Evaluation of fluid collection in the pericardial sinuses and recesses: noncontrast-enhanced electron beam tomography

Pericardial Recesses on Computed Tomography: Implications for the Pulmonologist

The pericardium comprises a double-walled fibrous-serosal sac that encloses the heart. Reflections of the serosal layer form sinuses and recesses. With advances in multidetector computed tomography (CT) technology, pericardial recesses are frequently detected with thin-section CT. Knowledge of pericardial anatomy on imaging is crucial to avoid misinterpretation of fluid-filled pericardial sinuses and recesses as adenopathy/pericardial metastasis or aortic dissection, which can impact patient management and treatment decisions. The authors offer a comprehensive review of pericardial anatomy and its variations observed on CT, potential pitfalls in image interpretation, and implications for the pulmonologist with respect to unnecessary diagnostic procedures or interventions.

Pericardial diverticulum arising from the right lateral superior aortic recess: a mimicker of cystic anterior mediastinal mass

AIM

To report the prevalence of pericardial diverticulum of the right lateral superior aortic recess (RSAR) on computed tomography (CT), to analyse the structural CT findings of whether or not the structure is large enough to be seen on chest radiographs, and to describe changes in size and shape of RSAR on follow-up CT.

MATERIALS AND METHODS

A well-circumscribed, fluid-attenuation lesion in the anterior mediastinum with the following CT features was defined as a pericardial diverticulum of the RSAR: no enhancing wall, communication with the RSAR, abutment to the heart with an acute angle, and moulding by adjacent structures. Chest CT images of 31 patients with the diverticulum were evaluated, including four selected from 1,130 consecutive patients (0.4%).

RESULTS

The diverticulum projected ventrally from the RSAR and its largest size on axial CT ranged between 12-56 mm. Although the RSAR and the largest diverticular portion were usually seen on the same axial image (n=19), the latter sometimes lay above (n=1) or below (n=11) the former. On sagittal images, the last 11 diverticula resembled teardrops hanging from the RSAR by small stems. All of the 24 patients, each with 1-31 follow-up CT examinations, showed size fluctuations ranging between 1-46 mm (mean, 16 mm) during a follow-up period of 0.5-172 months (mean, 65 months). The diverticulum was not identifiable in five cases and was identifiable but did not show a connection with the RSAR in three cases when the diverticulum was smallest in size.

CONCLUSIONS

In cases of cystic anterior mediastinal mass, a deliberate search for its connection with the RSAR on all available CT images including previous studies is necessary for the diagnosis of pericardial diverticulum of the RSAR.

A highly-detailed anatomical study of normal pericardial structures as revealed by in-vivo computed tomography and magnetic resonance images and ex-vivo novel 3D reconstructions from Visible Human Server

The pericardial cavity, sinuses, and recesses are frequently depicted on Computed Tomography (CT) and Magnetic Resonance (MR).

We here review the normal human pericardial structures as provided by MR imaging of young, healthy subject and CT scans acquired after iatrogenic coronary dissection. We compared such radiological information with cadaveric axial and sagittal sections of the human body provided by the Visible Human Server (VHS), Ecole Polytechnique Federale de Lousanne (EPFL), Switzerland.

Hemopericardium in the acute clinical setting: Are we ready for a tailored management approach on the basis of MDCT findings?

The clinical spectrum of pericardial effusions varies from innocuous serous fluid to life-threatening hemopericardium. A misdiagnosis may be made by similar clinical presentation of acute chest pain/hypotension. Echocardiography is the first-line test for diagnosis of pericardial effusion and its etiology, but sometimes there are different drawbacks to the correct cardiovascular ultrasound diagnosis. Radiologists are reporting an increasing amount of thoracic Multidetector CT examinations at the emergency department. Multidetector CT has now become an established and complementary method for cardiac imaging, and diseases of the pericardium can now be quickly identified with increasing certainty. The aim of this review is to discuss the hemopericardium key Multidetector CT features in acute clinical setting which indicate the need to proceed with predominantly medical or surgical treatment, however, being able to identify forms of bleeding pericardial effusion for which only "a watch and wait strategy" and/or deferred treatment is indicated. In the emergency care setting, radiologists must be aware of different findings of hemopericardium in order to address a tailored and timely management approach.

Pericardial Recess: Computed Tomography Findings of Varying Disorders

A pericardial recess is frequently seen in patients undergoing chest computed tomography (CT). It is important to be aware of the normal anatomy of the pericardium as it is often mistaken for normal variants and/or disease. Therefore, we will describe the anatomy and location of the pericardial recess and the specific findings in various diseases associated with the pericardial recess.

Computerized tomography of the transverse pericardial sinus: Normal or pathologic?

The transverse pericardial sinus is a uniquely located structure subdivided into many parts. However, discrepancies still exist on the nomenclature and divisions. As noninvasive diagnostic technology such as CT and MR imaging improve, the transverse pericardial sinus and constituent recesses are visualized with more clarity, increasing the risk for misinterpretation. In this review, we will explore the anatomy of the transverse pericardial sinus and associated recesses with the goal of heightening awareness regarding the differential diagnosis between normal and pathological states as seen on CT. In addition, the inconsistencies of the right lateral superior aortic recess are also addressed. Last, we describe the clinical and surgical significance of the transverse pericardial sinus. Clin. Anat. 30:61-70, 2017. © 2016 Wiley Periodicals, Inc.

Correlation of transesophageal ultrasound of the pericardium with computed tomography

OBJECTIVE

In this study, we assess the sensitivity and specificity of ultrasound and computed tomography (CT) for pericardial effusion and constrictive pericarditis.

MATERIALS AND METHODS

This was a retrospective, institutional review board-approved, and health insurance privacy accountability act compliant study performed at a single tertiary center over a 10-year period (2001-2011) for patients who had clinical symptoms of pericarditis and had undergone both cardiac CT imaging and transesophageal echocardiogram (TEE) in a span of 2 weeks.

INCLUSION CRITERIA

Inclusion criteria included patients with clinical symptoms of pericarditis, pericardial thickness measuring more than 2 mm on CT, and patients who had both cardiac CT imaging and TEE performed within 2 weeks.

EXCLUSION CRITERIA

Exclusion criteria included patients with pericardial thickness measuring 2 mm or less on CT, no TEE, TEE not done within 2 weeks of the thoracic CT, and calcified pericardium on CT.Computed tomographic images were retrospectively reviewed by 2 radiologists who were unaware of the TEE findings. Pericardial effusion on CT was deemed present if there was obliteration of the fat plane in the left pulmonic recess.

STATISTICAL ANALYSIS

Statistical analysis was performed using the R statistical environment (Rstat). Intraobserver and interobserver variability was estimated using Cohen κ- statistic (Cohen).

RESULTS

Forty-three cases constituted the study population (28 men and 15 women; mean age, 55 years; age range, 22-82 years). Twenty-one patients had pathologic confirmation of pericarditis.The findings for CT and TEE were discrepant in 10 cases. Intraobserver variability Cohen κ statistic was 0.855. Interobserver variability Cohen κ statistics were 0.54 and 0.49.

CONCLUSIONS

Computed tomography is sensitive to pericardial effusion and pericardial thickening, whereas TEE seems insensitive to isolated pericardial thickening.

Evaluation of the Pericardium with CT and MR

The pericardium plays an important role in optimizing cardiac motion and chamber pressures and serves as a barrier to pathology. In addition to pericardial anatomy and function, this review article covers a variety of pericardial conditions, with mention of potential pitfalls encountered during interpretation of diagnostic imaging. Normal and abnormal appearance of pericardium on CT and MR imaging is emphasized, including dynamic imaging correlates of pericardial pathophysiology.

Subcarinal collection following mediastinoscopy: a normal post-procedural CT finding

AIM

To determine the frequency with which a subcarinal collection is present at computed tomography (CT) following mediastinoscopy and to determine the CT features of the collection.

MATERIALS AND METHODS

All patients who underwent uncomplicated mediastinoscopy during a 1-year period were retrospectively identified. This list was cross-referenced to determine those patients who also underwent CT within 15 days after the procedure. Each post-mediastinoscopy CT examination was assessed in consensus by three fellowship-trained thoracic radiologists for the presence of subcarinal abnormalities, which were also characterized in terms of their size and density. Additional CT findings were recorded, including tracheobronchial wall thickening, paratracheal collections, mediastinal fat stranding, and mediastinal air.

RESULTS

The study cohort included 10 patients (seven men and three women) with mean age of 65 years (range 49-81 years). CT was performed a mean of 11 days following mediastinoscopy. The most common CT finding was an oval subcarinal collection in nine of 10 cases (size 1.1-3.2 cm). In all nine cases, the subcarinal collections were consistently lower in attenuation than the subcarinal lymph node in the same region on the pre-procedure CT examination. Other CT findings included anterior tracheobronchial wall thickening (n=7); paratracheal collection (n=6); mediastinal fat stranding (n=6); and mediastinal air in (n=4) cases.

CONCLUSION

A subcarinal collection was identified in 90% of cases following mediastinoscopy. Its rapid development and characteristic appearance help to distinguish it from a lymph node.

The high-riding superior aortic recess of the pericardium: MRI visualization in a child

We report a 4-year-old child with a high-riding superior aortic recess of the pericardium, initially misdiagnosed as a possible vascular malformation. The anatomy of the pericardial recesses is reviewed.

Pericardial ???Sleeve??? Recess of Right Inferior Pulmonary Vein Mimicking Adenopathy

OBJECTIVE

The purpose of this study was to assess the computed tomography (CT) features of the pericardial "sleeve" recess of the right inferior pulmonary vein misinterpreted as adenopathy.

METHOD

Six patients with fluid in the pericardial sleeve recess mistaken for adenopathy were retrospectively identified. The following CT features were assessed: location of fluid in relation to the vein, size, shape, attenuation, and mass effect on the inferior pulmonary vein.

RESULTS

The most common presentation was fluid inferior and posterior to the vein. The anterior and posterior components are typically spindle shaped, whereas the superior and inferior components are ovoid. The attenuation values of the fluid ranged from 2-32 H (mean = 13 H). None of the fluid collections exerted mass effect on the right inferior pulmonary vein.

CONCLUSION

Although fluid in the right pulmonary venous sleeve pericardial recess can mimic adenopathy, this accumulation has a characteristic appearance, and knowledge of this normal variant is useful in preventing misinterpretation.

Comparing Thin-Section and Thick-Section CT of Pericardial Sinuses and Recesses

OBJECTIVE

The aim of this study was to assess the prevalence and appearance of the pericardial sinuses and recesses on thin-section (2.5- or 3-mm) CT scans compared with thick-section (5- or 7-mm) CT scans.

MATERIALS AND METHODS

Nine hundred forty-one consecutive contrast-enhanced chest CT scans were retrospectively evaluated. Three hundred sixty-five patients underwent thin-section CT, and 576 patients underwent thick-section CT. The prevalence and appearance of every pericardial recess were determined.

RESULTS

Large recesses such as the superior aortic recess were depicted in 12.5-30.4% of patients using thick-section CT, whereas smaller recesses such as the postcaval recess were depicted in fewer than 5% of patients. With thin-section CT, the depiction rates increased significantly compared with thick-section CT (p < 0.01). Large recesses were depicted in 28.7-44.7% of patients, and smaller recesses were recognized in 10.8-19.8% of patients. Generally, most recesses were linear if they were small and became band-shaped as the fluid increased. However, the recesses were often visualized as crescent, triangle, spindle, ovoid, hemisphere, or irregular shapes.

CONCLUSION

Pericardial sinuses and recesses are more frequently and better depicted on thin-section CT scans. Knowledge of their locations and shapes is helpful for distinguishing pericardial fluid from abnormal findings such as lymphadenopathy and cystic lesions.

CT and MR Imaging of Pericardial Disease

In the evaluation of pericardial disease, computed tomography (CT) and magnetic resonance (MR) imaging traditionally have been used as adjuncts to echocardiography. However, CT and MR imaging are particularly useful as sensitive and noninvasive methods for evaluating loculated or hemorrhagic pericardial effusion, constrictive pericarditis, and pericardial masses. Both CT and MR imaging provide excellent delineation of the pericardial anatomy and can aid in the precise localization and characterization of various pericardial lesions, including effusion, constrictive pericarditis and pericardial thickening, pericardial masses, and congenital anomalies such as partial or complete absence of the pericardium. Both modalities provide a larger field of view than does echocardiography, allowing the examination of the entire chest and detection of associated abnormalities in the mediastinum and lungs. Soft-tissue contrast on CT scans and MR images also is superior to that on echocardiograms. Given the many potential applications of these modalities in the evaluation of pericardial diseases, familiarity with the CT and MR imaging features of these diseases is important.

Imaging of intrathoracic metastases of nonseminomatous germ cell tumors

Radiologic imaging is crucial in the evaluation of intrathoracic metastatic nonseminomatous germ cell tumors. Helical CT is the workhorse of radiologic staging and is sensitive in the detection of parenchymal nodules and mediastinal lymphadenopathy. CT may also demonstrate other less common sites of metastatic disease. Although, currently, no radiologic procedure is effective in distinguishing viable tumor or teratoma from residual fibrosis and necrosis, cross-sectional imaging remains essential in the presurgical evaluation of potential metastatic disease. FDG PET and CT-guided needle biopsy may be useful in select, high-risk patients.

Computed tomography-fluoroscopy guided drainage of pericardial effusions: experience in 11 cases

RATIONALE AND OBJECTIVES

The purpose of the study was to evaluate feasibility and safety of CT-fluoroscopy in the drainage of pericardial effusion in cases not accessible by sonography.

METHODS

Eleven drainages were performed in Seldinger-technique under CT-fluoroscopy on eight patients suffering from pericardial effusion. The inclusion criterion was a sonographically proved pericardial effusion not drainable under sonographic surveillance. In seven procedures the catheter was positioned using a medial, in four procedures a lateral approach from the apex was chosen.

RESULTS

All catheters could be placed successfully (11/11) in the pericardial effusion and allowed for draining of the effusion in 10 of 11 cases. One epicardial laceration necessitated a surgical approach. The elapsed total procedure time for the drainage was on average 18:23 +/- 8:58 minutes.

CONCLUSIONS

Visual surveillance by CT-fluoroscopy is a feasible method in the drainage of pericardial effusions even in cases not accessible by ultrasound.

Improved reproducibility of coronary artery calcium scoring by electron beam tomography with a new electrocardiographic trigger method

RATIONALE AND OBJECTIVES

To improve the interscan reproducibility with electron beam tomography (EBT) by choosing an optimal electrocardiographic (ECG) trigger time.

METHODS

Two hundred fourteen asymptomatic subjects found to have coronary artery calcium (CAC) on EBT were rescanned immediately to measure the interscan variability. Subjects were randomized to one of two different ECG trigger interval groups: the new trigger method (group 1) and the 80% R-R interval trigger method (group 2). The new trigger method was derived from a previous study of motion in the coronary arteries. In group 1 (new trigger method), the ECG trigger was programmed for a certain time (in ms) after the R wave, based on the resting heart rate. The triggers for group 1 were 360 (heart rate <50 beats per minute [bpm]), 340 (51--60 bpm), 314 (61--70 bpm), 300 (71--80 bpm), 290 (81--90 bpm), 280 (91--100 bpm), and 270 ms (>100 bpm). The interscan variation (CAC area and Agatston score) was compared between the two groups.

RESULTS

The interscan variability was significantly reduced using the new trigger method for both CAC area and score compared with the 80% trigger method. The individual lesion variation was also significantly reduced by the new trigger method compared with the 80% trigger method. Area measure had a significantly lower variability compared with the Agatston score.

CONCLUSIONS

These results strongly support the use of this new ECG trigger that relies on a rate-adjusted millisecond delay after the R wave instead of the more commonly used 80% R-R interval in EBT calcium studies.

Noninvasive measurement of pulmonary vascular resistances by assessment of cardiac output and pulmonary transit time

RATIONALE AND OBJECTIVES

Pulmonary vascular resistance is of special interest in many diseases. Usually it is determined invasively by catheterization, but cardiac output and pulmonary transit time can be ascertained by several noninvasive methods.

METHODS

Fourteen heart recipients (age 34-71 years) were examined by electron-beam CT of the heart. Cine and flow studies were performed using a total of 60 mL of contrast and a breath-hold of 20 seconds.

RESULTS

A mathematical model for calculating pulmonary vascular resistances from noninvasively measured cardiac outputs and pulmonary transit times was developed. Right-sided heart catheterization served as the reference method.

CONCLUSIONS

The formula created seems to allow a clinically valid estimate of pulmonary vascular resistance from noninvasively acquired data.