Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Whole Body Imaging”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

FDG-PET for evaluation of recurrent lymph node metastases in patients with surgically resected breast cancer: adding spot images to whole body images.

BACKGROUND: To evaluate the role of 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET), spot images were added to whole-body FDG-PET images in a patient with suspected lymph node recurrence of breast cancer. METHODS: FDG-PET spot images were obtained of 44 patients who had undergone surgical resection of breast cancer as were whole-body FDG-PET images. A total of 33 lesions in 19 patients (mean age, 59 years; range, 39-70 years) were diagnosed as lymph node recurrence clinically, and standardized uptake values (SUVs) were calculated for whole body images and spot images. Lesions were also scored from 1 (not clear) to 3 (very clear) for both the whole body and spot images. RESULTS: For mediastinal lymph node metastases, the SUVs of the spot images (SUVsp) (mean, 4.0; range, 2.1-6.6) were significantly higher than the SUVs of the whole body images (SUVwb) (mean, 3.3; range, 2.1-5.8). For other lymph node metastases (neck, axilla, etc.), there was no significant difference between SUVwb (2.6; 1.4-6.5) and SUVsp (2.8; 1.6-8.1). CONCLUSIONS: By adding spot images, the evaluation of lymph node metastases became easier. Adding spot images to whole-body FDG-PET may be useful.

Adult↗

Reducing loss of image quality because of the attenuation artifact in uncorrected PET whole-body images.

UNLABELLED: In whole-body PET, it is not unusual to shorten the study time by omitting the transmission scan and to ignore attenuation during reconstruction. If a transmission scan is available, many centers reconstruct the images with, but also without, attenuation correction. Although ignoring attenuation leads to an artifact in the reconstructed images, these images still provide valuable diagnostic information in oncologic applications. Several authors have reported that the attenuation artifact may actually increase the tumor-to-background ratio. In this study, we analyzed the causes of the artifact and proposed a new algorithm to reduce the adverse effects on visual image quality. METHODS: We analyzed the causes of the attenuation artifact mathematically and numerically, and we examined its effect on tumor-to-background ratio and on signal-to-noise ratio. In addition, we showed that the attenuation artifact may lead to loss of image detail in conventional maximum-likelihood expectation maximization (MLEM) reconstruction. A new maximum-likelihood algorithm allowing negative reconstruction values (NEG-ML) was derived to reduce this loss. RESULTS: The attenuation artifact consists of 2 components. The first component is the well-known scaling effect: The apparent activity is reduced because attenuation decreases the fraction of detected photons. The second component is a relatively smooth negative contribution that is added to attenuated regions surrounded by activity. The second component tends to increase the tumor-to-background ratio. However, a simulation experiment shows that this increase in signal may be entirely offset by an increase in noise. The negative contribution can interfere with the nonnegativity constraint of the MLEM algorithm, leading to loss of image detail in regions of high attenuation. The new NEG-ML algorithm avoids the problem by allowing negative pixel values. The algorithm is similar to MLEM in the suppression of the streak artifact but provides more anatomic information. In our department, it is in routine clinical use for reconstruction of PET whole-body images without attenuation correction. CONCLUSION: Ignoring attenuation may increase the tumor-to-background ratio, but this increase does not imply improved tumor detection. The NEG-ML algorithm reduces the adverse effect of the attenuation artifact on visual image quality.

Algorithms↗

Whole-body imaging with PET/MRI.

Whole-body positron emission tomography (PET) scanning with the radiolabeled glucose analogue 2-[fluorine-18]-fluoro-2-deoxy-D-glucose ( superset 18 F-FDG) can identify areas of cancerous involvement and distinguish malignant from benign lesions and therefore, plays an important role in the diagnosis and management of patients with cancer. PET facilitates the evaluation of metabolic and molecular characteristics of a wide variety of cancers, but it is limited in its ability to visualize anatomical structures. Whole-body magnetic resonance imaging (MRI) is a promising diagnostic modality for the diagnosis and management of patients with cancer, because of its high anatomical resolution. Whole-body PET and whole-body MRI allow to evaluate both the primary tumor and for the presence of metastasis at the same time. The combination of these two excellent diagnostic imaging modalities into a single scanner offers several advantages in comparison to PET and MRI alone. A hybrid PET/MRI facilitates the accurate registration of metabolic and molecular aspects of the diseases with exact correlation to anatomical findings, improving the diagnostic value in identifying and characterizing of malignancies and tumor staging. Thus, hybrid PET/MRI could be a very important diagnostic imaging modality in oncological applications in the decades to come, and possibly for use in cancer screening and cardiac imaging.

Fluorodeoxyglucose F18↗

Visualization of the bone/bone marrow of lower extremities in Ga-67 whole-body images.

Patients whose Ga-67 whole-body images showed increased uptake by the bone/bone marrow of the lower extremities were selected and classified into three types according to the extent and the grade of the visualization. These types were then compared with their serum iron levels, iron-binding capacities, and the results of several other serum biochemical tests. Of 374 consecutive whole body 72-hr images reviewed, 59 (15.8%) showed increased uptake of the tracer by the bone/bone marrow of the lower extremities. The three classified types were as follows: type T--visualization of both tibiae and femurs; type S--strong visualization of the femurs; and type W--weak visualization of the femurs. The serum iron concentration was significantly high in type T and low in type S. In conclusion, the pattern of Ga-67 uptake by the bone/bone marrow of the lower extremities fairly closely reflects the status of iron metabolism.

Adolescent↗

Use of whole-body imaging using Tc-99m RBC in patients with soft-tissue vascular lesions.

We investigated the usefulness of whole-body imaging as an adjunct to spot imaging in soft-tissue vascular lesions, such as hemangiomas and vascular malformations. Spot imaging of the known lesion and whole-body imaging were performed 1-3 hours after the injection of Tc-99m RBC in 42 patients with soft-tissue vascular lesions. Whole-body imaging was considered to be useful in only two patients, who had multiple distant occult lesions in addition to large known lesions. It was suggested that the routine addition of whole-body imaging is not cost effective in patients with soft-tissue vascular lesions, although it may be beneficial for detecting occult lesions in patients with hemangiomas.

Adolescent↗

External whole-body image of EGFP gene expression.

Whole-body optical imaging is an external and noninvasive procedure that enables the continuous visual monitoring of malignant growth and spread within intact animals. The human colon adenocarcinoma cell-line HCT-15 was transfected with a pIRES 2-EGFP vector, and stable enhanced green fluorescence protein (EGFP) expression was established (Fig.1). Approximately 10(6) HCT-15 EGFP stable transfectant cells were subcutaneously injected into the left flank of six-week-old male Balb/c-nu/nu mice. On post-injection day 78, the size of the subcutaneous tumor was 13.1 mm x 15.4 mm in diameter, as observed using an ORCA-C 7780-20 three-chip cooled color charge-coupled-device camera (Hamamatsu Photonics Systems, Hamamatsu City, Japan). An external fluorescent image of the tumor was acquired through the skin (Fig.2B). The tumor could be seen more clearly once the skin was removed (Fig.2D). Furthermore, in the peritoneal metastasis (Fig.3B) and liver metastasis models (Fig.3D), metastasis could also be seen through the skin. This new technology is a useful method for investigating tumor growth in vivo. In the future, this method could be applied to the detection of peritoneal, liver and lung metastasis in living animals.

Adenocarcinoma↗

Diffusion weighted whole body imaging with background body signal suppression (DWIBS): technical improvement using free breathing, STIR and high resolution 3D display.

PURPOSE: To examine a new way of body diffusion weighted imaging (DWI) using the short TI inversion recovery-echo planar imaging (STIR-EPI) sequence and free breathing scanning (diffusion weighted whole body imaging with background body signal suppression; DWIBS) to obtain three-dimensional displays. MATERIALS AND METHODS: 1) Apparent contrast-to-noise ratios (AppCNR) between lymph nodes and surrounding fat tissue were compared in three types of DWI with and without breath-holding, with variable lengths of scan time and slice thickness. 2) The STIR-EPI sequence and spin echo-echo planar imaging (SE-EPI) sequence with chemical shift selective (CHESS) pulse were compared in terms of their degree of fat suppression. 3) Eleven patients with neck, chest, and abdominal malignancy were scanned with DWIBS for evaluation of feasibility. Whole body imaging was done in a later stage of the study using the peripheral vascular coil. RESULTS: The AppCNR of 8 mm slice thickness images reconstructed from 4 mm slice thickness source images obtained in a free breathing scan of 430 sec were much better than 9 mm slice thickness breath-hold scans obtained in 25 sec. High resolution multi-planar reformat (MPR) and maximum intensity projection (MIP) images could be made from the data set of 4 mm slice thickness images. Fat suppression was much better in the STIR-EPI sequence than SE-EPI with CHESS pulse. The feasibility of DWIBS was showed in clinical scans of 11 patients. Whole body images were successfully obtained with adequate fat suppression. CONCLUSION: Three-dimensional DWIBS can be obtained with this technique, which may allow us to screen for malignancies in the whole body.

Abdominal Neoplasms↗

Comparison of (123)I and (131)I for whole-body imaging in thyroid cancer.

UNLABELLED: We compared the diagnostic sensitivities of (123)I and (131)I whole-body imaging in differentiated thyroid cancer. METHODS: Twelve thyroidectomized patients (3 previously treated with (131)I) were studied. After a period of thyroid hormone withdrawal, whole-body imaging was performed approximately 24 and 72-96 h after administration of 74-185 MBq (2-5 mCi) (123)I and 111-185 MBq (3-5 mCi) (131)I, respectively. RESULTS: Both (123)I and (131)I revealed residual thyroid tissue, present in 9 patients. (131)I detected metastases in 5 studies of 4 patients. In 4 of 5 studies, (123)I missed metastases shown by (131)I in 8 body regions including the neck, mediastinum, lungs, and bone and detected 3 other sites of metastasis only in retrospect. No lesion was better seen with (123)I than with (131)I. CONCLUSION: Although (123)I is adequate for imaging residual thyroid tissue, it appears to be less sensitive than (131)I for imaging thyroid cancer metastases.

Aged↗

Real-time whole-body imaging of an orthotopic metastatic prostate cancer model expressing red fluorescent protein.

BACKGROUND: We describe here, a whole-body imageable spontaneous metastatic model of human prostate cancer developed by surgical orthotopic implantation (SOI) and visualized by red fluorescent protein (RFP) expression. METHODS: Human prostate cancer PC-3 cells were transduced with the pLNCX2-DsRed-2-RFP retroviral vector containing the RFP and neomycin-resistance genes. A stable RFP-expressing PC-3 clone was selected in 800 microg/ml G418 in vitro and injected subcutaneously in nude mice. Stable high-level expression of RFP was maintained in the subcutaneously-growing tumors. To utilize RFP expression for metastasis studies, fragments of the subcutaneously-growing tumor, which were comprised of RFP-expressing cells, were implanted by SOI in the prostate of nude mice. RESULTS: Primary tumor growth, progression, and subsequent lymphatic metastases were visualized in live, intact animals in real time by whole-body RFP fluorescence imaging. In total, 100% of the experimental animals developed lymphatic metastasis, the growth of which was monitored in real time by whole-body imaging. The aggressive lymphatic metastasis in this model reflects one of the major metastatic routes of prostate cancer in human patients. Intravital RFP imaging visualized single cancer cells in the lung and bladder. Open RFP imaging at autopsy visualized extensive primary growth and highly disseminated lymph-node metastases. CONCLUSIONS: The long-wavelength emission of RFP enabled high sensitivity and resolution of microscopic tumor growth using appropriate imaging techniques. The model should be useful for the real-time evaluation of novel therapeutics for metastatic prostate cancer.

Animals↗

MRI and determination of T1 and T2 of solid polymers using a 1.5 T whole-body imager.

Spin-echo sequences with echo times as short as 3.5 msec were implemented on a standard 1.5 T NMR whole-body imager for 1H imaging of polymers in the solid-state. No modification of the NMR hardware designed for clinical usage was made. Beside images of different polymers a "self-portrait" of the polymeric materials of the receiver coil is given as a neat application. Based on imaging experiments the longitudinal and transverse relaxation time of polymers were investigated. The results indicate that using a standard whole-body imager, it is possible to provide additional information to other examination techniques in polymer and materials science.

Magnetic Resonance Spectroscopy↗

9:-9:15. 3D Data Acquisition for Whole Body Images on the ECAT HR+

Purpose: Evaluation of 3D clinical whole-body FDG PET imaging using recent improvements in data correction and reconstruction methods.Methods: Phantom studies following the NEMA NU 2-2000 draft were performed to evaluate count loss and accuracy of attenuation and scatter correction algorithms. Phantom results were used to estimate 3D vs. 2D efficiency. For patient studies, an established 2D imaging protocol (9 min emission, 3 min transmission acquisition per bed position, commencing 60 min after injection of 15 mCi FDG) was used. This was followed by a 3D acquisition of the same duration, commencing approximately 110 min later, so that 3D acquisition was performed with approximately 50% lower patient activity than 2D. Images were compared in terms of anatomic structural definition and visible artifacts.The count loss study showed that in a dose range of 10-15 mCi, 3D produced an approximately two-fold increase in effective NEC compared to 2D. The phantom imaging study showed slightly improved target to background ratios for both hot and the cold "lesions" when using 3D imaging. In 5 patients studied so far, comparison of 2D and 3D studies demonstrated no systematic differences in image quality between the two methods.Conclusion: 3D whole-body imaging with improved image reconstruction may permit a two-fold reduction in emission acquisition time or injected dose, without decrease in image quality compared to standard 2D imaging techniques.

Journal Article↗

(99m)Tc-MDP scintigraphic findings in children with leukemia: value of early and delayed whole-body imaging.

UNLABELLED: The purpose of this study was to reveal the bone scan abnormalities in children with leukemia and to show the value of whole-body scanning in early and delayed phases. METHODS: From a database of all patients with a diagnosis of leukemia from January 1990 to April 2000, 12 children (9 male, 3 female; mean age, 8.0 y; age range, 4.7--13.2 y) were identified for whom the diagnosis of leukemia was suggested on the basis of bone scans obtained as part of the initial work-up for unexplained skeletal pain. Early and delayed whole-body bone scans and radiographs were reviewed retrospectively. Areas of abnormal uptake on early and delayed phases were categorized into locations: metaphysis--diaphysis--epiphysis (MDE), pelvis, ribs, spine, and others. MDE lesions included abnormalities in the metaphysis extending into the diaphysis for some length: metaphysis/diaphysis, metaphysis only, diaphysis only, epiphysis only, and the entire bone. Pelvic and spine lesions were further characterized as focal or diffuse. RESULTS: Ten patients had lesions in 2 or more locations on both phases. Two patients had multiple lesions on the early scans but only rib lesions on the delayed scans. Lesions correlated with symptomatic sites in 8 patients on the delayed scans and in 11 patients on the early scans. The most common sites of abnormalities on the delayed scans were metaphyseal/diaphyseal, pelvis (focal), and ribs. The most common locations of lesions on the early scans were metaphyseal/diaphyseal, pelvis (diffuse or focal), and spine. More metaphyseal/diaphyseal lesions were seen on the early scans than on the delayed scans. Diffuse involvement of the pelvis and spine was seen only on the early phase. However, rib lesions were seen more frequently on the delayed scan. CONCLUSION: Early whole-body imaging in conjunction with delayed whole-body scanning may enhance the diagnostic accuracy of bone scanning in the evaluation of children with skeletal pain of obscure etiology, such as that associated with leukemia.

Adolescent↗

Whole body imaging in blunt multisystem trauma patients without obvious signs of injury: results of a prospective study.

HYPOTHESIS: The use of liberal whole body imaging (pan scan) in patients based on mechanism is warranted, even in evaluable patients with no obvious signs of chest or abdominal injury. DESIGN: Prospective observational study. SETTING: Academic level I trauma center. PATIENTS: All patients admitted following blunt multisystem trauma. INTERVENTION: Pan scan, including computed tomography (CT) of the head, cervical spine, chest, abdomen, and pelvis, with the following inclusion criteria: (1) no visible evidence of chest or abdominal injury, (2) hemodynamically stable, (3) normal abdominal examination results in a neurologically intact patient or unevaluable abdominal examination results secondary to a depressed level of consciousness, and (4) significant mechanisms of injury. Radiological findings and changes in treatment based on these findings were recorded. MAIN OUTCOME MEASURE: Any alteration in the normal treatment plan as a direct result of CT scan findings. These alterations include early hospital discharge, admission for observation, operative intervention, and additional diagnostic studies or interventions. RESULTS: One thousand patients underwent pan scan during the 18-month observation period, of which 592 were evaluable patients with no obvious signs of abdominal injury. Clinically significant abnormalities were found in 3.5% of head CT scans, 5.1% of cervical spine CT scans, 19.6% of chest CT scans, and 7.1% of abdominal CT scans. Overall treatment was changed in 18.9% of patients based on abnormal CT scan findings. CONCLUSIONS: The use of pan scan based on mechanism in awake, evaluable patients is warranted. Clinically significant abnormalities are not uncommon, resulting in a change in treatment in nearly 19% of patients.

Adult↗

Comparison of four scatter correction methods for patient whole-body imaging during therapeutic trials with iodine-131.

BACKGROUND: Activity in regions of interest can be measured using serial whole-body scintigraphic images to estimate the dose received by a patient after therapeutic injections. As scatter and attenuation introduce biases in quantitative measurements, these phenomena need to be corrected to allow accurate determination of tracer concentration. METHODS: The feasibility of iodine-131 whole-body imaging in list mode was studied over an extended spectrum (0-750 keV) in order to compare four scatter correction methods by the geometric mean approach (20%, Dual Energy Window, Triple Energy Window, and Spectral Factor Analysis methods). All data were corrected for attenuation using a Transmission Attenuation Correction prototype from Sopha Médical Vision international. The half-life of an iodine-131 standard source was calculated from scatter-corrected anterior views. Whole-body activities, using the Day 0, Hour 1, image as a reference (calibration from an administered dose) and an external calibration source (calibration from an imaged known-activity source), were calculated for three patients undergoing a radioimmunotherapy trial in order to assess the reliability of quantification by the geometric mean approach. RESULTS: Patient studies confirmed the clinical feasibility of this type of acquisition. As expected, all methods allowed determination of an accurate half-life for the calibration source. A slight impact of scatter correction was observed in quantification with calibration from an administered dose. For quantification with calibration from an imaged known-activity source, whole-body activity was overestimated by +100% to +200% with the 20% window, depending on the size of the patient, whereas errors were about +50% with scatter correction. However, the influence of patient morphology was less marked when a scatter correction method was used. CONCLUSIONS: When the geometric mean approach is used together with a sophisticated transmission acquisition device for quantification with calibration from an administered dose, the 20% energy window appears to be adequate. However, for quantification with calibration from an imaged known-activity source, accurate activity estimates cannot be obtained even when scatter correction is used to compensate for the influence of patient morphology.

Calibration↗

Detection of hemangiomas using whole-body imaging with technetium-99m labeled RBCs.

Hemangiomas are easily, quickly and relatively noninvasively detected using whole-body imaging with Tc-99m labeled RBCs. A case in which this method was used to confirm known lesions and detect additional unsuspected lesions is described. This method can also be useful in the detection and evaluation of other types of vascular malformations, such as arteriovenous communications. The lesions must be of sufficient size and flow to be seen. Applications include the examination of patients known to have one vascular malformation in a search for additional lesions and the screening of relatives of patients with familial conditions that include hemangiomas.

Adolescent↗

MR relaxometry on a whole-body imager: quality control.

Long-term monitoring of the average proton relaxation time T2 of phantoms measured on a Siemens MR whole-body imager showed very good repeatability and reproducibility. The repeatability (short-term precision) and reproducibility (long-term precision) of the average values of a relaxation time T2 approximately/= 81 ms, obtained by a standard 16-echo CPMG pulse sequence, were 2.6% and 9.7%, respectively. The Siemens Vision imager proved to be a suitable tool for T2 evaluation in vivo. Quality control was performed using the techniques of control diagrams developed by Shewhart, which proved to be an appropriate method for continuous quality control of relaxation time determination.

Magnetic Resonance Spectroscopy↗