Technetium-99m-sestamibi scintigraphy: an alternative approach for diagnosis and follow-up of active myeloma lesions after high-dose chemotherapy and autologous stem cell transplantation

Technetium-99m-sestamibi (MIBI) is a radionuclide tracer taken up by different malignant tumors. A total of 88 MIBI scans were carried out in 20 individuals with monoclonal gammopathy of unknown significance (MGUS) and 10 patients during follow-up for other cancers. Of these 58 MIBI scans were carried out in 46 myeloma patients: 15 at diagnosis, 14 during conventional chemotherapy, and 29 following high-dose sequential therapy and autologous peripheral blood progenitor support. A positive MIBI scan was exhibited by lof 10 with non-myeloma cancers and 2 of 20 with MGUS. In contrast, all stage II and III multiple myelomas (MM) were positive at diagnosis. Therefore, the sensitivity of the MIBI scan at diagnosis was 100%, whereas the specificity in this cohort was 93%. Four different MIBI patterns could be distinguished in MM patients: physiological, focal, diffuse, and extramedullary uptakes. In comparison to conventional skeletal radiographs, MIBI scans recognized a higher number of myeloma lesions at diagnosis. MIBI scans remained positive in all patients during conventional chemotherapy, and there was a direct correlation between MIBI result and clinical outcome of patients following high-dose therapy. Eighteen patients had a negative MIBI scan: 9 were in complete remission (CR), 8 in partial remission (PR), and 1 had progressive disease. Eleven patients showed lesions on the MIBI scan: 4 were in PR, 5 had progressive disease, 1 had a minimal response, and only 1 was in CR. A diffuse MIBI pattern reflected a higher bone marrow plasma cell number. In five patients, histologically or cytologically verified soft tissue myeloma lesions were correctly diagnosed by MIBI scan, while all plain radiographs showed none of them. MIBI has proven to be an effective tool in diagnosing biologically active myeloma.     

Tc99m-sestaMIBI uptake in nonsecretory multiple myeloma

Staging and monitoring of multiple myeloma (MM) is mainly based on monoclonal component quantification; the absence of such a parameter renders difficult follow up of patients with nonsecretory MM (nsMM). In this study our aims were to determine the specificity and sensitivity of Tc99m-sestaMIBI scintigraphy at diagnosis and during follow up of nsMM patients. Nine nsMM patients were prospectively studied at diagnosis and during treatment for a mean time of 33 months (range: 12–65 +). Tc99m-sestaMIBI (MIBI) scintigraphy was compared to conventional imaging (CI: X ray with CAT or NMR details) at diagnosis and during follow up. At diagnosis, CI and MIBI were concordant in three patients; CI showed more focal lesions than MIBI in four patients, while MIBI revealed more focal lesions than CI in two patients. During the follow up, MIBI uptake was normal in the four patients who achieved remission. Five patients did not achieve remission: CI and MIBI were concordant in three, while MIBI was falsely negative in two patients. In conclusion, Tc99m-sestaMIBI scintigraphy has high sensitivity (no false positive cases) and 78% specificity (2/9 false negative cases) in tracing active nsMM lesions; it should be considered complementary to CI for monitoring this rare disease.     

Tc99m-sestaMIBI uptake in nonsecretory multiple myeloma

Staging and monitoring of multiple myeloma (MM) is mainly based on monoclonal component quantification; the absence of such a parameter renders difficult follow up of patients with nonsecretory MM (nsMM). In this study our aims were to determine the specificity and sensitivity of Tc99m-sestaMIBI scintigraphy at diagnosis and during follow up of nsMM patients. Nine nsMM patients were prospectively studied at diagnosis and during treatment for a mean time of 33 months (range: 12-65+). Tc99m-sestaMIBI (MIBI) scintigraphy was compared to conventional imaging (CI: X ray with CAT or NMR details) at diagnosis and during follow up. At diagnosis, CI and MIBI were concordant in three patients; CI showed more focal lesions than MIBI in four patients, while MIBI revealed more focal lesions than CI in two patients. During the follow up, MIBI uptake was normal in the four patients who achieved remission. Five patients did not achieve remission: CI and MIBI were concordant in three, while MIBI was falsely negative in two patients. In conclusion, Tc99m-sestaMIBI scintigraphy has high sensitivity (no false positive cases) and 78% specificity (2/9 false negative cases) in tracing active nsMM lesions; it should be considered complementary to CI for monitoring this rare disease.     

Focal uptake on 18F-fluoro-2-deoxyglucose positron emission tomography images indicates cardiac involvement of sarcoidosis.

AIMS: To evaluate the value of (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET) in detecting cardiac sarcoidosis. METHODS AND RESULTS: Thirty-two patients with sarcoidosis and thirty controls were recruited. All subjects underwent cardiac (18)F-FDG PET after a 6 h fasting period, and subjects with sarcoidosis underwent blood testing, ECG, echocardiography, and (67)Ga and (99m)Tc-sestamibi (MIBI) scintigraphy. We classified (18)F-FDG PET images into four patterns ('none', 'diffuse', 'focal', and 'focal on diffuse') and found that all the control subjects exhibited either none (n=16) or diffuse (n=14) pattern. In contrast, fifteen subjects with sarcoidosis exhibited none, seven exhibited diffuse, eight exhibited focal, and two exhibited focal on diffuse patterns, with the prevalence of the focal and focal on diffuse patterns being significantly higher in the sarcoidosis group when compared with the control group (P<0.001). None of the 32 subjects with sarcoidosis exhibited abnormal findings on (67)Ga scintigraphy, and 4 exhibited abnormal findings on (99m)Tc-MIBI scintigraphy. CONCLUSION: Focal uptake of the heart on (18)F-FDG PET images is a characteristic feature of patients with sarcoidosis. Furthermore, (18)F-FDG PET has the potential to detect cardiac sarcoidosis that cannot be diagnosed by (67)Ga or (99m)Tc-MIBI scintigraphy.     

A comparison of fluorine-18 fluoro-deoxyglucose PET and technetium-99m sestamibi in assessing patients with multiple myeloma

OBJECTIVE: The extent of disease in patients with multiple myeloma or related conditions may be difficult to assess. In previous small studies, both FDG-PET (PET) and Tc-99m sestamibi scans (MIBI) have identified sites of occult disease in myeloma. METHODS: We reviewed the results for patients at our institution who have undergone PET and/or MIBI scans to assess myeloma. Concordance between the scans, ability to identify otherwise occult disease and impact on patient management was assessed. RESULTS: Thirty-six patients had > or =1 PET scan, 56 had > or =1 MIBI scan and 23 had concurrent PET and MIBI scans. MIBI detected additional sites to skeletal survey in 38 of 56 (68%) cases. PET detected additional sites to skeletal survey in 18 of 36 (50%) cases. MIBI generally detected more disease sites than PET. PET and MIBI were concordant in eight of 23 (35%) cases. The percentage plasma cell infiltrate within the marrow correlated with the number of sites detected by MIBI, but not by PET. In 23 of 69 cases (33%), scan results impacted on management, particularly by upstaging disease at diagnosis and by recognising subsequent disease progression. The results were also helpful for evaluating the presence of ongoing disease activity in previously irradiated sites remaining abnormal on skeletal survey following treatment. CONCLUSIONS: MIBI and PET are useful additional diagnostic tools for detecting otherwise occult sites of myeloma. The use of MIBI PET should particularly be considered in the evaluation of a patient with an early-stage plasma cell dyscrasia to exclude the presence of more extensive disease.     

Tc-99m methoxyisobutylisonitrile bone marrow imaging for predicting the levels of myeloma cells in bone marrow in multiple myeloma: correlation with CD38/CD138 expressing myeloma cells

The percentage of myeloma cells in bone marrow is subsequently an important index of disease in patients with multiple myeloma (MM). Bone marrow myeloma cells can be detected by strong CD38/CD138 positivity and light scatter characteristics using flow cytometry. The aim of the study was to evaluate the relationship between the degree of Tc-99m methoxyisobutylisonitrile (MIBI) uptake and the percentage of CD38/CD138 expressing myeloma cells in the bone marrow of patients with MM. A total of 15 patients with MM (mean age: 61.7+/-2.4 years; 7 F and 8 M) were included in the study. Tc-99m MIBI imaging was obtained 20 min after injection of 740 MBq Tc-99m MIBI. Planar spot images of the pelvis and thorax were acquired. The uptake of Tc-99m MIBI in the bone marrow was evaluated using a qualitative and also a semiquantitative scoring system for the bone marrow in areas that included the proximal femurs, anterior iliac crest, and sternum. In all patients, flow cytometry was performed for assessing the percentage of CD38/CD138 expressing myeloma cells in the bone marrow samples. There was a statistically significant positive correlation between the percentage of CD38/CD138 expressing plasma cells in bone marrow and both mean qualitative (r=0.689, p=0.005) and semiquantitative (r=0.669, p=0.006) results of Tc-99m MIBI uptake. In conclusion, our results indicate that increased Tc-99m MIBI uptake of bone marrow is related to the percentage of plasma cell infiltration of bone marrow. Tc-99m MIBI bone marrow imaging may be a useful tool for predicting the levels of myeloma cells in bone marrow of patients with MM.     

Detection of focal myeloma lesions by technetium-99m-sestaMIBI scintigraphy

BACKGROUND AND OBJECTIVE: The tracer tachnetium-99m-2-methoxy-isobutyl-isonitrile (Tc99m-sestaMIBI) has recently been shown to concentrate in some neoplastic tissues, including myeloma. We investigated the diagnostic capacity and limits of this procedure in tracing focal myeloma lesions, and compared them with those of conventional radiological procedures (Xr). DESIGN AND METHODS: We studied 55 patients suffering from multiple myeloma (MM) or solitary plasmacytoma in different stages and clinical conditions, or from monoclonal gammopathy of undefined significance (MGUS), by whole body scans obtained 10 minutes after injection of 555 MBq of Tc99m-sestaMIBI. Scans were defined as normal (physiological uptake only), diffuse (presence of bone marrow uptake), or focal (localized areas of uptake), and were compared to conventional skeletal Xr. RESULTS: Thirty patients showed no focal areas of Tc99m-sestaMIBI uptake; this group consisted of 5 patients with MGUS, 6 with MM in stage IA and 2 in stage IIA, 11 patients studied after effective chemotherapy and 6 in early relapse. Twenty-five patients showed one or more spots of focal uptake: all of them had active disease (untreated, resistant or relapsing MM). In the setting of tracing focal lesions, Tc99m-sestaMIBI scans were concordant with the radiological examination in 38 patients and discordant in 17. Among the latter, in 4 cases Tc99m-sestaMIBI revealed focal lesions not detected by Xr, and in 13 cases lytic areas detected by Xr did not show Tc99m-sestaMIBI uptake. INTERPRETATION AND CONCLUSIONS: In untreated patients, the number of lesions revealed by Tc99m-sestaMIBI was comparable to that shown by Xr, while in pretreated patients Tc99m-sestaMIBI traced a number of lesions lower than that detected by Xr. The reason for this discrepancy is that Tc99m-sestaMIBI traces only active lesions. Tc99m-sestaMIBI limitations in identifying focal lesions may derive from the dimension of the smallest traceable lesion (about one centimeter), and from the possibility that focal plasma cell localizations in collapsed bone may not be visualized due to inadequate vascularization. Tc99m-sestaMIBI scintigraphy is an interesting tool for diagnosing, staging and following up focal myeloma lesions, in the bone as well as in soft tissues. It is more specific than conventional Xr in identifying sites of active disease.     

Prevalence and risk of cancer of focal thyroid incidentaloma identified by 18F-fluorodeoxyglucose positron emission tomography for metastasis evaluation and cancer screening in healthy subjects

We performed a retrospective review of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) examination to determine the prevalence of thyroid FDG-PET incidentaloma in a patient group evaluated for metastasis of cancer and in a group of healthy subjects who underwent voluntary cancer screening. We also evaluated the risk of malignancy in focal thyroid FDG-PET incidentaloma and its association with standard uptake values (SUVs) (maximum and greater than 0.75 threshold). A total of 1330 subjects underwent FDG-PET for metastasis evaluation (n = 999) and cancer screening (n = 331). Twenty-nine of 1330 subjects (2.2%) showed focal (n = 21) or diffuse (n = 8) thyroid FDG-PET incidentaloma. There was no significant difference in the prevalence of thyroid FDG-PET incidentaloma between the two groups (19 of 999 vs. 10 of 331; P > 0.05). Four of 15 focal incidentalomas (26.7%) whose histological diagnoses were available showed papillary thyroid cancer. The maximum SUV (16.5 +/- 4.70) and greater than 0.75 threshold SUV (14.2 +/- 5.3) of malignant lesions were significantly higher than those of benign tumors (6.5 +/- 3.8 and 4.9 +/- 3.0; P < 0.05). In conclusion, thyroid FDG-PET incidentaloma has prevalence of 2.2%, and its prevalence was not different according to the purpose of the FDG-PET. The focal thyroid FDG-PET incidentaloma carries a high risk of malignancy, especially in cases with high SUVs. Therefore, focal thyroid FDG-PET incidentaloma with high SUVs warrants a pathological diagnostic procedure if it changes a patient's treatment plan or prognosis.     

A novel clinical indicator using Tc-99m sestamibi for evaluating cardiac mitochondrial function in patients with cardiomyopathies

BACKGROUND: Technetium 99m sestamibi (MIBI) is a technetium-labeled myocardial perfusion agent that is taken up by the myocardial cell in proportion to myocardial regional blood flow and remains fixed in the myocardial cell over a long period of time. Previous studies have suggested that MIBI shows very slow myocardial clearance after its initial uptake in an animal model, which is related to mitochondrial function. This study was designed to test the hypothesis that MIBI washout can be used to evaluate the severity of congestive heart failure in comparison to other clinical parameters in patients with cardiomyopathies. METHODS AND RESULTS: After administration of MIBI, 61 patients with nonischemic congestive heart failure (49 with dilated cardiomyopathy and 12 with other cardiomyopathies) and 7 normal control subjects were examined by electrocardiography-gated myocardial perfusion single photon emission computed tomography and planar data acquisition in the early and delayed phases (interval of 3 hours). Myocardial MIBI washout rates were calculated from the early and delayed planar images. Left ventricular function (systolic and diastolic) was analyzed by use of QGS data. Plasma levels of B-type natriuretic peptide and iodine 123 metaiodobenzylguanidine (MIBG) parameters were also measured. Patients were followed up for a mean of 12 months (range, 1-19 months). As the severity of the New York Heart Association (NYHA) functional class advanced, the washout rate of MIBI increased (21.6% +/- 2.4% in those with NYHA class I [n = 23], 28% +/- 4% in those with NYHA class II [n = 27], and 35% +/- 5% in those with NYHA class III [n = 10]; P < .05, analysis of variance). The washout rate of MIBI was positively correlated with the level of B-type natriuretic peptide (r = 0.31, P < .05), end-diastolic volume (r = 0.396, P < .01), and end-systolic volume (r = 0.496, P < .01) and was negatively correlated with left ventricular ejection fraction (r = 0.523, P < .01), peak filling rate (r = 0.444, P < .01), and first-third ejection fraction (r = 0.414, P < .01). The parameters of MIBG scintigraphy were calculated as the heart-mediastinum count ratio (1.9 +/- 3) and washout rate (38% +/- 4%). We found a significant relationship between the washout rate of MIBI and the heart-mediastinum count ratio of MIBG (r = 0.51, P < .01). Patients with a higher washout rate of MIBI had a higher cardiac event rate (> or =28%) than those with a lower washout rate (<28%) (P < .05). CONCLUSIONS: The myocardial washout rate of MIBI is thought to be a novel marker for the diagnosis of myocardial damage or dysfunction, providing prognostic information in patients with congestive heart failure.     

Clinical yield of computed tomography brain scans in older general medical patients

OBJECTIVES: To evaluate the clinical yield of computed tomography (CT) brain scans in a prospective cohort of older patients admitted to the general medicine service. DESIGN: Nested cohort study of 117 subjects enrolled in previous prospective cohort study of 919 subjects. SETTING: University-affiliated teaching hospital. PARTICIPANTS: Hospitalized general medical patients aged 70 and older who received one or more brain CT scans during their hospital stay. MEASUREMENTS: Review of medical records and interpretation of the first brain CT scan in these 117 patients for indications for ordering scans and clinically significant brain abnormalities. Medical records of patients with brain CT scans with abnormalities were reviewed for 2 weeks after the scan for changes in medical management resulting from scan findings. Three independent reviewers adjudicated the presence of abnormalities and resulting treatment changes. RESULTS: Of the 117 brain CT scans, 32 (27%) were ordered to exclude intracranial hemorrhage, 30 (26%) to exclude cerebrovascular accident (CVA), 16 (14%) for falls, 15 (13%) for syncope, seven (6%) to exclude subdural hemorrhage, five (4%) for mental status change, and 12 (10%) for other reasons. Of the 117 brain CT scans, 29 (25%) had abnormalities, including acute CVA or hemorrhage, old CVA, meningioma, and other abnormalities. Only 10 (9% of all scans, 34% of abnormal scans) resulted in treatment changes (including consultations, further imaging, stroke evaluation, and drug changes). The presence of focal neurological deficits was significantly associated with treatment changes after CT scans (odds ratio=13.2, 95% confidence interval=1.7-161.5). CONCLUSION: These results suggest that the overall clinical yield of brain CT scans in unselected older hospitalized patients is low. Targeting scans toward patients with new focal neurological deficits will help to improve clinical yield.     

Trends in allogeneic stem cell transplantation for multiple myeloma: a CIBMTR analysis

Allogeneic hematopoietic cell transplantation in multiple myeloma is limited by prior reports of high treatment-related mortality. We analyzed outcomes after allogeneic hematopoietic cell transplantation for multiple myeloma in 1207 recipients in 3 cohorts based on the year of transplantation: 1989-1994 (n = 343), 1995-2000 (n = 376), and 2001-2005 (n = 488). The most recent cohort was significantly older (53% > 50 years) and had more recipients after prior autotransplantation. Use of unrelated donors, reduced-intensity conditioning and the blood cell grafts increased over time. Rates of acute graft-versus-host (GVHD) were similar, but chronic GVHD rates were highest in the most recent cohort. Overall survival (OS) at 1-year increased over time, reflecting a decrease in treatment-related mortality, but 5-year relapse rates increased from 39% (95% confidence interval [CI], 33%-44%) in 1989-1994 to 58% (95% CI, 51%-64%; P < .001) in the 2001-2005 cohort. Projected 5-year progression-free survival and OS are 14% (95% CI, 9%-20%) and 29% (95% CI, 23%-35%), respectively, in the latest cohort. Increasing age, longer interval from diagnosis to transplantation, and unrelated donor grafts adversely affected OS in multivariate analysis. Survival at 5 years for subjects with none, 1, 2, or 3 of these risk factors were 41% (range, 36%-47%), 32% (range, 27%-37%), 25% (range, 19%-31%), and 3% (range, 0%-11%), respectively (P < .0001).     

Value of Tc-99m sestamibi scintigraphy in the detection of bone lesions in multiple myeloma: comparison with Tc-99m methylene diphosphonate

Technetium 99m-2-methoxyisobutylisonitrile (Tc-99m MIBI) is a lipophilic agent that accumulates preferentially within living malignant cells due to the higher transmembrane electrical potential as a consequence of the higher metabolic rate than in the surrounding normal cells. It has been effectively used to detect malignant tumors at diagnosis and follow-up and has been reported to be useful in detecting disease lesions in multiple myeloma. We studied 28 consecutive patients with multiple myeloma at diagnosis to determine the value of Tc-99m MIBI in comparison with Tc-99m methylene diphosphonate (MDP), conventional X-rays, computed tomography (CT) scan, and magnetic resonance imaging (MRI). We found 26 patients with obvious osteolytic lesions in X-rays, 22 patients with positive Tc-99m MIBI scans, and 15 patients with positive Tc-99m MDP scans. There was no coincidence of the positive lesions in the two scans, while in two patients the osteolytic areas were positive in the Tc-99m MDP scans, and in one case the osteolytic area was positive in the Tc-99m MIBI scan. The intensity of Tc-99m MIBI scans correlated with disease activity as determined by lactate dehydrogenase (LDH) (p<0.05), C-reactive protein (CRP) (p<0.01), beta2-microglobulin (p<0.05), and serum ferritin (p<0.01). We believe that Tc-99m MIBI scintigraphy can detect bone marrow lesions in myeloma patients that cannot be detected by other imaging methods and that it can be useful especially in solitary myeloma to exclude other involved sites. In addition, it could be a prognostic factor related to disease activity and multidrug resistance. We believe that a multicenter study is needed to evaluate the usefulness of this agent.     

Technetium-99m-sestamibi scintigraphy in multiple myeloma and related gammopathies: a useful tool for the identification and follow-up of myeloma bone disease

BACKGROUND AND OBJECTIVES: Technetium-99m 2-methoxy-isobutyl-isonitrile ((99m)Tc-sestamibi) has recently been proposed as a potential tracer in patients with multiple myeloma (MM), as its increased uptake in the bone marrow has been reported as indicator of myeloma activity. We evaluated the role of (99m)Tc-sestamibi scintigraphy in the detection of myeloma bone disease in MM and related gammopathies, and also assessed its relationship with clinical status and stage of the disease, focusing in particular on the early follow-up of a small series of MM patients treated with high-dose therapy. DESIGN AND METHODS: Forty-six consecutive patients affected by MM or monoclonal gammopathy of undefined significance (MGUS) were studied by whole body scans obtained 20 minutes after administration of 740 MBq of (99m)Tc-sestamibi. A semiquantitative uptake score was used and scintigraphic findings were correlated with clinical and laboratory data. RESULTS: All the MGUS patients showed a negative (99m)Tc-sestamibi scan. Among the 32 MM patients (25 with active disease and 7 in clinical remission) 24 showed a positive scan, while 8 presented only a physiologic uptake of the tracer. The uptake score correlated significantly with all the most relevant clinical variables. In the follow-up of 8 MM patients treated with high-dose chemotherapy (99m)Tc-sestamibi closely paralleled the activity of myeloma bone disease. Comparison with X-ray skeletal survey showed discordant results in 14 out of the overall 56 scans obtained (27%), with 10 cases of negative (99m)Tc-sestamibi scans but lytic bone lesions revealed by X-ray (7 of them were in clinical remission), and 4 negative X-ray surveys in patients with positive (99m)Tc-sestamibi scans. Overall sensitivity and specificity of (99m)Tc-sestamibi scintigraphy in detecting myeloma bone disease were 90% and 88%, respectively. INTERPRETATION AND CONCLUSIONS: This study provides additional evidence indicating that (99m)Tc-sestamibi scintigraphy closely reflects myeloma disease activity in bone marrow, with very high sensitivity and specificity. (99m)Tc-sestamibi scintigraphy is therefore suggested as a reliable new tool for the staging and follow-up of myeloma bone disease.     

Accuracy of [18F]fluorodopa positron emission tomography for diagnosing and localizing focal congenital hyperinsulinism

OBJECTIVES: Focal lesions in infants with congenital hyperinsulinism (HI) represent areas of adenomatosis that express a paternally derived ATP-sensitive potassium channel mutation due to embryonic loss of heterozygosity for the maternal 11p region. This study evaluated the accuracy of 18F-fluoro-l-dihydroxyphenylalanine ([18F]DOPA) positron emission tomography (PET) scans in diagnosing focal vs. diffuse disease and identifying the location of focal lesions. DESIGN: A total of 50 infants with HI unresponsive to medical therapy were studied. Patients were injected iv with [18F]DOPA, and PET scans were obtained for 50-60 min. Images were coregistered with abdominal computed tomography scans. PET scan interpretations were compared with histological diagnoses. RESULTS: The diagnosis of focal or diffuse HI was correct in 44 of the 50 cases (88%). [18F]DOPA PET identified focal areas of high uptake of radiopharmaceutical in 18 of 24 patients with focal disease. The locations of these lesions matched the areas of increased [18F]DOPA uptake on the PET scans in all of the cases. PET scan correctly located five lesions that could not be visualized at surgery. The positive predictive value of [18F]DOPA in diagnosing focal adenomatosis was 100%, and the negative predictive value was 81%. CONCLUSIONS: [18F]DOPA PET scans correctly diagnosed 75% of focal cases and were 100% accurate in identifying the location of the lesion. These results suggest that [18F]DOPA PET imaging provides a useful guide to surgical resection of focal adenomatosis and should be considered as a guide to surgery in all infants with congenital HI who have medically uncontrollable disease.     

Comparison of histological findings and parathyroid scintigraphy in hemodialysis patients with secondary hyperparathyroid glands

To determine the usefulness of parathyroid scintigraphy in histological estimation for secondary hyperparathyroidism (2HPT) using Tc-99m sestamibi or Tc-99m tetrofosmin. Tc-99m sestamibi (MIBI) and Tc-99m tetrofosmin (Tetro) parathyroid imaging following double-phase study, magnetic resonance imaging (MRI), and ultrasound were performed on 14 patients with 2HPT. All patients underwent parathyroidectomy. The uptake of two tracers in parathyroid areas was compared with the histopathologic findings. Forty-nine parathyroid glands were surgically explored and histologically proven to be hyperplastic. Of these, 42 were diagnosed with nodular type (N-type) hyperplasia, and 7 with diffuse type (D-type) hyperplasia. MIBI and Tetro parathyroid imagings detected 34 and 35 parathyroid glands, respectively. The sensitivity of MIBI was determined to be 76.2% (32/42) for N-type, and 28.6% (2/7) for D-type. The sensitivity of Tetro was determined to be 78.6% (33/42) for N-type and 28.6% (2/7) for D-type. The sensitivity of both MIBI and Tetro was significantly higher for N-type than for D-type, 76.2% (32/42) vs. 28.6% (2/7) in MIBI, P = 0.022; 78.6% (33/42) vs. 28.6% (2/7) in Tetro, P = 0.015. The sensitivity of MRI was determined to be 76.2% (32/42) for N-type and 42.9% (3/7) for D-type, and the sensitivity of ultrasound was 71.4% (30/42) for N-type and 71.4% (5/7) for D-type. There was no significant difference in the sensitivity of MRI or ultrasound between N-type and D-type. The uptake ratios of MIBI and Tetro were also greater for N-type than for D-type. The detectability of both MIBI and Tetro was greater for N-type than for D-type. Tc-99m MIBI or Tc-99m Tetro parathyroid scintigraphy therefore may be used clinically to distinguish N-type from D-type parathyroid gland hyperplasia.     

Effect of ischemia and postischemic dysfunction on myocardial uptake of technetium-99m-labeled methoxyisobutyl isonitrile and thallium-201

The myocardial uptake of a new technetium-99m-labeled myocardial perfusion agent, methoxyisobutyl isonitrile (Tc-99m MIBI), and thallium-201 was correlated with microsphere flow in an open chest canine model of low coronary flow and postischemic dysfunction. Eighteen dogs were given an injection of thallium-201 (0.5 mCi) and Tc-99m MIBI (5 mCi) either after 40 min of partial left anterior descending artery occlusion (Group I, 10 dogs) or during reperfusion after 15 min of left anterior descending artery occlusion (Group II, 8 dogs). Regional dysfunction was documented during injection in both groups by quantitative two-dimensional echocardiography. Regional blood flow was assessed by radiolabeled microspheres. The heart was excised 15 min after radionuclide injection and the left ventricle divided into 96 segments for gamma well counting. Among Group I dogs, central ischemic thallium-201 and Tc-99m MIBI activity (expressed as a percent of the activity in the corresponding nonischemic zone) was comparable, respectively, for endocardial (54 +/- 17% and 52 +/- 17%), mid-wall (71 +/- 20% and 69 +/- 17%) and epicardial (89 +/- 13% and 94 +/- 9%) segments and increased proportionally with flow. There was a good linear correlation among these endocardial segments between flow and both thallium-201 (r = 0.78) and Tc-99m MIBI (r = 0.85) activity. Among Group II dogs, central ischemic endocardial flow (59 +/- 14%) was comparable to thallium-201 (70 +/- 18%) and Tc-99m MIBI (74 +/- 12%) activity. Similarly, relative endocardial flow in the intermediate ischemic region (71 +/- 11%) was comparable to thallium-201 (77 +/- 11%) and Tc-99m MIBI (81 +/- 10%) activity. Thus, myocardial uptake of Tc-99m MIBI and thallium-201 is comparable under conditions of low coronary flow and postischemic dysfunction and closely parallels flow alterations.     

Repeat planar white cell scanning to monitor short-term therapy of active inflammatory bowel disease: a methodological study and comparison with clinical scores and novel inflammatory markers

OBJECTIVES: Radiolabelled white cell scans provide non-invasive quantification of inflammatory activity. Clinical activity scores measure severity of disease but are partly subjective. White cell scans may provide a suitable method of monitoring the treatment response of active inflammatory bowel disease. METHODS: Ten subjects with active ulcerative colitis and 13 subjects with active Crohn's disease were recruited. White cell scans were carried out before and 2 weeks after treatment. Prior to each scan, activity scores for ulcerative colitis or Crohn's disease were calculated and serum and faecal tumour necrosis factor-alpha and calprotectin measured. White cell scan activity at 1 h was calculated by using a validated visual grading system. RESULTS: Following anti-inflammatory treatment, 70% of white cell scans improved, 17% remained unchanged and 13% deteriorated. In the ulcerative colitis subgroup subjects there was modest agreement for change in scan score and activity scores. In the Crohn's disease subjects there was better agreement between change of white cell scan score and clinical scores. Planar white cell scans correlated with the van Hees activity index (r=0.68, P=0.002) and faecal calprotectin (r=0.58, P=0.0003). Changes in planar white cell scans correlated with changes in serum calprotectin (r=0.45, P=0.05). CONCLUSION: Non-invasive white cell scanning is a feasible and objective method to monitor the anti-inflammatory efficacy of treatments for active inflammatory bowel disease.     

Temporal 67gallium uptake is increased in temporal arteritis.

OBJECTIVE: We evaluated temporal 67gallium (Ga) uptake in temporal arteritis (TA) and the contribution of Ga scans to the diagnosis of TA. METHODS: Ga scans were performed prospectively in 19 patients with biopsy-proven TA and five TA patients with negative temporal artery biopsy. Controls were 18 elderly patients undergoing Ga scans for various inflammatory diseases. The temporal region of interest on head profiles was defined for comparison of uptake with a control parietal region of the same area. The Ga uptake ratio (GaUR) [(temporal region - parietal region)/parietal region] was evaluated for each temple by a computer and intra- and intergroup comparisons were made. RESULTS: GaUR was significantly higher in biopsy-proven TA patients (0.35+/-0.19) and biopsy-negative TA patients (0.31+/-0.03) than in controls (0.18+/-0.12) (P < 0.001), independently of recent temporal artery biopsy or short-duration steroid therapy. High GaUR (>0.4) had a 94% specificity and a 90% positive predictive value for TA diagnosis. After 6 months of steroid therapy, when patients were in remission, GaUR returned to baseline. CONCLUSION: Ga is specifically incorporated into the temporal area in TA patients which may be due to the granulomatous vasculitic process. Ga uptake ceases during remission. A high GaUR may contribute to TA diagnosis in temporal artery biopsy-negative patients and its role in the diagnosis of other localizations of the disease requires further evaluation.     

Taurine and osmoregulation: platelet taurine content, uptake, and release in type 2 diabetic patients

In this study, plasma and platelet taurine content and fluxes were determined in 38 type 2 diabetic patients and in 26 healthy control subjects. Taurine levels in diabetic patients were significantly lower than in control subjects both in plasma (32.1 v 48.6 micromol/L, P = .000) and platelets (148 v 183 nmol/mg protein, P = .043). Platelet taurine uptake in diabetic patients was significantly reduced (321.2 v 524.9 pmol total taurine 10(8) platelet(-1) min(-20), P = .000), whereas taurine release increased in comparison to healthy controls (38.7 v 29.5% of platelet 3H taurine at the start of incubation, P = .000). These results may reflect modified systems of taurine carriers or a compensatory mechanism in response to an increase of other organic osmolytes.     

Single-photon–emission computed tomography analysis of cerebral blood flow in the evaluation of central nervous system involvement in patients with systemic lupus erythematosus

Objective. Single-photon–emission computed tomography (SPECT) scanning was used to detect potential central nervous system (CNS) involvement in patients with systemic lupus erythematosus (SLE), by determining cerebral blood flow abnormalities. Methods. SPECT scans were performed on 35 SLE patients, grouped into 3 categories: those without neuropsychiatric symptoms (n = 10), those with definite neurologic or psychiatric disorders (n = 10), and those with mild symptoms such as headache or memory disturbances (n = 15). SPECT scan features were classified as normal or as focal or diffuse defects in uptake. Results. SPECT findings were normal in 9 of the 10 patients without CNS symptoms, and abnormal in 9 of the 10 patients with overt neuropsychiatric disease (with motor or sensory deficits). Interestingly, only 4 of the 15 patients (26.7%) with mild symptoms suggestive of CNS disease had normal SPECT findings; the 11 remaining patients showed focal (53.3%) or diffuse (20%) uptake defects. An association between SPECT findings and disease duration was also observed, but there was no correlation of SPECT results with overall disease activity, serologic findings, or medications used. Conclusion. Our data suggest that in a substantial proportion of patients, SPECT analysis may provide additional information on potential CNS involvement, and may therefore be useful in therapeutic decisionmaking and disease monitoring in order to prevent CNS damage.