Pao-Chun Lin

Neonatal cardiac multidetector row CT: why and how we do it

Neonatal congenital heart disease is a most difficult area of diagnostic radiology because of the small patient body size and fast resting heart rate. Recently, the spatial and temporal resolution of multidetector-row CT (MDCT) has evolved so that neonatal congenital heart disease can be precisely diagnosed. We describe the role of MDCT in neonatal congenital heart disease and offer tips for the scanning procedure to familiarize radiologists with this developing field.

Vertebral and carotid artery anomalies in patients with aberrant right subclavian arteries

BackgroundThere is little published evidence regarding the patterns and prevalence of vertebral artery (VA) and common carotid artery (CCA) anomalies in patients with an aberrant right subclavian artery (ARSCA).ObjectiveTo study the patterns and prevalence of VA and CCA anomalies in patients with ARSCA.Materials and methodsIn a 2-year period we reviewed the children referred with suspected vascular ring who had undergone multidetector-row CT. Patients with ARSCA were reviewed for VA and CCA patterns and their prevalence and relevance were calculated.ResultsIn total, 102 patients with ARSCA were identified. VA anomalies were present in 16 patients (15.7%), and CCA anomalies (common carotid trunk) in 21 patients (20.6%). In some patients with VA anomalies, the right VA arose from the right CCA and in some the left VA arose from the aortic arch. When the left VA arose from the aortic arch it was situated between the left CCA and the left SCA or between the left SCA and the ARSCA.ConclusionIf neurointerventionalists understand these potential anomalies and their prevalence, time and contrast medium could be saved when catheterizing the VA and CCA in patients with ARSCA.

Homogeneous enhancement in pediatric thoracic CT aortography using a novel and reproducible method: contrast-covering time.

OBJECTIVE This study compares the empiric setting and contrast-covering time (CCT) concept for i.v. contrast injection in pediatric thoracic CT aortography. SUBJECTS AND METHODS A total of 113 pediatric patients referred for thoracic CT aortography were classified into four groups: group 1 (1-5 years old, CCT), group 2A (6-10 years old, CCT), group 2B (6-10 years old, empiric setting), and group 3 (11-15 years old, CCT). The CT attenuation values from the left common carotid artery to the descending aorta were recorded every 0.5 second. The quantitative bolus geometric analysis of each group included average enhancement, SD within the patient, and slope of enhancement. Groups 2A and 2B were compared to determine whether better bolus geometry could be obtained with the CCT concept than with the traditional empiric setting. Groups 1, 2A, and 3 were compared to determine whether homogeneous bolus geometry could be obtained in different age groups. RESULTS More homogeneous enhancement was obtained with the CCT concept than the empiric setting with a smaller SD of enhancement (25.5 +/- 8.5 H vs 49.3 +/- 16.2 H, p < 0.001). Furthermore, in the three different age groups (groups 1, 2A, and 3) examined using the CCT concept, there was no significant difference in the average enhancement (415.7 +/- 83.6 H, 422.8 +/- 97.1 H, 392.0 +/- 78.5 H, respectively; all p > 0.05), SD of enhancement (28.5 +/- 9.8 H, 25.5 +/- 8.5 H, 28.5 +/- 14.6 H, respectively; all p > 0.05), or enhancement slopes (-5.6 +/- 18.0 H, -2.7 +/- 10.7 H, -5.4 +/- 12.3 H, respectively; all p > 0.05). CONCLUSION The CCT concept yields more homogeneous enhancement than the empiric setting. It also can routinely obtain homogeneous bolus geometry in patients in different age groups.

MDCT evaluation of congenital mitral-aortic intervalvular fibrosa aneurysm: implications for the aetiology and differential diagnosis.

Mitral-aortic intervalvular fibrosa aneurysm is a rare disease whose aetiology remains a matter of debate. Here we present the youngest reported patient with the disease, a 6-month-old boy, without a history of infection, which supports a congenital origin as initially proposed. Multidetector-row CT (MDCT) surpassed echocardiography in delineating the intracardiac anatomical details with high spatial resolution, confirming the important problem-solving role of MDCT in the diagnosis of congenital heart disease.

Arteriovenous Fistula and Graft Evaluation in Hemodialysis Patients Using MDCT: A Primer

OBJECTIVE Patent arteriovenous fistula (AVF) is related to better prognosis and quality of life for patients on long-term dialysis. When AVF dysfunction is suspected, MDCT is a good noninvasive tool for evaluating the entire AVF structure and determining reversible conditions for treatment. The aim of this article is to introduce the scanning and interpretation techniques and to illustrate the conditions related to early and late fistula failures. CONCLUSION MDCT is a fast, noninvasive, and accurate technique for diagnosing AVF complications. Radiologists familiar with these techniques can help to improve the prognosis and quality of life for hemodialysis patients.

Comprehensive MDCT Evaluation of Patients With Suspected May-Thurner Syndrome

OBJECTIVE The purpose of this essay is to introduce the MDCT protocol and interpretation techniques for optimal evaluation of patients with suspected May-Thurner syndrome. CONCLUSION May-Thurner syndrome is always the working diagnosis when a patient presents with unilateral left lower limb swelling without signs of infection. MDCT is useful for fast, comprehensive evaluation of the vascular system to determine whether May-Thurner syndrome or an alternative condition is present.

Comprehensive evaluation of patients suspected with deep vein thrombosis using indirect CT venography with multi-detector row technology: from protocol to interpretation

With the increased availability of multi-detector row CT, indirect CT venography has become an important non-invasive image modality for patients with suspected deep vein thrombosis. Use of indirect CT venography can not only diagnose/exclude deep vein thrombosis, but can also determine if there are other anomalies or diseases which might contribute to the patient’s symptoms. In this pictorial essay, we introduce the scanning protocol, post-processing techniques, and interpretation algorithm used in widely available 64 multi-detector row technology. We discuss several cases, including deep vein thrombosis in acute and chronic stages, anatomic variation, vena cava filter, and collateral veins. Lastly, we consider alternative diagnoses including varicose veins, infection, prosthesis failure of arthroplasty, traumatic vessel injury, and other musculoskeletal conditions. Radiologists should be familiar with the comprehensive interpretation of indirect CT venography to facilitate differential diagnosis and further treatment decision.

Comprehensive evaluation of CT pulmonary angiography for patients suspected of having pulmonary embolism

Recently, CT pulmonary angiography (CTPA), especially performed with multi-detector row CT, has become a key imaging modality for pulmonary embolism. However, CTPA that was performed under clinical suspicion of pulmonary embolism has been shown to lead to high prevalence of alternative diagnosis, up to 25.4%. A comprehensive evaluation of pulmonary and extrapulmonary abnormalities including cardiovascular lesions is critical in proper diagnosis and patient care. Radiologists should be familiar with the comprehensive interpretation of CTPA to facilitate differential diagnosis and further treatment decision.

Comprehensive evaluation of patients with suspected renal hypertension using MDCT: from protocol to interpretation.

OBJECTIVE The objectives of this article are to, first, describe the reasons for and details of the MDCT protocol for patients with suspected renal hypertension; second, explain the importance of comprehensive evaluation by MDCT in patients with suspected renal hypertension; third, review the image appearances of important conditions that may be encountered in the readers clinical practice; and, fourth, explain what information should be included in a comprehensive MDCT report for patients with suspected renal hypertension. CONCLUSION MDCT is widely used for renal artery evaluation in patients with resistant hypertension. Because the regions outside the renal arteries might also have diseases that contribute to the symptoms, a comprehensive interpretation including the renal arteries, renal parenchyma, adrenal glands, and scanned abdomen is very important. The scanning parameters should be adjusted according to the patients body habitus because some patients with suspected renal hypertension are children or young women. In this article, cases with illustrations showing the process from protocol to interpretation are provided.