Bright Blood Research Articles

Abstract 16686: Early Gadolinium Enhancement Represents Area at Risk Not Infarct Size: Timing and Kinetics Are Critical in Interpreting MRI of Acute Myocardial Infarction

Background: Recent papers have raised questions about whether gadolinium over-estimates infarct size and have indicated that early gadolinium enhancement (EGE) corresponds to the area at risk (AAR) rather than infarct size.Objective: To determine kinetics, timing, and size of early gadolinium enhancement as related to measurements of area at risk and infarct size in patients with acute myocardial infarction (MI). Methods: MRI was performed on 35 patients within 7 days of acute MI. T2-weighted images were acquired with bright blood methods to measure AAR. EGE images were acquired 1, 3, 5, and 7 minutes post-contrast with single-shot phase sensitive inversion recovery (PSIR). Late gadolinium enhanced (LGE) images were obtained 10-20 minutes post-contrast using segmented PSIR. EGE images were evaluated semi-quantitatively using a 2-SD threshold and with manual planimetry. LGE Infarct size was measured with the previously validated FACT algorithm. Microvascular obstruction was included in the hyperenhanced zone for EGE and LGE. Results: Of the 35 patients (26 were male, age 61±12 years old), 14 had subendocardial MI and 21 had transmural MI. For subendocardial MI, the correlation between EGE and T2-weighted AAR was only fair at 1 minute post contrast (r=0.68), but improved to (r=0.86-0.88) from 3 minutes to 7 minutes post-contrast administration. However, there was significant intersubject variability with regard to the optimal timing for EGE as a measure of AAR. For subendocardial MI, the best agreement between EGE and T2 weighted AAR occurred at 3 minutes in 4 subjects, 5 minutes in 4 subjects, and 7 minutes in 5 subjects. For transmural MI (n=21), the best agreement occurred at 7 minutes post-contrast. The maximal area of hyperenhancement on EGE correlated most closely with T2 AAR for subendocardial MI (r=0.91) and was significantly larger than MI size on LGE images (p<0.001 for all MI and for subendocardial MI). Conclusion: Myocardial gadolinium enhancement kinetics influence the size of the hyperenhanced zone such that early gadolinium enhancement between 3-7 minutes closely correlates with area at risk, and thus can over-estimate infarct size for non-transmural MI. Timing is critical when quantifying acute infarct size with gadolinium enhanced MRI.

The comparison of MR intragate and electrocardiogram-respiration triggered fast low-angle shot in imaging the structure and function of the heart

Objective A comparison between intragate and ECG-respiration triggered techniques was performed to determine their differences in measuring the structure and function of the heart at 7.0 T.Methods Ten normal ICR mice aged five to six weeks were examined on a 7.0 T MR scanner.A central slice with papillary muscle included at the short-axis view was scanned with a FLASH-cine bright blood sequence,FLASH-cine black blood sequence,IG-FLASH-sat-cine black blood sequence,and IG-FLASH-cine bright blood sequence.The area of the left ventricle of the end systole and end diastole ( including and excluding the myocardium) was measured with manually outlined ROIs.The increased area of the left ventricle and the myocardium from the end systolic to end diastolic phases was calculated.The signal intensity was measured from 8 ROIs which were evenly located at the myocardium of the end systole,and the mean and standard deviation were then determined.The coefficient of variation ( CV ) was derived by dividing the mean into the standard deviation.Results There was no significant difference ( the increased area of the myocardium t =0,P =1,the increased area of the left ventricle t =2.12,P =0.06) in the function index between the ECG-triggered black blood sequences [the increased area of the myocardium (0.100 ±0.018) cm2,the increased area of the left ventricle (0.060 ± 0.024) cm2] and intragate black blood sequences[the increased area of the myocardium (0.090 ± 0.014) cm2,the increased area of the left ventricle (0.060 ±0.012) cm2].No significant difference(the increased area of the myocardium t =1.56,P =0.15,the increased area of the left ventricle t =2.08,P =0.07 ) in the function index was observed between the ECG-triggered bright blood sequences [the increased area of the myocardium ( 0.100 ±0.018) cm2,the increased area of the left ventricle(0.060 ±0.014) cm2]and intragate bright blood sequences [the increased area of the myocardium (0.090 ±0.019) cm2,the increased area of the left ventricle (0.050 ±0.015) cm2].Furthermore,there was no significant difference(t =1,P =0.34) in the CV of the myocardium signal intensity of bright blood sequences between the ECG-triggering ( 0.050 ± 0.013 ) and intragate (0.040 ± 0.015 ),but significant difference ( t =4.51,P =0.001 ) in the CV of the myocardium signal intensity of black blood sequences between the ECG-triggering ( 0.070 ± 0.033 ) and intragate ( 0.160 ± 0.046 ) was obtained.Conclusions The intragate sequences could take the place of the ECG gate sequences in functional analysis of the heart( including bright blood and black blood sequences).The bright blood intragate sequences also could replace the bright blood ECG-triggered sequences in analyzing the signal of the myocardium. Key words: Heart; Magnetic resonance imaging; Animal experimentation

T2‐weighted cardiac MR assessment of the myocardial area‐at‐risk and salvage area in acute reperfused myocardial infarction: Comparison of state‐of‐the‐art dark blood and bright blood T2‐weighted sequences

To compare different state-of-the-art T2-weighted (T2w) imaging sequences combined with late gadolinium enhancement (LGE) for myocardial salvage area (MSA) assessment by cardiac magnetic resonance (CMR). T2w imaging has been used to assess the myocardial area at risk (AAR) in acute myocardial infarction (AMI) patients, but its clinical application is challenging due to technical and physical limitations. Thirty patients with reperfused AMI underwent complete CMR imaging 2-5 days after hospital admission. Myocardial AAR and MSA were quantified on four different T2w sequences: (a) free-breathing T2-prepared single-shot balanced steady-state free precession (T2p_ssbSSFP); (b) breathhold T2-weighted acquisition for cardiac unified T2 edema (ACUTE); (c) breathhold T2w dark-blood inversion recovery turbo-spin echo (IR-TSE) (short-term inversion recovery: STIR); and (d) free-breathing high-resolution T2 dark-blood navigated BLADE. The diagnostic performance of each technique was also assessed. Quantitative analysis showed significant differences in myocardial AAR extent as quantified by the four T2w sequences (P < 0.05). There were also significant differences in sensitivity, specificity and overall diagnostic performance. Detection and quantification of AAR, and thus of MSA, by T2wCMR in reperfused AMI patients varied significantly between different T2w sequences in the same clinical setting.

Evaluation of adipose tissue volume quantification with IDEAL fat–water separation

To validate iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) for adipose tissue volume quantification. IDEAL allows MRI images to be produced only from adipose-containing tissues; hence, quantifying adipose tissue should be simpler and more accurate than with current methods. Ten healthy controls were imaged with 1.5 Tesla (T) Spin Echo (SE), 3.0T T1-weighted spoiled gradient echo (SPGR), and 3.0T IDEAL-SPGR. Images were acquired from the abdomen, pelvis, mid-thigh, and mid-calf. Mean subcutaneous and visceral adipose tissue volumes were compared between the three acquisitions for each subject. There were no significant differences (P>0.05) between the three acquisitions for subcutaneous adipose tissue volumes. However, there was a significant difference (P=0.0002) for visceral adipose tissue volumes in the abdomen. Post hoc analysis showed significantly lower visceral adipose tissue volumes measured by IDEAL versus 1.5T (P<0.0001) and 3.0T SPGR (P<0.002). The lower volumes given by IDEAL are due to its ability to differentiate true visceral adipose tissue from other bright structures like blood vessels and bowel content that are mistaken for adipose tissue in non-fat suppressed images. IDEAL measurements of adipose tissue are equivalent to established 1.5T measurement techniques for subcutaneous depots and have improved accuracy for visceral depots, which are more metabolically relevant.

128 Bright blood t2 weighted MRI has higher diagnostic precision and accuracy than dark blood stir MRI for assessment of the ischaemic area-at-risk and myocardial salvage in acute myocardial infarction

<h3>Background</h3> T2-weighted MRI reveals myocardial oedema and enables estimation of the ischaemic area-at-risk and myocardial salvage in patients with acute myocardial infarction (MI). We compared the diagnostic accuracy of a new bright blood T2-weighted with a standard black blood T2-weighted MRI in patients with acute MI. <h3>Methods</h3> A breath hold bright blood T2-weighted ACUTE pulse sequence with normalisation for coil sensitivity and a breath hold T2 dark blood short τ inversion recovery (STIR) sequence were used to depict the area-at-risk in 54 consecutive acute MI patients. Infarct size was measured on gadolinium late contrast enhancement images. <h3>Results</h3> Compared with dark blood T2-weighted MRI, consensus agreements between independent observers for identification of myocardial oedema were higher with bright blood T2 -weighted MRI when evaluated per patient (p&lt;0.001) and per segment of left ventricle (p&lt;0.001). Compared to bright blood T2-weighted MRI, dark blood T2-weighted MRI under-estimated the area-at-risk compared to infarct size (p&lt;0.001). The 95% limits of agreement for inter-observer agreements for the ischaemic area-at-risk and myocardial salvage were wider with dark blood T2-weighted MRI than with bright blood T2-weighted MRI. Bright blood enabled more accurate identification of the culprit coronary artery with correct identification in 94% of cases compared to 61% for dark blood (p&lt;0.001). <h3>Conclusion</h3> Bright blood T2-weighted MRI has higher diagnostic accuracy than dark blood T2-weighted MRI. Additionally, dark blood T2-weighted MRI may underestimate area-at-risk and myocardial salvage.

T2-Cardiac Magnetic Resonance

The region of myocardium hypoperfused during ischemia, also known as the area at risk (AAR), has sought our attention since the earliest understandings of the wavefront of progressive myocardial infarction (MI) due to acute coronary syndromes (ACS).1 Edema took center stage as evidence accrued that cardiomyocytes take on water in the setting of ischemia and reperfusion2; this, in turn, led to the notion that the myocyte's survival was determined by whether sarcolemmal membrane resistance was exceeded.3 The development of nuclear scintigraphic techniques afforded demonstration of the perfusion deficit in vivo at the time of presentation. Comparison with histology in a number of autopsy hearts confirmed that in many patients, a large scintigraphic defect often was present despite a small area of irreversibly injured or infarcted myocardium; that is, there appeared to be myocardium at risk of irreversible injury but potentially salvageable.4 The authors presciently concluded that this group of patients had the “greatest promise for intervention.” Articles see p 210 and 228 Fast forward to the present era of rapid mechanical revascularization coupled with a host of pharmacological maneuvers to restore blood flow, and what do we find: reduced but still significant morbidity (≥3.4% patients per year develop heart failure after MI5), mortality (≈20% of men and women aged >40 years die in the first year after initial MI6), and cost of subsequent care (≈$32,000 per patient is spent in the first year after MI7). Although increased infarct size consistently portends worse outcomes,8,9 it would make sense to develop interventions that reduce ultimate infarct size while myocardium is still salvageable; this, in turn, requires reliable …

Gastrointestinal: Gastric foreign body causing intermittent gastric outlet obstruction

A 20-year-old man presented to the emergency department 14 days after ingestion of a 2 cm diameter folded beer bottle top. He stated that he had ingested the object unintentionally as part of an alcohol drinking game where the cap was in the bottom of his glass. For the next several days, he experienced intermittent epigastric discomfort exacerbated by food and lying supine. There was no fever, vomiting, cough or shortness of breath. He denied hematemesis or presence of melena. His past history included seizures secondary to recreational drug usage three years ago. He presented to his primary care physician. Clinical examination and laboratory tests were normal. Abdominal X-ray (Figure 1) revealed the presence of a folded cap within the distal stomach without evidence of obstruction. No further action was taken. He represented to hospital several days later, with episodic post-prandial vomiting and small volume, bright blood hematemesis and melena. His examination and laboratory tests were normal. Repeat abdominal radiograph showed no change in the position of the bottle cap. Endoscopy (Figure 2) was performed which confirmed a foreign body impacted at the pylorus. No other abnormality was seen. Attempted removal of the foreign body with a variety of endoscopic equipment, including diathermy snare, was unsuccessful. Surgical removal was required. Gastrotomy revealed that granulation tissue had grown into the fold of the cap. Surgical recovery was uneventful. Foreign body ingestion is an uncommon gastrointestinal presentation. The majority of presentations are due to unintentional ingestion in pediatric populations, with less than 20% in adults. The majority of adults who present with unintentional ingestion are elderly, intellectually impaired or affected by alcohol, whereas intentional episodes usually occur in psychiatric patients and prisoners. Management of foreign-body ingestion is influenced by the type of ingested material, the anatomic location of the object and local expertise available. Data suggests that 80% to 90% of ingested foreign bodies will pass spontaneously, with 10% to 20% requiring treatment by flexible endoscopy, and 1–14% by surgery. However, serious complications can occur including impaction, obstruction and perforation of the digestive or respiratory tract with significant morbidity and mortality. Contributed by

Abstract No. 340: Contrast-enhanced and non-contrast MR angiography for the interventionalist

1) Review techniques for contrast-enhanced MR Angiography. 2) Review techniques for non-contrast MR Angiography. 3) Provide clinical examples highlighting advantages and differences between contrast-enhanced and non-contrast MR Angiography. 4) Provide suggested guidelines for use of gadolinium agents in patients with renal insufficiency undergoing MR Angiography. Contrast-enhanced MR Angiography is a reference standard for the assessment of arterial disease. Once the examination of choice in patients with renal insufficiency, contrast-enhanced MR Angiography is now limited to patients with a glomerular filtration rate > 30 mL/min. Patients with renal insufficiency can be imaged with MR using non-contrast angiographic techniques which rely on a combination of stationary tissue suppression, flow-related enhancement, and bright-blood sequences. a) Contrast-enhanced MR Angiography: Performed using subtracted gradient echo 3-D datasets following the administration of a gadolinium chelate. The technique is flexible, enabling adjustment of the temporal and spatial resolutions for a given field of view and contrast kinetics. Use of blood pool agents enables prolonged data acquisitions with high spatial resolution. b) Non-contrast MR Angiography: Quiescent interval steady state (QISS) has been used for lower extremity angiography. Native space relies on bright blood sequences and differs from QISS in that it acquires a three-dimensional dataset. Flow-sensitive dephasing is a ECG triggered technique that relies on differences in flow in the arteries and veins between systole and diastole. Navigator gated three dimensional bright blood imaging enables assessment of the thoracoabdominal aorta. c) Comparison of contrast-enhanced and non-contrast techniques in assessment of the thoracic aorta, abdominal aorta, and arteries of the lower extremities. d. Guidelines for MR angiography protocols based on patient renal function will be reviewed. Contrast-enhanced MR angiography can be adapted for arterial assessment in any region of the body. By integrating non-contrast sequences into the clinical workflow, MR angiography can be performed safely in patients with renal insufficiency.

Time course of myocardial oedema in acute coronary syndrome assessed at 3 T using a bright blood T2-prepared SSFP sequence

Introduction Cardiac magnetic resonance (CMR) is used in the evaluation of acute coronary syndrome (ACS) to assess both area at risk (AaR) and area of necrosis. However, the time course and evolution of myocardial oedema in patients with ACS is not known. We sought to assess the change in myocardial oedema following percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI) and non-ST elevation ACS (NSTEACS).

Measuring aortic diameter with different MR techniques: Comparison of three‐dimensional (3D) navigated steady‐state free‐precession (SSFP), 3D contrast‐enhanced magnetic resonance angiography (CE‐MRA), 2D T2 black blood, and 2D cine SSFP

To compare nongated three-dimensional (3D) contrast-enhanced magnetic resonance angiography (CE-MRA) with 3D-navigated cardiac-gated steady-state free-precession bright blood (3D-nav SSFP) and noncontrast 2D techniques for ascending aorta dimension measurements. Twenty-five clinical exams were reviewed to evaluate the ascending aorta at 1.5T using: breathhold cine bright blood (SSFP), cardiac-triggered T2 black blood (T2 BB), axial 3D-nav SSFP, and nongated 3D CE-MRA. Three radiologists independently measured aortic size at three specified locations for each sequence. Means, SDs, interobserver correlation, and vessel edge sharpness were statistically evaluated. Measurements were greatest for 3D-nav SSFP and 3D CE-MRA and smallest for T2 BB. There was no significant difference between 3D-nav SSFP and 3D CE-MRA (P = 0.43-0.86), but significance was observed comparing T2 BB to all sequences. Interobserver agreement was uniformly >0.9, with T2 BB best, followed closely by 3D-nav SSFP and 2D cine SSFP, and 3D CE-MRA being the worst. Edge sharpness was significantly poorer for 3D CE-MRA compared to the other sequences (P < 0.001). If diameter measurements are the main clinical concern, 3D-nav SSFP appears to be the best choice, as it has a sharp edge profile, is easy to acquire and postprocess, and shows very good interobserver correlation.

Feasibility of Functional Cardiac MR Imaging in Mice Using A Clinical 3 Tesla Whole Body Scanner

To test the feasibility of cardiac MR imaging in mice using a clinical 3 Tesla whole body MR system for structural and functional analysis. Standard protocols for bright blood cine imaging were adapted for murine dimensions. To validate measurements of functional parameters the MR data were compared with high-resolution echocardiographic measurements. Cardiac imaging was carried out in CD 1 wild-type mice (n = 8). MR imaging studies were performed using a clinical 3 Tesla MR system (Achieva, Philips). All mice received 2 MR scans and 1 echocardiographic evaluation. For optimal MR signal detection a dedicated solenoid receive-only coil was used. Electrocardiogram signal was recorded using a dedicated small animal electrocardiogram monitoring unit. For imaging we used a retrospectively triggered TFE sequence with a repetition time of 12 ms and an echo time of 4 ms. A dedicated software patch allowed for triggering of cardiac frequency of up to 600 BPM. Doppler-echocardiography was performed using a VisualSonics Vevo 770 high-resolution imaging system with a 30 MHz scanhead. Axial/lateral resolution was 40 of 100 microm and temporal resolution was 150 to 300 frames/s (B-mode) and 1000 frames/s (M-mode) depending on the setting. MR imaging was successfully carried out in all mice with a sufficient temporal resolution and good signal-to-noise ratio and contrast-to-noise ratio levels allowing for identification of all relevant structures. Accordingly, there was a good scan-rescan reproducibility of MR measurements: Interassay coefficients of variance ranged from 4% for ejection fraction to 12% for endsystolic volume (ESV). Magnetic resonance imaging and echocardiography gave comparable results when using the same geometric model (Teichholz method): EDV: 60.2 +/- 6.1 microL/59.1 +/- 12.3 microL, ESV: 20.0 +/- 2.6 microL/20.7 +/- 7.7 microL, EF: 66.7% +/- 4.0%/65.2% +/- 9.9%, CO 19.5 +/- 3.6 mL/17.9 +/- 2.9 mL. Bland-Altman analysis gave acceptable limits of agreement between both methods: EDV (+28.2/-26.1), ESV (+16.3/-17.7), EF (+19.0/-16.1), CO (10.7/-7.5). When applying the Simpson's method MR volume estimates were significantly higher compared with echocardiography resulting in a lower estimate for the ejection fraction (60% +/- 3.9% vs. 66.7% +/- 4.0%). Cardiac MR imaging of mice using a clinical 3 Tesla MR system for functional analysis is feasible with sufficient spatial and temporal resolution, good repeatability and reliable results when compared with high-resolution echocardiography.

Reproducibility and accuracy of automated measurement for dynamic arterial lumen area by cardiovascular magnetic resonance

Bright blood cine images acquired using magnetic resonance imaging contain simple contrast that is tractable to automated analysis, which can be used to derive a measure of arterial compliance that is known to correlate with disease severity. The purpose of this work was to evaluate whether automated methods could be used reliably on a clinically relevant population, and to assess the precision of these measurements so that it could be compared with expert manual assessment. In this paper we apply an algorithm similar to that used by Krug et al., and the exact processing steps are described in detail to allowing easy reproduction of our methods. Phantoms of different sizes have been assessed and the MRI measurements are found to correlate well (r = 0.9998) with physical measurement. Reproducibility assessment was performed on 33 CAD subjects in three anatomical locations along the aorta. Six normal volunteers and ten patients with more severe aortic plaques were investigated to assess reproducibility and sensitivity to pathological changes, respectively. The performance was also assessed on carotid vessels in 40 patients with known arterial plaques. In the human aorta the method is found to be robust (failing in only 7% of cases, all due to clear errors with image acquisition), and to be quantifiably consistent with expert clinical measurement, but showing smaller errors than that approach [<1.21% (5.62 mm(2)) manual vs. <0.58% (2.71 mm(2)) automated, for the aortic area] and with reduced bias, and operated correctly in advanced disease. We have proved over a large number of subjects the superiority of this automated method for evaluating dynamic area changes over the Gold-standard manual approach.

Swallowing the Androgyne and Baptizing Mother: Some Modernist Twists to Two Basic Sacraments

Swallowing the Androgyne and Baptizing MotherSome Modernist Twists to Two Basic Sacraments Gerald Gillespie The Eucharist and Communion A detailed schematization of aspects of the feminine gathered from myth analysts like C. G. Jung and Joseph Campbell was among the helpful frameworks that Michael Palencia-Roth offered in his path-breaking comparative study of Joyce, Mann, and García-Márquez (1987). My purpose here is to illustrate how the interest of modernist writers in “feminine” characteristics and paradigms sometimes was channeled in revisions of mainstream ways for treating two fundamental sacraments, the Eucharist and baptism. Of course, there is nothing strange in the fact that writers of more recent times, liberated after many centuries of anthropological speculation about myth and religion, would play with the tradition of the sacraments as part of their culture’s poetic vocabulary. Switching or unifying “masculine” and “feminine” expressions of God was already attractive to some artists and writers of the high Middle Ages, as the researches of Caroline Bynum have established. A peaking of medieval fascination for the “body” of the Savior was manifested in the institution of a new feast day, Corpus Christi. One formative impulse can be traced to the nun Saint Juliana (1193–1258) of Mont Cornillon in Belgium who experienced a vision of a Eucharistic wafer which bled and she thought the sacrament was telling her to advocate the due observance of its mystery, Christ’s sacrifice nourishing humanity. One of her important confidants, Robert de Thorete, Bishop of Liège, called a synod in 1246 and ordered celebration of the new feast. The initiative was restarted when Jacques Pantaléon, Archdeacon of Liège, after his election as Pope Urban IV, declared the feast day of Corpus Christi in 1264 and asked no less a figure than Saint Thomas Aquinas to write liturgy for it that is still used and admired today. Probably antedating the official establishment of the celebration, ritual parades in which the host was carried about the towns in a monstrance amplified the public’s opportunity to venerate His real presence in the consecrated bread and thereby to reconstitute the community of belief. Jan van Eyck’s (1385–1441) famous painting of The Lamb of God (1432) from whose breast bright blood spurts to fill the chalice on the depicted altar is one of [End Page 63] many late recapitulations of the dramatic union of white flesh and bright red which the Eucharistic host suggested as nourishment. The lower central panel in the huge altarpiece of St. Bavo’s cathedral in Ghent showing the beneficent Lamb focuses our adoration on the potency of the sacrament in a divine order. The fountain of life stands in the foreground below the throne-like altar, connecting baptism with Christ’s nurturing. It is instructive to contrast to Van Eyck’s mystical symbolism the radical portrayal of Christ’s body in Michelangelo Merisi da Caravaggio’s (1571– 1610) painting The Doubt of Thomas (1602–1603). The painter Rembrandt’s version (1634) of the resurrected Christ’s appearance to his followers more traditionally and tastefully depicts Thomas’s amazement as Christ in an aureole of radiance lifts His garment to reveal the lance wound, while a number of other disciples look on similarly moved. Caravaggio, however, is provocatively naturalistic. Christ, with no halo, bares His chest with His right hand and with His left gently guides Thomas’s right hand as the “doubter” probes the vagina-like wound with a large sturdy forefinger. We enjoy a view close up to the intimately clustered group of three apostles next to the Savior whose feminine face is inclined tenderly toward the intrusive finger. Unmistakably baroque in its tendency, this tension-laden picture combines eroticizing the act of testing the Savior’s flesh with a feeling of paradox and controversy. We are made to puzzle over whether the painter is conveying a deliberately occulted message or teaching, rather than the standard story from Matthew. One of the mysteries suffering estrangement in the seventeenth century that may be reintroduced here is the motherhood of God and the “flesh” as God’s channel (feminized Christ). Of course, this is the moment of Miguel de...

Major Hepatectomy Induces Phenotypic Changes in Circulating Dendritic Cells and Monocytes

Patients undergoing major hepatectomy are at increased risk for post-operative morbidity and mortality, and changes in the phenotype of effector cells may predispose these patients to infectious sequelae. To better understand post-hepatectomy immune responses, peripheral blood from 15 hepatectomy patients was drawn immediately before and after liver resection and on post-operative days 1, 3, and 5. Circulating monocytes and dendritic cells were analyzed by flow cytometry for quantity, phenotype, activation status, human leukocyte antigen DR (HLA-DR) expression, and toll-like receptor-2 and -4 expression. Major hepatectomy increased the numbers of activated CD16(bright) blood monocytes and the percentage of activated dendritic cells, although monocyte HLA-DR expression was reduced. These results may represent both dysfunctional antigen presentation and pending anergy, as well as cellular priming of immune effector cells. Better understanding of the alterations in innate immunity induced by hepatectomy may identify strategies to reduce infectious outcomes.

Risk of Bleeding Following Percutaneous Endoscopic Gastrostomy (PEG): A Five Year Retrospective Study

Percutaneous Endoscopic Gastrostomy (PEG), the primary procedure for the long term nutrition of patients with swallowing disorders, is considered a high risk endoscopic procedure for bleeding complications. This retrospective review aims to determine predictive factors of bleeding complications associated with PEG, including the risk of anticoagulation and anti-platelet therapy. Methods: During a 5 year period (Jan 1, 2002 to Dec 31, 2006), 956 PEG were performed using a standard pull-through technique. Complete electronic medical records were available in 883 cases, and were reviewed for predictive factors of bleeding, bleeding complications, and interventions for hemostasis. Bleeding was defined as blood per PEG (bright blood, coffee ground material, heme-positive aspirate), hematemesis, melena, hematochezia, peri-stomal bleeding, drop in hemoglobin or occult blood in stool. Results: Of the 883 cases, 54.9% (n=495) were male, 45.1% (n=398) were female, with a mean age of 67.8 ± 16.6 years. Gastrointestinal bleeding following PEG occurred in 28 cases (3.2%), of which only 5 cases (0.57%) were found at endoscopy to be a result of PEG placement; 3 developed immediate peri-stomal bleeding, one of which required intra-dermal injection of epinephrine. Endoscopy on the other 2 patients revealed PEG related bleeding gastric ulcers treated with injection therapy. Blood transfusion was required in 1 patient. Cases were reviewed for the use of anti-platelet (aspirin, clopidogrel) or anticoagulants (heparin, enoxaparin, warfarin). Among cases where PEG related bleeding was identified, 100% (n=5) were on at least 1 anti-platelet or anticoagulant drug, with none having received clopidogrel. In the non-bleeding group, 62.53% (n=549) were on at least one anti-platelet or anticoagulant drug administered in proximity to PEG insertion, and 9.7% (n=85) were treated with clopidogrel. The mean cessation period for clopidogrel prior to PEG was 2.3 ± 2.14 days. A multiple logistic regression analysis of variables including gender, indication, or the use of anti-platelet or anticoagulant medications showed that none of these variables were statistically significant predictors of bleeding (p≥ 0.127). Conclusions: Bleeding complications associated with PEG placement are rare, even in the face of recent use of anticoagulants and anti-platelet medications. Specifically, clopidogrel did not contribute to an increase in bleeding outcomes, despite cessation of the drug a mean of 2.3 days prior to PEG. Prospective studies are needed to establish evidence-based guidelines for optimal cessation of anti-platelet or anticoagulant medications prior to PEG.

The reproducibility of cardiac T2* measurement in thalassaemia major patients using bright and black blood sequences

Regular blood transfusions are required for the long term survival of patients with thalassaemia major (TM) but this can cause tissue iron overload. Myocardial iron overload can lead to heart failure and subsequent death. Iron chelation therapy can reduce tissue iron levels but efficacy needs to be closely monitored. Ferritin levels and hepatic iron loading do not correlate well with cardiac iron levels thus the need for a reliable, non-invasive means of follow-up. Cardiovascular magnetic resonance (CMR) using a bright blood gradient echo sequence has been validated for the quantification of tissue iron levels. Signal intensity decreases with increasing echo time and the rate of decay is proportional to iron loading. This bright blood sequence has been widely used for clinical follow-up and efficacy of pharmacological intervention. A T2* <20 ms is considered indicative of cardiac iron overload. Contrast between blood pool and myocardium for this technique is however relatively low, and blood signal artifacts which propagate onto the myocardium can further reduce accuracy. A double inversion pulse black blood sequence has recently been developed to address these issues. It is of interest therefore to assess reproducibility in a larger group of patients and to compare differences according to iron overload levels.

2076 Comparison between black and bright blood T2* measurements in thalassemia

2076 Comparison between black and bright blood T2* measurements in thalassemia

Optimized 3D bright blood MRI of aortic plaque at 3 T

To evaluate the feasibility of an optimized bright blood MRI protocol at 3 T in combination with contrast agent administration for the detection and characterization of aortic high-risk plaques for the improved workup of acute stroke patients. ECG synchronized T1-weighted 3D gradient echo MRI was performed in 45 acute stroke patients. Data were acquired with high near isotropic spatial resolution (approximately 1 mm(3)) covering the entire thoracic aorta. To compensate for breathing and vessel motion artifacts, images were collected using respiratory navigator gating in combination with short diastolic data acquisition windows adjusted on a patient-by-patient basis. In patients with aortic plaques > or =3 mm in thickness, gadolinium contrast agent was administered and both pre- and post-contrast T1-weighted 3D measurements with identical vessel coverage were performed. Bright blood 3D MRI detected 33 high-risk plaques with an average maximum plaque thickness of 4.2+/-1.0 mm in 23 of 45 acute stroke patients. The availability of pre- and post-contrast images acquired within the same session enhanced the identification of calcified plaque components in 77% of all analyzed plaques: post-contrast MRI clearly improved the delineation of hypointense plaque cores in 23 of 30 cases and assisted in the classification of core shape and of core fraction. 3D bright blood MRI at 3 T was feasible for the detection of aortic high-risk sources and may help to improve the detection of causes of cerebral embolism in acute stroke patients.

Cardiac T2* Magnetic Resonance Imaging (MRI) in Iron Overload and Ventricular Diastolic Function.

Accumulation of iron in the heart leads to myocardial dysfunction and in severe cases heart failure. Myocardial hemosiderosis occurs in many hematological diseases treated with blood transfusions, including sickle cell anemia (SCA) and beta thalassemia (β-thal). MRI T2* can quantify myocardial iron non-invasively and can be compared to functional studies (e.g., echocardiography). Multiple MRI readers can introduce variation in the measurement. We investigated the relationship of myocardial MRI T2* with echo measurements of both systolic and diastolic function, and the variability introduced by different MRI reviewers. Patients were selected if they received ≥ 18 transfusions, or had a serum ferritin ≥ 1000 ng/mL. Study participants underwent 1.5 Tesla MRI T2* and echocardiography testing within 30 days. Echo measurements included left ventricular ejection fraction (LVEF), mitral annular tissue Doppler (TDV) e' velocity (a measure of LV diastolic function), left ventricular myocardial performance index (a measure of both systolic and diastolic function - LVMPI), and left ventricular mass index (LVMI). Regions of interest (ROI) were drawn in a homogeneous area of the intraventricular septum. Three independent reviewers, blinded to the patients' clinical status and the other 2 reviewers' results, performed the ROI analysis. Agreement among the 3 raters was assessed using interclass correlation coefficient (ICC). Echo findings were associated with heart T2* both as continuous and categorical (normal vs abnormal) variables. Forty-seven patients, median age 14 years (range 7 – 37), participated; 24 (51.1%) were female. Thirty-five (74.5%) had SCA, 8 (17%) had β-thal (major or intermedia), and 4 (8.5%) had bone marrow failure syndromes. Mean (±1SD) echo results were LVEF (±5.8) %, LVMI 86 (±20.4) g/m2, LVMPI 0.3 (±0.1), and TDV e' velocity 16.2 (±3.4) cm/sec. Only one patient had low LVEF, but 8 (17%) had high LVMPI and 20 (42%) had low TDV e' velocity. All patients had normal LVMI. The mean myocardium T2* ranged among the 3 reviewers from 27 to 33 (±6.9 to 8.7) msec. Agreement among the 3 raters had an ICC = 0.64. Median T2* values were significantly lower among patients with lower LVMI (32 versus 42 msec, p= 0.019). No other comparisons among echo and T2* results were significant. Median echo findings were compared with T2* values above and below 20 msec: lower LVMI (71 vs 89 g/m2, p=0.04), and higher LVMPI (0.48 versus 0.28, p=0.015) were found among patients with T2* < 20 msec. Mean serum ferritin was 2917 (±2239) ng/mL. Serum ferritin was significantly negatively associated with T2* values (ρ=−0.33, p=0.031). We conclude:1.Most patients had normal LV systolic function, but 42% had signs of diastolic dysfunction,2.LVMPI was associated with myocardial iron loading (T2*>20msec), suggesting diastolic dysfunction to be an early sign of myocardial dysfunction in cardiac hemosiderosis,3.Heart T2* was weakly associated with serum ferritin,4.The agreement among reviewers of the heart T2* technique was acceptable, but not high, likely reflecting technical difficulties of accurate myocardial ROI determination on “bright blood” T2* maps drawn on thin intraventricular septa.Dark blood techniques should therefore be investigated to reduce blood artifacts, potentially improving accuracy by eliminating artifacts from bright blood signals and thus reducing inter-rater variability in the ROI analysis of myocardial iron.

Classic Citations: Priapism: Reasons for Failure by Frank Hinman Jr

In his article from 1960, Frank Hinman Jr [1] through the description of seven cases of idiopathic priapism gave the features of this disease. All seven patients had had previous transient episodes of priapism and prolonged sexual excitement before the final episode; erection of the corpora cavernosa sparing of corpus spongiosum; presence of dark thick blood, without clots, inside the corpora and refilling with bright blood after aspiration; limited subsidence after aspiration and eventual nonrefilling after it; and partial or complete erectile dysfunction after the episode.