The role of 99mTc(V)-DMSA scan as compared to 99mTc-MDP and CT scans in imaging the primary tumor and metastases of osteosarcoma

The oncophilic complex of technetium-99m labeled pentavalent dimercaptosuccinic acid (99mTc(V)-DMSA) has been successfully used for the detection of primary and metastatic medullary thyroid cancer and for imaging various soft tissue tumors like lung, brain and prostate cancer. In this article, the role of 99mTc(V)-DMSA in the diagnosis of the primary tumor and metastases of osteosarcoma patients as compared to the 99mTc-MDP scan and the CT scan was studied. Twenty-eight patients with bone disease were referred to the Nuclear Medicine Department of Saint Savas Oncology Hospital in Athens from the Orthopedics Department of the same Hospital. From them, 18 (Group A) had osteosarcoma, 7 (Group B) osteomyelitis and 3 (Group C) bone fractures. The final diagnosis was made after fine needle aspiration biopsy. All patients were subjected to the 99mTc(V)-DMSA scan, the standard bone scan (99mTc-MDP) and CT scan. Group A patients showed a selective uptake of 99mTc(V)-DMSA in the primary tumor region. No abnormal 99mTc(V)-DMSA uptake was observed in the patients of Groups B and C. The 99mTc(V)-DMSA scan was found to be superior to the 99mTc-MDP and the CT scans in identifying metastases of osteosarcoma. Sensitivity was 100%, 86% and 98% respectively.     

Idiopathic hepatic uptake of (99m)Tc methylene diphosphonate: a case report

OBJECTIVE: Two sequential (99m)Tc methylene diphosphonate (MDP) scans were performed on a 42-y-old woman with insulin-dependent diabetes mellitus, chronic right pyelonephritis and anemia. The initial scan showed reduced skeletal uptake with intense and diffuse hepatic uptake. Because these findings were similar to those seen when excessive hydrolyzed-reduced (99m)Tc colloids are present in the radiopharmaceutical, the scan was repeated after an adequate time delay. Increased skeletal uptake was evident in the second scan, but the hepatic uptake persisted. Although there are numerous causes of soft tissue activity on (99m)Tc MDP bone scans, the responsible pathologic entity is not always clear. This study reviews several possible reasons for such uptake, although the exact mechanism in this case remains conjectural.     

Incidence, severity and clinical course of right ventricular involvement after acute inferior myocardial infarction; assessment by sequential 99Tcm-pyrophosphate scan and gated blood pool scan

To evaluate the incidence, severity and clinical course of right ventricular (RV) involvement after acute inferior myocardial infarction (IMI), 78 patients (pts) with IMI were investigated by both 99Tcm-pyrophosphate (PYP) scan and gated blood pool scan (GBPS). GBPS was performed at admission and 10 days, whereas 99Tcm-PYP scan was performed at 3 to 6 days. RV uptake of PYP was demonstrated in 25 (32%) pts on 99Tcm-PYP scan and RV akinesis or moderate hypokinesis by GBPS was observed in 39 (50%) pts on the acute scan; 25 pts (Group A) with positive RV uptake and 14 pts (Group B) with no RV uptake. In the remaining 39 pts (Group C) had normal RV wall motion. Severely depressed RVEF improved nearly 10 points on the tenth day in Group A (from 30.8 +/- 12.3 to 40.9 +/- 6.7%, p less than 0.01) and Group B (from 35.6 +/- 8.2 to 44.5 +/- 10.5%, p less than 0.01), respectively. Group C showed normal RVEF (from 47.4 +/- 7.6 to 50.1 +/- 10.2%). Fourteen pts of 39 (Groups A and B) who had developed shock or hypotension improved strikingly after appropriate therapy except for one death during their hospital course. Our data demonstrated: some patients with RV dysfunction in IMI do not have severe necrosis as judged by PYP scanning, those with positive RV uptake and depressed RV function show a lower degree of recovery than those with no RV uptake, but start from a lower initial value of RV function, and the combination of 99Tcm-PYP scan and GBPS offers prognostic information in IMI with RV dysfunction.     

A false negative by planar scintigraphy liver hemangioma, diagnosed by technetium-99m-red blood cells and technetium-99m-sulfur colloid single photon emission tomography scan

We present a 42-year-old patient who was examined in the Gastroenterology Department of Gaziantep University for chronic abdominal pain, nausea and vomiting. Ultrasonography showed a 4.7 cm solid hepatic mass on the right lateral side of the right lobe of the liver. The patient was then sent to the Nuclear Medicine Department of Gaziantep University for liver scan. After injecting autologous red blood cells labeled with 740 MBq of technetium-99m ((99m)Tc-RBC), early and delayed anterior planar images of the liver showed no significant findings because of the right kidney shine through the liver. Two days later, after injecting again 740 MBq of (99m)Tc-RBC, we performed a single photon emission tomography (SPET) scan but still this scan was nondiagnostic even in the delayed images of the liver. Three days later, after the iv injection of 185 MBq of technetium-99m-sulphur colloid ((99m)Tc-SC), we observed in the delayed SPET images of the liver, a mismatch defect with decreased focal uptake of (99m)Tc-SC at 60 min while the uptake of (99m)Tc-RBC at the same area was normal or slightly increased. The patient was then operated due to bleeding in the abdominal cavity. A cavernous hemangioma was found, confirmed by histology. The absorbed dose from all three diagnostic scanning procedures was: 4 mSv. In conclusion, the mismatch of the SPET delayed images between the (99m)Tc-RBC and the (99m)Tc-SC scans indicated that this procedure was effective for the diagnosis of liver cavernous hemangioma located in this unusual position.     

99mTc-human serum albumin scans in children with protein-losing enteropathy.

Protein-losing enteropathy (PLE) can be diagnosed scintigraphically using 99mTc-human serum albumin (HSA) scans. METHODS: To evaluate the usefulness of this method in detecting enteric protein loss, we retrospectively reviewed the 99mTc-HSA scans of 18 children presenting consecutively with PLE. RESULTS: Enteric 99mTc-HSA uptake was noted in 12 patients (8 boys, 4 girls) with a mean age of 7.4 y. Early dynamic images showed abdominal uptake that was most likely in the small bowel in 91% of the scans. Delayed images showed abnormal accumulation that was localized in the colon in 73% and in the small bowel in 27% of the scans. A 4-mo follow-up scan obtained in 3 patients showed reduced HSA uptake after a high-protein, low-fat, medium-chain triglyceride oil-based diet and fat-soluble vitamins. Mean serum albumin, total protein, gammaglobulin, and calcium levels were significantly decreased. Ten patients (from 4 families) were diagnosed to have primary intestinal lymphangectasia. One patient had active Salmonella enterocolitis, and 1 had giardiosis. 99mTc-HSA was normal in the remaining 6 patients (3 boys, 3 girls) with a mean age of 3.5 y (range, 2-5 y). Mean serum albumin, total protein, gammaglobulin, and calcium levels were less decreased than those of the first group. Five of these patients had primary intestinal lymphangactesia (associated with infantile systemic hyalinosis in 1 patient). The remaining patient had normal duodenal biopsy, and the cause of protein loss remained unknown. CONCLUSION: The 99mTc-HSA scan is useful in the evaluation of children with PLE, especially those with severe hypoproteinemia and hypoalbuminemia, presumably reflecting a high rate of protein loss.     

A comparison of iodine-123 meta-iodobenzylguanidine scintigraphy and single bone marrow aspiration biopsy in the diagnosis and follow-up of 26 children with neuroblastoma

In staging neuroblastomas, the demonstration of tumoural invasion of the bone marrow is an important criterion with regard to the therapeutic prospects and the prognosis. Iliac crest aspiration sampling has been used routinely for the detection of bone marrow metastases in neuroblastoma. However, due to the limited character of the sampling, it sometimes leads to false-negative results. Another procedure which is used to determine the extent of neuroblastoma is metaiodobenzylguanidine (mIBG) scintigraphy. In order to establish the respective merits of both diagnostic techniques retrospectively, 148 iodine-123 mIBG scans of 26 children with neuroblastoma have been re-evaluated and compared with the results of routine bone marrow samples obtained within a 4-week period before or after scanning. Three types of mIBG uptake in the bone/bone marrow could be differentiated: (1) no visualization of the skeleton; (2) diffuse uptake in the skeleton with or without focally increased uptake, which indicates massive, diffuse bone marrow invasion by the tumour; and (3) focal tracer accumulation in one or several bones. No tracer uptake was observed in the skeleton in 91 scans. In 89 of the 91 the bone marrow biopsy was negative. Twenty-four scans showed diffuse skeletal uptake with or without foci. The bone marrow biopsies were negative for eight of those 24 scans. Hyperactive foci in one or more bones without diffuse tracer accumulation in the skeleton were detected in 33 scans. In only 7 of these 33 scans did bone marrow biopsy specimens from the iliac MDP crest contain neuroblastoma cells. Available technetium-99m methylene diphosphonate (MDP) whole-body scintigrams were also compared with the corresponding mIBG scans. Thirty-eight mIBG scans showed no visualization of the skeleton; ^99mTc-MDP scintigrams were also normal. Seven patients with diffuse mIBG uptake in the skeleton appeared as normal on the ^99mTc-MDP scans. Among 27 cases showing focal mIBG uptake in the skeleton with or without diffuse uptake, only I8 demonstrated a hot spot on the bone scintigram. The results of our study indicate that for the assessment of bone marrow infiltration by neuroblastoma, 1231-mIBG scintigraphy is more sensitive than the conventional cytological examination of bone marrow smears routinely obtained from the iliac crest, has a very high sensitivity in excluding bone marrow invasion, has a high specificity for detecting bone marrow invasion, appears to be able to detect early tumoural deposits in the bone marrow before osseous invasion occurs as shown on the MDP scans and is superior to ^99mTc-MDP bone scan in detecting bone/bone marrow metastases of neuroblastoma. In patients with a positive mIBG scan in the skeleton, bone marrow biopsy will not yield additional information. Correspondence to: K. Osmanagaoglu     

A report on the incidence of intestinal 99mTc-methylene diphosphonate uptake of bone scans and a review of the literature

BACKGROUND: In addition to well-known specific conditions for soft-tissue uptake of bone-seeking radiotracers, there is a limited number of reports on intestinal uptake of (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) on bone scans. AIM: To describe the incidence of intestinal accumulation of (99m)Tc-MDP on bone scans in adult patients, define the patterns of this unusual finding and review the literature on its causes. METHODS: Two thousand, one hundred and forty-four consecutive patients have been evaluated for intestinal (99m)Tc-MDP uptake on bone scans. Intestinal uptake was observed visually 3-4 h after the administration of the radiopharmaceutical. A whole-body bone scan and various spot views of the abdomino-pelvic region were obtained with a dual-headed gamma camera to evaluate the intestinal uptake. Delayed scans were also obtained as well as co-relative imaging and/or colonoscopic studies in some of intestinal uptake patients. Six patients had delayed scans of the abdomino-pelvic region. Fourteen patients had comparable scans either a year before or a year later. The positive intestinal uptake scans were further grouped according to the localization and intensity (mild uptake: lower than iliac bone; moderate uptake: equal to iliac bone; significant uptake: higher than iliac bone). RESULTS: Twenty-two (17 female, five male) patients out of 2144 with a mean age of 57 years showed intestinal (99m)Tc-MDP uptake. The localization was mainly (20/22) in the right abdomino-pelvic region projecting on and in the configuration of ascending colon while one patient showed intestinal uptake all over the abdomen and one displayed diffuse intestinal radioactivity in his right hemithorax. The majority of the cases showed moderate to intense intestinal uptake (18/22). Six patients showed a decrease, disappearance or alteration in the intestinal uptake on the delayed images. Re-evaluation bone scans in five patients 1 year later showed no intestinal uptake this time. Among nine patients with prior bone scans 1 year before, intestinal uptake was negative in seven at that time. No significant pathology was obtained on the correlative images. CONCLUSION: (99m)Tc-MDP uptake can be observed in the intestines in 1% of bone scans with a prominent localization in the ascending colon and rarely all over the intestines or in thorax due to Chilaiditi's syndrome, as well. The mechanism of intestinal uptake is still unclear in some of the patients. Delayed imaging, additional spot views and SPECT studies help in the differentiation of this finding from possible misinterpretation. Intestinal (99m)Tc-MDP uptake on bone scan could be an intermittent process and should be included among other well-known reasons of soft-tissue uptake.     

Scintigraphic elvaluation of liver metastases from thyroid carcinoma.

Thirty-one patients with carcinoma of the thyroid were evaluated using 131-I scan of the torso including the area of the liver. Focal areas of 131I uptake were found in the liver in two patients with follicular thyroid carcinoma. Both patients showed associated abnormalities on 99m-Tc-sulfur colloid liver scans. The remaining 29 patients showed either no uptake or a normal diffuse pattern of 131-I uptake in liver. Careful evaluation of the liver is recommended on the radioiodine body scan for metastases in patients with thyroid carcinoma.     

Detection of hepatic metastases in diffuse fatty infiltration by CT: the complementary role of imaging

Six patients undergoing computed tomographic (CT) evaluation for possible abdominal and pelvic metastases were shown to have diffuse fatty infiltration of the liver and findings indeterminate for hepatic metastases. In two patients with diffuse fatty infiltration and no focal hepatic lesions on CT, technetium-99m sulfur colloid imaging demonstrated focal hepatic defects confirmed to represent metastases. In four patients with diffuse fatty infiltration and hyperdense liver foci on CT, radionuclide imaging demonstrated normal uptake in the hyperdense foci confirmed to represent areas of normal liver spared by fatty infiltration. In each of the six patients, clinical management was altered by the radionuclide findings.     

Randomized, single-blind, factorial design study of the interaction of food and time on intestinal activity in 99mTc-tetrofosmin stress myocardial perfusion scintigraphy

PURPOSE: Intestinal activity at the inferior myocardial wall represents an issue for assessment of myocardial perfusion imaging (MPI) with 99mTc-labelled tracers. The aim of this study was to investigate the effect of time and food on upper abdominal activity in 99mTc-tetrofosmin MPI. METHODS: The study population consisted of 152 consecutive patients referred for routine MPI. All patients underwent 2-day stress-rest 99mTc-tetrofosmin single-photon emission computed tomography MPI. Before stress testing, patients were randomized in a factorial design to four different regimens. Group A: early scan (image acquisition initiated within 15 min after injection of the tracer) and no food; group B: early scan and food (two pieces of white bread with butter and a minimum of 450 ml of water); group C: late scan (image acquisition 30-60 min after injection of the tracer) and no food; and group D: late and scan with food. Patients underwent standard bicycle exercise or pharmacological stress test. The degree of upper abdominal activity was evaluated by trained observers blinded to the randomization code. The primary endpoint was the proportion of accepted scans in the intention-to-treat population in stress MPI. RESULTS: The results showed statistical significant impact on both time and food on upper abdominal activity. The primary endpoint showed that the acceptance rate improved from 55% in group A to 100% success rate in group D. An early scan reduced the acceptance rate by 30% versus a late scan [hazard ratio 0.70, 95% confidence interval 0.58-0.84; P<0.0001], whereas the addition of food improved the success rate versus no food by 27% (hazard ratio 1.27, 95% confidence interval 1.07-1.51; P=0.006). No significant interaction between food and time was observed. An analysis of accepted scans according to the actual scan time and food consumption confirmed the findings of the intention-to-treat analysis. In addition, similar findings were seen in 116 of 152 patients with a rest MPI (success rate of 53% in group A vs. 96% in group D). CONCLUSION: A combination of solid food and water administered after injection of the tracer and delayed image acquisition led to significant and clinically relevant decrease of interfering upper abdominal activity in 99mTc-tetrofosmin MPI.     

Combined use of bone and bone marrow scintigraphies for the diagnosis of active sacroiliitis: A new approach

Diagnosis of sacroiliitis (SI) with bone scintigraphy may involve difficulties even with a quantitative approach. The aim of this study was to evaluate the combined use of bone and bone marrow scintigraphies for the diagnosis of active sacroiliitis. Thirty-one patients who were clinically suspected to have SI were included in the study. Bone and bone marrow scintigraphies were done after injections of 740 MBq of 99mTc-MDP (MDP) and 370 MBq of 99mTc-sulfur colloid (SC) respectively with a 2-day interval. Both visual and quantitative assessment of MDP uptake and visual assessment of SC uptake in sacroiliac joints were performed. Also sacroiliac joint radiographic findings for each patient were evaluated and graded from 0 to 4 according to the New York grading system. Patients were divided into 2 groups according to their x-ray findings (Group A: grade 0-2, Group B: grade 3-4). A total of 14 patients (10 bilateral, 4 unilateral) had increased MDP uptake with decreased/normal SC uptake. Twelve of 14 patients had grade 0-2 radiographic changes while only 2 patients had grade 3-4 radiographic changes. Increased MDP uptake with decreased/normal SC uptake is the most common scintigraphic pattern seen in acute phase SI in which radiographic findings are generally found to be normal or slightly changed. In at least in 8 patients the decreased bone marrow uptake of SC was demonstrated, supporting the diagnosis. Although our results did not reveal any significant superiority of bone marrow scintigraphy to bone scan for the detection of active sacroiliitis, combined use of bone and bone marrow scintigraphies was presented as an alternative method to characterize patients with active sacroiliitis.     

Chronic osteomyelitis: monitoring by 99mTc phosphate and 67Ga citrate imaging

Thirteen patients with chronic osteomyelitis, treated for 6 months with rifampin, had serial 99mTc phosphate and 67Ga scans to determine their value in assessing response to treatment. In patients who responded to treatment, gallium scans were deemed more accurate than 99mTc phosphate bone scans. The gallium scans, although still abnormal at the end of 6 months of antibiotic therapy, showed an improvement trend in all the responders except one in whom fracture recurred. Worsening or lack of improvement on gallium scans predicted active bone infection in five of six "clinical-failure" patients who had documented active bone infection. 67Ga scans eventually became normal in all patients who remained asymptomatic (excluding one with recurrent fracture). 99mTc phosphate scans became normal in only one of five clinical responders. All nonresponders had persistently abnormal scans, although after 6 months of therapy only four of seven showed worsening or no improvement on the scan. Therefore, 67Ga is preferred over 99mTc phosphate bone scans in the assessment of response to therapy in chronic bone infection. Clinical utility of the gallium scan is most significant in patients whose clinical assessment is uncertain, but routine use of this technique does not appear to be warranted. Gallium images are most valuable when obtained over a period of time, so that the trend of improvement versus nonimprovement is evident.     

Liver metastases from prostate cancer at 11C-Choline PET/CT: a multicenter,retrospective analysis

Aim

During our daily clinical practice using 11C-Choline PET/CT for restaging patients affected by relapsing prostate cancer (rPCa) we noticed an unusual but significant occurrence of hypodense hepatic lesions with a different tracer uptake. Thus, we decided to evaluate the possible correlation between rPCa and these lesions as possible hepatic metastases.

Materials and methods

We retrospectively enrolled 542 patients diagnosed with rPCa in biochemical relapse after a radical treatment (surgery and/or radiotherapy). Among these, patients with a second tumor or other benign hepatic diseases were excluded. All patients underwent 11C-Choline PET/CT during the standard restaging workup of their disease. We analyzed CT images to evaluate the presence of hypodense lesions and PET images to identify the relative tracer uptake. In accordance to the subsequent oncological history, five clinical scenarios were recognized [Table 1]: normal low dose CT (ldCT) and normal tracer distribution (Group A); evidence of previously unknown hepatic round hypodense areas at ldCT with normal rim uptake (Group B); evidence of previously known hepatic round hypodense areas at ldCT stable over time and with normal rim uptake (Group C); evidence of previously known hepatic round hypodense areas at ldCT, in a previous PET/CT scan, with or without rim uptake and significantly changing over time in terms of size and/or uptake (Group D); evidence of hepatic round hypodense areas at ldCT with or without rim uptake confirmed as prostate liver metastases by histopathology, triple phase ceCT, ce-ultra sound (CEUS) and clinical/biochemical evaluation (Group E). We evaluated the correlation with PSA level at time of scan, rim SUVmax and association with local relapse or non-hepatic metastases (lymph nodes, bone, other parenchyma).

Results

Five hundred and forty-two consecutive patients were retrospectively enrolled. In 140 of the 542 patients more than one 11C-choline PET/CT had been performed. A total of 742 11C-Choline PET/CT scans were analyzed. Of the 542 patients enrolled, 456 (84.1%) had a normal appearance of the liver both at ldCT and PET (Group A). 19/542 (3,5%) belonged to Group B, 13/542 (2.4%) to Group C, 37/542 (6.8%) to Group D and 18/542 (3.3%) to Group E. Mean SUVmax of the rim was: 4.5 for Group B; 4.2 for Group C; 4.8 for Group D; 5.9 for Group E. Mean PSA level was 5.27 for Group A, 7.9 for Group B, 10.04 for Group C, 10.01 for Group D, 9.36 for Group E. Presence of positive findings at 11C-Choline PET/CT in any further anatomical area (local relapse, lymph node, bone, other extra hepatic sites) correlated with an higher PSA (p?=?0.0285). In both the univariate and multivariate binary logistic regression analyses. PSA, SUVmax of the rim, local relapse, positive nodes were not associated to liver mets (Groups D-E) (p?>?0.05). On the contrary, a significant correlation was found between the presence of liver metG (group D-E) and bone lesions (

Conclusion

Our results indicate that liver metastases in relapsing prostate cancer may occur frequently. The real incidence evaluation needs more investigations. In this case and despite technical limitations, Choline PET/CT shows alterations of tracer distribution within the liver that could eventually be mistaken for simple cysts but can be suspected when associated to high trigger PSA, concomitant bone lesions or modification over time. In this clinical setting an accurate analysis of liver tracer distribution (increased or decreased uptake) by the nuclear medicine physician is, therefore, mandatory.

     

Differentiation of bone and bone marrow infarcts from osteomyelitis in sickle cell disorders

To determine whether imaging techniques can differentiate osteomyelitis from bone infarction in sickle cell disorders, 39 sets of bone scans (BS) and bone marrow scans (BMS) were performed on 31 patients with sickling disorders and bone pain. In addition, three patients who had either a BS or a BMS were included. Results were analyzed according to whether scans were performed three days or less (Period 1), four to six days (Period 2), or seven or more days (Period 3) after the onset of pain. Regardless of the period, all but five BMS for 34 episodes of assumed infarction showed decreased uptake. BS findings varied depending on the time interval, with none of the ten in Period 1 showing increased uptake, but all 11 in Period 3 showing increased uptake. However, in Period 2, about half of the 13 BS showed increased uptake. All three patients with osteomyelitis in Period 3 had increased uptake on BS. The BMS done in one of these patients showed decreased uptake. Three patients with cellulitis had normal BS and BMS. One patient with septic arthritis had normal BMS, but slightly increased uptake on BS. Although typical imaging patterns are present in early and late infarction (Periods 1 and 3), the patterns for late infarction may not differ from those of advanced osteomyelitis. Therefore, imaging studies are only of value in differentiating infarction from osteomyelitis when both BS and BMS are performed soon after the appearance of symptoms.     

Chronic recurrent multifocal osteomyelitis demonstrated by Tc-99m methylene diphosphonate bone scan

A 12-year-old Middle Eastern girl presented with abdominal pain, weight loss, and intermittent pain in both thighs. She was initially suspected of Crohn disease, but this diagnosis was excluded after extensive gastromedical evaluation. Plain x-rays of the femora were normal, whereas the initial Tc-99m methylene diphosphonate (MDP) bone scan showed several foci with increased activity in both femurs. MR scan showed excessive periostal inflammatory and mild intramedullary changes in both femurs. A percutaneous bone biopsy demonstrated changes consistent with chronic recurrent multifocal osteomyelitis (CRMO). The patient's symptoms disappeared spontaneously, but reappeared 1.5 years later, which led to a new MDP bone scan that showed normal findings.     

Diffuse thoracoabdominal radioactivity seen in bone imaging

Diffusely increased radioactivity in the thoracoabdominal region (lower thorax and/or upper abdomen) occasionally has been observed when performing Tc-99m phosphonate bone studies. To assess the significance of activity in this finding, 1100 bone scintigrams were reviewed and the clinical data and other diagnostic imaging procedures were evaluated in these cases. With the exclusion of Tc-99m sulfur colloid liver-spleen scans 18 patients were found to have mild but diffuse increased radioactivity in the thoracoabdominal region either on the right or left. Clinical findings in these cases with abnormal uptakes were pleural effusions (six cases), hepatic colonic metastases (six cases), splenic metastases from bronchogenic carcinoma (one case), abdominal and peritoneal colonic metastases (one case), a massive metastatic squamous cell carcinoma (from lung) in the right lower chest (one case), and defective radiopharmaceuticals (three cases). Since the defective radiopharmaceuticals contained 5% of hydrolyzed reduced Tc-99m colloid by thin-layer chromatography, each of three patients received approximately 740 mu Ci of Tc-99m sulfur colloid. Factors to be considered in the interpretation of diffuse thoraco-abdominal activity from a bone agent should include splenic or hepatic metastases, a Tc-99m sulfur colloid splenic or hepatic metastases, a Tc-99m sulfur colloid study within the previous 24 hours, pleural effusion, faulty radiopharmaceuticals, and abdominal and peritoneal colonic metastases.     

Necrotizing enterocolitis: assessment of bowel viability with color doppler US

PURPOSE: To determine whether absence of bowel wall perfusion at color Doppler ultrasonography (US) is indicative of bowel necrosis in neonates with necrotizing enterocolitis (NEC). MATERIALS AND METHODS: This study was approved by the research ethics board, and informed consent was obtained. Sixty-two neonates enrolled in the prospective study underwent US of the bowel wall. Neonates were divided into two groups. Group A included 30 control subjects with gestational ages (GAs) ranging from 24 to 41 weeks. Group B included 32 neonates with GAs ranging from 24 to 40 weeks who were clinically proved to have or suspected of having NEC. All neonates in group B underwent abdominal radiography. Normative values were calculated in group A. In group B, the sensitivities and specificities of color Doppler US and abdominal radiography for detection of bowel necrosis were computed by using the modified Bell staging criteria for NEC as the reference standard. RESULTS: Two neonates were excluded from group B; thus, a total of 60 neonates were included in the study. In group A, bowel wall thickness ranged from 1.1 to 2.6 mm. Bowel wall perfusion was detected with color Doppler US in all 30 neonates. Color Doppler signals ranged from one to nine dots per square centimeter. Twenty-two of 30 neonates in group B received a diagnosis of NEC. Mild to moderate NEC was diagnosed in 12 neonates. Color Doppler US depicted an isolated segment of bowel-absent blood flow in two neonates; this finding was confirmed with laparotomy. In 10 neonates with severe NEC, color Doppler US depicted isolated or multiple segments of bowel with absent perfusion. Pneumoperitoneum was present in only four neonates. The remaining eight neonates at risk for NEC had no evidence of loops without perfusion at color Doppler US. The sensitivity of free air at abdominal radiography as a positive sign for severe NEC with necrotic bowel was 40% compared with the 100% sensitivity of absence of flow at color Doppler US (P = .03). CONCLUSION: Color Doppler US is more accurate than abdominal radiography in depicting bowel necrosis in NEC.     

The value of quantitative uptake of (99m)Tc-MDP and (99m)Tc-HMPAO white blood cells in detecting osteomyelitis in violated peripheral bones

Our objective in this study was to evaluate whether measurement of quantitative uptake of (99m)Tc-methylene diphosphate (MDP) and (99m)Tc-hexamethylpropyleneamine oxime (HMPAO) white blood cells (WBCs) is useful in detecting osteomyelitis in peripheral bony lesions. METHODS: Twenty-four patients (12 men and 12 women; age range, 25-72 y) were referred for imaging because of clinically suspected osteomyelitis. They had a traumatic fracture (n = 10), knee prosthesis (n = 5), hip prosthesis (n = 2), diabetic foot (n = 4), or chronic osteomyelitis (n = 3). Three-phase bone scanning and (99m)Tc-HMPAO WBC studies were performed on all patients within the same week. Regions of interest were drawn over the abnormal bony sites and the contralateral normal sites, and the abnormal-to-normal uptake ratios (A/N ratios) were obtained for both studies. RESULTS: All patients had abnormal findings on 3-phase bone scanning, whereas 17 (71%) had abnormal findings on (99m)Tc-HMPAO WBC studies, of which 15 were confirmed to be true-positive. In those 15 patients, the mean A/N ratios for (99m)Tc-MDP and (99m)Tc-HMPAO WBC were 3.0 +/- 1.6 (range, 1.3-6.2) and 1.8 +/- 0.3 (range, 1.4-2.2), respectively. In the other 9 patients, whose scan results were clinically confirmed to be true-negative, the mean A/N ratios for (99m)Tc-MDP and (99m)Tc-HMPAO WBC were 2.1 +/- 1.2 and 1.2 +/- 0.2, respectively. In the group with a (99m)Tc-MDP A/N ratio greater than 2 (n = 15), 87% (13/15) had a high (99m)Tc-HMPAO WBC A/N ratio (>1.5), including 2 that were false-positive. In the remaining 2 patients, one with chronic osteomyelitis and the other with a recent hip prosthesis, (99m)Tc-HMPAO WBC ratios were normal. In the group with a bone A/N ratio of less than 2 (n = 9), only 4 patients (44%) were true-positive for acute osteomyelitis. CONCLUSION: (99m)Tc-MDP bone scanning alone, with an A/N ratio of more than 2, is useful in detecting osteomyelitis in violated bone except in the case of a recent hip prosthesis or chronic osteomyelitis.     

Bone scanning in the diagnosis of acute osteomyelitis

Fifty-nine patients with suspected osteomyelitis were referred to the Nuclear Medicine Service for bone scanning during a twelve month period. The bone scan correctly identified abnormal sites in 18 of 19 patients with osteomyelitis (sensitivity of 95%) while the radiograph detected only 6 of 19 (sensitivity of 32%). In this clinical setting, the bone scans and radiographs had specificities of 92% and 89% respectively. Technetium-99m phosphate radiopharmaceuticals are superior to the previously used isotopes of fluorine and strontium in that they are readily available, can be imaged with conventional instruments, and allow high quality scans to be completed within 4 h. Routine bone scanning should be performed in patients presenting with suspected osteomyelitis and normal radiographs. The scan can be helpful in confirming or excluding the clinical suspicion and can lead to a more rapid institution of appropriate treatment.     

Bone scanning in the diagnosis of acute osteomyelitis

Fifty-nine patients with suspected osteomyelitis were referred to the Nuclear Medicine Service for bone scanning during a twelve month period. The bone scan correctly identified abnormal sites in 18 of 19 patients with osteomyelitis (sensitivity of 95%) while the radiograph detected only 6 of 19 (sensitivity of 32%). In this clinical setting, the bone scans and radiographs had specificities of 92% and 89% respectively. Technetium-99m phosphate radiopharmaceuticals are superior to the previously used isotopes of fluorine and strontium in that they are readily available, can be imaged with conventional instruments, and allow high quality scans to be completed within 4 h. Routine bone scanning should be performed in patients presenting with suspected osteomyelitis and normal radiographs. The scan can be helpful in confirming or excluding the clinical suspicion and can lead to a more rapid institution of appropriate treatment.