Poul Henning Madsen

Efficacy of FDG PET/CT imaging for venous thromboembolic disorders: preliminary results from a prospective, observational pilot study.

Purpose In recent years, several case reports have described venous thromboembolism (VTE) on FDG PET/CT. In this short communication, we present results from a proof-of-concept pilot study aimed at providing some preliminary data on the efficacy of FDG PET/CT in prospective patients with suspected VTE. Patients and Methods Fifteen patients with suspected deep venous thrombosis (DVT) and/or pulmonary embolism (PE) were included prospectively and underwent a whole-body FDG PET/CT. Patients were divided into 4 groups as follows: DVT+ (DVT proven by high clinical suspicion and positive compression ultrasound), DVT− (DVT ruled out by low clinical suspicion and negative compression ultrasound), PE+ (PE proven by high clinical suspicion and positive lung scintigraphy), and PE− (PE ruled out by low clinical suspicion and normal lung scintigraphy). Images were interpreted visually by 2 experienced nuclear medicine physicians independently and without knowledge of other imaging results. Results Seven DVT+, 6 DVT−, 6 PE+, and 1 PE− were included. Five patients were suspected of both DVT and PE. FDG PET/CT correctly diagnosed the presence or lack of DVT in all patients, whereas results are more ambiguous in PE with only 2 of 6 PE patients showing FDG avidity. The readers agreed in all cases. Conclusions Although further studies are warranted for further clarification, our preliminary data substantiate that FDG PET/CT is a viable modality for assessing VTE, at least for DVT. We believe our results add positively to the limited data on this subject and are promising enough to warrant further larger series.

Potential role of FDG PET/CT imaging for assessing venous thromboembolic disorders.

The diagnosis of venous thromboembolism (VTE) remains a subject of debate and controversy. As pointed out by Rondina et al in this issue of Clinical Nuclear Medicine, an approach based on 2-deoxy-2-[F]fluoro-D-glucose PET/CT (FDG-PET/CT) could prove useful and improve patient management. In their pivotal study of 12 patients with confirmed proximal thrombosis in the lower extremity, they describe specificity of 87.5% to 100% and sensitivity of 87.5% to 100%, depending on SUVmax threshold used. They used the nonaffected leg and patients without VTE as controls. FDG-PET/CT imaging seems very promising for the detection of active thrombi throughout the body in patients with suspected deep venous thrombosis (DVT) or pulmonary embolism (PE), and in addition, it potentially can unmask underlying causes of VTE (eg, occult malignancies). With these advantages, it may supplement or replace existing techniques, which have inherent drawbacks. As also addressed by Rondina et al, FDG-PET/CT may add a new dimension owing to its unique ability to distinguish acute from chronic VTE, thereby ensuring early initiation of anticoagulant therapy only in cases of active thrombi and emboli.

FDG-PET/CT for venous thromboembolic disorders: Preliminary results

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Radionuclide Diagnosis of Pulmonary Embolism

Diagnostic imaging plays an integral role in the diagnostic workup of suspected pulmonary embolism, and several modalities have been employed over the years. In recent years, the choice has been narrowed to either computer tomographic or radionuclide based methods, i.e. computer tomographic angiography (CTA) and ventilation-perfusion scintigraphy (V/Q-scan). Both methods display advantages and shortcomings, and while we provide some insights into CTA and alternative methods, the papers main focus is a review of the V/Q-scan. We discuss basic considerations, interpretation criteria, clinical value, and controversies of conventional planar lung scintigraphy as well as the more contemporary 3-dimensional imaging technique of single photon emission tomography (SPECT) with or without CT.

Symptomatology, Clinical Presentation and Basic Work up in Patients with Suspected Pulmonary Embolism

Basic knowledge of pulmonary embolism is relevant to most practicing physicians. Many medical specialties care for patients with increased risk of pulmonary embolism, why recognition of relevant symptoms, a thorough medical history, assessment of the clinical condition of the patient and possibly referral to a relevant facility should be a part of the skills of all clinicians. Sudden onset dyspnea, chest pain, syncope and hemoptysis are essential symptoms of pulmonary embolism, and in most of these patients basic investigations like arterial blood gas analysis, electrocardiogram, chest x-ray and biochemical analyses are appropriate. In addition, lung ultrasound and echocardiography are indicated in many of these patients. The information available from the medical history, clinical assessment and basic investigation form the basis on which the decision about further diagnostic imaging and intensity of treatment and monitoring can be made. These decisions can be guided by clinical scoring systems like the Wells score, revised Geneva score and the PESI.

A Case of Unexplained Hypoxemia

We present a patient with acute-onset dyspnea and unexplained severe hypoxemia. No signs of severe cardiopulmonary disease, pulmonary arterial hypertension, or pulmonary embolism were present. The patient was diagnosed with hepatopulmonary syndrome, since liver disease of alcoholic origin was present, markedly increased alveolar-arterial oxygen difference existed, and intrapulmonary vascular dilations were demonstrated. The condition of the patient did not improve and he was referred for liver transplantation, which is the only treatment option with documented efficacy. The case highlights the importance of thinking outside the thorax when evaluating patients with dyspnea.

Pitfall in lung ultrasound: 'pseudo B-line' seen in both hydropneumothorax and in a cup of coffee

One of the lung ultrasound (LUS) signs which can be used to exclude the presence of pneumothorax is the B-line artefact. The presence of a B-line artefact indicates that the two pleural blades are in contact. Most of the research describing LUS for the diagnosis of pneumothorax is limited to pneumothorax without concomitant pleural effusion. This case report presents how a B-line was visualised using LUS in a patient with hydropneumothorax and, in addition, a simple model is used to provide a possible explanation on this phenomenon.

Diagnostic delay in malignant pleural mesothelioma due to physicians fixation on history with non-exposure to asbestos

To establish the diagnosis of virtually any disease, the clinician must combine a variety of information. Often emphasised in this context is thorough medical history-taking including information on exposure to factors leading to or being associated with the disease in question. Continuous assessment of all available information is of utmost importance, as fixation on single details can be misguiding with inappropriate consequences in both the diagnostic and therapeutic approach. This case report presents how an atypical medical history led to a delay in the diagnosis of malignant pleural mesothelioma due to a low a priori likelihood of the disease because of non-exposure to asbestos. We highlight the fact that postrationalisation and attempts to renew a diagnostic approach must be carried out each time diagnostic dilemmas emerge, and when some or all diagnostic clues disagree.