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1.
J Appl Clin Med Phys ; 24(10): e14056, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37261890

RESUMO

PURPOSE: The aim of this study was to reduce scan time in 177 Lu planar scintigraphy through the use of convolutional neural network (CNN) to facilitate personalized dosimetry for 177 Lu-based peptide receptor radionuclide therapy. METHODS: The CNN model used in this work was based on DenseNet, and the training and testing datasets were generated from Monte Carlo simulation. The CNN input images (IMGinput ) consisted of 177 Lu planar scintigraphy that contained 10-90% of the total photon counts, while the corresponding full-count images (IMG100% ) were used as the CNN label images. Two-sample t-test was conducted to compare the difference in pixel intensities within region of interest between IMG100% and CNN output images (IMGoutput ). RESULTS: No difference was found in IMGoutput for rods with diameters ranging from 13 to 33 mm in the Derenzo phantom with a target-to-background ratio of 20:1, while statistically significant differences were found in IMGoutput for the 10-mm diameter rods when IMGinput containing 10% to 60% of the total photon counts were denoised. Statistically significant differences were found in IMGoutput for both right and left kidneys in the NCAT phantom when IMGinput containing 10% of the total photon counts were denoised. No statistically significant differences were found in IMGoutput for any other source organs in the NCAT phantom. CONCLUSION: Our results showed that the proposed method can reduce scan time by up to 70% for objects larger than 13 mm, making it a useful tool for personalized dosimetry in 177 Lu-based peptide receptor radionuclide therapy in clinical practice.


Assuntos
Redes Neurais de Computação , Radioisótopos , Humanos , Método de Monte Carlo , Cintilografia , Receptores de Peptídeos
2.
J Appl Clin Med Phys ; 23(12): e13734, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35906892

RESUMO

PURPOSE: To investigate the accuracy and biases of predicted lung shunt fraction (LSF) and lung dose (LD) calculations via 99m Tc-macro-aggregated albumin (99m Tc-MAA) planar imaging for treatment planning of 90 Y-microsphere radioembolization. METHODS AND MATERIALS: LSFs in 52 planning and LDs in 44 treatment procedures were retrospectively calculated, in consecutive radioembolization patients over a 2 year interval, using 99m Tc-MAA planar and SPECT/CT imaging. For each procedure, multiple planar LSFs and LDs were calculated using different: (1) contours, (2) views, (3) liver 99m Tc-MAA shine-through compensations, and (4) lung mass estimations. The accuracy of each planar-based LSF and LD methodology was determined by calculating the median (range) absolute difference from SPECT/CT-based LSF and LD values, which have been demonstrated in phantom and patient studies to more accurately and reliably quantify the true LSF and LD values. RESULTS: Standard-of-care LSF using geometric mean of lung and liver contours had median (range) absolute over-estimation of 4.4 percentage points (pp) (0.9 to 11.9 pp) from SPECT/CT LSF. Using anterior views only decreased LSF errors (2.4 pp median, -1.1 to +5.7 pp range). Planar LD over-estimations decreased when using single-view versus geometric-mean LSF (1.3 vs. 2.6 Gy median and 7.2 vs. 18.5 Gy maximum using 1000 g lung mass) but increased when using patient-specific versus standard-man lung mass (2.4 vs. 1.3 Gy median and 11.8 vs. 7.2 Gy maximum using single-view LSF). CONCLUSIONS: Calculating planar LSF from lung and liver contours of a single view and planar LD using that same LSF and 1000 g lung mass was found to improve accuracy and minimize bias in planar lung dosimetry.


Assuntos
Embolização Terapêutica , Neoplasias Hepáticas , Humanos , Estudos Retrospectivos , Radioisótopos de Ítrio/uso terapêutico , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Pulmão/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/radioterapia , Embolização Terapêutica/métodos , Microesferas
3.
J Appl Clin Med Phys ; 23(10): e13744, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35946828

RESUMO

PURPOSE: The aim of this work was to investigate the lesion detectability of Tc-99m planar scintigraphy acquired with a low-energy high-resolution and sensitivity (LEHRS) collimator and processed by Clarity 2D for patients with different body sizes through phantom study. METHODS: A NEMA IEC body phantom set was covered by two layers of 25-mm-thick bolus to construct phantom in three different sizes. All image data were performed on a Discovery NM/CT 870 DR with an LEHRS collimator and processed by Clarity 2D with blend ratio a of 0%, 20%, 40%, 60%, 80%, and 100%. The lesion detectability in gamma scintigraphy was evaluated by calculating the contrast-to-noise ratio (CNR). Multiple linear regression methods were used to analyze the impact of body size, target size, and Clarity 2D blending weight on the lesion detectability of Tc-99m planar scintigraphy. RESULTS: It was found that changing the blend ratio could improve CNR, and this phenomenon was more significant in anterior view than in posterior view. Our results also suggested that the blend ratio should be selected according to patient body size in order to maintain consistent CNR. Hence, when a blend ratio of 60% was used for a patient before cancer treatment, a lower blend ratio should be used for the same patient experiencing treatment-related weight loss to achieve consistent lesion detectability in Tc-99m planar scintigraphy acquired with LEHRS and processed by Clarity 2D. CONCLUSION: The magnitude of photon attenuation and scattering is higher in patients with larger body size, so Tc-99m planar scintigraphy usually has lower lesion detectability in obese patients. Although photon attenuation and scattering are inevitable during image formation, their impacts on image quality can be eased by employing appropriate image protocol parameters.


Assuntos
Cintilografia , Humanos , Imagens de Fantasmas , Tamanho Corporal
4.
Respiration ; 98(3): 230-238, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31167210

RESUMO

BACKGROUND: Endoscopic lung volume reduction (ELVR) therapy using one-way valves is used to treat chronic obstructive pulmonary disease patients with severe heterogeneous emphysema. A successful treatment results in atelectasis of the treated pulmonary lobe with subsequent reduction of ventilation (V) and perfusion (Q). OBJECTIVE: We evaluated the effects of ELVR on the targeted lobe using a new 3-dimensional ventilation and perfusion (V/Q) single-photon emission computed tomography (SPECT)/computed tomography (CT) analysis, which allows for simultaneous semi-automatic lobar pulmonary quantification of volume, ventilation and perfusion, on the first consecutive patients treated with ELVR at Rigshospitalet, Denmark. V/Q planar scintigraphy and V/Q SPECT/CT and lung function measurements were performed before and 6 months after intervention. RESULTS: We included 24 subjects (60 years, range 46-74 years; 37.5% men) with a baseline FEV1 of 25% predicted and RV of 257% predicted. V/Q SPECT/CT-assessed volume of the targeted lobe decreased by a mean of -395 mL and a relative mean of -26.8%, whilst ventilation and perfusion decreased by a relative mean of -37.1 and -25.7%. There was a significant increase in the same parameters of the non-targeted lobe(s) on the ipsilateral side. None of these changes were found in the analysis of planar V/Q imaging. The total lung volume decreased on average by -420 mL. Six months after ELVR, FEV1 had increased by 22%. Significant correlations were found between changes in FEV1 and changes in the volume of the treated lobe (SPECT/CT). CONCLUSION: Semi-automatic SPECT/CT analysis can quantify volume, ventilation and perfusion changes in pulmonary lobes and may be used in the assessment of patient eligibility for ELVR, identifying target lobes, and evaluation of the regional effects of treatment.


Assuntos
Broncoscopia , Pneumonectomia , Enfisema Pulmonar/diagnóstico por imagem , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos , Cintilografia de Ventilação/Perfusão/métodos , Idoso , Feminino , Volume Expiratório Forçado , Capacidade Residual Funcional , Humanos , Processamento de Imagem Assistida por Computador , Medidas de Volume Pulmonar/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Capacidade de Difusão Pulmonar , Enfisema Pulmonar/cirurgia , Volume Residual , Índice de Gravidade de Doença , Instrumentos Cirúrgicos , Capacidade Pulmonar Total , Resultado do Tratamento
5.
J Neural Transm (Vienna) ; 122(10): 1421-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26003179

RESUMO

Decreased myocardial uptake of I-123 metaiodobenzylguanidine (MIBG) is an important finding for diagnosis of Parkinson's disease (PD). This study compared I-123 MIBG SPECT and planar imaging with regard to their diagnostic yield for PD. 52 clinically diagnosed PD patients who also had decreased striatal uptake on FP-CIT PET/CT were enrolled. 16 normal controls were also included. All underwent cardiac MIBG planar scintigraphy and SPECT separately. Myocardial I-123 MIBG uptake was interpreted on planar and SPECT/CT images separately by visual and quantitative analysis. The final diagnosis was made by consensus between two readers. Kappa analyses were performed to determine inter-observer agreement for both methods. Sensitivity, specificity, and accuracy were compared with McNemar's test. The sensitivity, specificity, and accuracy were 84.6, 100, and 88.2% for planar images and 96.2, 100 and 97.1% for SPECT, respectively, with a significant difference between the two imaging methods (p < 0.031). All inter-observer agreements were almost perfect (planar scintigraphy: κ = 0.82; SPECT: κ = 0.93). Heart-to-mediastinum ratios from PD patients with negative planar and positive SPECT scans (group A) and patients with positive planar and positive SPECT scans (group B) were 1.69 ± 0.16 (1.59-1.85) and 1.41 ± 0.15 (1.20-1.53), respectively, and showed significant difference (p = 0.023). Lung-to-mediastinum ratios for groups A and B were 2.16 ± 0.20 (1.96-2.37) and 1.6 ± 0.19 (1.3-1.78), respectively, and were significantly higher in the former (p = 0.001). I-123 MIBG SPECT has a significantly higher diagnostic performance for PD than planar images. Increased lung uptake may cause false-negative results on planar imaging.


Assuntos
3-Iodobenzilguanidina , Coração/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único , Tropanos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico , Estudos Prospectivos , Sensibilidade e Especificidade
6.
Expert Rev Med Devices ; 19(5): 393-403, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35695477

RESUMO

INTRODUCTION: Handheld gamma cameras and gamma probes have been successfully implemented for enabling nuclear image or radio-guidance in minimally-invasive procedures. There is an opportunity for large field-of-view interventional planar scintigraphy and SPECT imaging to complement these small field-of-view devices for two reasons. First, a large field-of-view camera enables imaging of relatively larger organs and activity accumulations that are not close to the patient's skin. And second, more precise corrections can be implemented in the SPECT reconstruction algorithm, improving its quality. AREAS COVERED: This review article discusses the progress that has been made in the field of large field-of-view interventional planar scintigraphy and SPECT imaging. First, an overview of planar scintigraphy and SPECT is provided. Second, an exploration is given of the potential applications where large field-of-view interventional planar scintigraphy and SPECT imaging may be employed. And third, the requirements for scanner hardware are discussed and an overview of the possible system configurations is provided. EXPERT OPINION: We believe that there is an opportunity for large field-of-view interventional planar scintigraphy and SPECT imaging to assist clinical workflows. A major effort is now required to evaluate the prototype systems in clinical studies so that valuable practical experience can be obtained.


Assuntos
Tomografia Computadorizada de Emissão de Fóton Único , Humanos , Cintilografia
7.
Endocr Connect ; 11(5)2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35521806

RESUMO

Background: Planar scintigraphy has long been indicated in patients receiving I-131 therapy for thyroid cancer to determine the anatomic location of metastases. We studied our experience upon implementing additional single-photon emission (SPECT)-CT scanning in these patients. Method: We performed a retrospective study of consecutive adult patients with newly diagnosed thyroid cancer treated with I-131 between 2011 and 2017. Radiologic findings detected with planar scintigraphy alone vs those identified with SPECT-CT scanning were primary endpoints. Result: In this study, 212 consecutive patients with thyroid cancer were analyzed in two separate cohorts (107 planar scintigraphy alone and 105 planar scintigraphy with SPECT-CT). The addition of SPECT-CT resulted in more findings, both thyroid-related and incidental. However, we identified only 3 of 21 cases in which SPECT-CT provided an unequivocal additional benefit by changing clinical management beyond planar scintigraphy alone. No difference in the detection of distant metastatic disease or outcome was identified between cohorts. Conclusion: Synergistic SPECT-CT imaging in addition to planar nuclear scintigraphy adds limited clinical value to thyroid cancer patients harboring a low risk of distant metastases, while frequently identifying clinically insignificant findings. These data from a typical cohort of patients receiving standard thyroid cancer care provide insight into the routine use of SPECT-CT in such patients.

8.
Int J Antimicrob Agents ; 57(2): 106232, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33232733

RESUMO

BACKGROUND: Ventilator-associated pneumonia is common and is treated using nebulized antibiotics. Although adequate pulmonary biodistribution is important for antibiotic effect, there is a lack of data for both intravenous (IV) and nebulized antibiotic administration during mechanical ventilation. OBJECTIVE: To describe the comparative pulmonary regional distribution of IV and nebulized technetium-99m-labeled tobramycin (99mTc-tobramycin) 400 mg in a mechanically-ventilated ovine model. METHODS: The study was performed in a mechanically-ventilated ovine model. 99mTc-tobramycin 400 mg was obtained using a radiolabeling process. Computed tomography (CT) was performed. Ten sheep were given 99mTc-tobramycin 400 mg via either an IV (five sheep) or nebulized (five sheep) route. Planar images (dorsal, ventral, left lateral and right lateral) were obtained using a gamma camera. Blood samples were obtained every 15 min for 1 h (4 time points) and lung, liver, both kidney, and urine samples were obtained post-mortem. RESULTS: Ten sheep were anesthetized and mechanically ventilated. Whole-lung deposition of nebulized 99mTc-tobramycin 400 mg was significantly lower than with IV (8.8% vs. 57.1%, P<0.001). For both administration routes, there was significantly lower deposition in upper lung zones compared with the rest of the lungs. Dorsal deposition was significantly higher with nebulized 99mTc-tobramycin 400 mg compared with IV (68.9% vs. 58.9%, P=0.003). Lung concentrations of 99mTc-tobramycin were higher with IV compared with nebulized administration. There were significantly higher concentrations of 99mTc-tobramycin in blood, liver and urine with IV administration compared with nebulized. CONCLUSIONS: Nebulization resulted in lower whole and regional lung deposition of 99mTc-tobramycin compared with IV administration and appeared to be associated with low blood and extra-pulmonary organ concentrations.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Pulmão/metabolismo , Respiração Artificial , Tobramicina/administração & dosagem , Tobramicina/farmacocinética , Administração por Inalação , Administração Intravenosa , Aerossóis , Animais , Feminino , Modelos Animais , Nebulizadores e Vaporizadores , Ovinos , Tecnécio , Tobramicina/sangue
9.
Ann Nucl Med ; 33(3): 160-168, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30456550

RESUMO

OBJECTIVE: Radio-guided sentinel node (SN) biopsy is a standard method used in the treatment of early breast cancer. Single photon emission computed tomography with computed tomography (SPECT/CT) has been commonly used for SN detection. SPECT/CT adds precise anatomical information of SN sites, and it is reported that more SNs may be detectable on SPECT/CT than on planar imaging. We here investigate which breast cancer patients have benefited from SPECT/CT over planar imaging. METHODS: A total of 273 breast cancer patients including 80 with ipsilateral breast tumor relapse (IBTR) underwent both multiple-view planar imaging and SPECT/CT for SN detection. The number of SNs, the patients who had benefitted from SPECT/CT, and the SN procedure failure rate were compared between SPECT/CT and planar imaging. Factors influencing the visualization of para-sternal and ipsilateral level II, III nodes, and contralateral axillary nodes were also analyzed using logistic regression analysis. RESULTS: The number of hot spots did not differ between SPECT/CT and multiple-view planar imaging. Eight contaminated patients and 52 patients with visualized extra-level I axillary nodes benefited from identifying precise anatomical sites. Even though radioactive nodes could be harvested in most (192/193) of the non-IBTR patients (7/8 in non-SN visible patients), no radioactive nodes could be found during surgery in 11 of 80 IBTR patients. Axillary surgery (dissection) increased the visualization of para-sternal and level II, III axillary nodes, and previous irradiation increased the visualization of contralateral axillary nodes. CONCLUSION: Multiple-view planar imaging was equivalent to SPECT/CT for depicting hot nodes for radio-guided SN detection in breast cancer. SPECT/CT was useful when precise anatomical information was necessary, especially regarding sentinel lymph nodes other than ipsilateral axilla. Logistic regression analysis revealed that axillary surgery (dissection) increased the visualization of para-sternal and level II, III axillary nodes, and the only relevant factor influencing visualization of contralateral axillary SNs was previous radiation to the breast.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Biópsia Guiada por Imagem , Mamografia/métodos , Cintilografia/métodos , Biópsia de Linfonodo Sentinela , Tomografia Computadorizada por Raios X , Adulto , Mama/diagnóstico por imagem , Mama/patologia , Mama/cirurgia , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Biópsia Guiada por Imagem/métodos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Linfonodos/cirurgia , Pessoa de Meia-Idade , Biópsia de Linfonodo Sentinela/métodos , Tomografia Computadorizada por Raios X/métodos
10.
Asia Ocean J Nucl Med Biol ; 6(2): 80-89, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29998140

RESUMO

OBJECTIVES: This study sought to determine the diagnostic yield of SPECT/CT in localizing axillary sentinel lymph nodes (SLNs) in early breast cancer patients where planar scintigraphy (PS) was equivocal or negative. METHODS: Prospective analysis of early stage breast cancer patients with non-palpable axillary nodes undergoing SLN localization prior to nodal sampling for axillary staging. PS findings were categorized as: Category A: non-visualization of SLN; Category B: unusual uptake location; Category C: equivocal uptake / difficult interpretation. The K-coefficient of Cohen was used to evaluate the correlation between PS and SPECT/CT results. PS and SPECT/CT images were interpreted separately, and SLN identification on each of the modalities was correlated to BMI (Body mass index) and peroperative radio guided results. RESULTS: Between April 2015 and January 2017, 1028 early breast cancer cases underwent sentinel lymphoscintigraphy. Of total, 134 (13%) patients underwent SPECT/CT in addition to PS. All were females with mean age of 48.15 years (range: 26-82 years). Right sided in 68, left in 64 and 2 with bilateral carcinoma. By TNM classification: 49 (37%) T1, 78 (58%) T2 and 7 (5%) had DCIS/Paget's disease.Overall SLNs were detected on both PS and SPECT/CT in 60% cases. Of category A (n=54); 35/54 (64%) SLN localized on SPECT/CT; 32 were level-I; 2 Level-II; 1 Level-III nodes. In 19, SLN was not localized. Of category B (n=18), 5 had prior lumpectomy, SPECT/CT localized tracer uptake to 17 level-I sentinel nodes, 3 level-II and level III / IMC in 9. Of category C (n=62), 29 had prior lumpectomy. SPECT/CT confirmed SLN in all the cases. Radio-guided surgery confirmed SPECT/CT results. The correlation between the two techniques was low (K=0.34). Where PS was negative; SPECT/CT localized nodes in statistically significant number of cases (=0.01). PS identified SLN uptakes in 80/134 (60%) cases with a mean BMI of 21.6±4.8 kg/m2 while SPECT/CT detected ''hot'' nodes in 115/134 (86%) cases with a mean BMI of 29.6±5.6 kg/m2. For overweight/obese patients (n=59) (BMI>25 kg/m2), PS failed to identify SLNs in 49 and SPECT/CT failed to do so in 18 (<0.001). CONCLUSION: SPECT/CT has diagnostic yield and helps in precise SLN localization where planar imaging is negative or shows unusual site of uptake.

11.
J Craniomaxillofac Surg ; 45(6): 839-844, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28434828

RESUMO

PURPOSE: To analyse the correlation between the level of activity measured in the single photon emission computed tomography (SPECT) and the pathological findings in patients with condylar hyperplasia (CH). MATERIALS AND METHODS: All patients evaluated in our department between 2007 and 2014 with a diagnosis of condylar hyperplasia who had undergone SPECT, evidenced signs of activity, and had undergone surgery were included. We included 28 patients, of whom 20 were women and 8 men. RESULTS: The male:female ratio was 2,5:1. The mean age of the subjects was 24.4 years at the time of diagnosis (with a range between 14 and 42 years). In 19 cases the affected condyle was the right, and in the remaining 9 it was the left (ratio R:L 2,1:1). On the SPECT, in 16 patients a high level of activity was identified (57.1%) and in the remaining 12 a low level (42.9%). Only 13 patients (6 in the low-activity group and 7 in the high-activity group) presented with islands of cartilage. When comparing the results between the two groups, the main differences were observed in the parameters related to the islands of cartilage. These were more frequent in the group with high activity compared with low activity (5.5 versus 0 per mm2 of median). Besides being more frequent, these islands were larger (more than double) in the high-activity group (385.1 µm versus 169.7 µm of median). This is the only statistically significant difference found, a fact that can be explained by the small sample size in the study. CONCLUSION: Radioisotope tests are the best indicator of the level of activity in condylar hyperplasia, which seems to be directly related to the intensity signal collection.


Assuntos
Côndilo Mandibular/diagnóstico por imagem , Côndilo Mandibular/patologia , Articulação Temporomandibular/diagnóstico por imagem , Articulação Temporomandibular/patologia , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Adulto , Ácido Etidrônico , Feminino , Humanos , Hiperplasia/diagnóstico por imagem , Hiperplasia/patologia , Hiperplasia/cirurgia , Masculino , Côndilo Mandibular/cirurgia , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Articulação Temporomandibular/cirurgia
12.
World J Nucl Med ; 16(4): 303-310, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29033679

RESUMO

The incremental value of single-photon emission computed tomography-computed tomography (SPECT-CT) over planar bone scintigraphy and SPECT in detecting skeletal lesions in breast cancer patients and its effect on patient management is assessed in this study. This is a prospective study which was conducted over 1-year duration. Whole-body planar scintigraphy, SPECT, and SPECT-CT were performed in 85 breast cancer patients with total of 128 lesions. Correlative imaging and clinical follow-up was used as the reference standard. McNemar's multistep analysis was performed for each patient and each lesion. On patient-wise analysis, 47 patients had equivocal diagnosis on planar bone scintigraphy, 28 on SPECT, and eight on SPECT-CT. On lesion-wise analysis, there were 72 equivocal lesions on planar bone scintigraphy, 48 on SPECT, and 15 on SPECT-CT. Overall, SPECT-CT resulted in a significant reduction in the proportion of equivocal diagnosis on both patient-wise (P < 0.004) and lesion-wise basis (P < 0.004), irrespective of the skeletal region involved. The sensitivity on a per-patient basis was 43%, 58%, and 78% for planar bone scintigraphy, SPECT, and SPECT-CT, respectively. Similarly, the specificity was 85%, 92%, and 94% for planar bone scintigraphy, SPECT, and SPECT-CT, respectively. Patient management was correctly altered in 32% of the patients based on SPECT-CT interpretation. Our data suggest that adding SPECT-CT to whole-body imaging significantly improves sensitivity and specificity in diagnosing bone metastases and significantly reduces the proportion of equivocal diagnosis in all regions of the skeleton. The most important outcome is derived from the accurate alteration in patient management clinically by down- and up-staging of patients and a more precise identification of metastatic extent.

13.
Springerplus ; 5(1): 1270, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27540503

RESUMO

INTRODUCTION: Meckel's diverticulum is a common congenital abnormality of gastrointestinal tract in children. Planar scintigraphy using Technetium-99m pertechnetate is widely used in the diagnosis of Meckel's diverticulum. Single photon emission computed tomography/computed tomography (SPECT/CT) fusion imaging may help to locate the Meckel's diverticulum lesion. We now present a Meckel's diverticulum case which tends to be missed. CASE DESCRIPTION: The patient was diagnosed with Mecke's diverticulum by planar scintigraphy in 2007. After seven years, a recurrence of hematochezia made the patient undergo planar scintigraphy again. However, the concentration on planar image was located at the right kidney level, we could not determine whether it was caused by physiological uptake of the right kidney or by an ectopic gastric mucosa. Using SPECT/CT technique, we confirmed that the lower part of the concentration was from a Meckel's diverticulum from the small intestine based on the functional and anatomical information together. DISCUSSION AND EVALUATION: For concentrations about the kidney level, planar scintigraphy is not enough to be diagnostic of Meckel's diverticulum. SPECT/CT imaging may be beneficial for a definitive diagnosis. Also, fusion images may provide precise localization of the lesion. To make sure that patients obtain optimal benefit from a SPECT/CT examination, we have to balance the priority between information of anatomic location and avoiding redundant radiation to the patients. CONCLUSIONS: Our case study suggest that for cases with ambiguous planar scintigraphy images, SPECT/CT imaging should be performed to obtain a definitive diagnosis.

14.
Comput Biol Med ; 43(10): 1341-52, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24034725

RESUMO

Patient-specific dosimetry calculations are often performed for radioiodine therapy in patients with Graves' hyperthyroidism. The radioiodine doses are typically calculated to deliver the desired amount of radiation based on gland size and radioactive iodine uptake. Thus the estimation of thyroid gland volume is of great importance for radioiodine therapy. In clinical practice, thyroid volume determinations are usually performed with ultrasonography (US) or with planar scintigraphy (PS). In traditional planar scintigraphic studies, the thyroid boundary is estimated using a fixed threshold value if the shape of the thyroid is well-defined or a manually drawn region of interest (ROI) if the thyroid shape is irregular. The thyroid volume is then calculated based on the area thus determined. Delineating the thyroid area on a planar scintigram is not easy when applying a fixed threshold value. Moreover, hand-drawn ROIs are time consuming, tedious, and highly operator-dependent. In this study, for a PS image, a fully automated thyroid volume estimation system mainly consisting of four steps, i.e. preprocessing, image contrast enhancement, image segmentation, and automated ROI finding, was proposed to obtain the maximum height and area of each thyroid lobe, and thus calculate the thyroid volume using either Himanka-Larsson's formula or Allen-Goodwin's formula. A set of 40 Graves's disease patients regarded as training set were used to determine empirically some parameters operated in the system. A set of 30 Graves's disease patients being independent of the training set, regarded as test set for thyroid volume measurements were used for comparisons and performance analyses. In this study, the US was adopted as a standard reference. The statistical analyses were performed with bias, precision, and relative differences. The results of thyroid volume estimation from the proposed approach correlated well with those from US, and the statistical performance analyses showed good agreement between them. In comparison, our automated approach with Allen-Goodwin's formula had not only good correlation with US (R(2)=0.99) but also the best bias (0.8), precision (±2.32 ml), and low relative differences (2.2 ± 6.1%). It is expected that this automated computer-assisted approach can help physicians in the determination of patient-specific administered activities for treatment of thyroid disease.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Cintilografia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Glândula Tireoide/diagnóstico por imagem , Adulto , Idoso , Algoritmos , Feminino , Doença de Graves/diagnóstico por imagem , Doença de Graves/patologia , Doença de Graves/radioterapia , Humanos , Radioisótopos do Iodo/uso terapêutico , Masculino , Pessoa de Meia-Idade , Glândula Tireoide/patologia
15.
Pol J Radiol ; 77(2): 19-21, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22844305

RESUMO

BACKGROUND: Knowledge of thyroid gland volume plays a key role in the treatment of thyroid diseases by radioactive iodine 131I. Radioiodine therapy is a routine procedure of treatment hyperthyroidism for over 50 years. MATERIAL/METHODS: Today modern diagnostic has a number of medical diagnostics instruments whose using to estimate of thyroid volume. Undoubtedly these method we can include a ultrasonography (US) and planar scintigraphy (PS) whose characterized by noninvasive. RESULTS/CONCLUSIONS: The aims of this papers is evaluate of thyroid volume on the basis of method ultrasonography and planar scintigraphy.

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