Spiral CT angiography of the pulmonary circulation

Pulmonary Artery Aneurysm in a Patient with Nontuberculous Mycobacteria Infection

Nontuberculous mycobacterial (NTM) infection sometimes leads to the development of pulmonary artery aneurysm (PAA), a rare but life-threatening complication. We herein report a 64-year-old woman with a history of NTM infection who presented with severe hemoptysis. Computed tomography revealed a ruptured PAA, which was treated successfully with pulmonary artery embolization. Subsequent right total pneumonectomy was performed to control infection. This case emphasizes the need to consider PAA in patients with NTM infection who present with hemoptysis. Early detection and appropriate management are critical for preventing this fatal complication.

Mycotic Pulmonary Artery Aneurysm a Rare Complication of Ventricular Septal Defect With Infective Endocarditis: A Case Report

Introduction

Pulmonary artery aneurysms encompass a wide range of presentations and forms. Mycotic aneurysms represent a particular subset of focal dilatation of the vessel wall with high morbidity and mortality rates. Herein, we report the case of a 32 year old patient, with a prior history of ventricular septal defect presenting with a mycotic pulmonary artery aneurysm associated with infective endocarditis and septic emboli.

Case presentation

We present the case of a 32 year old male with known history of congenital ventricular septal defect presented to the emergency department with signs of sepsis and dyspnea. Blood cultures were positive for methicillin-sensitive Staphylococcus aureus. An echocardiogram found evidence of endocarditis with multiples intra cavitary vegetations. A CT angiogram demonstrated major right ventricular dilatation, multiple nodules and peripheral opacities, scattered throughout the lungs, indicative of septic emboli. Segmental saccular dilatation of the left lateral basal pulmonary artery consistent with a mycotic aneurysm formation was found. The patient was started on intravenous antibiotics and given the overall satisfactory evolution a conservative approach was pursued. The patient was discharged with antibiotics and scheduled for surgical repair of the ventricular septal defect.

Conclusion

To our knowledge, mycotic aneurysms associated to congenital heart malformation like ventricular septal wall defect remains a rare condition with few reported cases in the literature. Being aware of this entity is important for every practicing radiologist to allow for early diagnosis and treatment.

Clinical results of high probability ventilation/perfusion scintigraphy in the diagnosis of pulmonary embolism

Purpose

While computed tomography pulmonary angiography plays an effective role in the diagnosis and prognosis of pulmonary embolism (PE), there are not enough studies regarding ventilation/perfusion (V/Q) scintigraphy. We aimed to evaluate the clinical outcomes of PE patients whose V/Q scintigraphy was reported as high probability for PE.

Method

Demographic data, Simplified Pulmonary Embolism Severity Index (SPESI), radiological findings, V/Q scintigraphy and echocardiographic (ECHO) findings, laboratory data, treatment information and comorbidities of 43 patients whose V/Q scintigraphy was reported as high probability for PE between January 2020 and January 2023 was recorded. Perfusion scintigraphy defects were classified as subsegmental, multiple subsegmental, segmental, and multiple segmental. Those with subsegmental, multiple subsegmental, and segmental perfusion defects were classified as Group 1, and those with multiple segmental defects as Group 2.

Results

The mean age of the patients was 74 years (31-94), being 27 women (62.8 %) and 16 men (37.2 %), and there was no significant difference between the two groups. Multisegmental perfusion defect was detected in 23 (53.5 %) patients. 25 % of patients reported as high-probability PE had a SPESI score of ≥2. There was no significant difference between Groups 1 and 2 in terms of SPESI scoring. Perfusion defect had no significant correlation with SPESI score, D-Dimer, Troponin, pulmonary artery systolic pressure, right ventricular dilatation, and length of hospital stay. The presence of comorbidity was significantly positively correlated only with the SPESI score. There was no difference between the two groups regarding laboratory, radiological, echocardiographic findings, presence of comorbidity, unit of treatment, and duration of hospitalization.

Conclusion

Parameters predicting clinical severity and providing treatment benefits are required in PE patients diagnosed with V/Q scintigraphy.

Computed tomography of pulmonary veins: review of congenital and acquired pathologies

Newer-generation CT scanners with ultrawide detectors or dual sources offer millisecond image acquisition times and significantly decreased radiation doses compared to historical cardiac CT and CT angiography. This technology is capable of nearly freezing cardiac and respiratory motion. As a result, CT is increasingly used for diagnosing and monitoring cardiac and vascular abnormalities in the pediatric population. CT is particularly useful in the setting of pulmonary vein evaluation because it offers evaluation of the entire pulmonary venous system and lung parenchyma. In this article we review a spectrum of congenital and acquired pulmonary venous abnormalities, including potential etiologies, CT imaging findings and important factors of preoperative planning. In addition, we discuss optimization of CT techniques for evaluating the pulmonary veins.

Computed tomographic angiography (CTA) diagnosis of a rare meandering right pulmonary vein (MRPV)

Meandering right pulmonary vein (MRPV) is an exceedingly rare congenital pulmonary vascular variant with less than 20 reported cases. MPVR is a tortuous aberrant venous drainage of the right pulmonary upper lobe anastomosing with the right lower pulmonary vein instead of directly joining the left atrium. The variant is benign with an orthotopic venous drainage without any kind of shunting. The differential diagnosis mostly comprises the scimitar syndrome but also primary varix, arteriovenous malformations, and pulmonary sequestration. We report a case of MRPV fortuitously diagnosed in a 70-year-old patient. Multi-detector computed tomographic angiography (CTA) with MPR, MIP, and 3D reconstructions allowed the diagnosis obviating the need for invasive procedures.

Variabilities in Reference Standard by Radiologists and Performance Assessment in Detection of Pulmonary Embolism in CT Pulmonary Angiography

Annotating lesion locations by radiologists' manual marking is a key step to provide reference standard for the training and testing of a computer-aided detection system by supervised machine learning. Inter-reader variability is not uncommon in readings even by expert radiologists. This study evaluated the variability of the radiologist-identified pulmonary emboli (PEs) to demonstrate the importance of improving the reliability of the reference standard by a multi-step process for performance evaluation. In an initial reading of 40 CTPA PE cases, two experienced thoracic radiologists independently marked the PE locations. For markings from the two radiologists that did not agree, each radiologist re-read the cases independently to assess the discordant markings. Finally, for markings that still disagreed after the second reading, the two radiologists read together to reach a consensus. The variability of radiologists was evaluated by analyzing the agreement between two radiologists. For the 40 cases, 475 and 514 PEs were identified by radiologists R1 and R2 in the initial independent readings, respectively. For a total of 545 marks by the two radiologists, 81.5% (444/545) of the marks agreed but 101 marks in 36 cases differed. After consensus, 65 (64.4%) and 36 (35.6%) of the 101 marks were determined to be true PEs and false positives (FPs), respectively. Of these, 48 and 17 were false negatives (FNs) and 14 and 22 were FPs by R1 and R2, respectively. Our study demonstrated that there is substantial variability in reference standards provided by radiologists, which impacts the performance assessment of a lesion detection system. Combination of multiple radiologists' readings and consensus is needed to improve the reliability of a reference standard.

COVID-19 Viral Pneumonia Complicated with Acute Pulmonary Embolism: A Descriptive Study

OBJECTIVE

To evaluate acute pulmonary embolism in patients with 2019 novel coronavirus (COVID-19) pneumonia using pulmonary CT angiography. Subjects and Methods. From 95 symptomatic patients confirmed with COVID-19 by RT-PCR from 1 May to 14 July 2020 in Dallah Hospital, Riyadh, Saudi Arabia, CT angiography was done for 25 patients suspected to have pulmonary embolism and have no contraindication for contrast study. 11 cases of them showed CT evidence of acute pulmonary embolism (PE). Retrospectively, CT angiography was analyzed and detailed findings were recorded. This study was approved by the Institutional Review Board of our hospital, and the patient consent was waived.

RESULTS

The mean age of the included patients was 49 ± 11 years; the youngest was 22 years, and the oldest was 64 years. Common symptoms in the 25 cases that underwent CT angiography were fever that was noted in 21/25 cases (84%), shortness of breath in 18/25 cases (72%), cough in 16/25 cases (64%), and severe myalgia/body fatigue in 13/25 cases (52%). The less common symptoms were sore throat in 11/25 cases (44%) and headache in 10/25 cases (40%). Regarding CT findings, 4/25 cases (16%) had unilateral lung disease and 21/25 cases (84%) had bilateral disease, with slight predilection for the right lower lobe (10/25 cases, 40%). Pure ground-glass opacity (GGO) was seen in 13/25 cases (52%), and GGO with consolidation was seen in 12/25 cases (48%). Common accompanying CT signs included crazy paving stone sign in 15/25 cases (60%) and air bronchogram in 12/25 cases (48%). From the 25 patients that showed respiratory deterioration and elevated serum D-dimer level, 11 cases confirmed to have acute pulmonary embolism, while 14 cases showed negative result for pulmonary embolism. 6/11 were male and 5/11 were female. Pulmonary embolism was diagnosed at a mean of 21 days from symptom onset. Unilateral acute pulmonary embolism was seen in 3/11 cases, while 8/11 cases showed bilateral distribution. Among 11 cases with acute pulmonary embolism, no emboli at the central level could be seen, but 3 cases showed pulmonary embolism at the lobar level, 3 cases at the segmental level, and 5 cases at lobar, segmental, and subsegmental levels.

CONCLUSION

In patients with confirmed COVID-19, we should maintain a high suspicion for its thromboembolic complications such as acute pulmonary embolism that was mainly diagnosed at the end of 3rd week from symptom onset. We suggest that whenever a CT evaluation of the parenchymal involvement of COVID-19 pneumonia is performed, a simultaneous evaluation of the pulmonary arteries is also essential in order to identify early signs of associated pulmonary embolism.

Accuracy of PE rule-out strategies in pregnancy: secondary analysis of the DiPEP study prospective cohort

Objective

Recent studies suggest that combinations of clinical probability assessment (the YEARS algorithm or Geneva score) and D-dimer can safely rule out suspected pulmonary embolism (PE) in pregnant women. We performed a secondary analysis of the DiPEP (Diagnosis of Pulmonary Embolism in Pregnancy) study data to determine the diagnostic accuracy of these strategies.

Methods

The DiPEP study prospectively recruited and collected data and blood samples from pregnant/postpartum women with suspected PE across 11 hospitals and retrospectively collected data from pregnant/postpartum women with diagnosed PE across all UK hospitals (15 February 2015 to 31 August 2016). We selected prospectively recruited pregnant women who had definitive diagnostic imaging for this analysis. We used clinical data and D-dimer results to determine whether the rule out strategies would recommend further investigation. Two independent adjudicators used data from imaging reports, treatments and adverse events up to 30 days to determine the reference standard.

Results

PEs were diagnosed in 12/219 (5.5%) women. The YEARS/D-dimer strategy would have ruled out PE in 96/219 (43.8%) but this would have included 5 of the 12 with PEs. Sensitivity for PE was 58.3% (95% CI 28.6% to 83.5%) and specificity 44.0% (37.1% to 51.0%). The Geneva/D-dimer strategy would have ruled out PE in 46/219 (21.0%) but this would have included three of the 12 with PE. Sensitivity was 75.0% (95% CI 42.8% to 93.3%) and specificity 20.8% (95% CI 15.6% to 27.1%). Administration of anticoagulants prior to blood sampling may have reduced D-dimer sensitivity for small PE.

Conclusion

Strategies using clinical probability and D-dimer have limited diagnostic accuracy and do not accurately rule out all PE in pregnancy. It is uncertain whether PE missed by these strategies lead to clinically important consequences.

A comprehensive review on the diagnosis and management of intimal sarcoma of the pulmonary artery

Only a few hundred cases of intimal sarcomas of pulmonary artery (ISPA) were reported on the literature. Diagnosis of this rare entity is a challenging dilemma with the need for a high expertise in the radiological and pathological identification of ISPA. Treatment strategies rely initially on an early aggressive surgery aiming for complete surgical resection with clear margins while no clear recommendations guiding the choice for additional drug therapy or radiotherapy exist. In this article, we perform an extensive review of the literature on ISPA with details on the clinical presentation, diagnosis and management strategies. An additional goal of this paper is to make practicing oncologists aware of this rare entity with clear idea on the initial management.

Computed Tomography Pulmonary Angiography during Pregnancy: Radiation Dose of Commonly Used Protocols and the Effect of Scan Length Optimization

Objective

To evaluate the radiation dose for pregnant women and fetuses undergoing commonly used computed tomography of the pulmonary arteries (CTPA) scan protocols and subsequently evaluate the simulated effect of an optimized scan length.

Materials and Methods

A total of 120 CTPA datasets were acquired using four distinctive scan protocols, with 30 patients per protocol. These datasets were mapped to Cristy phantoms in order to simulate pregnancy and to assess the effect of an effective radiation dose (in mSv) in the first, second, or third trimester of pregnancy, including a simulation of fetal dose in second and third trimesters. The investigated scan protocols involved a 64-slice helical scan at 120 kVp, a high-pitch dual source acquisition at 100 kVp, a dual-energy acquisition at 80/140 kVp, and an automated-kV-selection, high pitch helical scan at a reference kV of 100 kV_ref. The effective dose for women and fetuses was simulated before and after scan length adaptation. The original images were interpreted before and after scan length adaptations to evaluate potentially missed diagnoses.

Results

Large inter-scanner and inter-protocol variations were found; application of the latest technology decreased the dose for non-pregnant women by 69% (7.0–2.2 mSv). Individual scan length optimization proved safe and effective, decreasing the fetal dose by 76–83%. Nineteen (16%) cases of pulmonary embolism were diagnosed and, after scan length optimization, none were missed.

Conclusion

Careful CTPA scan protocol selection and additional optimization of scan length may result in significant radiation dose reduction for a pregnant patient and her fetus, whilst maintaining diagnostic confidence.

The diagnosis of pulmonary embolism without contrastis not always Challenging: be aware of hyperdense lumen sign

Acute pulmonary embolism (PE) diagnosis is a challenging task, despite the advanced diagnostic methods for both clinicians and radiologists. Awareness of the “hyperdense lumen sign” in patients obtained un-enhanced computarized tomography (CT) of chest mayhelp to establish an acute PE diagnosis, especially in clinically non suspected PE patients. A 78-year-old woman was brought to our emergency department (ED) with an aphasia complaint. The patient's dizziness improved in ED. Neurological examination returned to base line status but sinus tachycardia and low saturation value on room air were continuing. Un-enhanced CT of the chest demonstrates hyperdense material within the right main pulmonary artery. Contrast-enhanced CTPA demonstrated hypodense filling defect within the rigth main pulmonary artery consistent with PE. Independent of the patient's complaint, the measurement of all vital signs is important especially in elderly patients. Emergency physicians have to be aware of that the “hyperdense lumen sign” may point out PE and should be prevented from delayed recognition.

Evaluation of the proximal coronary arteries in suspected pulmonary embolism: diagnostic images in 51% of patients using non-gated, dual-source CT pulmonary angiography

PURPOSE

This retrospective study reports the frequency and severity of coronary artery motion on dual-source high-pitch (DSHP), conventional pitch single-source (SS), and dual-source dual-energy (DE) CT pulmonary angiography (CTPA) studies.

METHODS

Two hundred eighty-eight consecutive patients underwent CTPA scans for suspected pulmonary embolism between September 1, 2013 and January 31, 2014. One hundred ninety-four at DSHP scans, 57 SS scans, and 37 DE scans were analyzed. Coronary arteries were separated into nine segments, and coronary artery motion was qualitatively scored using a scale from 1 to 4 (non-interpretable to diagnostic with no motion artifacts). Signal intensity, noise, and signal to noise ratio (SNR) of the aorta, main pulmonary artery, and paraspinal muscles were also assessed.

RESULTS

DSHP CTPA images had significantly less coronary artery motion, with 30.1% of coronary segments being fully evaluable compared to 4.2% of SS segments and 7.9% of DE segments (p < 0.05 for all comparisons). When imaging with DSHP, the proximal coronary arteries were more frequently evaluable than distal coronary arteries (51% versus 11.3%, p < 0.001). Without ECG synchronization and heart rate control, the distal left anterior descending coronary artery and mid right coronary artery remain infrequently interpretable (7% and 9%, respectively) on DSHP images.

CONCLUSIONS

DSHP CTPA decreases coronary artery motion artifacts and allows for full evaluation of the proximal coronary arteries in 51% of cases. The study highlights the increasing importance of proximal coronary artery review when interpreting CTPA for acute chest pain.

Comprehensive Cross-sectional Imaging of the Pulmonary Veins

The pulmonary veins carry oxygenated blood from the lungs to the heart, but their importance to the radiologist extends far beyond this seemingly straightforward function. The anatomy of the pulmonary veins is variable among patients, with several noteworthy variant and anomalous patterns, including supernumerary pulmonary veins, a common ostium, anomalous pulmonary venous return, and levoatriocardinal veins. Differences in pulmonary vein anatomy and the presence of variant or anomalous anatomy can be of critical importance, especially for preoperative planning of pulmonary and cardiac surgery. The enhancement or lack of enhancement of the pulmonary veins can be a clue to clinically important disease, and the relationship of masses to the pulmonary veins can herald cardiac invasion. The pulmonary veins are also an integral part of thoracic interventions, including lung transplantation, pneumonectomy, and radiofrequency ablation for atrial fibrillation. This fact creates a requirement for radiologists to have knowledge of the pre- and postoperative imaging appearances of the pulmonary veins. Many of these procedures are associated with important potential complications involving the pulmonary veins, for which diagnostic imaging plays a critical role. A thorough knowledge of the pulmonary veins and a proper radiologic approach to their evaluation is critical for the busy radiologist who must incorporate the pulmonary veins into a routine "search pattern" at computed tomography (CT) and magnetic resonance imaging. This article is a comprehensive CT-based imaging review of the pulmonary veins, including their embryology, anatomy (typical and anomalous), surgical implications, pulmonary vein thrombosis, pulmonary vein stenosis, pulmonary vein pseudostenosis, and the relationship of tumors to the pulmonary veins. Online supplemental material is available for this article. ^©RSNA, 2017.

Medical problems in pregnancy

The prevalence of medical problems in pregnancy is increasing because of a complex interplay between demographic and lifestyle factors, and developments in modern medicine. Maternal mortality and morbidity resulting from treatable medical conditions, such as venous thromboembolism, epilepsy and autoimmune disease, have not decreased in recent years. This is despite a marked decrease in overall maternal mortality. It is vital that all physicians acquire a basic knowledge and understanding of medical problems in pregnancy. This includes prepregnancy measures such as counselling and optimisation of medical therapy, as well as multidisciplinary management throughout pregnancy and the postpartum period. Prompt recognition and treatment of acute and chronic illness is of clear benefit, and most drugs and many radiological investigations may be used in pregnancy.

Medical problems in pregnancy

The prevalence of medical problems in pregnancy is increasing because of a complex interplay between demographic and lifestyle factors, and developments in modern medicine. Maternal mortality and morbidity resulting from treatable medical conditions, such as venous thromboembolism, epilepsy and autoimmune disease, have not decreased in recent years. This is despite a marked decrease in overall maternal mortality. It is vital that all physicians acquire a basic knowledge and understanding of medical problems in pregnancy. This includes prepregnancy measures such as counselling and optimisation of medical therapy, as well as multidisciplinary management throughout pregnancy and the postpartum period. Prompt recognition and treatment of acute and chronic illness is of clear benefit, and most drugs and many radiological investigations may be used in pregnancy.

Unusual meandering right upper lobe pulmonary vein draining into right middle lobe pulmonary vein: a case report

Meandering right pulmonary vein is a rare vascular anomaly that requires accurate diagnosis to avoid unnecessary procedures and unintended vascular injury during operation. We describe an unusual meandering right upper lobe pulmonary vein draining into the left atrium via the right middle lobe pulmonary vein.

The Diagnostic Role of Ultrasound in the Chest

Although the plain radiograph and computed tomography remain undoubtedly the primary imaging modalities in the investigation of chest pathology, ultrasound can play an important complementary role, both in the diagnostic workup of a patient and in their subsequent management. Its lack of ionizing radiation, bedside availability and dynamic imaging capacity afford ultrasound certain advantages over other techniques; particularly in the critical care setting where conventional radiography is often suboptimal. This article reviews the technique and diagnostic application of ultrasound in the assessment of pathologies of the diaphragm, pleura, lung, mediastinum and chest wall.

Radiology in the Intensive Care Unit (Part 2)

This review of intensive care unit (ICU) radiology has been divided into two sections. In Part 1, previously published, the discussion focused on the role of the portable radiograph in the evaluation of the critically ill patient and the impact of the introduction of digital radiography and picture-archiving communications systems on patient care. Part 2 of this review will emphasize the role of computed tomography and the increasing contribution of image-guided interventional procedures in patient management. The deleterious effects of mechanical ventilation due to barotrauma will also be discussed.

Pulmonary thrombo-embolism in pregnancy: diagnosis and management

KEY POINTS

Venous thromboembolism (VTE) in pregnancy remains a leading cause of direct maternal mortality in the developed world and identifiable risk factors are increasing in incidence.VTE is approximately 10-times more common in the pregnant population (compared with non-pregnant women) with an incidence of 1 in 1000 and the highest risk in the postnatal period.If pulmonary imaging is required, ventilation perfusion scanning is usually the preferred initial test to detect pulmonary embolism within pregnancy. Treatment should be commenced on clinical suspicion and not be withheld until an objective diagnosis is obtained.The mainstay of treatment for pulmonary thromboembolism in pregnancy is anticoagulation with low molecular weight heparin for a minimum of 3 months in total duration and until at least 6 weeks postnatal. Low molecular weight heparin is safe, effective and has a low associated bleeding risk.

EDUCATIONAL AIMS

To inform readers about the current guidance for diagnosis and management of pulmonary thromboembolism in pregnancy.To highlight the risks of venous thromboembolism during pregnancy.To introduce the issues surrounding management of pulmonary thromboembolism around labour and delivery.

Bilateral meandering pulmonary veins

Meandering pulmonary veins is a rare clinical entity that can be mistaken for more complex congenital syndromes such as hypogenetic lung syndrome. We report imaging findings in a rare incidentally detected case of bilateral meandering pulmonary veins. We briefly discuss the role of imaging in diagnosing this condition, with particular emphasis on contrast-enhanced CT.

An anomalous unilateral single pulmonary vein associated with a bone morphogenetic protein receptor II gene mutation

Anomalous unilateral single pulmonary vein (AUSPV), a rare congenital anomaly, is associated with an aberrant course but normal drainage, and resembles arteriovenous malformation (AVM). We treated a 26-year-old man with AUSPV in the right lung and an anomalous segmental pulmonary vein in the left lung. CT revealed a tortuous vascular shadow with an enhancement pattern identical to that of the pulmonary vein, suggesting AUSPV. This was confirmed by pulmonary angiography. Although pulmonary AVMs were not detected on angiography, microvascular AVMs could not be excluded because delayed bubbles appeared on contrast echocardiography. A genetic examination revealed a missense mutation of BMPR2.

Low-contrast agent dose dual-energy CT monochromatic imaging in pulmonary angiography versus routine CT

OBJECTIVE

This study aimed to retrospectively evaluate the feasibility and reliability of low-contrast agent dose dual-energy computed tomography (DECT) monochromatic imaging in pulmonary angiography.

METHODS

Computed tomography pulmonary angiography was performed in 86 patients, 41 in 120-kVp computed tomography (CT) and 45 in DECT with low-contrast agent dose. The images in DECT were reconstructed at optimal kiloelectron-voltage (keV), demonstrating the best contrast-to-noise ratio between pulmonary artery and soft tissue, and at 70 keV. Image quality was compared by quantitative and subjective indexes. The radiation doses were recorded.

RESULTS

Compared with 120-kVp CT, optimal keV showed superior quantitative indexes with inferior subjective image quality, whereas 70 keV demonstrated no statistical difference in quantitative indexes with superior subjective image quality. All suspicious pulmonary embolisms in DECT were diagnosed confidently by combination of 2 kinds of monochromatic imaging. The radiation dose in DECT is almost twice as 120-kVp CT.

CONCLUSIONS

Low-contrast agent dose DECT monochromatic imaging in pulmonary angiography accommodates superior intravascular enhancement and contrast in pulmonary arteries, and improves diagnostic confidence with compatible radiation dose.

Pulmonary embolus in pregnancy

Venous thromboembolism remains in the top three leading causes of maternal death in the US, representing 10.2% of pregnancy-related deaths. Risk of developing a pulmonary embolus appears to increase throughout pregnancy, with a peak in incidence in the early postpartum period. Overall the incidence of VTE is 0.6-1.8 VTEs per 1000 deliveries. Diagnosis and management of pulmonary embolus can prove challenging, but the aim should be to optimize maternal outcome while minimizing hemorrhagic complications. Low-molecular-weight heparin is a safe and effective treatment for the majority of cases of pregnancy-related pulmonary embolus.

Multiple pulmonary artery aneurysms in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a rare genetic disorder characterised by multiple hamartomas, caused by inactivating mutations of the TSC1/TSC2 tumour suppressor genes. Classical pulmonary involvement in tuberous sclerosis complex (TSC) consists of lymphangioleiomyomatosis and/or multiple micronodular pneumocyte hyperplasia (MMPH). Association of TSC with pulmonary artery aneurysm (PAA) has been only exceptionally described. We report here the first case of TSC with multiple PAA in combination with MMPH, cardiac rhabdomyomas and bone, skin and brain involvement.

Pregnancy-associated venous thrombosis

Pregnant women are at an increased risk of venous thromboembolism (VTE) and the consequences of an acute event in pregnancy can be debilitating, long-lasting or fatal. Screening for risk factors early in pregnancy and the provision of thromboprophylaxis are useful ways of preventing VTE in some women, but even when performed diligently, acute events are likely to remain common for the foreseeable future. It is therefore important for obstetric and non-obstetric clinicians to recognize the symptoms and signs of deep vein thrombosis and pulmonary embolism in pregnancy, to understand how a diagnosis can be reached in an effective yet safe manner and to be aware of the available treatment modalities.

[Non-tumoral vascular disorders of the lung in the adulthood]

Non-tumoral vascular disorders of the lung are multiple, even if cases diagnosed in the adulthood are rare. They include congenital or acquired conditions, which related symptoms, if present, are non specific. This explains why their diagnosis is challenging and usually delayed. Surgery is the cornerstone of their treatment, although interventional radiology represents currently a less invasive alternative option for some of them.

Contralateral decubitus positioning enhances computed tomographic angiographic evaluation of pulmonary vasculature in a patient with a pulmonary arteriovenous malformation

Computed tomographic pulmonary angiography has become the diagnostic procedure of choice in patients suspected of having a pulmonary embolus. However, intrapulmonary shunting of blood in a variety of pathologic conditions can cause suboptimal opacification of the pulmonary arterial circulation and result in a suboptimal or even nondiagnostic study. Radiologists should be aware of these conditions and be familiar with positioning techniques to minimize such shunting. We report a patient suspected of having pulmonary embolism, in whom a preexisting unilateral arteriovenous malformation prevented adequate evaluation of the pulmonary circulation. Positioning the patient in the contralateral decubitus position significantly enhanced image quality.

Ventilation/perfusion imaging of the lung using ultra-short echo time (UTE) MRI in an animal model of pulmonary embolism

PURPOSE

To test the feasibility of ultra-short echo time (UTE) MRI for assessment of regional pulmonary ventilation/perfusion in a standard 3 Tesla clinical MRI system.

MATERIALS AND METHODS

MRI of the lungs was conducted with an optimized three-dimensional UTE sequence in normal rats and in a rat model of pulmonary embolism (PE) induced by a blood clot. Changes in signal intensities (SIs) due to inhalation of molecular oxygen or intravenous (i.v.) injection of Gd, which represents the distribution of ventilation and perfusion, respectively, were assessed in the lung parenchyma.

RESULTS

The UTE MRI with a TE of 100 μs could detect and map the changes in SI of the lung parenchyma due to the inhalation of 100% oxygen or i.v. injection of Gd in normal rats. Reduced T1 resulting from oxygen inhalation was also quantified. These changes were not observed on the images that were obtained simultaneously with a conventional range of TE (2.3 ms). Furthermore, the method could delineate the embolized lesions where the lung ventilation and perfusion were mismatched in a rat model with PE.

CONCLUSION

These results show the feasibility and diagnostic potential of UTE MRI for the assessment of pulmonary ventilation and perfusion which is essential for the evaluation of a variety of lung diseases.

Postpartum pneumomediastinum: an uncommon cause for chest pain

This case report refers to a 32-year-old primiparous woman with a mild asthma, who had a normal vaginal delivery in a birthing pool and developed an acute postpartum chest pain due to pneumomediastinum and subcutaneous chest emphysema. After 72 hours of observation, she was discharged home without any residual symptoms.

Dynamic MR perfusion imaging: capability for quantitative assessment of disease extent and prediction of outcome for patients with acute pulmonary thromboembolism

PURPOSE

To compare directly the capabilities of multidetector-row computed tomography (MDCT) and MRI for disease severity assessment and outcome prediction for acute pulmonary thromboembolism (APTE) patients.

MATERIALS AND METHODS

Fifty consecutive APTE patients underwent MDCT, MR angiography, dynamic perfusion MRI, treatment and follow-up examination. Pulmonary blood flow (PBF), pulmonary blood volume, and mean transit time maps were generated from perfusion MRI, and all segmental parameters were determined by using region of interest measurements. Receiver operator curve analyses were used to determine the most accurate parameter for diagnosis of the APTE segment. Then, APTE index from perfusion MRI (PE(perfusion MRI) index), right ventricle/left ventricle (RV/LV) diameter ratio and APTE indexes from embolic burdens observed on MDCT (PE(CT) index) and MR angiography (PE(MRA) index) were calculated. Finally, ability to differentiate mortality (n = 8) from survival (n = 42) groups and to predict patient outcome were statistically assessed.

RESULTS

PBF was a significantly more accurate parameter than others (P < 0.05). When feasible threshold value was applied, specificity and accuracy of RV/LV diameter ratio and PE(Perfusion MRI) index were significantly higher than those of PE(CT) and PE(MRA) indexes (P < 0.05). Logistic regression analysis demonstrated that each index was a significant predictor (P < 0.05).

CONCLUSION

Dynamic perfusion MRI can be effective for disease extent assessment and outcome prediction for APTE patients.

Evidence base for the management of venous thromboembolism in pregnancy

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), is a leading cause of maternal mortality during pregnancy. DVT and PE are commonly suspected due to many mimicking signs and symptoms that are normal in pregnancy. However, validated diagnostic approaches are lacking, and a fear of teratogenic/oncogenic exposure from imaging procedures affects the acceptability of diagnostic approaches used for VTE during pregnancy. DVT and PE treatment in pregnancy is also challenging due to this lack of validated diagnostic approaches, changes in maternal physiology, and the need for intact hemostasis at the time of delivery/epidural analgesia. Prevention requires an optimal balancing of absolute increased bleeding risk from pharmacologic thromboprophylaxis and the absolute benefit of reduced DVT and PE, which, while serious, are relatively uncommon.

Triple-rule-out CT angiography for evaluation of acute chest pain and possible acute coronary syndrome

Triple-rule-out (TRO) computed tomographic (CT) angiography can provide a cost-effective evaluation of the coronary arteries, aorta, pulmonary arteries, and adjacent intrathoracic structures for the patient with acute chest pain. TRO CT is most appropriate for the patient who is judged to be at low to intermediate risk for acute coronary syndrome (ACS) and whose symptoms may also be attributed to acute pathologic conditions of the aorta or pulmonary arteries. Although a regular cardiac rhythm remains an important factor in coronary CT image quality, newer CT scanners with 64 or more detector rows afford rapid electrocardiographically (ECG) gated imaging to provide high-quality TRO CT studies in patients with a heart rate of up to 80 beats per minute. Injection of iodinated contrast material (< or = 100 mL) is tailored to provide simultaneous high levels of arterial enhancement in the coronary arteries and aorta (> 300 HU) and in the pulmonary arteries (> 200 HU). To limit radiation exposure, the TRO CT examination does not include the entire chest but is constrained to incorporate the aortic arch down through the heart. Scanning parameters, including prospective ECG tube current modulation and prospective ECG gating with the "step-and-shoot" technique, are tailored to reduce radiation exposure (optimally, 5-9 mSv). When performed with appropriate attention to timing and technique, TRO CT provides coronary image quality equal to that of dedicated coronary CT angiography and pulmonary arterial images that are free of motion artifact related to cardiac pulsation. In an appropriately selected emergency department patient population, TRO CT can safely eliminate the need for further diagnostic testing in over 75% of patients.

Automatic detection of pulmonary embolism in CTA images

Pulmonary embolism (PE) is a common life-threatening disorder for which an early diagnosis is desirable. We propose a new system for the automatic detection of PE in contrast-enhanced CT images. The system consists of candidate detection, feature computation and classification. Candidate detection focuses on the inclusion of PE--even complete occlusions--and the exclusion of false detections, such as tissue and parenchymal diseases. Feature computation does not only focus on the intensity, shape and size of an embolus, but also on locations and the shape of the pulmonary vascular tree. Several classifiers have been tested and the results show that the performance is optimized by using a bagged tree classifier with two features based on the shape of a blood vessel and the distance to the vessel boundary. The system was trained on 38 CT data sets. Evaluation on 19 other data sets showed that the system generalizes well. The sensitivity of our system on the evaluation data is 63% at 4.9 false positives per data set, which allowed the radiologist to improve the number of detected PE by 22%.