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PubMed2001

Demonstration of different patterns of musculoskeletal, soft tissue and visceral involvement in melioidosis using 99m Tc stannous colloid white cell scanning.

Melioidosis is an infectious disease that can present with multiple foci of disease involvement. Assessment of disease extent can be difficult, especially in musculoskeletal, visceral and soft tissue infection. This study examined the usefulness of white cell scans in this condition. 99mTc stannous colloid white cell scanning was performed in 21 patients with culture-proven melioidosis. Scan results were compared with clinical assessment and correlated with other forms of imaging. White cell scans demonstrated all but one of the clinically apparent sites of musculoskeletal, visceral and other soft tissue infection. Unsuspected disseminated soft tissue lesions were seen in two patients, including femoral node uptake in both, and these patients subsequently presented with relapsing musculoskeletal disease. Unsuspected musculoskeletal disease was found in one patient. Clinically suspected musculoskeletal disease was accurately excluded by white cell scan in another patient. The results of white cell scanning were also examined in disease of other viscera. Renal and prostatic disease were visualized. Unsuspected parotid involvement was found in two patients. Only one of two spinal lesions was visualized. Pulmonary disease was not necessarily associated with abnormal uptake. White cell scanning is a quick and effective way of assessing the extent of musculoskeletal, visceral and soft tissue disease in melioidosis.

Adult↗
PubMed2001

Different patterns of lymphoscintigraphic findings in patients with intestinal lymphangiectasia.

Technetium-99m antimony sulfide colloid lymphoscintigraphy conveniently demonstrates intestinal leakage of lymph in patients with intestinal lymphangiectasia. However, we found no intestinal radioactivity in some patients. We evaluated lymphoscintigraphic findings and compared them with clinical data. Technetium-99m antimony colloid lymphoscintigraphy was performed in 12 patients (age, 8.9+/-6.4 years; male:female=8:4) with histologically proven intestinal lymphangiectasia. After subcutaneous injection of 103.6 MBq of technetium-99m antimony colloid into the webs of both feet, sequential abdominal images were obtained up to 24 h post-injection. Four patients underwent technetium-99m methylene diphosphonate bone scintigraphy. Patients were divided into two groups according to the presence or absence of intestinal radioactivity. Five showed intestinal activity (Group 1), but seven did not (Group 2). No Group 1 patient had a history of ascites, while all Group 2 patients had ascites as the initial manifestation. Serum total protein and albumin levels were significantly lower in Group 1 patients than in Group 2 patients. In three Group 1 patients, technetium-99m methylene diphosphonate bone scintigraphy revealed intestinal radioactivity, while in one Group 2 patient this was not found. We observed two types of lymphoscintigraphic pattern in patients with intestinal lymphangiectasia. To clarify the exact pathophysiology, further study is required.

Adolescent↗
PubMed2003

99mTc-SnF2 colloid "LLK": particle size, morphology and leucocyte labelling behaviour.

99mTc-SnF2 colloid (Radpharm LLK) leucocyte labelling agent is used in whole blood, exploiting phagocytosis. The objectives of this work were to optimize leucocyte labelling in leucocyte-enriched plasma, and to investigate: (i) the effect of temperature and other factors on labelling efficiency; (ii) the selectivity for different leucocyte types; (iii) the viability of the labelled cells and efflux of the radiolabel; and (iv) the physical characteristics of the colloid. Density gradient centrifugation was used to investigate the labelling efficiency, cell selectivity and efflux, Trypan blue to study the viability, and laser scattering, electron microscopy and membrane filtration to investigate particle size and morphology. Particles appeared as loose, coiled, chain-like aggregates of much smaller particles (<0.05 microm). The aggregate diameter ranged from <0.1 to >5 microm and increased with time. The distribution of radioactivity amongst the particle sizes varied widely. The labelling efficiency in leucocyte-rich plasma was enhanced at 37 degrees C compared to room temperature, and by centrifuging during labelling. The selectivity for different leucocyte types varied markedly between batches and blood samples, in some cases showing preference for mononuclear cells and in others for granulocytes. Viability was excellent and comparable with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO)-labelled cells. A significant fraction of radiolabel, comparable to that observed with 99mTc-HMPAO, was lost from leucocytes during incubation in vitro over 4 h. Thus, 99mTc-SnF2 is a convenient, efficient labelling agent for leucocytes, but shows variable cell selectivity which may be linked to particle size variability, and there is significant efflux of radioactivity from labelled cells.

Cell Survival↗
PubMed2003

Sentinel node detection using 99mTc-rhenium sulphide colloid in breast cancer patients: evaluation of 1 day and 2 day protocols, and a dose-finding study.

Sentinel node (SN) biopsy is a promising replacement for standard axillary lymph node dissection for the staging of early breast cancer, and various techniques have been studied to identify SNs with dye or radioactive colloid. This study assesses the effect of the dose of radioactivity and the time before biopsy in order to set standards for the use of 99mTc-rhenium sulphide for the detection of SNs in breast cancer patients. Sixty patients with stage T1-2 N0 M0 breast cancer underwent SN biopsy, which was immediately followed by standard axillary dissection to confirm the SN results. For SN biopsy, 99mTc-rhenium colloid was injected peritumorally. A 1 day (morning injection and afternoon surgery) or 2 day (day before afternoon injection and morning surgery) protocol was applied. A dose-finding study was performed simultaneously using 7.4-37 MBq for the 1 day protocol and 37-74 MBq for the 2 day protocol. A scintigram was taken at 2 h for the 1 day protocol and 16 h for the 2 day protocol. After the injection of blue dye, SN biopsy was performed with a gamma probe, followed by standard axillary node dissection. The radiation exposure received by the surgical team during the operation was monitored. Histopathological comparison between SNs and axillary nodes was performed. Patient characteristics that might affect the radiocolloid uptake by SNs were assessed. SNs were identified in all patients regardless of the dose or administration protocol used. Two patients showed false negative pathological SN results, and the negative predictive value was 96% and the positive predictive value was 100%. In addition, radiation exposure to the surgical team and the amount of radioactive surgical waste were low, especially at lower doses. Two groups of patient characteristics were related to SN uptake. One was the body mass index (BMI) and the other was the age or menopausal status. Patients with a larger BMI tended to take up a smaller amount of 99mTc colloid. Older or post-menopausal patients showed lower SN uptake. 99mTc-rhenium sulphide colloid is an efficient radiopharmaceutical for SN detection. Both 1 day and 2 day protocols have equally good efficacy, and the recommended dose is 7.4 MBq for the 1 day protocol and 37 MBq for the 2 day protocol. Patients with larger BMI and older or post-menopausal patients tend to take up less 99mTc colloid.

Adult↗
PubMed2004

Concentration of 99mTcO4-/188ReO4- by a single, compact, anion exchange cartridge.

BACKGROUND: This paper describes a simple and inexpensive post-elution anion exchange cartridge system for the concentration of 99mTcO4-/188ReO4-. METHOD AND RESULTS: The system is based on generator elution with a mixture of 0.7 M acetic acid and 0.0225 M sodium chloride instead of physiological saline to provide high specific volume solutions of 99mTc and 188Re from 99Mo-99mTc and 188W-188Re generators, respectively. The passage of the bolus through an amine-type (Accell Plus QMA Sep-Pak) anion exchange cartridge results in trapping of the microscopic levels of the pertechnetate or perrhenate. Subsequent elution of the anion exchange cartridge with 2 ml of saline then provides high specific volume solutions of pertechnetate or perrhenate. CONCLUSION: This new approach works effectively to obtain concentrated solutions of 99mTcO4- and 188ReO4- from commercially available alumina based Mo-Tc and W-Re generators, respectively.

Anion Exchange Resins↗
PubMed1997

An investigation of lymphatic function following free-tissue transfer.

Despite microsurgical advances in the repair of severed arteries, veins, and nerves, disrupted lymphatics are not usually identified or reconnected during replantation. Although temporary swelling of a replanted part is attributed to lymphedema, this condition resolves without microsurgical intervention. Spontaneous regeneration or reconnection of lymphatics is thought to occur in such situations. Microsurgical free-flap transfer is clinically analogous to replantation in that it also results in a complete division of all lymphatic channels exiting the flap. The ability of lymphatics to regenerate after flap reconstruction, either pedicled or free, has received little attention because safe and accurate techniques for visualization and evaluation of the status of these structures have not been available. As a result of recent advances in radiocolloid lymphoscintigraphic imaging techniques, it is possible to demonstrate lymphatic flow in a physiologic, anatomic, and noninvasive manner. These methods can be applied to free-flap models to document lymphatic function after surgical treatment and determine when and to what extent such a process of growth occurs. We studied 10 consecutive patients having free-flap reconstruction. These flaps were performed for chronic osteomyelitis (6) and unstable wound coverage (4). Microvascular flaps used were latissimus dorsi, scapular-parascapular fasciocutaneous, lateral arm, rectus abdominis, temporoparietal, and free toe. Radiocolloid lymphoscintigraphy with technetium-99m-antimony trisulfide colloid (Sb2S3) was done on all patients by injection directly into the free-flap dermis. All patients were studied between 8 and 44 days (mean 23.6) after free-flap transfer. Following injection into each flap, rapid egress of the radiotracer along lymphatic pathways with progression to locoregional nodes was observed in all patients. Reestablishment of lymphatic pathways following microvascular free-tissue transfer was demonstrated by radionuclide lymphoscintigraphic techniques in 10 consecutive patients who had reconstruction for extremity wounds.

Adolescent↗
PubMed1998

Unilateral absent pulmonary perfusion due to bronchogenic carcinoma.

Ventilation-perfusion lung scans are commonly done in the diagnosis of pulmonary thromboembolic disease. We describe a patient in whom absent perfusion involving an entire lung was due to bronchogenic carcinoma. Echocardiography and chest computed tomography were essential tests in evaluating a nonembolic etiology.

Bronchoscopy↗
PubMed1997

Single-dose isotope injection for both preoperative lymphoscintigraphy and intraoperative sentinel lymph node identification in melanoma patients.

For patients with melanoma the 'sentinel' lymph node biopsy technique, although simple in concept, has the potential to provide misleading information if great care is not taken to ensure accurate sentinel node (SN) identification. The method initially reported involved lymphatic mapping by injection of blue dye around the primary melanoma site. Preoperative lymphoscintigraphy was subsequently shown to improve both the speed and accuracy of SN identification. More recently, intraoperative use of a hand-held gamma probe has been recommended, and it is likely that maximum reliability of SN biopsy will be achieved if all three manoeuvres are undertaken. As originally described, use of a gamma probe intraoperatively followed injection of tracer a short time before the surgical procedure. We report a simpler method of confirming SN identity with a gamma probe, using residual activity in the node following lymphoscintigraphy the previous day. In 21 patients close concordance with preoperative lymphoscintigram results and intraoperative findings after blue dye injection confirmed the reliability of the technique. Avoiding the need for repeat isotope administration on the day of surgery simplifies logistics, reduces costs, minimizes inconvenience and radiation dose for patients, and eliminates potential health and safety problems for operating theatre staff.

Antimony↗
PubMed1998

Variability of cutaneous lymphatic flow rates in melanoma patients.

Preoperative lymphoscintigraphy was performed in 198 consecutive patients with cutaneous melanoma prior to their definitive surgical treatment. After intradermal injection of antimony sulphide colloid labelled with technetium-99m, lymphatic flow rates were measured in each patient and found to vary according to the location of the primary tumour. The fastest flow rates occurred from melanoma sites on the distal limbs, particularly the lower limbs. The slowest flow rates were from the head and neck region and the proximal limbs, especially the upper arms and shoulders. Lack of flow in the early dynamic images occurred most commonly for tumours on the upper arms and shoulders. These results can be used to optimize the timing of blue dye injection prior to surgery and may influence the sentinel node biopsy method to be used in individuals who show no early drainage.

Antimony↗
PubMed2003

Skull base osteomyelitis secondary to malignant otitis externa.

PURPOSE OF REVIEW: Skull base osteomyelitis secondary to malignant otitis externa was first described in 1959. Since then, advances have been made in the diagnosis, treatment, and clinical outcomes of this condition. RECENT FINDINGS: This review discusses the pathophysiology and microbiology of malignant otitis externa. The review highlights the sometimes subtle presenting symptoms and recent advances in imaging and their practical application to diagnosing and monitoring the disease. Therapy for malignant otitis externa has changed since this entity was first described; this article reviews the medical, surgical, and adjuvant therapies and the relevant controversies. SUMMARY: The review discusses the history, pathogenesis, diagnosis, and treatment of skull base osteomyelitis in the context of malignant otitis externa with particular emphasis on HIV, children, and other immunodeficient states.

AIDS-Related Opportunistic Infections↗
PubMed1995

Physiological responses, organ distribution, and circulation kinetics in anesthetized rats after hypovolemic exchange transfusion with technetium-99m-labeled liposome-encapsulated hemoglobin.

Physiological responses and circulation properties of liposome-encapsulated hemoglobin (LEH) labeled with technetium-99m (99mTc) were measured in rats after a 10% (170 mg/kg hemoglobin; 430 mg/kg phospholipid) or a 50% (450 mg/kg hemoglobin, 2.3 g/kg phospholipid) hypovolemic exchange transfusion (n = 5 per exchange group). Mean arterial pressure returned to baseline values (105 +/- 8 mmHg) by 90 min post-infusion for both groups. By 20 h, mean arterial pressure remained at baseline values for the 10% group, but dropped to 30 +/- 14 mmHg for the 50% group. For both groups, bradycardia was seen after the exchange period, but heart rate recovered by 30 min for the 10% group and by 90 min for the 50% group. The 99mTc-LEH remained in circulation longer for the 50% group (18.2 h half-life) than for the 10% group (2.4 h half-life). Removal of 99mTc-LEH from the bloodstream was via the liver and spleen. At 20 h, 99mTc-LEH accumulation in these organs was greater for the 10% group (liver, 36.2 +/- 1.7%; spleen, 37.5 +/- 2.5%) than for the 50% group (liver, 17.0 +/- 1.4%; spleen, 17.1 +/- 1.4%). The data show that there is less clearance of 99mTc-LEH from the bloodstream by the reticuloendothelial system after a 50% hypovolemic exchange transfusion, thus supporting the possible use of LEH as an oxygen-carrying resuscitative fluid in situations of severe blood loss.

Anesthetics↗
PubMed1997

Fifth metacarpal stress fracture in a female softball pitcher.

PURPOSE: This article describes a previously unreported fifth metacarpal stress fracture. CASE SUMMARY: A female softball pitcher presented with gradual development of dorsal pain in her pitching hand. A radioisotope scan showed increased uptake in the fifth metacarpal. This supported a clinical diagnosis of a stress fracture, and the patient was treated with a period of relative rest. At 6 weeks, the patient was able to return to pitching with technique modification. DISCUSSION: Seven cases of metacarpal stress fractures have been reported, yet none involved the fifth metacarpal. The causes of a fifth metacarpal stress fracture differ from those of other metacarpals and may be a combination of extrinsic forces from the ball and intrinsic forces from muscle pull. Although treatment involves the standard rest period, technique must be assessed and appropriately adjusted. RELEVANCE: Metacarpal stress fractures should be considered in athletes with persistent hand pain where repetitive grip function is used.

Adolescent↗
PubMed2003

99mTc-peptide-peptide nucleic acid probes for imaging oncogene mRNAs in tumours.

Imaging oncogene mRNA in tumours would provide a powerful tool for the early detection of occult malignant lesions. The goal was to prepare a chimera consisting of a dodecamer antisense peptide nucleic acid (PNA) specific for c-MYC oncogene overexpressed in human breast cancer cells and a chelating moiety that facilitates quantitative radiolabelling with 99mTc and evaluate it for hybridization and tissue distribution in laboratory animals. The pentapeptide chelator-PNA dodecamer specific for c-MYC mRNA was extended from a solid support by 9-fluorenylmethyloxycarbonyl (Fmoc) coupling. Similarly, a chelator-PNA chimera with four central mismatches was also prepared which served as a control. The chimeras were purified, characterized and evaluated for hybridization to c-MYC mRNA by fluorescent, real-time polymerase chain reaction (RT-PCR). The chimeras were labelled with 99mTc and their tissue distribution was examined in athymic nude mice bearing experimental human breast tumours. 99mTc radiolabelling was quantitative and presented a single peak in reversed phase liquid chromatography. Fluorescent real-time polymerase chain reactions using primer and fluorescent probe sets previously calculated for c-MYC mRNA demonstrated inhibition of reverse transcription by the c-MYC specific chimera as compared to that of the control. Tissue distribution studies of antisense and mismatch chimeras at 4 h and 24 h after administration displayed modest accumulation in the liver, and appreciable levels in tumours. These observations suggest that 99mTc-peptide-PNA probes might be useful for imaging gene expression in tumours, and the approach is worthy of further investigation.

Animals↗
PubMed2006

Colloid scintigraphy in non-alcoholic steatohepatitis: a conventional diagnostic method for an emerging disease.

AIM: Non-alcoholic steatohepatitis (NASH) is a progressive liver disease characterized by diffuse fatty infiltration and Kupffer cell dysfunction which contributes to its pathogenesis. Since the liver biopsy, which is considered the 'gold standard' in diagnosing NASH, has some limitations other imaging methods have been explored as alternatives. Colloid scintigraphy is a good method reflecting Kupffer cell activity and we found it worthwhile to evaluate this technique in NASH. We aimed to present the common scintigraphic features and their clinicopathologic correlations in NASH. METHODS: Twenty-two new patients (11 female, mean age 43.7+/-10.8) with biopsy-proven NASH underwent colloid liver scintigraphy. The dynamic, static and SPECT images were performed after intravenous injection of 185 MBq Tc tin colloid. Hepatic perfusion, blood pool clearance time, colloid shift to spleen and bone marrow were assessed and liver right/left lobe ratio was calculated. RESULTS: The values calculated on static and tomographic (SPECT) images showed good correlation. Liver right/left lobe ratio was altered in all patients. Blood pool clearance time was prolonged in seven (32%) but hepatic perfusion was normal in all patients. Colloid shift to the spleen was observed in 55% of patients using SPECT analysis. No correlation between scintigraphy parameters and histological or biochemical findings were observed. CONCLUSION: Altered liver right/left lobe ratio was the universal finding in all our NASH patients. Other common scintigraphic features of NASH include colloid shift to spleen and prolonged blood pool clearance time. Liver scintigraphy might be a promising non-invasive tool in the follow-up of NASH patients in therapeutic trials.

Adult↗
PubMed2003

Impact of internal mammary sentinel node imaging in breast cancer.

A 28-year-old woman underwent mammary lymphoscintigraphy for evaluation of the sentinel node status of a small infiltrating ductal carcinoma in the central, lower, and outer quadrant of the left breast confirmed by biopsy. The patient was scheduled for lumpectomy and sentinel node biopsy. Lymphoscintigraphy showed increased uptake at two sites of the peritumorally injected tracer (60 MBq; 1.6 mCi rhenium sulfur nanocolloid) in internal mammary nodes, two of which were located most proximal to the tumor and related to the tumor by two distinct lymphatic ducts. An axillary lymph node was also detected. At surgery, the gamma probe confirmed the location of all the hot spots, and four nodes were harvested: one axillary, two first internal mammary nodes in the third intercostal space, and one internal mammary node in the second intercostal space. Histologic analysis revealed that the axillary sentinel node was free of disease, but the two first intramuscular sentinel nodes were metastatic. The second-echelon internal mammary node above the sentinel nodes (second intercostal space) was free of disease. This case shows the benefit of imaging all the drainage pathways of a breast tumor and retrieving nonaxillary lymph nodes, which may be the only positive nodes. As a result of the findings, the patient's prognosis may be altered and the subsequent therapeutic approach may be modified. Although exclusive involvement of the internal mammary chain is well established and relatively rare (occurring in approximately 5% of cases), it is important to remember that the axillary status of a breast tumor is not the only major prognostic factor.

Adenocarcinoma↗
PubMed2003

Sentinel node mapping in patients with malignant melanoma using melanoma Tc-99m colloidal rhenium sulfide.

PURPOSE: The aim of the study was to localize the sentinel lymph node using lymphoscintigraphy aided by Tc-99m colloidal rhenium sulfide. MATERIALS AND METHODS: Thirty consecutive patients with histologically proved melanoma, but no clinical evidence of metastases, were examined before operation by injecting 20 to 40 MBq (0.5 to 1.1 mCi) Tc-99m colloidal rhenium sulfide with a mean particle size of 100 nm (range, 50 to 200 nm) intradermally around the lesion. Lymphoscintigraphy was performed immediately after injection. In addition, blue dye was injected before operation. A hand-held gamma probe guided the sentinel node biopsy. RESULTS: Lymphoscintigraphy revealed hot spots in all patients. During surgery, the sentinel node was identified in all 30 patients. The number of sentinel nodes per patient ranged from 1 to 4 (mean, 1.9). Histologic examination confirmed the metastatic involvement of the sentinel lymph node in 11 of 30 patients. The sentinel lymph node-positive rate was 22.4%, which was comparable to findings using Tc-99m-labeled nanocolloids. CONCLUSION: The findings indicate that Tc-99m-bound colloidal rhenium sulfide is suitable for sentinel node mapping.

Adult↗