Role of SPECT/CT compared with MRI in the diagnosis and management of patients with wrist trauma occult fractures.

BACKGROUND: The diagnosis of wrist fractures, especially scaphoid fractures, remains a challenge because of nonunion risk. Currently, new hybrid technologies are emerging such as SPECT/CT systems, which combine functional and anatomical data sets. So, we wanted to evaluate the utility of SPECT/CT in the management of occult carpal fractures. METHODS: In this study, all patients addressed at the orthopedic department at Brest University Hospital for wrist pain after trauma with initial normal plain radiographs were prospectively included. Patients with normal radiographs but with signs strongly suggestive of clinical fracture underwent a bone SPECT/CT and an MRI of the wrist. Therapeutic management took into account the results of all modalities, and all patients were followed up for at least 6 months and reviewed by the same surgeon. SPECT/CT findings were compared with those of the other modalities and follow-up. RESULTS: From December 2009 to May 2011, 57 patients were enrolled. Fifty-seven SPECT/CT and 52 MRI scans were obtained. Twenty-eight patients had normal imaging results, whereas 29 patients presented bone bruise and/or fractures. Ten patients were concordant according to SPECT/CT and MRI; 2 patients presented fractures on SPECT/CT without MRI performed; 17 patients had partially discordant results. Only 1 patient presented a nonunion at the follow-up, whereas both investigations were positive. CONCLUSIONS: This study highlights the good performances of SPECT/CT, which allows the detection of most occult carpal fractures. When a carpal occult fracture is strongly suspected clinically, SPECT/CT might be proposed at first intention after normal radiographs.

Diagnostic accuracy of single-photon emission tomography ventilation/perfusion lung scan in the diagnosis of pulmonary embolism.

BACKGROUND: Planar ventilation/perfusion (V/Q) lung scintigraphy is a validated tool for the diagnosis of pulmonary embolism (PE). Nevertheless, given the high rate of nonconclusive V/Q, further investigation is often necessary. V/Q single-photon emission CT (SPECT) scan could improve V/Q performance, but sparse data are available on its accuracy. This study assessed the diagnostic performance of V/Q SPECT scan in a cohort of consecutive patients with suspected PE. METHODS: Three hundred twenty-one consecutive patients with a clinical suspicion of PE were prospectively included. Patients suspected of having PE were managed according to a reference diagnostic strategy validated by a 3-month follow-up. In addition to the reference strategy, patients had a V/Q SPECT scan, the results of which were compared with the initial work-up results. RESULTS: Prevalence of PE was 0 of 41 (0%; 95% CI, 0%-9%), six of 134 (4%; 95% CI, 2%-9%),15 of 36 (42%; 95% CI, 27%-58%), and 28 of 32 (88%; 95% CI, 72%-95%) in the normal, low,intermediate, and high V/Q SPECT scan probability groups, respectively. The combination of V/Q SPECT scan with clinical probability was diagnostic in 88% of patients. CONCLUSIONS: V/Q SPECT scan results show satisfactory accuracy for PE diagnosis. Validation of dedicated interpretation criteria is required, followed by outcome studies that use V/Q SPECT scan as part of a diagnostic strategy to rule out PE. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01183026; URL: www.clinicaltrials.gov

Noninvasive diagnosis of pulmonary embolism.

BACKGROUND: We designed a simple and integrated diagnostic algorithm for acute pulmonary embolism (PE). Diagnosis was based on clinical probability assessment, plasma D-dimer testing, then sequential testing to include lower limb venous compression ultrasonography, ventilation perfusion lung scan, and chest multidetector CT (MDCT) imaging. METHODS: We included 321 consecutive patients presenting at Brest University Hospital in Brest, France, with clinically suspected PE and positive d-dimer or high clinical probability. Patients in whom VTE was deemed absent were not given anticoagulants and were followed up for 3 months. RESULTS: Detection of DVT by ultrasonography established the diagnosis of PE in 43 (13%). Lung scan associated with clinical probability was diagnostic in 243 (76%) of the remaining patients. MDCT scan was required in only 35 (11%) of the patients. The 3-month thromboembolic risk in patients not given anticoagulants, based on the results of the diagnostic protocol, was 0.53% (95% CI, 0.09-2.94). CONCLUSIONS: A diagnostic strategy combining clinical assessment, d-dimer, ultrasonography, and lung scan gave a noninvasive diagnosis in the majority of outpatients with suspected PE and appeared to be safe.

Detection of occult wrist fractures by quantitative radioscintigraphy: a prospective study on selected patients.

OBJECTIVE: To determine the value of quantitative radioscintigraphy (QRS) in the diagnosis of wrist trauma occult fractures. PURPOSE: Because of the risk of non-union, the diagnosis of wrist fractures, including scaphoid fractures, is essential but remains difficult despite many imaging modalities. The aim of the study was to assess the benefits of QRS in the diagnosis of occult post-trauma wrist fractures. METHODS: This prospective study included all patients presenting at the orthopaedic department at Brest University Hospital for wrist pain after trauma with initial normal plain radiographs. Patients with normal radiographs but strongly suspected of fracture underwent QRS consisting of three-phase bone scintigraphy with quantitative analysis. When a fracture was suspected the radiograph and scintigraphy were fused to precisely locate the fracture if the index was higher than 2. If the index was lower than 1.9, fracture was excluded. Between these two indices, other investigations, such as magnetic resonance imaging, were performed. All patients were followed for at least 3 months and reviewed by the same surgeon. Patients underwent a physical examination and possibly other investigations. RESULTS: From April 2006 to July 2008, 87 patients were enrolled (34 women, 53 men; median age 29 years; range, 15-87 years). Among the 46 pathologic bone scintigrams, 55 occult fractures were highlighted. At follow-up, none presented non-union. One had an undetermined QRS. Among the 40 negative results for QRS at follow-up, only one had a non-union. Sensitivity and negative predictive value were 97 and 98%, respectively for carpal fractures. CONCLUSION: This study highlights the benefit of QRS, which allows the detection of most occult carpal fractures and reduces the risks of complications such as pseudoarthritis.

Management of suspected pulmonary embolism patients with low clinical and low V/Q probability.

OBJECTIVE: To assess whether guidelines for the management of suspected PE, recommending that ventilation/perfusion (V/Q) scintigraphy should be followed by other imaging in case of non-diagnostic result, and interpreted along with the clinical probability, are applied in daily practice. DESIGN: Two-year audit study. SETTING: Tertiary hospital in France. PARTICIPANTS: All patients referred to the nuclear medicine department for a suspected pulmonary embolism (PE), with a low clinical probability, a positive D-Dimer test, and a low V/Q scintigraphy. INTERVENTION: We reviewed medical records to collect data on further diagnostic strategy and therapeutic management. MAIN OUTCOME MEASURE: Thromboembolic risk during a three-month follow up in patients who did not undergo anticoagulation therapy on the basis of a negative diagnostic work up. RESULTS: Of the 456 selected patients, PE was excluded on the basis of a low pretest probability and a low V/Q scintigraphy probability without further testing in 184 (group 1). In the other 272 patients (group 2), 4 venous thromboembolism (VTE) events were diagnosed by leg vein ultrasonography and/or computed tomography pulmonary angiography. In patients who did not receive anticoagulant treatment during follow up, one patient from group 1 (0.6%, 95% confidence interval 0.1 to 3.3) and two patients from group 2 (0.9%, 95% CI 0.2 to 3.2) had an acute venous thromboembolic event. CONCLUSION: Different attitudes are adopted by physicians in patients with a low clinical probability and a low V/Q scintigraphy probability, without impact on safety, as assessed by a non-significant difference in the three-month thromboembolic risks between these two groups.

Premature atherosclerosis in HIV positive patients and cumulated time of exposure to antiretroviral therapy (SHIVA study).

BACKGROUND: With the advent of antiretroviral therapy regimens in HIV positive patients, it is crucial to consider their long-term benefits to risk ratios. The responsibility of treatment in premature atherosclerosis is not clear. Thus, the aim of this study is to evaluate the impact of exposure to reverse transcriptase inhibitors (nucleosidic and non-nucleosidic) and to protease inhibitors on the cardiovascular status of an entire hospital based cohort of patients. METHODS: 154 patients were included. Using a linear analysis, we sought an association between the cumulative time of exposure to these three classes of antiretroviral drugs and the carotid intima-media thickness measured by ultrasonography and a cardiovascular composite score. RESULTS: The study confirms premature atherosclerosis, which not only correlates with the usual risk factors, such as triglyceride level, but also with protease inhibitor exposure, especially that of lopinavir. Nevertheless as regards current drug exposure, the clinical impact was low: five clinical complications of atherosclerosis and only one out of 35 scintigraphic and ECG exercise tests warranted a coronary angiography which was negative. CONCLUSION: These data should not lead to the rejection of protease inhibitors but should strengthen the prevention of cardiovascular diseases as an integral part of the management of HIV patients.

Management of suspected venous thromboembolism: the impact of a multifaceted intervention.

OBJECTIVE: To achieve a common strategy in the event of a suspected venous thromboembolism. DESIGN: A multifaceted intervention, combining an audit strategy and implementation of local guidelines: phase 1, the first step, consisted of a 6-month audit to identify dysfunction; during phase 2, intervention, local guidelines were formulated by a working group and then implemented; phase 3 consisted of a re-audit over a 6-month period following the intervention. SETTING: A tertiary hospital, France. PARTICIPANTS: 419 patients with suspected venous thromboembolism in phase 1; 287 patients with suspected pulmonary embolism in phase 3. RESULTS: First phase: a dysfunction was observed in three of five criteria under study: (i) the diagnostic procedure lasted more than 48 hours in 114 patients (27.2%); (ii) no anticoagulant therapy at the time of suspicion in 116 patients (27.7%); (iii) an inconclusive lung scan without further testing in the event of a suspected pulmonary embolism in 40 patients (14%); the intervention phase was thus restricted to the management of suspected pulmonary embolism; similar results were found during the phase 3 re-audit. CONCLUSION: No improvement in the diagnostic work-up in the event of a suspected pulmonary embolism was observed following this multifaceted intervention.

Octreotide imaging plus bone scintigrams to optimally localize gastroenteropancreatic neuroendocrine tumors.

PURPOSE: In-111 pentetreotide (Octreotide) is highly sensitive for detecting gastroenteropancreatic neuroendocrine tumors and their metastases. However, a lack of landmarks makes it difficult to localize them anatomically. To overcome this difficulty, the authors simultaneously obtained Octreotide and bone tomoscintigrams, in addition to standard planar images. They used a bicolor scale to display pairs of scintigrams to easily identify the distribution of both tracers. METHODS: Twenty-one hours after Octreotide injection, Tc-99m MDP was also administered to the patients. Three hours later, dual-energy planar and tomographic data were acquired simultaneously. The latter were reconstructed using a filtered back-projection algorithm using a Metz filter. Both sets of data were displayed simultaneously using a bicolor scale, such that Octreotide data appear in green and bone data in red. RESULTS: Planar, tomographic, and three-dimensional data were obtained. With this approach, foci of abnormal uptake are localized more precisely. Hard data can be transmitted easily to referring physicians, who appreciate this compact and efficient means to locate foci of abnormal uptake, especially during surgery planning. However, this method is not well suited to the visualization of small lesions with low Octreotide uptake because the intensity range is drastically reduced. Such lesions are better seen on Octreotide planar images and standard tomoscintigrams. CONCLUSIONS: This approach, which involves only standard image processing, provides landmarks to easily localize significant Octreotide uptake. It can be implemented readily in most nuclear medicine workstations. It complements but does not replace the usual method to display Octreotide data.