Varicella zoster infection associated rhabdomyolysis demonstrated by Tc-99m MDP imaging.
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Aged↗
Biomedical subjects
Abass Alavi
Publications and source records attributed to Abass Alavi.
Fluorodeoxyglucose positron emission tomography excludes pericardial metastasis by recurrent lung cancer.
Fluorodeoxyglucose (FDG) positron emission tomography (PET) has been shown to be useful in the diagnosis and staging of a variety of malignancies. Because of its high sensitivity, FDG PET frequently detects malignant lesions that are not demonstrated clearly by anatomic imaging modalities. FDG PET usually has high negative predictive value and, therefore, negative studies are highly suggestive of a benign process. The authors present a patient in whom transesophageal echocardiography and magnetic resonance imaging described pericardial metastasis from a recurrent lung cancer, which on FDG PET was shown correctly to suggest benign scar tissue.
Carcinoma, Small Cell↗
Diffuse bone marrow involvement of Hodgkin lymphoma mimics hematopoietic cytokine-mediated FDG uptake on FDG PET imaging.
Whole-body fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET) has been useful in the management of a variety of malignancies. In patients with chemotherapy followed by bone marrow stimulants such as granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor, the bone marrow will have diffuse, increased FDG accumulation. Therefore, diffuse bone marrow FDG uptake is commonly attributable to the effect of hematopoietic cytokines. However, diffuse bone marrow FDG uptake can also be caused by bone marrow involvement by malignancy. The authors report a patient with diffuse bone marrow involvement of Hodgkin disease that appears indistinguishable from hematopoietic cytokine-mediated FDG bone marrow uptake.
Adolescent↗
Unrecognized renal transplants as a potential source of false-positive interpretation of FDG PET.
Renal transplantation has become an effective therapy for patients with late-stage renal disease. Fluorodeoxyglucose (FDG) positron emission tomography (PET) is accepted as an important diagnostic technique in the evaluation of suspected or known malignancies or other disorders in the day-to-day practice of medicine. Because FDG is excreted from the kidneys into the urine, unrecognized renal transplants can appear as malignant lesions. Familiarity with the clinical history is a prerequisite in the correct interpretation of FDG PET images in this setting. In addition, FDG PET images should be correlated with anatomic images when such studies are available. When neither clinical history nor anatomic images are available, a combination of "abnormal" activity in the pelvis and absence of normal renal activity should raise suspicion of the existence of a renal transplant.
Adult↗
Potential false-positive FDG PET imaging caused by subcutaneous radiotracer infiltration.
Whole-body fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scanning has been useful in the management of a variety of malignancies with high accuracy. However, numerous nonmalignant lesions can also result in increased FDG accumulation and consequently may cause potential false-positive interpretation if the causes are not recognized. A single focus of FDG accumulation in the axilla can often easily be attributed to tracer infiltration when the injection was on the same side. However, multiple foci of FDG uptake can be similar to malignant lesions. A case is presented in which the follow-up study clarified the nature of multifocal increased FDG uptake in the axilla.
Axilla↗
Roles of positron emission tomography with fluorine-18-deoxyglucose in the detection of local recurrent and distant metastatic sarcoma.
Sarcomas are a heterogeneous group of tumors comprising approximately 1% of all malignancies. Definitive treatment of sarcoma is surgical resection. However, after surgical removal, 40% to 60% of the patients will develop local or distant recurrence. Therefore, the early detection and treatment of recurrence is an important part of modern sarcoma therapy. Positron emission tomography with fluorine-18-deoxyglucose (FDG-PET) has been highly successful in detecting and staging a variety of malignancies. However, its use in the management of patients with sarcoma is less defined. The purpose of our study was to assess the potential roles of FDG-PET in the detection of local recurrence and distant metastases. In this retrospective study, the images of 33 FDG-PET scans, reports of 29 computed tomography (CT) scans, and 8 magnetic resonance imaging (MRI) scans from 28 patients were compared with surgical pathology or clinical follow up for at least 6 months. FDG-PET detected all 25 cases of local and distant recurrences with 100% sensitivity. CT was able to detect 18 of the 22 possible cases of recurrent disease, whereas MRI was able to detect 5 of 7 cases of recurrent disease. PET was particularly useful in patients with extensive histories of surgery and radiation therapy, precisely the setting in which CT and MRI have the lowest specificity and sensitivity. In conclusion, FDG-PET was a sensitive test to detect local and distant recurrences of sarcoma and this warrants further investigation.
Adolescent↗
Radiation-induced esophagitis on FDG PET imaging.
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Aged↗
Paraneoplastic encephalitis associated with cystic teratoma is detected by fluorodeoxyglucose positron emission tomography with negative magnetic resonance image findings.
The role of fluorodeoxyglucose (FDG) positron emission tomography (PET) as a functional imaging technique used in the evaluation of a variety of malignancies has been well known. Paraneoplastic encephalitis is a rare central nervous complication, which has been reported in some tumors. Traditionally, magnetic resonance imaging of the brain is performed to aid in its diagnosis. The authors report a case of paraneoplastic encephalitis, associated with cystic teratoma, which had positive FDG-PET findings but appeared normal on magnetic resonance imaging.
Adult↗
Intense fluorodeoxyglucose activity in pulmonary amyloid lesions on positron emission tomography.
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Aged↗
Cerebral blood flow during meditative prayer: preliminary findings and methodological issues.
Meditative practices typically require several coordinated cognitive activities. This study measured changes in cerebral blood flow during "verbal" based meditation by Franciscan nuns involving the internal repetition of a particular phrase. These results are compared with those we previously described in eight Buddhist meditators who use a type of "visualization" technique. Three experienced practitioners of verbal meditation were injected via i.v. at rest with 260 MBq of Tc-99m HMPAO and scanned 30 min. later on a triple head SPECT camera for 45 min. Following the baseline scan, subjects meditated for approximately 40 min. at which time they were injected with 925 MBq of HMPAO while they continued to meditate for 10 min. more (total of 50 min. of meditation). The injection during meditation was designed not to disturb practice. Subjects were scanned 20 min. later for 30 min. Counts were obtained for regions of interest for major brain structures and normalized to whole-brain blood flow. Compared to baseline, mean verbal meditation scans showed increased blood flow in the prefrontal cortex (7.1%), inferior parietal lobes (6.8%), and inferior frontal lobes (9.0%). There was a strong inverse correlation between the blood flow, change in the prefrontal cortex and in the ipsilateral superior parietal lobe (p<.01). This study on a limited number of subjects demonstrated the feasibility of studying different types of meditation with neuroimaging techniques, suggested that several coordinated cognitive processes occur during meditation, and also raised important methodological issues.
Adult↗
Use of ibritumomab tiuxetan anti-CD20 radioimmunotherapy in a non-Hodgkin's lymphoma patient previously treated with a yttrium-90-labeled anti-CD22 monoclonal antibody.
Ibritumomab tiuxetan is a novel radioimmunotherapeutic agent that has a high response rate in relapsed or chemotherapy-refractory CD20+ B-cell non-Hodgkin's lymphoma. Whereas chemotherapy agents can successfully be used multiple times in a given patient, there are few data on the repeated use of radioimmunotherapy in terms of efficacy or morbidity, and no reports as yet involving radioconjugates that target different antigens We report on a patient who was treated successfully with yttrium-90-labeled humanized anti-CD22 monoclonal antibody (90Y-epratuzumab). Upon relapse 3 years later, the patient was treated again with radioimmunotherapy consisting of 90Y-ibritumomab tiuxetan anti-CD20 monoclonal antibody, with a good response and acceptable bone marrow suppression. This case report demonstrates the potential for repeated treatments with radioimmunotherapy agents in patients with chemotherapy-refractory non-Hodgkin's lymphoma.
Antibodies, Monoclonal↗
Components of professional competence for nuclear medicine physicians.
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Clinical Competence↗
Radioimmunotherapy of non-Hodgkin's lymphoma with 90Y-DOTA humanized anti-CD22 IgG (90Y-Epratuzumab): do tumor targeting and dosimetry predict therapeutic response?
UNLABELLED: A DOTA (1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid)-conjugated, (111)In- and (90)Y-labeled humanized antibody to CD22, epratuzumab, was studied in patients with non-Hodgkin's lymphoma (NHL) to assess biodistribution and tumor targeting, pharmacokinetics, dosimetry, and anti-antibody response. Of particular interest was to evaluate whether pretherapy targeting and tumor dosimetry could predict therapeutic responses. METHODS: Patients received a pretherapy imaging study with (111)In-DOTA-epratuzumab IgG (0.75 mg/kg), followed about 1 wk later with (90)Y-DOTA-epratuzumab starting at a dose level of 0.185 GBq/m(2) (5 mCi/m(2)) in patients who had prior high-dose chemotherapy (group 2), and at 0.370 GBq/m(2) in patients who did not have a prior transplant (group 1), with escalation in 0.185-GBq/m(2) increments. RESULTS: The effective blood half-life for (111)In-DOTA epratuzumab was 36.1 +/- 7.9 h (n = 25) compared with 35.2 +/- 7.0 h for (90)Y-DOTA-epratuzumab (n = 22). The whole-body half-life for (90)Y-DOTA-epratuzumab estimated from (111)In-DOTA-epratuzumab scintigraphy was 58.3 +/- 4.7 h (n = 20), with urine collection confirming the loss of between 2.2% and 15.9% of the injected activity over 3 d (n = 3). One-hundred sixteen of 165 CT-confirmed lesions were visualized with (111)In-DOTA-epratuzumab. Radiation-absorbed doses to liver, lungs, and kidneys averaged 0.55 +/- 0.13 (n = 17), 0.28 +/- 0.06 (n = 17), and 0.38 +/- 0.07 mGy/MBq (n = 10), respectively, with 0.14 +/- 0.02 and 0.23 +/- 0.04 mGy/MBq delivered to the whole-body and red marrow, respectively. Tumor doses (n = 14 lesions in 10 patients) ranged from 1.0 to as much as 83 mGy/MBq for a 0.5-g lesion (median, 7.15 mGy/MBq). Group 2 patients were more likely to experience significant hematologic toxicities, but doses of up to 0.370 GBq/m(2) of (90)Y-DOTA-epratuzumab were tolerated with standard support measures, whereas patients in group 1 tolerated doses of up to 0.740 GBq/m(2) with the potential for further escalation. Anti-tumor effects were seen in both indolent and aggressive NHL. The data also suggest that anti-tumor responses of potentially equal magnitude can occur irrespective of tumor targeting and tumor size. Hence, tumor response did not correlate with the radiation dose delivered or with the tumor being visualized by external imaging. An anti-antibody response to epratuzumab was detected by an enzyme-linked immunosorbent assay in only 2 of 16 patients. CONCLUSION: These results suggest that (90)Y-DOTA-epratuzmab is a promising agent for the treatment of NHL and warrants further study. There was evidence suggesting that in this system, factors other than tumor radiation dose and targeting may be involved in the success of radioimmunotherapy.
Adult↗
Radiologic diagnosis of brain death.
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Adult↗
Use of a corrected standardized uptake value based on the lesion size on CT permits accurate characterization of lung nodules on FDG-PET.
The purpose of this study was to determine the actual standardized uptake value (SUV) by using the lesion size from computer tomography (CT) scan to correct for resolution and partial volume effects in positron emission tomography (PET) imaging. This retrospective study included 47 patients with lung lesions seen on CT scan whose diagnoses were confirmed by biopsy or by follow up CT scan when the PET result was considered negative for malignancy. Each lesion's FDG uptake was quantified by the SUV using two methods: by measuring the maximum voxel SUV (maxSUV) and by using the lesion's size on CT to calculate the actual SUV (corSUV). Among small lesions (2.0 cm or smaller on CT scan), ten were benign and 17 were malignant. The average maxSUV was 1.43+/-0.77 and 3.02+/-1.74 for benign and malignant lesions respectively. When using an SUV of 2.0 as the cutoff to differentiate benignity and malignancy, the sensitivity, specificity, and accuracy were 65%, 70%, and 67% respectively. When an SUV of 2.5 was used for cutoff, the sensitivity, specificity, and accuracy were 47%, 80%, and 59% respectively. The average corSUV was 1.65+/-1.09 and 5.28+/-2.71 for benign and malignant lesions respectively. Whether an SUV of either 2.0 or 2.5 was used for cutoff, the sensitivity, specificity, and accuracy remained 94%, 70%, and 85% respectively. The only malignant lesion that was falsely considered benign with both methods was a bronchioalveolar carcinoma which did not reveal any elevated uptake of fluorine-18 fluorodeoxyglucose (FDG). Of the large lesions (more than 2.0 cm and less than 6.0 cm), one was benign and 19 were malignant and the corSUV technique did not significantly change the accuracy. It is concluded that measuring the SUV by using the CT size to correct for resolution and partial volume effects offers potential value in differentiating malignant from benign lesions in this population. This approach appears to improve the accuracy of FDG-PET for optimal characterization of small lung nodules.
Adult↗
Persistent non-specific FDG uptake on PET imaging following hip arthroplasty.
Hip arthroplasty is a common surgical procedure, but the diagnosis of infection associated with hip arthroplasty remains challenging. Fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) has been shown to be a promising imaging modality in settings where infection is suspected. However, inflammatory reaction to surgery can result in increased FDG uptake at various anatomic locations, which may erroneously be interpreted as sites of infection. The purpose of this study was to assess the patterns and time course of FDG accumulation following total hip replacement over an extended period of time. Firstly, in a prospective study nine patients with total hip replacement were investigated to determine the patterns of FDG uptake over time. Three FDG-PET scans were performed in each patient at about 3, 6 and 12 months post arthroplasty. Secondly, in a retrospective analysis, the medical and surgical history and FDG-PET imaging results of 710 patients who had undergone whole-body scans for the evaluation of possible malignant disorders were reviewed. The history of arthroplasty and FDG-PET findings in the hip region were reviewed for this study. Patients with symptomatic arthroplasties or related complaints during FDG-PET scanning were excluded from the analysis. During the entire study period, all nine patients enrolled in the prospective study were demonstrated to have increased FDG uptake around the femoral head or neck portion of the prosthesis that extended to the soft tissues surrounding the femur. Among the patients reviewed in the retrospective study, 18 patients with a history of 21 hip arthroplasties who were asymptomatic at the time of FDG-PET scan met the criteria for inclusion. The time interval between the hip arthroplasty and the FDG-PET study ranged from 3 months to 288 months (mean+/-SD: 80.4+/-86.2 months). In 81% (17 of 21) of these prostheses, increased FDG uptake could be noted around the femoral head or neck portion of the prosthesis. The average time interval between arthroplasty and FDG-PET scan in these patients was 71.3 months. In only four prostheses (19%, 4 of 21) was no abnormally increased FDG uptake seen around the prostheses or adjacent sites. The average time interval in these patients was 114.8 months. It is concluded that following hip arthroplasty, non-specifically increased FDG uptake around the head or neck of the prosthesis persists for many years, even in patients without any complications. Therefore, to minimize the number of false-positive results for infection with PET studies obtained to evaluate a painful hip prosthesis, caution should be exercised when interpreting FDG uptake around the head or neck portion of the prosthesis.
Arthroplasty, Replacement, Hip↗
Subareolar and peritumoral injection identify similar sentinel nodes for breast cancer.
BACKGROUND: Sentinel lymph node (SLN) mapping with radioisotope and blue dye is rapidly becoming the standard of care for breast cancer. The optimal location for injection of radioisotope and blue dye is still being investigated. The goal of this study was to determine whether blue dye injection into the subareolar (SA) location localized the same sentinel nodes as the peritumoral (PT) location for patients with breast cancer. METHODS: Three hundred thirty-two patients with biopsy-proven operable breast cancer or ductal carcinoma in situ at two institutions underwent SLN mapping. Eighty-three patients had PT injection of blue dye (group 1), and 249 patients had SA injection of blue dye (group 2). All patients underwent PT injection of (99m)Tc-labeled sulfur colloid. RESULTS: The two groups were similar in age, previous biopsy type, and tumor size, location, and histology. The mean number of SLNs identified was 2.4 (range, 0-9) in group 1 and 2.5 (range, 0-11) in group 2. The SLN identification rate was 95% for group 1 and 97% for group 2. The isotope success rate was 94% for both groups. The blue dye success rate was 84% for group 1 and 90% for group 2. The isotope/blue dye concordance rate was 87% for group 1 and 90% for group 2. At a median follow-up of 28 months (range, 14 to 40), there were no axillary recurrences in any of the 332 patients. CONCLUSIONS: These data suggest that delivery of mapping reagents in the SA and PT locations identifies similar lymph nodes. Because of simplicity and the similarity in node identification between SA and PT injection, further investigation of the SA site for delivery of SLN mapping reagents for breast cancer is warranted.
Adult↗
Disturbed visual processing contributes to impaired reading in Alzheimer's disease.
The relationship between visual processing dysfunction and oral reading impairment was investigated in 17 patients with probable or possible Alzheimer's disease (AD). When dementia severity was controlled, a significant relationship was found between single word oral reading impairments and difficulties discriminating words written in different fonts and photographs of objects in different orientations, which are all functions believed to be dependent on the integrity of left ventral temporal-occipital visual association regions. By contrast, there was no significant relationship between reading performance and the score on a test of spatial localization, believed to be more dependent on parietal lobe function. There was also no relationship between reading ability and discrimination of unfamiliar faces, a function thought to engage right inferotemporal lobe structures. In contrast to the significant association between impaired reading and certain visual processes, when dementia severity was controlled, there was no relationship between reading and lexical semantic impairment. These results highlight the contribution of visual processing deficits to impaired oral reading in AD and further suggest that this association may derive from neuropathological changes in areas of the left temporal occipital lobes specialized for high-level visual processing.
Aged↗