Search PubMed⌕ Search

Biomedical subjects

Hongming Zhuang

Publications and source records attributed to Hongming Zhuang.

At least 55 records · Page 3Linked to original sources
PubMed2004

Implications of PET based molecular imaging on the current and future practice of medicine.

The last quarter century has witnessed the introduction of a variety of powerful techniques that have allowed visualization of organ structure and function with exquisite detail. This in turn has brought about a true revolution in the day-to-day practice of medicine. Structural imaging with x-ray computerized tomography and magnetic resonance imaging has added tremendously to many areas of medicine, including preoperative evaluation of patients. Many surgical procedures have been replaced by minimally invasive techniques, which have become a reality only because of the availability of modern imaging modalities. However, despite such accomplishments, structural imaging is quite insensitive for detecting early disease in which there often are no gross structural alterations in organ anatomy. Therefore, these modalities should be complemented by methodologies that can detect abnormalities at the molecular and cellular levels. The introduction of [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) in 1976 as a molecular imaging technique clearly has shown the power of this approach for treating a multitude of serious disorders. The impact of FDG-PET has been particularly impressive in patients with cancer diagnosis, for whom it has become important in staging, monitoring response to treatment, and detecting recurrence. In this review, we emphasize the role of FDG-PET in the assessment of central nervous system maladies, malignant neoplastic processes, infectious and inflammatory diseases, and cardiovascular disorders. New radiotracers are being developed and promise to expand further the list of indications for PET. These include novel tracers for cancer diagnosis and treatment capable of detecting hypoxia and angiogenesis. Prospects for developing new tracers for imaging other organ diseases also appear very promising.

Animals↗
PubMed2004

Evolving role of positron emission tomography in the management of patients with inflammatory and other benign disorders.

Fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) has evolved from a research imaging modality assessing brain function in physiologic and pathologic states to a pure clinical necessity. It has been successfully used for diagnosing, staging, and monitoring a variety of malignancies. FDG-PET imaging also is evolving into a powerful imaging modality that can be effectively used for the diagnosis and monitoring of a certain nononcological diseases. PET has been shown to be very useful in the diagnosis of osteomyelitis, painful prostheses, sarcoidosis, fever of unknown etiology, and acquired immunodeficiency syndrome. Based on recent observations, several other disorders, such as environment-induced lung diseases, atherosclerosis, vasculitis, back pain, transplantation, and blood clot, can be successfully assessed with this technique. With the development and the introduction of several new PET radiotracers, it is expected that PET will secure a major role in the management of patients with inflammatory and other benign disorders.

Bacterial Infections↗
PubMed2004

Spontaneous regression of follicular, mantle cell, and diffuse large B-cell non-Hodgkin's lymphomas detected by FDG-PET imaging.

Spontaneous regression of non-Hodgkin lymphoma (NHL) has been reported in low-grade tumors but is an extremely rare event in intermediate- and high-grade disease. Documentation of spontaneous regression by serial fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging has not been reported in the literature. We present 3 cases of spontaneous regression, 1 each of follicular lymphoma (FL), mantle cell lymphoma (MCL), and diffuse large B-cell lymphoma (DLBCL), which showed spontaneous regression on serial FDG-PET imaging. All patients underwent serial whole-body FDG-PET scans 60 minutes after intravenous injection of 9-11 mCi of this radiotracer. None of them had any chemotherapy, radiotherapy, or surgery after the baseline PET scan. Spontaneous regression of disease in all 3 cases was correlated with conventional imaging and clinical course. All 3 patients had positive FDG-PET results on their baseline scan. There was complete disappearance of FDG uptake on a follow-up PET scan for the patient with follicular lymphoma. These results suggest complete regression. The patients with MCL and DLBCL both showed a significant reduction in FDG uptake on serial whole-body PET scans, suggesting partial regression in both cases. Although spontaneous regression of lymphoma is uncommon, this phenomenon can be successfully demonstrated by FDG-PET imaging. Therefore, serial PET imaging may play an important role in detecting this unusual event and may further enhance our understanding of the biologic behavior of this malignancy.

Aged↗
PubMed2004

Clinical validation of fully 3-D versus 2.5-D RAMLA reconstruction on the Philips-ADAC CPET PET scanner.

INTRODUCTION: Fully three-dimensional (3-D) reconstruction algorithms have the potential to better utilize PET data acquired in true 3-D acquisition modes, as compared to 2-D approaches involving data reduction through rebinning procedures followed by a 2-D or 2.5-D reconstruction. Our previous studies, involving simulated and real phantom data from PET scanners working purely in 3-D acquisition mode, showed that the fully 3-D reconstruction approaches bring appreciable improvement on physical measures and visual image quality as well. Reconstruction procedures utilized in those studies were based upon the row action maximum likelihood algorithm (RAMLA) implemented on our clinical scanners. The purpose of this study was to investigate if the fully 3-D RAMLA reconstruction software brings an appreciable improvement in clinical image quality and reader confidence. MATERIALS AND METHODS: Ninety patient scans acquired on the Philips CPET scanner at our institution were reconstructed using 2.5-D RAMLA and 3-D RAMLA with differing reconstruction parameters. These scans were blindly presented to four experienced PET scan readers who graded various aspects of image quality. RESULTS: Our study concluded that 3-D RAMLA on the CPET scanner reduces artifacts and image noise and improves clinical confidence in interpreting PET images. CONCLUSION: This study led to the routine use of 3-D RAMLA reconstruction on the CPET scanner at our institution.

Algorithms↗
PubMed2004

Catheter-related focal FDG activity on whole body PET imaging.

INTRODUCTION: Whole body FDG positron emission tomography (PET) scan is increasingly being used in the management of a variety of cancers and infections. Cancer patients and other very sick patients have central venous catheters, which could be associated with common complications like thrombosis and infections. We describe catheter-related focal FDG uptake on whole body FDG PET scans in 4 patients. MATERIALS AND METHODS: Four patients underwent whole body FDG-PET scanning 60 minutes after intravenous injection of F18-FDG (2 for localization of site of infection, 1 for primary cancer site localization, and 1 for restaging of colon cancer). The whole body PET images were compared and correlated with the patients' history, radiology and laboratory tests. RESULTS: Focal and intense FDG activity is seen in all 4 patients at the distal end of the intravenous catheter. The average SUV of this activity was 6.3 (n = 3). Catheter-related thrombosis was identified as the cause of FDG activity in 3 patients, whereas catheter-related infection was considered in one patient. CONCLUSION: Focal and intense FDG activity, in relation to the distal end of a central venous catheter, has a benign etiology, usually seen with catheter-related venous thrombosis and can be seen with catheter related infection.

Aged↗
PubMed2004

Iatrogenic artifacts on whole-body F-18 FDG PET imaging.

PURPOSE: Whole-body F-18 FDG PET images frequently show artifacts related to medical and surgical interventions. We present some of the common artifact patterns in this atlas article. MATERIALS AND METHODS: We studied whole-body F-18 FDG PET images of 30 adult patients (17 males and 13 females). Of these, 9 patients had lymphoma, 7 had colon cancer, 6 had lung cancer, 3 had lung nodules, 2 each had breast and bladder cancer, and 1 patient had brain cancer. All patients had a history of some surgical or medical intervention for malignant or some other associated disease. RESULTS: PET images of 8 patients showed artifacts related to implanted prostheses and ports and 9 patients showed artifacts related to percutaneous insertion or opening of catheters, tubes, and stomas. Six patients had artifacts from previous surgery, 3 from previous radiation therapy, 3 from previous chemotherapy, and 1 from changes in glucose metabolism. CONCLUSIONS: Medical and surgical interventions can give rise to artifacts on whole-body F-18 FDG PET images. The possibilities and patterns of these artifacts should be kept in mind while reporting these studies.

Adult↗
PubMed2004

Is 18F-FDG PET more accurate than standard diagnostic procedures in the detection of suspected recurrent melanoma?

UNLABELLED: The aim of this study was to determine the accuracy of (18)F-FDG PET in detecting recurrent melanoma. METHODS: PET findings were compared with those obtained by standard diagnostic clinical procedures (CP) to establish the role of PET in the management of patients with melanoma. From 156 patients with confirmed melanoma and recurrence suspected by clinical examination, 184 PET scans were retrospectively reviewed. Histology or clinical follow-up was used for final diagnosis. RESULTS: The sensitivity and specificity of PET for detecting lesions on an individual-patient basis were 74% and 86%, respectively, compared with respective values of 58% and 45% for CP alone. The overall accuracy for PET was 81%, compared with 52% for other methods. PET was more accurate (91% vs. 67%) than CP in detecting locoregional disease and distant metastases (85% vs. 55%), and PET results led to a change in the planned clinical management of 36% of patients included in this study. PET was more accurate than CT in detecting skin lesions, malignant lymph nodes, and metastases to the abdomen, liver, and bone. In the assessment of pulmonary disease, PET showed higher specificity (92% vs. 70%) than CT for the detection of lung parenchyma lesions; however, the sensitivity was better for CT (93%) than for PET (57%). CONCLUSION: PET is better than CP in detecting locoregional disease and distant metastases in all sites except the lung, where it appears to be a useful adjunct to CT. The use of PET as a routine clinical tool can lead to a substantial change in the clinical management of suspected recurrent melanoma.

Abdominal Neoplasms↗
PubMed2004

18F-FDG PET for evaluation of the treatment response in patients with gastrointestinal tract lymphomas.

UNLABELLED: (18)F-FDG PET is highly sensitive and specific for evaluation of the treatment response of nodal and extranodal diseases in patients with malignant lymphomas. However, no data are available in the literature with regard to (18)F-FDG PET for evaluation of the treatment response in patients with lymphomas with gastrointestinal tract (GIT) involvement. This study was undertaken to investigate the usefulness of (18)F-FDG PET in monitoring the response to the treatment of lymphomas in this setting. METHODS: We retrospectively analyzed 19 patients with different types of lymphomas (10 diffuse large B-cell lymphomas, 4 follicular lymphomas, 3 mantle cell lymphomas, and 2 Hodgkin's disease) involving GIT. Among 19 patients, 4 had gastric involvement, 13 had small bowel involvement, and 2 had small bowel plus colon involvement by lymphomas. All patients underwent (18)F-FDG PET before and after the completion of therapy. The results of (18)F-FDG PET were compared with the results of CT and clinical outcome; the presence of relapse was determined on the basis of positive biopsy results or clinical follow-up data. RESULTS: Of the 19 posttreatment PET scans, 13 showed no pathologic (18)F-FDG uptake, whereas 6 showed persistent (18)F-FDG uptake. Among the 13 patients who had negative PET scans, only 1 patient (7.7%) relapsed, whereas all 6 patients (100%) who had persistent abnormal (18)F-FDG uptake on posttherapy PET scans relapsed. Posttreatment CT scans were negative for 10 patients but showed persistent disease in the remaining 9 patients. Among the 10 patients who had negative CT scans, 9 remained in remission and 1 (10%) relapsed. Of the 9 patients who showed persistent disease, 6 (67%) relapsed and 3 (33%) remained in remission after the mean follow-up of 20 mo. The sensitivity, specificity, positive and negative predictive values, and accuracy of posttherapy (18)F-FDG PET were 86%, 100%, 100%, 92%, and 95%, respectively. The corresponding values for CT were 67%, 75%, 75%, 90%, and 79%, respectively. Patients with positive (18)F-FDG PET results had statistically significantly lower disease-free survival (DFS) (0%) than did those with positive CT results (33%) (P = 0.04). There was no statistically significant difference in DFS between patients with negative (18)F-FDG PET results and patients with negative CT results. CONCLUSION: A positive (18)F-FDG PET scan after the completion of chemotherapy in patients with lymphomas with GIT involvement is a strong predictor of relapse. (18)F-FDG PET has higher diagnostic accuracy than CT in the detection of residual disease after therapy. Despite the mild physiologic (18)F-FDG uptake in the GIT, (18)F-FDG PET has potential value in monitoring the response to treatment in patients with GIT lymphomas, particularly when pretreatment PET results are positive.

Adult↗
PubMed2004

18F-FDG PET in evaluation of adrenal lesions in patients with lung cancer.

UNLABELLED: The purpose of this study was to assess the role of PET with (18)F-FDG in differentiating benign from metastatic adrenal masses detected on CT or MRI scans of patients with lung cancer. METHODS: This retrospective study analyzed (18)F-FDG PET scans of patients with lung cancer who were found to have an adrenal mass on CT or MRI scans. One hundred thirteen adrenal masses (75 unilateral and 19 bilateral; size range, 0.8-4.7 cm) were evaluated in 94 patients. PET findings were interpreted as positive if the (18)F-FDG uptake of the adrenal mass was greater than or equal to that of the liver. PET findings were interpreted as negative if the (18)F-FDG uptake of the adrenal mass was less than that of the liver. All studies were reviewed independently by 3 nuclear medicine physicians, and the results were then correlated with clinical follow-up or biopsy results when available. RESULTS: PET findings were positive in 71 adrenal masses. Sixty-seven of these were eventually considered to be metastatic adrenal disease. In the remaining 4, no changes in lesion size were noted on follow-up examinations. PET findings were negative in 42 adrenal masses, of which 37 eventually proved to be benign. Among the 5 adrenal masses that were false-negative, one was a large necrotic metastasis; 1 was a 2.4-cm lesion with central hemorrhaging, and the remaining 3 were lesions of less than 11 mm. The sensitivity, specificity, and accuracy for detecting metastatic disease were 93%, 90%, and 92%, respectively. CONCLUSION: (18)F-FDG PET is an accurate, noninvasive technique for differentiating benign from metastatic adrenal lesions detected on CT or MRI in patients with lung cancer. In addition, PET has the advantage of assessing the primary cancer sites and detecting other metastases.

Adrenal Gland Neoplasms↗
PubMed2003

Rapid normalization of osseous FDG uptake following traumatic or surgical fractures.

It is known that following a traumatic fracture or surgical intervention, bone scintigraphy reveals positive results for an extended period of time, posing a challenge when evaluating patients for possible malignancy or superimposed osteomyelitis. Previous reports indicate that acute fractures can also result in increased fluorine-18 fluorodeoxyglucose (FDG) accumulation and therefore cause difficulties when patients are evaluated for other indications by FDG-PET. The purpose of this study was to assess the pattern and time course of abnormal FDG uptake following traumatic or surgical fracture. A total of 1,517 consecutive patients who underwent whole-body FDG-PET imaging were retrospectively studied. A history of fractures or orthopedic intervention was obtained from an interview prior to scanning. The FDG-PET results were compared with the results of other imaging studies, including bone scans, radiographs, CT, and MRI, as well as surgical pathology reports. Thirty-seven patients with a known date of traumatic or surgical fracture were identified. Among these, 14 had fractures or surgery within 3 months prior to FDG-PET, while 23 had fractures or surgical intervention greater than 3 months prior to FDG-PET. FDG-PET showed no abnormally increased uptake at the known fracture or surgical sites in 30 of these patients. Notably, in the 23 patients with fractures more than 3 months old, all but one showed no abnormally increased uptake. Furthermore, the positive FDG uptake in this exception was a result of complicating osteomyelitis. In the 14 patients with a history of fracture less than 3 months old, only six had abnormally increased FDG uptake. Following traumatic or surgical fractures, FDG uptake is expected to be normal within 3 months unless the process is complicated by infection or malignancy.

Adult↗