Impact of Patient-reported Symptom Information on the Interpretation of MRI of the Lumbar Spine.

Background Distinguishing lumbar pain generators from incidental findings at MRI can be difficult. Dictated reports may become lists of findings that cannot be ranked in order of diagnostic importance. Purpose To determine whether patient-reported symptom information can improve the interpretation of lumbar spine MRI by using the spine specialist as the reference standard. Materials and Methods This prospective, single-center, multireader study analyzed 240 participants who completed pre-MRI symptom questionnaires between May 2022 and February 2023. At the time of clinical MRI reporting, radiologists recorded pain generators in consecutive participants, creating two study groups by alternating interpretations with versus without symptom questionnaire results (SQR). Diagnostic certainty was recorded using a numeric scale of 0 to 100. Types, levels, and sides of pain generators were compared with reference diagnoses by calculating Cohen κ values with 95% CIs. Participant characteristics and diagnostic certainties were compared using the Wilcoxon rank sum, Pearson χ2, or Kruskal-Wallis test. Interrater agreement was analyzed. Results There was no difference in age (P = .69) or sex (P = .60) between participants using SQR (n = 120; mean age, 61.0 years; 62 female) and not using SQR (n = 120; mean age, 62.5 years; 67 female). When radiologists were compared with specialists, agreements on pain generators were almost perfect for interpretations using SQR (type: κ = 0.82 [95% CI: 0.74,0.89]; level: κ = 0.88 [95% CI: 0.80, 0.95]; side: κ = 0.84 [95% CI: 0.75, 0.92]), but only fair to moderate for interpretations not using SQR (type: κ = 0.26 [95% CI: 0.15, 0.36]; level: κ = 0.51 [95% CI: 0.39, 0.63]; side: κ = 0.30 [95% CI: 0.18, 0.42]) (all P < .001). Diagnostic certainty was higher for MRI interpretations using SQR (mean, 80.4 ± 14.9 [SD]) than MRI interpretations not using SQR (60.5 ± 17.7) (P < .001). Interrater agreements were substantial (κ = 0.65-0.78) for MRI interpretations using SQR but only fair to moderate (κ = 0.24-0.49) for MRI interpretations not using SQR (all P < .001). Conclusion Patient-reported symptom information enabled radiologists to achieve nearly perfect diagnostic agreement with clinical experts. © RSNA, 2024 See also the editorial by Isikbay and Shah in this issue.

Circulating and Imaging Biomarkers of Radium-223 Response in Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: Radium-223 improves overall survival (OS) and reduces skeletal events in patients with bone metastatic castration-resistant prostate cancer (CRPC), but relevant biomarkers are lacking. We evaluated automated bone scan index (aBSI) and circulating tumor cell (CTC) analyses as potential biomarkers of prognosis and activity. PATIENTS AND METHODS: Patients with bone metastatic CRPC were enrolled on a prospective single-arm study of standard radium-223. 99mTc-MDP bone scan images at baseline, 2 months, and 6 months were quantitated using aBSI. CTCs at baseline, 1 month, and 2 months were enumerated and assessed for RNA expression of prostate cancer-specific genes using microfluidic enrichment followed by droplet digital polymerase chain reaction. RESULTS: The median OS was 21.3 months in 22 patients. Lower baseline aBSI and minimal change in aBSI (<+0.7) from baseline to 2 months were each associated with better OS (P = .00341 and P = .0139, respectively). The higher baseline CTC count of ≥5 CTC/7.5 mL was associated with worse OS (median, 10.1 v 32.9 months; P = .00568). CTCs declined at 2 months in four of 15 patients with detectable baseline CTCs. Among individual genes in CTCs, baseline expression of the splice variant AR-V7 was significantly associated with worse OS (hazard ratio, 5.20 [95% CI, 1.657 to 16.31]; P = .00195). Baseline detectable AR-V7, higher aBSI, and CTC count ≥5 CTC/7.5 mL continued to have a significant independent negative impact on OS after controlling for prostate-specific antigen or alkaline phosphatase. CONCLUSION: Quantitative bone scan assessment with aBSI and CTC analyses are prognostic markers in patients treated with radium-223. AR-V7 expression in CTCs is a particularly promising prognostic biomarker and warrants validation in larger cohorts.

Dual energy computed tomography cannot effectively differentiate between calcium pyrophosphate and basic calcium phosphate diseases in the clinical setting.

Background: Recent reports suggested that dual-energy CT (DECT) may help discriminate between different types of calcium phosphate crystals in vivo, which would have important implications for the characterization of crystal deposition occurring in osteoarthritis. Purpose: Our aim was to test the hypothesis that DECT can effectively differentiate basic calcium phosphate (BCP) from calcium pyrophosphate (CPP) deposition diseases. Methods: Discarded tissue after total knee replacement specimens in a 71 year-old patient with knee osteoarthritis and chondrocalcinosis was scanned using DECT at standard clinical parameters. Specimens were then examined on light microscopy which revealed CPP deposition in 4 specimens (medial femoral condyle, lateral tibial plateau and both menisci) without BCP deposition. Regions of interest were placed on post-processed CT images using Rho/Z maps (Syngo.via, Siemens Healthineers, VB10B) in different areas of CPP deposition, trabecular bone BCP (T-BCP) and subchondral bone plate BCP (C-BCP). Results: Dual Energy Index (DEI) of CPP was 0.12 (SD â€‹= â€‹0.02) for reader 1 and 0.09 (SD â€‹= â€‹0.03) for reader 2, The effective atomic number (Zeff) of CPP was 10.83 (SD â€‹= â€‹0.44) for reader 1 and 10.11 (SD â€‹= â€‹0.66) for reader 2. Nearly all DECT parameters of CPP were higher than those of T-BCP, lower than those of C-BCP, and largely overlapping with Aggregate-BCP (aggregate of T-BCP and C-BCP). Conclusion: Differentiation of different types of calcium crystals using DECT is not feasible in a clinical setting.

Symptom-imaging correlation in lumbar spine pain.

Lumbar spine MRI is associated with a high prevalence of morphological abnormalities in both symptomatic and asymptomatic individuals. A difficult challenge, therefore, is distinguishing the relevant findings causing symptoms from incidental findings. The accurate diagnosis of pain generator is important because misdiagnosis can negatively impact patient management and outcome. Spine physicians use clinical symptoms and signs to interpret lumbar spine MRI and make treatment decisions. Symptom-MRI correlation enables the targeted inspection of images for pain generator. Radiologists can also use clinical information to improve diagnostic confidence and the value of dictated reports. Because high-quality clinical information may be difficult to obtain, radiologists often generate lists of lumbar spine abnormalities that are otherwise difficult to rank as pain generators. Based on the literature review, this article attempts to distinguish the MRI abnormalities that may represent incidental findings from the abnormalities that are more commonly associated with lumbar spine-related symptoms.

A novel core biopsy needle with shorter dead space for percutaneous image-guided musculoskeletal biopsies - how does it compare with an established core biopsy needle?

PURPOSE: To compare diagnostic yield and utility of a novel core biopsy needle (NCBN) with shortened tip dead space for percutaneous musculoskeletal biopsies with an established core biopsy needle (ECBN). METHODS: This study was IRB approved and HIPAA compliant. All percutaneous biopsies using an NCBN performed between July 2020 and August 2021 were retrospectively reviewed. Data on patient demographics, biopsy technique, biopsy needle, and histopathology were collated. RESULTS: Thirty-six patients were included in this study, 16 (44%) undergoing biopsy with both an NCBN and an ECBN, and 20 (56%) with an NCBN only. All 36 NCBN biopsies were 16 gauge. Fifteen (94%) of the ECBN biopsies were 14 gauge, and 1 (6%) was 16 gauge. Thirty-four (94%) of the NCBN and 15 (94%) of the ECBN biopsies were diagnostic. No adverse events were identified. CONCLUSION: Both the NCBN and ECBN have high diagnostic rates. No adverse events were identified. NCBN could be considered for biopsy of lesions limited by anatomic location or near adjacent critical structures.

Contribution of positron emission tomography/magnetic resonance imaging in musculoskeletal malignancies.

Positron emission tomography/computed tomography (PET/CT) is a promising hybrid imaging technique for evaluating musculoskeletal malignancies. Both technologies, independently are useful for evaluating this type of tumors. PET/MR has great potential combining metabolic and functional imaging PET with soft tissue contrast and multiparametric sequences of MR. In this paper we review the existing literature and discuss the different protocols, new available radiotracers to conclude with the scarce evidence available the most useful/probable indications of the PET MR for the for musculoskeletal malignancies.

Observer agreement in the choice of lumbar spine injection for pain management.

BACKGROUND AND PURPOSE: Lumbar spine MRI can help guide the choice of corticosteroid injection in pain management. We investigated whether patient-reported symptom information from a questionnaire could improve agreement in the choice of type, level, and side of injection. MATERIALS AND METHODS: In this prospective observational study, 120 patients (median age 64, 70 men) were recruited from patients referred for pain management. After informed consent, they completed electronic questionnaires that obtained symptom information for later use during MRI reviews. In 3 research arms, 6 radiologists chose injections that would ideally deliver corticosteroid to the presumed sources of pain in (1) MRI studies reviewed with symptom information from questionnaires, (2) MRI studies reviewed without symptom information, and (3) MRI reports. Blinded to questionnaire results, radiologists providing clinical care and interviewing patients chose ideal therapeutic injections to establish reference standards. Injections were categorized by type, level, and side and compared using percent agreement and kappa statistics. Interreading agreement was analyzed. RESULTS: Compared to the reference standard, kappa agreements for injection types, levels, and sides were almost perfect when MRIs were reviewed knowing symptoms (0.85-0.93), fair without symptoms (0.23-0.35) (all P < .001) and fair in MRI reports (0.24-0.36) (all P < .001). Interreading kappa agreements were almost perfect knowing symptoms (0.82-0.90), but only moderate without symptoms (0.42-0.49) (all P < .001). CONCLUSIONS: Radiologists reviewing lumbar spine MRI converged on the type, level, and side of ideal therapeutic injection whether they obtained symptom information from direct patient interview or electronic questionnaire. Observer agreement was significantly lower without symptom information.

Impact of Patient-Reported Symptom Information on Agreement in the MRI Diagnosis of Presumptive Lumbar Spine Pain Generator.

BACKGROUND. Lumbar spine MRI is associated with a high prevalence of interpretive errors by radiologists. Treating physicians can obtain symptom information, correlate symptoms with MRI findings, and distinguish presumptive pain generators from incidental abnormalities. OBJECTIVE. The purpose of this study was to capture symptom information using a patient questionnaire, review lumbar spine MRI examinations with and without symptom information, diagnose pain generators, and compare MRI diagnoses with clinical reference diagnoses. METHODS. In this prospective study, 120 participants (70 men and 50 women; median age, 64 years; interquartile range, 49.5-74 years) were recruited from patients referred for lumbar spine injections between February and June 2019. Participants completed electronic questionnaires regarding their symptoms before receiving the injections. For three research arms, six radiologists diagnosed pain generators in MRI studies reviewed with symptom information from questionnaires, MRI studies reviewed without symptom information, and MRI reports. Interreading agreement was analyzed. Blinded to the questionnaire results, the radiologists who performed injections obtained patient histories, correlated symptoms with MRI findings, and diagnosed presumptive pain generators. These diagnoses served as clinical reference standards. Pain generators were categorized by type, level, and side and were compared using kappa statistics. Diagnostic certainty was recorded using numeric values (0-100) and was compared using Wilcoxon rank-sum test RESULTS. When compared with the reference standard, agreement for the type, level, and side of pain generator was almost perfect in MRI examinations reviewed with symptom information (κ = 0.82-0.90), fair to moderate in MRI examinations reviewed without symptom information (κ = 0.28-0.51) (all p < .001), and fair to moderate in MRI reports (κ = 0.27-0.45) (all p < .001). Interreading agreement was almost perfect when MRI examinations were reviewed with symptom information (κ = 0.82-0.90) but was only moderate without symptom information (κ = 0.42-0.56) (all p < .001). Diagnostic certainty levels were highest for radiologists performing injections (mean [± SD], 90.0 ± 9.9) and were significantly higher for MRI review with symptom information versus without symptom information (means for reading 1, 84.6 ± 13.1 vs 62.9 ± 20.7; p < .001). CONCLUSION. In lumbar spine MRI, presumptive pain generators diagnosed using symptom information from electronic questionnaires showed almost perfect agreement with pain generators diagnosed using symptom information from direct patient interviews. CLINICAL IMPACT. Patient-reported symptom information from a brief questionnaire can be correlated with MRI findings to distinguish presumptive pain generators from incidental abnormalities.

SNMMI Procedure Standard/EANM Practice Guideline on Pediatric 18F-FDG PET/CT for Oncology 1.0.

PREAMBLEThe Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM) is a professional nonprofit medical association founded in 1985 to facilitate communication worldwide among individuals pursuing clinical and academic excellence in nuclear medicine. SNMMI and EANM members are physicians, technologists, and scientists specializing in the research and practice of nuclear medicine.The SNMMI and EANM will periodically put forth new standards/guidelines for nuclear medicine practice to help advance the science of nuclear medicine and improve service to patients. Existing standards/guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner, if indicated. Each standard/guideline, representing a policy statement by the SNMMI/EANM, has undergone a thorough consensus process, entailing extensive review. The SNMMI and EANM recognize that the safe and effective use of diagnostic nuclear medicine imaging requires particular training and skills, as described in each document. These standards/guidelines are educational tools designed to assist practitioners in providing appropriate and effective nuclear medicine care for patients. These guidelines are consensus documents, and are not inflexible rules or requirements of practice. They are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the SNMMI and the EANM cautions against the use of these standards/guidelines in litigation in which the clinical decisions of a practitioner are called into question.The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by medical professionals taking into account the unique circumstances of each case. Thus, there is no implication that action differing from what is laid out in the standards/guidelines, standing alone, is below standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the standards/guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the standards/guidelines.The practice of medicine involves not only the science, but also the art of dealing with the prevention, diagnosis, alleviation, and treatment of disease. The variety and complexity of human conditions make it impossible for general guidelines to consistently allow for an accurate diagnosis to be reached or a particular treatment response to be predicted. Therefore, it should be recognized that adherence to these standards/guidelines will not ensure a successful outcome. All that should be expected is that the practitioner follows a reasonable course of action, based on their level of training, the current knowledge, the available resources, and the needs/context of the particular patient being treated.PET and computerized tomography (CT) have been widely used in oncology. 18F-FDG is the most common radiotracer used for PET imaging. The purpose of this document is to provide imaging specialists and clinicians guidelines for recommending, performing, and interpreting 18F-FDG PET/CT in pediatric patients in oncology. There is not a high level of evidence for all recommendations suggested in this paper. These recommendations represent the expert opinions of experienced leaders in this field. Further studies are needed to have evidence-based recommendations for the application of 18F-FDG PET/CT in pediatric oncology. These recommendations should be viewed in the context of good practice of nuclear medicine and are not intended to be a substitute for national and international legal or regulatory provisions.

Impact of a fast free-breathing 3-T abdominal MRI protocol on improving scan time and image quality for pediatric patients with tuberous sclerosis complex.

BACKGROUND: Magnetic resonance imaging (MRI) of the abdomen can be especially challenging in pediatric patients because of image quality degradation from respiratory motion. Abdominal MR protocols tailored for free-breathing children can potentially improve diagnostic image quality and reduce scan time. OBJECTIVE: To evaluate the performance of a free-breathing 3-T MRI protocol for renal evaluation in pediatric patients with tuberous sclerosis complex (TSC). MATERIALS AND METHODS: A single institution, Institutional Review Board-approved, retrospective database query identified pediatric TSC patients who underwent a free-breathing 3-T MR abdominal protocol including radial and respiratory-triggered pulse sequences and who also had a prior abdominal MRI on the same scanner using a traditional MR protocol utilizing signal averaging and Cartesian k-space sampling. Scan times and use of sedation were recorded. MR image quality was compared between the two protocols using a semiquantitative score for overall image quality and sharpness. RESULTS: Forty abdominal MRI studies in 20 patients were evaluated. The mean scan time of the fast free-breathing protocol was significantly lower (mean: 42.5±9.8 min) compared with the traditional protocol (58.7±11.7 min; P=<0.001). Image sharpness was significantly improved for radial T2-weighted and T1-weighted triggered Dixon and radial T1-weighted fat-suppressed post-contrast images in the free-breathing protocol, while image quality was significantly higher on radial and Dixon T1-weighted sequences. CONCLUSION: A free-breathing abdominal MR protocol in pediatric TSC patients decreases scan time and improves image quality and should be considered more widely for abdominal MRI in children.

Radiation dose and intra-articular access: comparison of the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections.

PURPOSE: To compare the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections with respect to successful intra-articular needle placement, fluoroscopy time, radiation dose, and dose area product (DAP). MATERIALS AND METHODS: This retrospective study was IRB-approved and HIPAA-compliant. 498 fluoroscopically guided tibiotalar joint injections were performed or supervised by one of nine staff radiologists from 11/1/2010-12/31/2013. The injection approach was determined by operator preference. Images were reviewed on a PACS workstation to determine the injection approach (lateral mortise versus anterior midline) and to confirm intra-articular needle placement. Fluoroscopy time (minutes), radiation dose (mGy), and DAP (µGy-m(2)) were recorded and compared using the student's t-test (fluoroscopy time) or the Wilcoxon rank sum test (radiation dose and DAP). RESULTS: There were 246 lateral mortise injections and 252 anterior midline injections. Two lateral mortise injections were excluded from further analysis because no contrast was administered. Intra-articular location of the needle tip was documented in 242/244 lateral mortise injections and 252/252 anterior midline injections. Mean fluoroscopy time was shorter for the lateral mortise group than the anterior midline group (0.7 ± 0.5 min versus 1.2 ± 0.8 min, P < 0.0001). Mean radiation dose and DAP were less for the lateral mortise group than the anterior midline group (2.1 ± 3.7 mGy versus 2.5 ± 3.5 mGy, P = 0.04; 11.5 ± 15.3 µGy-m(2) versus 13.5 ± 17.3 µGy-m(2), P = 0.006). CONCLUSION: Both injection approaches resulted in nearly 100% rates of intra-articular needle placement, but the lateral mortise approach used approximately 40% less fluoroscopy time and delivered 15% lower radiation dose and DAP to the patient.

[Economic impact of dengue and dengue hemorrhagic fever in the State of Zulia, Venezuela, 1997-2003]. / Impacto económico del dengue y del dengue hemorrágico en el Estado de Zulia, Venezuela, 1997-2003.

OBJECTIVES: To determine the direct and indirect costs of medical care provided to cases of dengue and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) between 1997 and 2003 in Zulia State, Venezuela. METHODS: The total number of patients with dengue and DHF/DSS was obtained from records belonging to the Regional Epidemiology Office of the state of Zulia and from reports of cases that were confirmed in the Virology Section of Dr. Americo Negrette's Clinical Research Institute, Zulia University, Maracaibo, Venezuela, between 1 January 1997 and 31 December 2003. Direct costs included the cost of emergency medical care for all cases and hospital costs for cases with DHF/DSS (cost per bed-day and laboratory expenses). The costs connected to absence from work among patients over 15 years of age and mothers who accompanied their children under 15 years of age comprised the indirect costs, which were adjusted for the proportion of men and women in the labor force. Calculations were based on the minimum yearly wage, and results were given in United States dollars, converted according to each year's average exchange rate. RESULTS: During the study period, 33,857 cases of dengue and DHF/DSS were seen. Of them, 30 251 (89.35%) were cases of dengue, and 3606 (10.65%) were cases of DHF/DSS. Six cases of DHF/DSS died (lethality rate: 0.2 per 100 cases of DHF/DSS). Direct costs were 474,251.70 US dollars; of these costs, 132,042.30 US dollars were spent on emergency medical care and 342,209.40 US dollars on the hospital costs of DHF/DSS cases. Indirect costs were 873,825.84 US dollars and comprised 64.8% of overall expenditures (1 ,48,077.54 US dollars) connected to this disease during the study years. CONCLUSIONS: This is the first study on the economic impact of dengue in the state of Zulia and in Venezuela. In spite of some limitations, results show that dengue is an important public health problem that causes great expense because of temporary absenteeism from work and that undermines regional and national economic development.

Impacto económico del dengue y del dengue hemorrágico en el Estado de Zulia, Venezuela, 1997-2003 / Economic impact of dengue and dengue hemorrhagic fever in the State of Zulia, Venezuela, 1997-2003

OBJETIVOS: Determinar los costos directos e indirectos asociados con la atención de los casos de dengue y de dengue hemorrágico o síndrome de choque por dengue (DH/SCD) entre los años 1997 y 2003 en el Estado de Zulia, Venezuela. MÉTODOS: El número total de pacientes con dengue y DH/SCD se obtuvo de los registros de la Dirección Regional de Epidemiología del Estado de Zulia y de los informes de casos confirmados en la Sección de Virología del Instituto de Investigaciones Clínicas Dr. Américo Negrette, de la Facultad de Medicina, Universidad del Zulia, Maracaibo, entre el 1.° de enero de 1997 y el 31 de diciembre de 2003. Como costos directos se consideraron el costo de la atención médica de urgencia de todos los casos y los costos de hospitalización de los casos con DH/SCD (costo por día-cama y costos de laboratorio). Los costos asociados con la ausencia laboral de los enfermos mayores de 15 años y de las madres acompañantes de los enfermos menores de 15 años conformaron los costos indirectos, ajustados según la proporción de hombres y mujeres en la fuerza laboral activa del país. Para el cálculo se utilizó el salario mínimo anual y los resultados se expresaron en dólares estadounidenses, según la tasa de cambio promedio de cada año. RESULTADOS: En el período estudiado se atendieron 33 857 casos de dengue y de DH/SCD; de ellos, 30 251 (89,35 por ciento) fueron de dengue y 3 606 (10,65 por ciento) de DH/SCD. Seis de estos fallecieron (letalidad 0,2 por 100 casos de DH/SCD). Los costos directos fueron US$ 474 251,70; de esa suma, US$ 132 042,30 correspondieron a la atención en los servicios de urgencia y US$ 342 209,40 a los gastos de hospitalización de los casos con DH/SCD. Los costos indirectos ascendieron a US$ 873 825,84 y representaron 64,8 por ciento del gasto total (US$ 1 348 077,54) relacionado con esta enfermedad en los años estudiados. CONCLUSIONES: Este es el primer estudio acerca del impacto económico del dengue en el Estado de Zulia y en Venezuela. A pesar de que el estudio tuvo algunas limitaciones, los resultados demuestran que el dengue constituye un importante problema de salud pública que ocasiona grandes gastos por ausentismo laboral temporal y que afecta considerablemente al desarrollo de la economía regional y nacional.

Objectives. To determine the direct and indirect costs of medical care provided to cases of dengue and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) between 1997 and 2003 in Zulia State, Venezuela. Methods. The total number of patients with dengue and DHF/DSS was obtained from records belonging to the Regional Epidemiology Office of the state of Zulia and from reports of cases that were confirmed in the Virology Section of Dr. Americo Negrette's Clinical Research Institute, Zulia University, Maracaibo, Venezuela, between 1 January 1997 and 31 December 2003. Direct costs included the cost of emergency medical care for all cases and hospital costs for cases with DHF/DSS (cost per bedday and laboratory expenses). The costs connected to absence from work among patients over 15 years of age and mothers who accompanied their children under 15 years of age comprised the indirect costs, which were adjusted for the proportion of men and women in the labor force. Calculations were based on the minimum yearly wage, and results were given in United States dollars, converted according to each year's average exchange rate. Results. During the study period, 33 857 cases of dengue and DHF/DSS were seen. Of them, 30 251 (89.35%) were cases of dengue, and 3 606 (10.65%) were cases of DHF/DSS. Six cases of DHF/DSS died (lethality rate: 0.2 per 100 cases of DHF/DSS). Direct costs were US$ 474 251.70; of these costs, US$ 132 042.30 were spent on emergency medical care and US$ 342 209.40 on the hospital costs of DHF/DSS cases. Indirect costs were US$ 873 825.84 and comprised 64.8% of overall expenditures (US$ 1 348 077.54) connected to this disease during the study years. Conclusions. This is the first study on the economic impact of dengue in the state of Zulia and in Venezuela. In spite of some limitations, results show that dengue is an important public health problem that causes great expense because of temporary absenteeism from work and that undermines regional and national economic development.