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R B Noto

Publications and source records attributed to R B Noto.

15 recordsLinked to original sources
PubMed2001

Pre-operative localization of parathyroid adenomas: a comparison of power and colour Doppler ultrasonography with nuclear medicine scintigraphy.

AIM: To compare power and colour Doppler ultrasonography (US) with nuclear medicine scintigraphy (NM) in the preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). MATERIALS AND METHODS: Thirty-one patients with biochemical evidence of PHPT underwent pre-operative US and NM for parathyroid adenoma localization. Both studies were interpreted independently without prior knowledge of the other study's findings. All patients had surgical removal of the parathyroid adenoma utilizing standard neck exploration or minimally invasive unilateral surgical techniques with rapid serum assay of circulating parathyroid hormone levels. RESULTS: All patients had single parathyroid adenomas at surgery. Prospective sensitivities for US, NM and both studies combined were 65%, 68%, and 74%, respectively, with a positive predictive value of 100% each. The adenoma was localized by only one imaging modality in 16% of cases. CONCLUSIONS: US and NM provide complementary roles in the pre-operative localization of parathyroid adenomas in patients with PHPT.

Adenoma↗
PubMed2001

Thyroid storm in a child following radioactive iodine (RAI) therapy: a consequence of RAI versus withdrawal of antithyroid medication.

A 7.5-yr-old boy with Graves' disease, difficult to control with antithyroid medication and radioactive iodine (RAI) therapy, developed thyroid storm encephalopathy on day 13 after withdrawal of methimazole therapy, 4 days after iodine-131 treatment. We attributed his thyroid storm to withdrawal of antithyroid medication as opposed to RAI therapy. We interpret this case as indicating that there may be a need to reevaluate the duration of antithyroid medication withdrawal before RAI therapy for hyperthyroid children at increased risk for thyroid storm.

Antithyroid Agents↗
PubMed1999

Advances in nuclear medicine: current concepts.

As described above, many scintigraphic studies have recently become available which provide vital clinical information in a wide variety of diseases. The future of nuclear medicine also appears bright. Modifications to current gamma cameras will likely occur in the next few years to replace sodium iodide crystals with new scintillators like oxyorthosilicates which have better imaging characteristics for both single photon and positron-emitting radionuclides. Ongoing computer improvements will allow improved reconstruction and processing with newer systems already capable of advanced iterative reconstruction algorithms. Development of new radiopharmaceuticals is progressing at a rapid pace, with emphasis on new tracers that can provide information about diseases at the molecular level, such as receptor imaging agents. In addition, radiolabeled tracers for therapeutic purposes will continue to progress, including monoclonal antibodies labeled with beta emitters. Overall, nuclear medicine will continue to evolve in many new directions and provide useful functional imaging data about a variety of different organ systems and diseases.

Angioplasty, Balloon, Coronary↗
PubMed1996

Apathy and loss of insight in Alzheimer's disease: a SPECT imaging study.

Apathy and loss of insight as correlates of behavior in Alzheimer's disease (AD) were studied in 40 patients by using clinical scales and cerebral blood flow measurements from SPECT imaging. Apathy was significantly correlated with decreased right temporoparietal perfusion and problem behaviors. Loss of insight was significantly correlated with decreased right temporo-occipital perfusion and impairment in daily functioning. Dementia severity as measured by the Mini-Mental State Examination (MMSE) was a poor predictor of behavioral problems or daily functioning. These data suggest that global measures of cognitive ability, which are weighted toward measuring left hemisphere function, are less important as indicators of management problems in AD than are measures of right hemisphere function such as motivation and insight.

Activities of Daily Living↗
PubMed1996

Single-photon emission CT in the evaluation of recurrent brain tumor in patients treated with gamma knife radiosurgery or conventional radiation therapy.

PURPOSE: To differentiate radiation necrosis from tumor recurrence using single-photon emission CT (SPECT). METHODS: Forty-two thallium-201 SPECT scans were obtained in 33 adult patients. All patients had previously been treated with either conventional external-beam radiation therapy (XRT) (26 patients) or gamma knife radiosurgery (16 patients) and had subsequent contrast-enhanced MR examinations before nuclear medicine imaging. Patients were injected intravenously with 4 mCi of thallous chloride Tl 201 with rapid acquisition of SPECT scans thereafter. Findings on thallium-201 SPECT scans were categorized as either positive or negative on the basis of an abnormal focus of increased activity in the area of the known lesion. Evaluation of the accuracy of the thallium-201 SPECT scan was made by correlation with subsequent histologic or cytologic analysis (28 cases) or, in cases in which biopsy was not performed, by subsequent clinical course or MR findings (14 cases). RESULTS: For all patients in this series, the sensitivity and specificity of thallium-201 SPECT scans in detecting tumor recurrence were 94% and 63%, respectively. The sensitivity and specificity for patients who had been treated with XRT were 95% and 60%, respectively. The sensitivity and specificity for patients who had been treated with gamma knife therapy were 92% and 67%, respectively. Tumor/scalp (T/S) ratios were calculated for all patients. High T/S ratios (> 2.0) had a positive predictive value for tumor recurrence of 92%. T/S ratios less than 0.5 had a negative predictive value for tumor recurrence of 83%. CONCLUSION: Thallium-201 SPECT is a sensitive and accurate test to differentiate tumor recurrence from radiation necrosis in a population of patients with abnormal MR findings. This technique was equally efficacious in patients who had undergone gamma knife radiosurgery and in those who had received XRT.

Adult↗
PubMed1994

Tc-99m MDP uptake in osteopoikilosis.

A Tc-99m bone scan of a patient with classic roentgenographic findings of osteopoikilosis revealed multiple foci of increased activity that corresponded to many of the sclerotic foci on the roentgenograms. The authors presume that the abnormal bone scan in this patient reflects active osseous remodeling, similar to what has been observed in bone islands. Previous reports have emphasized the critical role of the radionuclide bone scan for distinguishing osteopoikilosis from osteoblastic bone metastases in patients with a known or suspected primary malignancy. In a young patient, an abnormal bone scan does not exclude the diagnosis of osteopoikilosis if the roentgenographic findings are characteristic of that entity.

Adult↗
PubMed1991

Diagnosis and management of the infected total joint arthroplasty.

The preoperative diagnosis of the infected orthopedic implant is complicated by lack of a single precise test to forewarn patient and surgeon of the presence of microorganisms. Given the overall limitation of accuracy of preoperative diagnosis to approximately 80% when 111In scanning, preoperative aspiration, and ESR are considered, it would seem prudent to approach each revision surgery with the possibility in mind of subclinical sepsis as the cause for failure of the implant. The essentials of surgical technique including thorough debridement of the wound and removal of all existing foreign bodies, especially including PMMA bone cement, are critical to minimizing the risk for occurrence or persistence of sepsis. Although the use of antibiotic impregnated bone cement may enhance the treatment of orthopedic sepsis, the data available to date lead to the conclusion that two-stage revision surgery in the face of known sepsis remains the cornerstone of surgical therapy for the infected implant, along with aggressive and rational antibiotic treatment. The surgeon is offered the following guidelines in the management of the septic total hip arthroplasty. 1. Preoperative evaluation including ESR, 111In WBC scan, and aspiration for culture and sensitivity (fluoroscopically guided for the hip) will produce on average approximately 80% accuracy. 2. Intraoperative cultures at the time of revision surgery should be obtained prior to administration of systemic antibiotics; three tissue specimens (hip capsule, femoral membrane, acetabular membrane) should be submitted for culture and sensitivity determination. 3. Careful debridement of the surgical site of granulation tissue and all foreign bodies (e.g., PMMA) should be performed within the limits of patient safety to maximize the likelihood of success.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

State-of-the-art adrenal imaging.

The adrenal gland is a common site of disease, and detection of adrenal masses has increased with the expanding use of cross-sectional imaging. Radiology is playing a critical role in not only the detection of adrenal abnormalities but in characterizing them as benign or malignant. The purpose of the article is to illustrate and describe the appropriate radiologic work-up for diseases affecting the adrenal gland. The work-up of a suspected hyperfunctioning adrenal mass (pheochromocytoma and aldosteronoma) should start with appropriate biochemical screening tests followed by thin-collimation computed tomography (CT). If results of CT are not diagnostic, magnetic resonance (MR) and nuclear medicine imaging examinations should be performed. CT has become the study of choice to differentiate a benign adenoma from a metastasis in the oncology patient. If the attenuation of the adrenal gland is over 10 HU at nonenhanced CT, contrast material-enhanced CT should be performed and washout calculated. Over 50% washout of contrast material on a 10-minute delayed CT scan is diagnostic of an adenoma. For adrenal lesions that are indeterminate at CT in the oncology patient, chemical shift MR imaging or adrenal biopsy should be performed. Certain features can be used by the radiologist to establish a definitive diagnosis for most adrenal masses (including carcinoma, infections, and hemorrhage) based on imaging findings alone.

Adrenal Gland Diseases↗
PubMedDate not supplied

A single-photon emission computed tomography imaging study of driving impairment in patients with Alzheimer's disease.

Single-photon emission computed tomography (SPECT) was used in this study to examine the neurophysiologic basis of driving impairment in 79 subjects with dementia. Driving impairment, as measured by caregiver ratings, was significantly related to regional reduction of right hemisphere cortical perfusion on SPECT, particularly in the temporo-occipital area. With increased severity of driving impairment, frontal cortical perfusion was also reduced. Clock drawing was more significantly related to driving impairment than the Mini-Mental State Examination (MMSE). Driving impairment in Alzheimer's disease is related to changes in cortical function which vary according to the severity of the disease. Cognitive tests of visuoperceptual and executive functions may be more useful screening tools for identifying those at greatest risk for driving problems than examinations like the MMSE that are weighted toward left-hemisphere-based verbal tasks.

Activities of Daily Living↗
PubMedDate not supplied

A SPECT imaging study of MRI white matter hyperintensity in patients with degenerative dementia.

We investigated the correlation between cortical perfusion and white matter hyperintensities on magnetic resonance images (MRI) of patients with dementia. The study included 40 subjects, each of whom had undergone both MRI and single-photon emission computed tomography (SPECT) studies as part of their diagnostic evaluation for degenerative dementia. Two neuroradiologists rated the MRI films for severity of periventricular white matter changes on a 0-5 point scale and severity of subcortical white matter changes on a 0-4 point scale. Twelve regions of interest from association cortex were sampled for the semiquantitative analysis of SPECT images. No relationship was found between these global MRI ratings and semiquantitative or qualitative SPECT findings. Dementia severity as measured by the Mini-Mental State Examination and the Clinical Dementia Rating was significantly correlated with SPECT, whereas age was significantly correlated with MRI ratings, particularly in the periventricular regions. These data support the view that cortical SPECT abnormalities are not associated with global MRI abnormalities in the subcortical and periventricular regions of patients with a clinical picture of degenerative dementia.

Aged↗
PubMedDate not supplied

Lateralized cortical perfusion in women with Alzheimer's disease.

OBJECTIVE: To define the pathophysiologic substrate of gender differences in cognition and behavior in Alzheimer's disease (AD). DESIGN: Hemispheric regional cerebral blood flow (rCBF) was studied in a consecutive series of dementia patients using single photon emission computed tomography (SPECT). PARTICIPANTS: Subjects included 300 outpatients who were studied with SPECT as part of a diagnostic evaluation for degenerative dementia or memory disorder. METHOD: Based on qualitative descriptions by a radiologist, subjects were classified as having unilateral left, unilateral right, bilateral, or no perfusion defects. Semiquantitative analysis of SPECT images was also performed using region of interest radionuclide counts normalized to the cerebellum. RESULTS: Among 174 females and 126 males, unilateral left hemisphere defects were found more commonly in women than men (24% vs 10%; chi 2 = 9.4; P = .009). This observation was most significant for the 103 females and 62 males regarded as having probable AD (26% vs 8%; chi 2 = 9.3; P = .01). In a multiple regression model of clinical variables, shorter duration of disease and female gender were significant independent predictors of the unilateral left hemisphere pattern among those with probable AD. Age, family history, education, handedness, and severity of cognitive impairment were not significant contributors. CONCLUSIONS: Women with AD exhibit greater heterogeneity in rCBF than men. Asymmetry in rCBF occurs more often in women. In some cases, this is related to relative preservation of right hemisphere function in women.

Aged↗
PubMedDate not supplied

Is altropane SPECT more sensitive to fluoroDOPA PET for detecting early Parkinson's disease?

BACKGROUND: Positron emission tomography (PET) cameras are expensive and scarce, and the tests are non-reimbursable. A less costly and more available test such as a single photon emission computed tomography (SPECT) may be helpful in the diagnosis of early or atypical Parkinson's disease (PD) if its sensitivity is comparable to a PET scan. Altropane is an iodinated form of the N-allyl analog of WIN 35,428 which acts as a dopamine transport inhibitor. When radiolabeled with the gamma emitting isotope [123I], altropane serves as a SPECT ligand with high affinity and selectivity for the dopamine transporter. It is a good marker for dopamine neurons and is useful in detecting PD. MATERIAL AND METHODS: We describe 2 patients with typical, early PD and their [123I]-altropane SPECT and [18F]-6-flouroDOPA PET scan results which were performed within a three-month interval. PET studies were performed using a PC-4096 scanner (Scanditronix AB, Sweden) with 15 axial slices and resolution of 6 mm FWHM. The SPECT acquisitions were performed on a MultiSPECT gamma camera (Siemens, Hoffman Estates, IL) equipped with fan-beam collimators with an intrinsic resolution of 4.6 FWHM (for Case 1) and a DSI Ceraspect camera with an annular crystal, with resolution of approximately 6.4 mm FWHM (for Case 2). RESULTS: Both patients, aged 54 and 38 years, had a one-year history of intermittent right hand tremor with right arm rigidity and hypokinesia and bradykinesia on fine finger movements. A significant and sustained improvement of their parkinsonian symptoms was noted using a dopamine agonist. SPECT and PET scans showed non-diagnostic fluoroDOPA PET scans with clear unilateral striatal reduction of tracer uptake contralateral to their parkinsonian side on altropane SPECT scans. CONCLUSIONS: Altropane SPECT may be an accessible and sensitive imaging modality for detecting early PD. Further and more controlled studies are needed to define its potential role in detecting presymptomatic, early and atypical PD cases.

Adult↗