Non-Coronary Cardiac CT Imaging

Incidental Finding of Subannular Perfused Aortic Root Abscess

An 83-year-old female presented with aortic valve stenosis requiring surgery, which was diagnosed with a transthoracic echocardiography three years ago. However, the patient declined the surgery at that time due to personal reasons. Three years later she presented again with signs of dizziness and weakness and progression of the aortic valve stenosis. Cardiac catheterization and a computed tomography scan were performed before the planned surgery. Surprisingly, a huge subannular perfused abscess hole around the aortic root companying a pericardial effusion was revealed. The patient underwent an urgent aortic root replacement with a tissue valve and an aortic ascending replacement without any complications. Intraoperative inspection confirmed an active aortic root and valve endocarditis.

Nongated Cardiac Computed Tomographic Angiograms for Detection of Embolic Sources in Acute Ischemic Stroke

Background and Purpose—

We assessed the feasibility of obtaining diagnostic quality images of the heart and thoracic aorta by extending the z axis coverage of a non–ECG-gated computed tomographic angiogram performed in the primary evaluation of acute stroke without increasing the contrast dose.

Methods—

Twenty consecutive patients with acute ischemic stroke within the 4.5 hours of symptom onset were prospectively recruited. We increased the longitudinal coverage to the domes of the diaphragm to include the heart. Contrast administration (Omnipaque 350) remained unchanged (injected at 3–4 mL/s; total 60–80 mL, triggered by bolus tracking). Images of the heart and aorta, reconstructed at 5 mm slice thickness in 3 orthogonal planes, were read by a radiologist and cardiologist, findings conveyed to the treating neurologist, and correlated with the transthoracic or transesophageal echocardiogram performed within the next 24 hours.

Results—

Of 20 patients studied, 3 (15%) had abnormal findings: a left ventricular thrombus, a Stanford type A aortic dissection, and a thrombus of the left atrial appendage. Both thrombi were confirmed by transesophageal echocardiography, and anticoagulation was started urgently the following day. None of the patients developed contrast-induced nephropathy on follow-up. The radiation dose was slightly increased from a mean of 4.26 mSV (range, 3.88–4.70 mSV) to 5.17 (range, 3.95 to 6.25 mSV).

Conclusions—

Including the heart and ascending aorta in a routine non–ECG-gated computed tomographic angiogram enhances an existing imaging modality, with no increased incidence of contrast-induced nephropathy and minimal increase in radiation dose. This may help in the detection of high-risk cardiac and aortic sources of embolism in acute stroke patients.

Ischemic stroke: etiologic work-up with multidetector CT of heart and extra- and intracranial arteries

PURPOSE

To assess the potential of a single-session multidetector computed tomography (CT) protocol, as compared with established methods, for the etiologic work-up of acute ischemic stroke.

MATERIALS AND METHODS

Patients found to have recently experienced an ischemic stroke were recruited for this prospective study after institutional review board approval was obtained. Each patient was scheduled for two evaluation strategies: (a) a standard approach involving transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE), duplex ultrasonography (US) of the neck vessels, and magnetic resonance (MR) angiography of the neck and brain vessels; and (b) a protocol involving single-session multidetector CT of the heart, neck, and brain vessels. The authors sought to determine the major etiologic factors of stroke, including cardiac sources of embolism and atheroma of the aortic arch and the extra- and intracranial vessels, by using both strategies.

RESULTS

Multidetector CT, MR imaging, and duplex US were performed in 46 patients, 39 of whom also underwent TEE. The sensitivity and specificity of multidetector CT were 72% (18 of 25 cases) and 95% (20 of 21 cases), respectively, for detection of cardiac sources and 100% (24 of 24 cases) and 91% (20 of 22 cases), respectively, for detection of major arterial atheroma. For the 46 cases of stroke, the final etiologic classifications determined by using the standard combination approach were cardiac sources in 20 (44%) cases, major arterial atheroma in nine (20%), multiple sources in four (9%), and cryptogenic sources in 13 (28%). Multidetector CT facilitated correct etiologic classification for 38 (83%) of the 46 patients.

CONCLUSION

Multidetector CT is a promising tool for etiologic assessment of ischemic stroke, although the identification of minor cardiac sources with this examination requires the establishment of robust criteria.

MDCT evaluation of the cardiac venous system

PURPOSE

This study was undertaken to evaluate the usefulness of electrocardiographically (ECG)-gated multidetector-row computed tomography (MDCT) for the assessment of the coronary venous system and detection of its anatomical variants, in order to identify those suitable for lead placement in cardiac resynchronisation therapy (CRT).

MATERIALS AND METHODS

We retrospectively examined the coronary MDCT studies of 89 patients (73 males, 16 females, average age 62.5 years, range 31-79) referred for suspected coronary artery disease. The cardiac venous system was assessed in all patients using three-dimensional (3D) postprocessing on a dedicated Vitrea workstation (five patients were excluded from the analysis).

RESULTS

The coronary sinus, the great cardiac vein, the anterior interventricular vein and the middle cardiac vein were visualised in all cases. The lateral cardiac vein was visualised in 56/84 patients (67%) and the posterior cardiac vein in 63/84 patients (75%), never both missing. Along the postero-lateral wall of the left ventricle, only one branch was present in 44 cases, two branches in 21 cases and three or more branches in 19/84 cases (22%). Evaluation of the maximum diameter revealed that the lateral vein was dominant over the posterior vein in 20/40 cases. The small cardiac vein was visualised in 11/84 cases.

CONCLUSIONS

MDCT provides good depiction of the cardiac venous system, enabling the study of the vessel course and the identification of anatomical variants. Hence, this imaging technique could be proposed for the preoperative planning of CRT in selected patients.

Interventional electrophysiology and cardiac resynchronization therapy: delivering electrical therapies for heart failure

Implantable devices have become a readily available option for patients with heart failure. Not only do these patients develop bradycardia and ventricular tachycardia, but their ventricular dysfunction can often improve with cardiac resynchronization therapy. However, this is a complex and rapidly developing clinical science for which the physician chooses techniques and selects patients on the basis of the results of clinical trials, clinical experience, and rapidly evolving tools. The results depend on the interplay of these complex variables. Placement of the left ventricular lead has forced the device physician to develop new skills and/or interdisciplinary relationships with physicians with vascular intervention, imaging, and surgical skills. Familiarity with the cardiac venous anatomy, occlusive venography, venoplasty, guide wire tools, guiding catheters, stenting, and new intracardiac visualization and magnetic intracardiac lead positioning tools are examples of just a few of the novel skills that are useful in the delivery of cardiac resynchronization therapy. Beyond implantation, these patients and devices require specialized follow-up with continued medical therapy and echo-guided adjustments of device programming. Finally, there are ongoing controversies and many as yet unanswered questions that are the subject of ongoing and planned clinical trials.

Utilization of low-dose multidetector CT and virtual bronchoscopy in children with suspected foreign body aspiration

BACKGROUND

Foreign body aspiration is common in children, especially those under 3 years of age. Chest radiography and CT are the main imaging modalities for the evaluation of these children. Management of children with suspected foreign body aspiration (SFBA) mainly depends on radiological findings.

OBJECTIVE

To investigate the potential use of low-dose multidetector CT (MDCT) and virtual bronchoscopy (VB) in the evaluation and management of SFBA in children.

MATERIALS AND METHODS

Included in the study were 37 children (17 girls, 20 boys; age 4 months to 10 years, mean 32 months) with SFBA. Chest radiographs were obtained prior to MDCT in all patients. MDCT was performed using a low-dose technique. VB images were obtained in the same session. Conventional bronchoscopy (CB) was performed within 24 h on patients in whom an obstructive abnormality had been found by MDCT and VB.

RESULTS

Obstructive pathology was found in 16 (43.25%) of the 37 patients using MDCT and VB. In 13 of these patients, foreign bodies were detected and removed via CB. The foreign bodies were located in the right main bronchus (n = 5), in the bronchus intermedius (n = 6), in the medial segment of the middle lobe bronchus (n = 1), and in the left main bronchus (n = 1). In the remaining three patients, the diagnosis was false-positive for an obstructive pathology by MDCT and VB; the final diagnoses were secretions (n = 2) and schwannoma (n = 1), as demonstrated by CB. In 21 patients in whom no obstructive pathology was detected by MDCT and VB, CB was not performed. These patients were followed for 5-20 months without any recurrent obstructive symptomatology.

CONCLUSIONS

Low-dose MDCT and VB are non-invasive radiological modalities that can be used easily in the investigation of SFBA in children. MDCT and VB provide the exact location of the obstructive pathology prior to CB. If obstructive pathology is depicted with MDCT and VB, CB should be performed either for confirmation of the diagnosis or for the diagnosis of an alternative cause for the obstruction. In cases where no obstructive pathology is detected by MDCT and VB, CB may not be clinically useful.