise that the extent and presence of MVO are primarily related to the extent of ischaemic injury rather than reperfusion injury. Method 94 acute STEMI subjects were studied. 75 were prospectively recruited into a study of ventricular remodelling post STEMI. 19 subjects were routine clinical CMR examinations undertaken in non-reperfused, late-presenting patients (>12 h symptoms) to assess viability. Subjects were assessed on a Siemens Avanto 1.5T system. LV function and volumes were assessed using SSFP. Ten minutes after intravenous injection of gadolinium contrast (0.2 mmol/kg), delayed contrast-enhanced images were acquired using a segmented inversion-recovery gradient-echo sequence. IS was defined as areas of hyperenhancement with signal intensity (SI) >50% of peak SI in the infarct core (Full-Width Half-Maximum technique). MVO was defined as hypointensity within areas of infarct. Independent T Test and Mann-Whitney U Test analyses were used for normally and non-parametrically distributed data respectively. Statistical significance was taken at p Results There was no significant difference in age, sex, prevalence of angina, proportion of STEMI with left anterior descending artery IRA, TIMI score or Rentrop (degree of collateralization) score in early reperfused (PCI or Thrombolysis 2 Analysis showed a trend towards higher prevalence of MVO in non-reperfused STEMI (71.4% vs 55.2%). Late PCI patients (n=6) demonstrated a trend towards higher volumes and greater extent of IS and MVO compared with non-reperfused and rescue PCI (n=8) patients. No differences were seen between rescue PCI and non-reperfused patients. Conclusions The prevalence and extent of myocardial and microvascular injury (IS, MVO) on CMR in non-reperfused STEMI is at least as much as that occurring in those undergoing early reperfusion therapy. This is despite a significantly longer time to CMR in non-reperfused patients, which would be expected to result in a reduction in IS and MVO. MVO is not exclusive to reperfusion and may represent the degree of ischaemic injury. Median (25th–75th quartiles) where non-normally distributed. Total study group (n=94) consists of early reperfused, non-reperfused, late PCI and rescue PCI patients.

Contrast-induced acute kidney injury and clinical outcomes after intra-arterial and intravenous contrast administration: Risk comparison adjusted for patient characteristics by design

Direct comparisons between risk of contrast induced acute kidney injury (CI-AKI) after intra-arterial versus intravenous contrast administration are scarce. We estimated and compared the risk of CI-AKI and its clinical course after both modes of contrast administration in patients who underwent both. One hundred seventy patients who received both intra-arterial and intravenous contrast injections within one year between 2001 and 2010 were included. Primary outcome was occurrence of CI-AKI. Secondary outcomes were duration of hospital stay, the need for dialysis, recovery of renal function, and mortality. The risk of CI-AKI was 24/170 (14.0%, 95% CI 9.6-20.2) after intra-arterial contrast injection versus 20/170 (11.7%, 95% CI 7.7-17.5) after intravenous contrast administration, which led to a relative risk of 1.2 (95% CI 0.7-2.1). None of the patients had a need for dialysis. Median duration of hospital stay in CI-AKI patients was 15.0 days (2.5-97.5, percentile 1-92) after intra-arterial and 15.5 days (2.5-97.5, percentile 0-38) after intravenous contrast procedures. Renal function recovered after CI-AKI in 13/24 after intra-arterial and in 10/20 patients after intravenous contrast administration. Mortality risks in CI-AKI patients were slightly higher than in non-CI-AKI patients, hazard ratios 1.6 (95% CI 0.7-3.7) for intra-arterial and 1.7 (95% CI 0.7-4.4) for intravenous contrast administration, adjusted for confounders. The risk of CI-AKI, and its clinical course was similar after intra-arterial and intravenous contrast media administration, after adjustment by design for patient-related risk factors.