CT of intracardiac and intrapericardial masses

Computed tomographic (CT) equipment capable of high-resolution, rapid-sequence scanning allows detection of intracardiac and intrapericardial masses. Two patients with intrapericardial masses (pheochromocytoma, organized hematoma) and three patients with intracardiac masses (right ventricular rhabdomyosarcoma, right atrial metastasis, and left atrial thrombus) are presented. CT is the imaging method of choice for displaying pericardial masses directly and may be superior to echocardiography and angiocardiography in the detection of ventricular thrombi. In patients with cardiac tumors, CT evaluates extent of disease including invasion of contiguous vessels and pulmonary metastases better than echocardiography. Dynamic scanning after bolus intravenous injection of contrast material is recommended for the evaluation of patients with suspected masses involving the heart or pericardium.     

Pulmonary embolism, right ventricular strain, and intracardiac thrombus-in-transit: Evaluation using comprehensive cardiothoracic computed tomography

A 67-year-old woman presented with symptoms of exertional chest discomfort and dyspnea that had been progressive over the past few days. Her initial evaluation was significant of a mildly elevated troponin-T level and T-wave inversion in leads V₁-V₂ on an electrocardiogram (ECG). Initial suspicion was for acute coronary syndrome. However, a transthoracic echocardiogram showed normal left ventricular systolic function, moderate right ventricular enlargement with moderate decrease in systolic function, possible left atrial mass or thrombus, and a possible right atrial mass or thrombus versus a prominent Chiari network. ECG-gated comprehensive cardiothoracic computed tomography (CT) with a 64-slice multidetector CT was done to assess for pulmonary embolism or acute coronary syndrome and to further evaluate the possible right and left atrial masses. This showed large bilateral pulmonary embolism, interatrial thrombus in transit through a patent foramen ovale, and minimal coronary atherosclerosis. Dynamic imaging showed right ventricular enlargement with severe systolic dysfunction. The patient underwent successful pulmonary thromboembolectomy, removal of intracardiac thrombus, and closure of patent foramen ovale.     

Two-dimensional echocardiography in the diagnosis of intracardiac masses: A prospective study with anatomic validation

The accuracy of two-dimensional echocardiography in the detection of intracardiac masses was verified in 334 patients who underwent cardiac catheterization in our laboratory over 21 consecutive months. A complete two-dimensional echocardiographic (2DE) examination was performed a day before catheterization. The presence or absence of a mass was verified at surgery in 77 patients who successively underwent mitral or aortic valve replacement (51), left ventricular aneurysmectomy with or without myocardial revascularization (25), and resection of atrial myxoma (2). In 32 patients 2DE revealed the presence of a mass-left or right atrial thrombi in 12, left atrial myxoma in 2, left ventricular thrombi in 16, and endocardial vegetations in 2. The other 45 patients were free of intracardiac masses on 2DE. Anatomic verification at surgery revealed the presence of an intracardiac mass in 34 patients. In 30 (true positives) of these, 2DE revealed the mass as well, and in 4 (false negatives) the presence of a mass had not been identified by 2DE. In 2 patients (false positives) the predicted mass was not found at surgery. Absence of a mass was correctly predicted by 2DE in 41 patients (true negatives). Thus 2DE detected intracardiac masses with sensitivity of 88.2% and a specificity of 95.3%. We recommend that 2DE be performed in all patients prior to hemodynamic study and/or cardiac surgery to enable safer management of patients with intracardiac masses during cardiac catheterization and/or cardiac surgery.     

Detection and characterization of intracardiac thrombi on MR imaging

OBJECTIVE: The aim of our study was to compare the diagnostic accuracy achieved using different MR techniques with the diagnostic accuracy achieved using transthoracic and transesophageal echocardiography to detect intracardiac thrombi. MATERIALS AND METHODS: Twenty-four patients with known or suspected intracardiac thrombi were examined using MR imaging and echocardiography. All MR examinations were performed on a 1.5-T MR scanner using dark-blood-prepared half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences, fast imaging steady-state free precession (trueFISP) cine sequences, and inversion recovery gradient-echo fast low-angle-shot (inversion recovery turbo FLASH) sequences after injection of 0.2 mmol/kg of gadolinium diethylene triamine pentaacetic acid. RESULTS: MR imaging and echocardiography revealed 12 thrombi-two in the right atrium, one in the right ventricle, three in the left atrium, and six in the left ventricle. Compared with echocardiography, MR imaging revealed three additional thrombi in the left ventricle; these thrombi were confirmed at surgery. All 15 thrombi appeared as filling defects on early contrast-enhanced inversion recovery turbo FLASH MR images. Only seven thrombi were detected on HASTE images, and 10 thrombi were seen on trueFISP images. Four thrombi showed enhancement 10-20 min after contrast material injection and were characterized as organized clots. CONCLUSION: Contrast-enhanced inversion recovery turbo FLASH sequences were superior to dark-blood-prepared HASTE and trueFISP cine MR images in revealing intracardiac thrombi. Compared with transthoracic echocardiography, MR imaging was more sensitive for the detection of left ventricular thrombi. The characterization of thrombi may be used to predict the risk of embolism, which is higher for subacute clots than for organized thrombi.     

Right ventricular mural thrombus caused by myocardial infarction diagnosed by computed tomography

Thrombi of the left ventricle are common sequelae to acute anterior myocardial infarctions that involve the apex of the heart and produce akinetic or dyskinetic wall thickening patterns. While infarctions of the right ventricle are being increasingly recognized in the setting of inferior myocardial infarcts, little data on in vivo clot formation in the right ventricle of the heart are available in these patients. In the current study we were able to demonstrate a right ventricular mural thrombus using gated computed tomography of the heart. Although an abnormality in the right ventricle extending from the septal margin of the ventricle into the outflow tract could be identified with standard blood pool computed tomographic images and from cross sectional echocardiograms, only with cardiac gating could the relationship between the mass (thrombus) and the noncontractile section of the right ventricular myocardium be clearly identified. We conclude that cardiac gating may help in the evaluation of cardiac masses, and in particular cardiac thrombi. This will be particular valuable in the setting of recent or remote infarction, as the relationship between wall-motion abnormalities and thrombus formation has been well documented.     

Preablation assessment for the left atrium: comparison of ECG-gated cardiac CT with echocardiography

RATIONALE AND OBJECTIVES: Evaluate the role of two-dimensional echocardiography and electrocardiographically (ECG)-gated contrast-enhanced multislice computed tomographic (MSCT) cardiac imaging to assess cardiac anatomy, specifically pulmonary venous anatomy and left atrial thrombus, in a selected group of patients before catheter-based atrial fibrillation ablation. MATERIALS AND METHODS: Left atrial anatomy and associated findings in 34 consecutive patients scheduled for electrophysiologic testing who underwent both echocardiography and ECG-gated 16-slice MSCT cardiac imaging were retrospectively compared. Results from two-dimensional transthoracic echocardiography (TTE), cardiac MSCT, electrophysiologic study (EPS), and transesophageal echocardiography (TEE) (when performed) were taken from the official medical record without prior knowledge of this study when interpretation was rendered for clinical use. Electronic record review included: presence of left atrial thrombus (defined as constant filling defect on at least two echocardiographic views or filling defect on computed tomography) and location, pulmonary venous anatomy, and other cardiac, mediastinal, or pulmonary abnormalities. RESULTS: Left atrial thrombus was identified by cardiac MSCT alone in five patients (15%). Pulmonary venous variants were identified with cardiac MSCT in two patients (6%). Both MSCT and echocardiography were normal in 17 subjects (79%). Echocardiography was better at identifying associated valvular abnormalities that were seen in 10 patients (29%). Cardiac MSCT angiography alone identified other cardiac and noncardiac abnormalities, including suspicious pulmonary malignancy, mediastinal adenopathy, and coronary stenosis in 15 patients (44%). CONCLUSIONS: Echocardiography and cardiac MSCT angiography often provide complimentary findings during the preprocedural evaluation for patients with atrial fibrillation requiring ablation. Cardiac MSCT may provide significant additional information about the left atrium, mediastinum, coronary circulation, and visualized lung fields. Based on this study, we would advise that patients considered for radiofrequency ablation for uncontrolled right atrial fibrillation have both echocardiography and ECG-gated contrast-enhanced cardiac MSCT performed as part of the preprocedure evaluation.     

Visualization of right atrial thrombus associated with constrictive pericarditis by indium-111 oxine platelet imaging

A right atrial thrombus is not often seen and only a few reports of visualization have been described. We report a 44-yr-old man who had a large atrial thrombus associated with constrictive pericarditis. Two-dimensional echocardiography and computed tomography showed a large right atrial mass. Indium-111 oxine platelet deposition was demonstrated on the surface of thrombus by platelet imaging. Platelet imaging was useful for differential diagnosis from cardiac tumor, and as an indication for surgical treatment, since right atrial thrombus may have a high risk of pulmonary embolism or severe right heart failure.     

Usefulness of electron beam tomography in the prone position for detecting atrial thrombi in chronic atrial fibrillation

OBJECTIVE: We compared the usefulness of electron beam tomography (EBT) in the prone position relative to that in the supine position for detecting atrial thrombi. METHODS: We studied 96 patients with chronic atrial fibrillation, of whom 71 were scanned in the supine position and 25 were scanned in the prone position. Electron beam tomography was performed twice after contrast medium injection to obtain early- and late-phase images. RESULTS: Filling defects were detected in 13 patients in the supine position by EBT. Transesophageal echocardiography (TEE) revealed a thrombus in the region of the filling defect in 9 patients. In 4 patients, filling defects in the left atrial appendage were not confirmed as thrombi by TEE. Filling defects were detected in 4 patients in the prone position, all of which were confirmed as thrombi by TEE. CONCLUSION: Electron beam tomography in the prone position is an effective technique for reducing false-positive results in the detection of atrial thrombi.     

Superior vena cava and right atrial thrombus detected on lung perfusion scintigraphy

Ventilation and perfusion scanning is still used as the first modality for evaluating pulmonary embolism in pregnant and renal failure patients and those who are allergic to radiographic contrast. Hot spots in the right atrial area on perfusion scan are the result of the presence of thrombi. These thrombi are of 2 varieties. One type is a free-floating thrombus, which needs emergency thrombectomy, and another type is thrombus formation in the atria, predisposed by the presence of catheters. We report a study showing essentially normal perfusion but intense tracer uptake in the superior vena cava and right atrium. Noncontrast computed tomography confirmed the thrombus.     

Detection of acute atrial thrombus in a porcine model with atrial fibrillation with tc 99m-apcitide

RATIONALE AND OBJECTIVES: Technetium-99m apcitide (AcuTect) is a peptide with high affinity and specificity for glycoprotein IIb/IIIa receptors on platelets and is currently approved for the diagnosis of deep venous thrombosis. This study evaluates the use of Tc-99m apcitide for detecting intracardiac thrombus in an animal model with atrial fibrillation. METHODS: Thrombogenic material (0.23+/- 0.03 g) was implanted within the left atrium of 5 swine with induced atrial fibrillation. Scintigraphy was performed with a small field of view gamma camera (minimum of 400000 counts) 1 hour after implantation at 10, 60, and 120 minutes after the injection of the Tc-99m apcitide. Animals were then euthanized and a postmortem examination performed to confirm thrombus formation. RESULTS:: In all animals, thrombi and microthrombi were confirmed within the left atrial appendage. The average wet weight of the thrombus was 1.4 +/- 0.2 g. Tc-99m apcitide detected left atrial thrombus in all animals. CONCLUSIONS: This study suggests that AcuTect may prove useful for detecting intracardiac thrombus in future clinical studies in man.     

Various findings of cardiac thrombi on MDCT and MRI

Cardiac thrombus accompanies risk for peripheral embolization, either into the systemic circulation (from the left heart) or into the pulmonary arteries (right heart). In fact, the presence of peripheral emboli should prompt the search for a source within the heart. Echocardiography is the present technique of choice. Also, computed tomography and magnetic resonance imaging may provide additional information. In this article, we will demonstrate various features of cardiac thrombus on computed tomography and magnetic resonance imaging such as mural thrombus after myocardial infarction, thrombus at left atrial appendage in patients with mitral stenosis, thrombus mimicking tumor, organized thrombus containing calcification at left atrium, and compact moderator band mimicking thrombus.     

CT features of cardio-pericardial masses

The results of dynamic computed tomography (CT) in 13 patients with intracardiac filling defects and one with a pericardial lipoma are presented. The intracardiac filling defects were due to thrombus in five cases, myxoma in three, hydatid cysts in three, haemangiopericytoma in one and sarcoma in one. These kinds of lesions are well identified by CT which seems to be superior to echocardiography in the characterisation of the components and in the evaluation of the malignant spreading masses.     

Multidetector computed tomography for the detection of left atrial appendage thrombus: a comparative study with transesophageal echocardiography

OBJECTIVE: To determine the diagnostic performance of multidetector computed tomography (MDCT) for the detection of left atrial appendage (LAA) thrombus as compared with transesophageal echocardiography. METHODS: Multidetector computed tomography was evaluated in 43 patients qualitatively for the presence or absence of a filling defect in the LAA and compared with transesophageal echocardiography. Additionally, a ratio of the mean computed tomographic attenuation in the LAA apex to the mean computed tomographic attenuation in the aortic root was used for quantitative evaluation. RESULTS: A filling defect visualized in the LAA by MDCT corresponded to a sensitivity of 70% (7/10), a specificity of 82% (27/33), and a negative predictive value of 90% (27/30) for detection of LAA thrombus. When using quantitative parameters, MDCT demonstrated a sensitivity of 80% (8/10), a specificity of 73% (24/33), and a negative predictive value of 92% (24/26). Multidetector computed tomography was not able to differentiate LAA thrombus from spontaneous echo contrast by either visual evaluation or by quantitative parameters. CONCLUSIONS: Multidetector computed tomography remains limited for the detection of LAA thrombus. However, a subgroup of patients at very high risk for LAA thrombus may benefit from the high negative predictive value of cardiac MDCT.     

Availability of111In-labeled platelet scintigraphy in patients with postinfarction left ventricular aneurysm

Eighteen patients with postinfarction left ventricular aneurysms (LVAs) were examined with Indium-111-labeled autologous platelet scintigraphy to identify intracardiac thrombi and to investigate the effect of antithrombotic agents on thrombogenesity within their LVAs. Left ventriculography (LVG), and two-dimensional echocardiography were also carried out to assess the diagnostic ability of the platelet imaging. Indium-111-platelet scintigraphy for the detection of LVA mural thrombi had a sensitivity of 60% and a specificity of 100%. Four of six patients with false-negative scintigraphic studies had been under antiplatelet therapy. Eight of the nine patients who had showed active platelet deposition on initial examination had not received antiplatelet therapy. Thereafter, five of these nine were treated with tichlopidine (300 mg/day) for 29.8 +/- 5.0 days. On the second platelet study, two had resolution and the other three had interruption of intra-aneurysmal deposition, which remained positive. In only one patient of the three, the third platelet study was performed after warfarin therapy. It took two weeks after beginning the therapy to completely interrupt platelet deposition within the LVA in this patient. ECG gated radionuclide ventriculography and Thallium-201-myocardial scintigraphy were also performed to assess left ventricular wall motion of left ventricular ejection fraction (LVEF) and myocardial blood perfusion. Thallium-201-SPECT showed apical or anteroapical perfusion defects and the radionuclide ventriculography correctly identified all 18 apical and anteroseptal aneurysms which were confirmed by LVG methods. The comparison between the thrombus positive group and the thrombus negative group was carried out on both the LVEF and the period from the last myocardial infarction to the initial platelet scanning study. There were no statistical differences in the LVEF and the interval (34.5 +/- 12.5% vs 37.3 +/- 14.6%, 39.6 +/- 52.6 days vs 89.6 +/- 108.3 days) between the two groups. These results suggest that Indium-111-labeled platelet scintigraphy can be a reliable method for the identification of active left ventricular mural thrombi and a practical method of judging antiplatelet and anticoagulant therapy.     

Right heart thrombus in transit: a series of two cases

Right heart thrombus in transit is an increasingly recognized medical emergency with very high mortality rate. Echocardiography helps to establish the diagnosis and can differentiate between right heart thrombi that result from atrial fibrillation and those originating from deep venous thrombosis. We present two cases of right heart thrombus in transit diagnosed with echocardiography that were managed with different approaches.     

Right atrial thrombi: Percutaneous mechanical thrombectomy

The current therapeutic options for right atrial thrombi—surgical embolectomy and thrombolysis— are associated with high mortality and such patients often have contraindications to these therapeutic options. the purpose of this study was to evaluate the feasibility of endovascular right atrial embolectomy. Two patients with contraindications to thrombolysis and surgery were treated by a femoral approach. A catheter was placed in the right atrium, under fluoroscopic control, and a basket device was used to trap the thrombus. The location and extent of the thrombus was established before the procedure by transesophageal echocardiography (TEE) and the procedure was performed with TEE and fluoroscopy. Thrombi were withdrawn in the basket into the inferior vena cava (IVC) and a filter was inserted by a jugular approach and positioned in the IVC, just above the thrombi. The basket was removed leaving the thrombus below the filter. One patient died immediately after the procedure. In conclusion, endovascular extraction of right atrial thrombi may represent a potential therapeutic alternative, particularly in patients with contraindications to thrombolysis and surgery.     

超声检查在急性肺栓塞诊断中的应用价值

目的 探讨超声检查在急性肺栓塞诊断中的应用价值。方法 对临床综合诊断为急性肺栓塞的15例病人行超声心动图检查，综合分析。结果 经超声心动图检查15例患者，发现右房内血栓1例，肺动脉内血栓1例。15例均有右心负荷过重表现，伴有不同程度的三尖瓣返流，返流速度加快，肺动脉压明显增高。7例发现下肢深静脉内血栓。结论 超声心动图在肺动脉栓塞病人的筛查、评价患者的右心功能及疗效方面有重要价值。     

二尖瓣狭窄合并左心房血栓患者的经皮二尖瓣球囊成形术

目的　评价经皮二尖瓣球囊成形术 (PBMV)治疗风湿性二尖瓣狭窄合并左心房血栓的临床疗效和安全性。方法　 2 7例风湿性二尖瓣狭窄合并左心房血栓患者进行PBMV ,19例食管超声心动图 (TEE)有左心房内新鲜血栓者术前经华法令抗凝治疗 3～ 6个月。结果　 2 7例风湿性二尖瓣狭窄合并左心房血栓患者进行PBMV均成功。 19例TEE有左心房内新鲜血栓者 ,PBMV术前经华法令抗凝治疗后 ,TEE复查示 9例左心房血栓消失 ,10例左心房内血栓明显缩小 ,机化为高强回声团块的陈旧性血栓 ;5例经胸心脏超声发现左心房陈旧性血栓 ,未行TEE也未予华法令治疗者 ,术中 1例发生脑栓塞。其余患者均无并发症发生。结论　对风湿性二尖瓣狭窄伴有心房纤维颤动患者 ,PBMV前应常规行TEE检查 ;二尖瓣狭窄伴左心房血栓者经充分抗凝治疗后行PBMV是安全可行的。     

CT depiction of portal vein thrombi after creation of ileal pouch-anal anastomosis

PURPOSE: To determine the presence and location of portal vein thrombi in patients who have undergone ileal pouch-anal anastomosis (IPAA) and who were scanned with computed tomography (CT). MATERIALS AND METHODS: During a 4-year period, 92 of 702 patients underwent contrast medium-enhanced CT after a total proctocolectomy with an IPAA. These CT scans were retrospectively reviewed for portal vein thrombus presence, location, and occlusive nature, as well as any accompanying enhancement abnormalities of the hepatic parenchyma. Only 13 patients who had initial CT scans that were positive for thrombi underwent follow-up examinations, and these were reviewed for resolution or progression of the original findings. RESULTS: Portal vein thrombi were present in 41 (45%) of the 92 patients; 24 (59%) of the 41 were isolated, often multiple, segmental right lobe thrombi. Five patients had both right and left segmental vein involvement. Eleven patients had various combinations of main portal vein, right and left portal vein, or segmental vein thrombi. One patient had an isolated superior mesenteric vein thrombus. Twenty-two of 25 superior mesenteric vein, main portal vein, and right and left portal vein thrombi were nonocclusive, while most (63 of 86) of the segmental vein thrombi were occlusive. Wedge-shaped, peripheral areas of hepatic parenchymal hyperenhancement that were distal to the thrombi were present in 30 (73%) of the 41 patients. Follow-up scans obtained in the 13 patients with portal vein thrombi showed thrombi resolved in five patients, progression to cavernous transformation occurred in one patient, and parenchymal enhancement changes persisted in seven patients. In the seven patients with persistent enhancement changes, four had complete resolution of thrombi. CONCLUSION: Portal vein thrombi appear to be relatively common after IPAA surgery and are most likely segmental, multiple, and occlusive. Peripheral wedge-shaped areas of hepatic parenchymal hyperenhancement commonly accompany these thrombi.     

Short-axis circumferential profiles of the heart in healthy subjects: comparison of T1-201 SPECT and two-dimensional echocardiography

To correlate the findings at thallium-201 single photon emission computed tomography (SPECT) with left ventricular anatomy, circumferential wall thickness was measured in 12 healthy subjects with two-dimensional echocardiography. At the midpapillary level, eight anatomic structures were identified with echocardiography, as were four maxima (papillary muscles and junctions of the left ventricular myocardium with the right ventricle, both anteriorly and posteriorly) and the intervening minima (including the septum). Tl-201 SPECT was performed in the same subjects. The normalized circumferential count profiles of the short-axis sections that included the papillary muscles showed the same basic pattern as that on echocardiograms. In most cases, the posterior papillary muscle and the posterior junction with the right ventricle were not distinguishable from each other, which produced three circumferential profile maxima instead of four. When values from all subjects were averaged, left ventricular anatomy was less evident in the circumferential profile. Left ventricular anatomic structures were reflected to a similar degree with either 180 degrees or 360 degrees data sampling.