Orla Buckley

Iodinated Contrast Opacification Gradients in Normal Coronary Arteries Imaged with Prospectively ECG-Gated Single Heart Beat 320-Detector Row Computed Tomography

Background—To define and evaluate coronary contrast opacification gradients using prospectively ECG-gated single heart beat 320-detector row coronary angiography (CTA). Methods and Results—Thirty-six patients with normal coronary arteries determined by 320×0.5-mm detector row coronary CTA were retrospectively evaluated with customized image postprocessing software to measure Hounsfield Units at 1-mm intervals orthogonal to the artery center line. Linear regression determined correlation between mean Hounsfield Units and distance from the coronary ostium (regression slope defined as the distance gradient Gd), lumen cross-sectional area (Ga), and lumen short-axis diameter (Gs). For each gradient, differences between the 3 coronary arteries were analyzed with ANOVA. Linear regression determined correlations between measured gradients, heart rate, body mass index, and cardiac phase. To determine feasibility in lesions, all 3 gradients were evaluated in 22 consecutive patients with left anterior descending artery lesions ≥50% stenosis. For all 3 coronary arteries in all patients, the gradients Ga and Gs were significantly different from zero (P<0.0001), highly linear (Pearson r values, 0.77 to 0.84), and had no significant difference between the left anterior descending, left circumflex, and right coronary arteries (P>0.503). The distance gradient Gd demonstrated nonlinearities in a small number of vessels and was significantly smaller in the right coronary artery when compared with the left coronary system (P<0.001). Gradient variations between cardiac phases, heart rates, body mass index, and readers were low. Gradients in patients with lesions were significantly different (P<0.021) than in patients considered normal by CTA. Conclusions—Measurement of contrast opacification gradients from temporally uniform coronary CTA demonstrates feasibility and reproducibility in patients with normal coronary arteries. For all patients, the gradients defined with respect to the coronary lumen cross-sectional area and short-axis diameters are highly linear, not significantly influenced by the coronary artery (left anterior descending artery versus left circumflex versus right coronary artery), and have only small variation with respect to patient parameters. Preliminary evaluation of gradients across coronary artery lesions is promising but requires additional study.

99mTc bone scintigraphy superscans: a review.

Whole-body bone scintigraphy (bone scan) using a 99mTc-labelled pharmaceutical is one of the most commonly performed radionuclide examinations. In the normal patient, both the osseous components of the skeletal system as well as the kidneys and bladder are visualized. A superscan is defined as a bone scan which demonstrates markedly increased skeletal radioisotope uptake relative to soft tissues, in association with absent or faint genito-urinary tract activity. While a superscan is relatively uncommon, its recognition is important, as it is associated with a number of important underlying diseases. The purpose of this review article is to describe the causes and variable features of a superscan and depict patterns which may aid in defining the underlying cause for the scan. In addition, we will discuss other investigations that may help further to identify the underlying disease in such cases.

Cardiac Masses, Part 1: Imaging Strategies and Technical Considerations

OBJECTIVE The objective of this article is to discuss optimal imaging strategies for the evaluation of cardiac masses. The advantages and disadvantages of echocardiography, cardiac MRI, gated cardiac CT, and nuclear imaging will be discussed and specific techniques presented. CONCLUSION Multimodality imaging plays a pivotal role in the diagnosis and surgical planning of cardiac masses. Clinical features, such as patient age, location, and imaging characteristics of the mass will determine the likely differential diagnosis.

Predicting Benefit From Revascularization in Patients With Ischemic Heart Failure Imaging of Myocardial Ischemia and Viability

Case History: A 62-year-old male with a history of hypertension and coronary artery disease with prior stenting to the left circumflex artery presented with chest pain. Echocardiography on admission demonstrated a globally reduced ejection fraction of 10% to 15% with regional wall-motion abnormality consistent with prior anterior and inferolateral infarction. End-diastolic volume of the left ventricle (LV) was 210 mL. Coronary angiography showed evidence of multivessel disease, with 100% occlusion of the left anterior descending coronary artery, 70% in-stent restenosis of the left circumflex artery, and 90% stenosis of the posterior descending artery. To evaluate for the presence of ischemia, the patient underwent a rest-stress myocardial perfusion imaging study, which showed a large area of moderate ischemia throughout the mid left anterior descending coronary artery territory. In addition, there was a small area of scar in the proximal left circumflex artery territory (Figure 1). Clinical discussion ensued as to whether this patient would benefit from bypass surgery or percutaneous revascularization.

Cardiac masses, part 2: key imaging features for diagnosis and surgical planning.

OBJECTIVE The objectives of this article are to discuss key radiologic features that differentiate primary and secondary cardiac masses. Clinical scenarios are included to highlight stepwise radiologic workup of tumors of the pericardium, epicardium, myocardium, valves, and chambers. The involvement of key cardiac anatomic structures will also be emphasized to determine resectability and guide surgical planning. CONCLUSION Multimodality imaging plays a pivotal role in diagnosis and surgical planning of cardiac masses. Clinical features, such as patient age, location, and imaging characteristics of the mass will determine the likely differential diagnosis. In addition to radiologic evaluation of the mass itself, involvement of valvular apparatus, extent of myocardial involvement, or presence of associated coronary artery involvement is necessary to determine resectability and surgical technique.

Imaging features of intramural hematoma of the aorta

Intramural Hematoma (IMH) is defined as localized hemorrhage within the aortic wall and is included in the acute aortic syndrome spectrum with aortic dissection and penetrating aortic ulcer. The mortality from IMH is similar to classic aortic dissection (21%). 16% of patients with IMH will evolve to classic aortic dissection over time. Despite this confusion exists regarding the precise definitions and radiologic features of IMH versus penetrating ulcers with mural thrombus and overt aortic dissection.

Resolution of Iatrogenic Aortic Dissection Illustrated by Computed Tomography

An 83-year-old man with known history of known coronary artery disease (prior coronary artery bypass surgery and percutaneous coronary intervention), hypertension, and hypercholesterolemia presented with ongoing exertional angina and dyspnea despite medical therapy. A dipyridamole rubidium-82 stress test showed moderate-sized ischemia in the inferior and inferolateral territory. An echocardiogram showed mild segmental left ventricular dysfunction with an ejection fraction of 45% and mild mitral regurgitation. Angiography showed severe native triple vessel disease, patent left internal mammary artery graft to left anterior descending artery, patent stents in saphenous vein graft to obtuse marginal, and occluded vein graft to right coronary artery (RCA; previously known to be occluded). The native RCA was diffusely diseased with subtotal occlusions in its mid and distal segments including severe proximal posterior descending artery disease and was partly collateralized from obtuse marginal (Figure 1A). Given the ongoing symptoms on medical therapy, decision was made to proceed with percutaneous coronary intervention to RCA. Figure 1. RCA angiographic appearance: preprocedure (A), contrast in the false lumen of the aortic root dissection originating from RCA ostium (image at the time of ostial stent deployment) (B), and final angiographic appearance (C). The RCA ostium was engaged with an 8F Amplatz (AL 0.75) guide (chosen for extra support in a calcified, diffusely diseased artery), and the total occlusions in the mid and distal RCA were crossed using a PT Graphix guide wire (Boston Scientific, Natick, Mass). Rotational atherectomy with 1.50-mm burr was performed to …

Hemolytic Anemia Caused by Iatrogenic Arteriovenous Iliac Fistula and Successfully Treated by Endovascular Stent-Graft Placement

Hemolytic Anemia Caused by Iatrogenic Arteriovenous Iliac Fistula and Successfully Treated by Endovascular Stent-Graft Placement A 33-year-old man was admitted to our hospital for investigation and treatment of lower back pain. MRI of the lumbar spine revealed degenerative change and significant disk protrusion at the L5–S1 level, which was treated by lumbar diskectomy and laminectomy. Postoperatively, the patient developed back pain that was managed conservatively, and he was discharged. He was readmitted 3 months later with lethargy and persisting back discomfort. Physical examination was unremarkable. Laboratory investigations revealed anemia with elevated reticulocytes and lactate dehydrogenase (LDH) with reduced serum haptoglobins, consistent with hemolytic anemia from intravascular hemolysis. CT scans revealed indirect evidence of an arteriovenous fistula with opacification of a distended inferior vena cava in the arterial phase (Fig. 1A). A conventional angiogram confirmed the fistula between the right common iliac artery and left common iliac vein (Fig. 1B). The fistula developed secondary to the previous spinal surgery because of inadvertent trauma to the iliac vessels, and the rapid flow within the fistula resulted in hemolytic anemia. The fistula was subsequently treated with a covered stent-graft (Fig. 1C) with successful resolution of the patient’s hematologic parameters. The patient was discharged and remains well. Hemolytic anemias are generally classified into intravascular and extravascular hemolysis. In this case, the hemolytic anemia was intravascular and related to destruction of erythrocytes from high flow through the iliac fistula. Fistulas usually develop as a result of inflammation or trauma to the vessel or surrounding tissue. Trauma to the iliac vessels occurred inadvertently during surgery in this case. Vascular injury during spinal surgery is a known but unusual complication reported to occur with an incidence of 0.017% [1]. Retroperitoneal hemorrhage is well documented, but fistula formation is rare. The precise incidence of this complication is unknown, but one series reported arteriovenous fistula in 5 of 3,500 cases [2]. Previously, conventional angiography was necessary to make the diagnosis of a fistula; however, CT is now performed in the initial assessment of such patients [3]. CT findings include early filling and distention of the venous system and direct visualization of the fistula. Until recently, open surgical repair was the only treatment, and it had a significant operative mortality. In recent years, however, covered stent-graft technology has allowed for many fistulas of this kind to be treated in a minimally invasive fashion [4]. In the case we have presented, a covered stent-graft was successful in eliminating the iliac arteriovenous fistula and, thus, the patient’s hemolysis.

Cardiomyopathy of uncertain etiology: Complementary role of multimodality imaging with cardiac MRI and 18FDG PET.

A 59-year-old female with longstanding history of tachyarrhythmias was admitted for syncope and recurrent ventricular tachycardia. She had a past medical history of hyperlipidemia, hypothyroidism, atrial fibrillation, and wide complex tachycardia that had been attributed to Wolf-Parkinson-White syndrome. Her medications included atenolol, propafenone, synthroid, and lipitor. Her 12-lead ECG was notable for sinus rhythm with marked 1st degree heart block, right bundle branch block, and left anterior fascicular block (Figure 1). The echocardiogram on admission demonstrated a moderately dilated left ventricle with normal wall thickness. There was global left ventricular hypokinesis with an estimated ejection fraction (LVEF) of 20%. There was mild right ventricular dilatation with mild global reduction in right ventricular systolic function. Figure 1 12 lead ECG notable for Sinus rhythm (black arrow indicates p wave) with marked 1st degree heart block, right bundle branch block and left anterior fascicular block. To evaluate for possible obstructive CAD, the patient underwent invasive coronary angiography which demonstrated normal coronary artery anatomy with no evidence of atherosclerotic disease (Figure 2A, B). Figure 2 Coronary angiography found no evidence of coronary artery disease, A shows the selective catheterization and opacification of the LAD and LCX, and B the RCA. An endomyocardial biopsy from the right ventricular septum was then obtained to evaluate for infiltrative disease. Five biopsy samples were acquired. The endomyocardial biopsy demonstrated diffuse subendocardial myocyte vacuolization, which was thought to be demand-related given the tachyarrhythmias and normal coronary arteries (Figure 3). Specifically, there was no evidence of active myocarditis, granulomatous inflammation, acute or recent myocardial infarction, amyloid heart disease, or iron deposition. Figure 3 Endomyocardial biopsy shows no evidence of granulomatous disease. There is diffuse subendocardial myocyte vacuolization suggestive of chronic ischemia thought to be related to demand-related given the tachyarrhythmias and normal coronary arteries. Cardiac Magnetic Resonance (CMR) imaging was performed to find a potential cause of her cardiomyopathy and source of her ventricular tachycardia. CMR demonstrated severe reduction in global systolic function with and LVEF of 24% and RVEF of 20%. There was no myocardial edema on T2 weighted sequences and no evidence of increased myocardial iron deposition. Delayed enhancement images acquired 10 minutes after injection of 0.15 mmol/kg gadolinium demonstrated abnormal enhancement of the thinned myocardium in a near transmural pattern, was most prominent along the basal to mid anterior wall and septum (Figure 4A, B, C). Collectively, the non-coronary distribution, the septal involvement, and the subendocardial sparing were features highly suggestive of a non-ischemic cardiomyopathy and raise the possibility for myocardial infiltration with sarcoid. Figure 4 A Myocardial late gadolinium enhanced imaging of the short axis of the basal myocardium shows myocardium thinning and diffuse transmural late gadolinium enhancement which spares only the inferior and inferolateral segments. Late gadolinium enhancement ... Given the incongruous results of the CMR and endomyocardial biopsy, there was a concern for a false negative biopsy. The patient subsequently underwent a rest 82Rubidium and 18FDG PET study, which demonstrated a medium sized perfusion defect with corresponding 18FDG uptake (i.e., perfusion-metabolic mismatch) involving the mid and basal anterior and anteroseptal walls. In light of the fact that the patient had normal coronary arteries, this PET pattern was highly suspicious for an active inflammatory process (Figure 5). The whole body 18FDG PET study also showed multiple 18FDG avid lymph nodes in the cervical, mediastinal, and subdiaphragmatic regions (Figure 6). Figure 5 Resting 82Rubidium PET myocardial perfusion images showing a perfusion abnormality in the basal to mid anterior and antero septal segments (top row). This defect is matched on 18FDG PET images by focal 18FDG PET avidity in the basal to mid anterior and ... Figure 6 Coronal image from the 18FDG PET study demonstrates 18FDG avid left supra clavicular node and mediastinal nodes (white arrows) and myocardium. Subsequent biopsy of a subcarinal lymph node demonstrated histological features of sarcoidosis (Figure 7). The patient was placed on immunosuppression and an implantable defibrillator was inserted. Figure 7 A and B is a low power image of the lymph node biopsy from a subcarinal lymph node which shows effacement of normal lymph node architecture by well-formed non-necrotizing granulomata. Higher power image in B demonstrates a high power image of the granulomatous ...

The Demise of the Case Report

WEB This is a Web exclusive article. n November 2005, a key editorial decision was made by the American Journal of Roentgenology (AJR) that case reports would no longer be accepted for submission to the journal [1]. This change in policy was made following the guidance of the Executive Council of the American Roentgen Ray Society and was prompted by a report of the Publications Committee. One of the reasons for the decision to no longer accept case reports is that there was a huge increase in the number of manuscripts submitted to AJR after the opening of the portal for Web-based online manuscript submission. To counteract the potential buildup of a backlog of case reports, stricter criteria for publication were adopted. In addition, case reports were generally deemed not to have as much merit as original research and were therefore preferentially sacrificed to allow more space to publish full articles. This policy is not unique to the AJR; in fact, no longer publishing case reports has become an adopted stance by many American, Asian, and European journals both within and without the field of radiology. Although this decision carries significant merit, there are some disadvantages to this policy. It provided a timely and useful exercise to discuss the case for and the case against the rejection of case reports.