Blood Cell Scintigraphy Research Articles

Fever of unknown origin in pediatrics: role of nuclear medicine.

Fever of unknown origin (FUO) is a debated issue in numerous scientific studies in adult patients with a not jet-defined workflow in a clinical and diagnostic setting. Few works are published about pediatric patients even if FUO represents a challenging, not infrequent scenario in hospital and outpatient recovery. The fever might be the onset symptom of a transient mild infection or the beginning of a more difficult-to-diagnose and serious pathological condition. In the adult workflow 18FDG PET-CT is nowadays playing a relevant role, considering the limited spread of conventional 99mTc-HMPAO-White Blood Cells scintigraphy. It represents a robust tool for diagnosing the eventual site of infection, but it is limited by procedural complexity and long duration, up to 24 hours. The WBC-scintigraphy is also not suitable for children, only for young adults or adolescents, considering the relevant blood sample entity and the procedural risk for sensitive subjects. The most assessed clinical and diagnostic know-how on Pediatric FUO are summarized and a synthetic flow-chard is presented to support the clinical management and to choose the best diagnostic pathway.

Umbilical Varices: A Potential Pitfall in Gastrointestinal Bleed Scintigraphy Interpretation.

Tc-99m labeled red blood cell (RBC) scintigraphy is commonly used in the evaluation of acute gastrointestinal (GI) bleeding. On Tc-99m RBC studies, GI bleeding is seen as an initial focus of increased radiotracer activity that on subsequent images increases in intensity and changes position in a pattern that confirms to segments of bowel. We report a case of a patient with multiple episodes of GI bleeding referred to detect the source of bleeding. A Tc-99m labeled RBC scan was performed and the findings showed a focal abnormal hot spot in the mid quadrant of the abdomen, seen promptly in initial dynamic images. Subsequent static and single-photon emission computed tomography-CT (SPECT-CT) images found it to be umbilical varices. Most varices fill promptly as in this case and should not be misinterpreted as a focus of hemorrhage. SPECT-CT should be used in such cases so that that false-positive interpretation can be avoided.

The application of technetium-99m-red blood cell scintigraphy in the diagnosis of orbital cavernous hemangioma.

ObjectiveThe purpose of this study was to evaluate the clinical value of technetium-99m-red blood cell (99mTc-RBC) scintigraphy in the diagnosis of orbital cavernous hemangioma (OCH).Patients and methodsForty-one patients with pathologically confirmed orbital mass, of which 10 were OCH, underwent 99mTc-RBC scintigraphy in this study. The scanning procedure included an initial perfusion phase, followed by an early and a delayed blood pool phase. All patients underwent ultrasonography and computed tomography (CT), and 15 patients also underwent MRI.ResultsAll 10 OCH patients had no abnormal findings on radionuclide angiographic images and early blood pool phase, but increased activity was found during delayed blood pool phase. All other non-OCH orbital tumours did not have this tracer pattern. The radioactivity ratios of tumour to nontumour were 2.96±0.05 and 1.14±0.25, respectively, which had a statistically significant difference (t=15.18, P<0.001). Although nine of 10 OCH patients were diagnosed correctly with one false-positive case using ultrasound, both CT and MRI could not provide a definitive diagnosis.Conclusion99mTc-RBC scintigraphy is a reliable and useful procedure for the diagnosis of OCH. It may be considered as one of the routine clinical screening tools for the diagnosis of OCH and as a complement investigation to ultrasonography and CT.

A rare cause for severe recurrent lower gastrointestinal bleeding in a 12 year old patient

Abstract The cause for severe, recurrent lower gastrointestinal (LGI) bleeding in children can usually be diagnosed readily by means of the commonly used investigative/diagnostic techniques such as colonoscopy, laparoscopy ± laparotomy. Occasionally less commonly used investigations may be necessary to look for more elusive causes of LGI bleeding such as capsule endoscopy, angiography, technetium-99m (99m Tc)-labeled red blood cell (RBC) scintigraphy, cross-sectional imaging such as CT/MRI (including angiography) and laparotomy combined with on-table small bowel enteroscopy. We report a case of severe, recurrent LGI bleeding that had occurred over several years, where the cause remained elusive despite numerous investigations and interventions. The etiology of this was eventually found to be a gastric duplication cyst infiltrating into adjacent transverse colon and causing bleeding from peptic ulceration in the colon. The process by which this diagnosis was made and the lessons learned are discussed.

Evaluation of Bone or Soft Tissue Infection with Tc-99m Hmpao White Blood Cell Scintigraphy: Semiquantitative Method

Objective: Aim the aim of this study was to investigate semiquantitatively the diagnostic performance of Tc-99m hexamethypropylene amine oxime labeled white blood cell (Tc-99m HMPAO-WBC) scintigraphy in patients with suspected bone or soft tissue infections. Methods: Material and Method twenty one patients who applied to Nuclear Medicine Departmant (for suspected prosthesis infection, diabetic foot, bone infection, graft infection) were evaluated retrospectively. Tc-99m HMPAO WBC scintigraphy imaging were performed to all patients. Planar images were taken 1., 2., and 4. hours after injecting the labeled leukocytes. Evaluation of infection with Tc-99m HMPAO WBC scintigraphy was done semiquantitatively. Relative uptake was determined by setting the region of interest (ROI) of lesion area on the anterior view. Rectangular ROI was set on the against limb (nonlesion). The ratio of the average pixel count in the lesion (L) to that in the non-lesion (NL) (L/NL ratio) was calculated at 1., 2., and 4. hours images. Final diagnosis was based on histopathology, microbiologic assays, or clinical and imaging follow-up. Results: 0.55 and 1.55±0.74, 1.42±0.55, 1.40±0.55 in positive and control groups, respectively. Positive group revealed a statistically significant increase L/NL values in the data 3 hours images (p=0.002). However, no statistically significant was found between L/NL values in 3 hours imaging data in control group (p=0.223). All the data in the positive group found Zehra Pinar Koc1, Yasemin Bulut2, Sinan Canpolat3, Ayhan Uysal4, Mehmet Sarac5 1Firat University Faculty of Medicine, Department of Nuclear Medicine, Elazig, Turkey 2Firat University Faculty of Medicine, Department of Clinic Microbiology, Elazig, Turkey 3Firat University Faculty of Medicine, Department of Phsiology, Elazig, Turkey 4Firat University Faculty of Medicine, Department of Cardiovascular Surgery, Elazig, Turkey 5Firat University Faculty of Medicine, Department of Pediatric Surgery, Elazig, Turkey Evaluation of Pulmonary Infection in Rabbits by Tc-99m Hmpao Labeled Leukocyte Scintigraphy

Reply to comment by Koranda: 99mTc-HMPAO-labelled leucocytes in musculoskeletal infections—the choice of reference tissue for a semiquantitative analysis

Dear Sir, We thank Dr. Koranda for his comment and questions [1] regarding our article aimed at defining the best image acquisition protocols and interpretation criteria for white blood cell (WBC) scintigraphy with Tc-HMPAO-labelled leucocytes in musculoskeletal infections [2]. As a conclusion of our retrospective study, we recommend using a dual acquisition protocol with acquisition times of 3–4 h and 20–24 h after reinjection. Acquisition times for the scans have to be corrected for decay of the radionuclide and the images should be displayed with the number of counts and the same intensity scale, making comparisons between images possible without observer bias. Visual analysis, in the majority of cases, is sufficient for diagnosis. Increased uptake or enlargement of area of uptake over time is considered positive for an infection, whereas a decreased or stable uptake over time is considered negative for an infection. In all major subgroups of patients (suspected infected hip prosthesis, suspected infected knee prosthesis, suspected osteomyelitis, suspected infected osteosynthesis), visual analysis showed better sensitivity, specificity and diagnostic accuracy compared to semiquantitative analysis. However, in cases where visual analysis does not allow an easy interpretation and diagnosis, there is an added value of applying a semiquantitative analysis. Increase of a lesion to reference tissue (L/R) ratio over time is considered positive for an infection. Dr. Koranda questioned the reference sites that were used for the semiquantitative analysis. In our study we compared four different reference regions: contralateral tissue, ipsilateral bone marrow, contralateral bone marrow and the anterior superior iliac crest. However, calculation of background in all regions was not always possible. In some cases the anterior superior iliac crest was not in the field of view, and sometimes also bone marrow (ipsior contralateral) was not visible. We were able to calculate (in a total of 297 patients) L/R ratios in 285 patients for contralateral tissue, in 169 patients for ipsilateral bone marrow, in 177 patients for contralateral bone marrow and in 73 patients only for the anterior superior iliac crest. Overall, the diagnostic accuracy for the contralateral tissue was the best (84.2 %) as compared to 81.7 % for ipsilateral bone marrow, 76.8 % for contralateral bone marrow and 82.2 % for the anterior superior iliac crest. Dr. Koranda states that the diagnostic accuracy of the method using the anterior superior iliac crest as a reference region was determined in the subgroup of patients with infected hip prosthesis only and that the diagnostic accuracy of all other methods was calculated for larger groups of patients [1]. Indeed, in the infected hip prosthesis subgroup all four reference regions were calculated and, of course, in this group we were able to calculate a relatively high number of anterior superior iliac crests as reference tissue compared to the other groups, since this reference region was mostly included in the field of view. However, even in eight patients with a suspected infected hip prosthesis, the anterior superior iliac crest was not in the field of view or was only visible with superimposed bowel uptake. A. W. J. M. Glaudemans (*) : E. F. J. de Vries :R. H. J. A. Slart : R. A. J. O. Dierckx :A. Signore Department of Nuclear Medicine andMolecular Imaging, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands e-mail: a.w.j.m.glaudemans@umcg.nl

Incidental detection of a bleeding gastrointestinal stromal tumor on Tc-99m red blood cell scintigraphy

The role of 99m-technetium labeled red blood cell (RBC) scintigraphy in acute gastro-intestinal bleed is well-established. The authors report a case of a bleeding gastrointestinal stromal tumor (GIST) incidentally discovered on Tc-99m RBC scintigraphy.

Multiple ileal ulcers and an ileal Dieulafoy's lesion induced by loxoprofen sodium

Loxoprofen sodium is one of the non‐steroidal anti‐inflammatory drugs (NSAIDs) that is a prodrug. Several adverse effects of the drug have been described, but ileal ulcer has not been reported so far. We experienced an 87‐year‐old male patient with disk herniation complicated with loxoprofen sodium‐induced multiple ileal ulcers and an ileal Dieulafoy's lesion that caused massive intestinal bleeding. The patient was saved by wedge resection of the Dieulafoy's lesion and discontinuance of the NSAID. 99mTc‐red blood cell scintigraphy and intraoperative enteroscopy of the small bowel were useful in the diagnosis. This is the first case of multiple ileal ulcers with an ileal Dieulafoy's lesion induced by loxoprofen sodium.

Hemangiomas of the maxillofacial area. Usefulness of 99cm-labelled red cell scintigraphy

Recent work reports the usefulness of radionuclides in the study of hepatic hemangiomas. In particular, 99Tcm-red blood cell (RBC) scintigraphy is useful to evaluate the vascularization and to plan the therapy. The aim of this paper is to confirm the usefulness of 99Tcm-RBC scans in the detection and follow-up of maxillofacial hemangiomas. Results using this technique in a selected group of patients with maxillofacial hemangiomas are reported.

Periarticular bone sites associated with traumatic injury: false-positive findings with In-111-labeled white blood cell and Tc-99m MDP scintigraphy.

The authors evaluate the reliability of combined indium-111-labeled white blood cell (WBC) and technetium-99m methylene diphosphonate (MDP) bone scan interpretations at sites of suspected periarticular osteomyelitis with radiographic evidence of adjacent traumatic arthropathy. A review of all orthopedic patients who underwent In-111 WBC-Tc-99m MDP scintigraphy over a 7-year period revealed a subset of 32 such cases that also included results of bone-biopsy cultures. Twenty-eight patients had a history of traumatic intraarticular injury, and four had periarticular fracture malunion or nonunion. Compared with intraoperative culture results, blinded In-111 WBC-Tc-99m MDP scan interpretations included four true-positive, 17 true-negative, and 10 false-positive results, and one false-negative result. The predictive values for positive and negative scans were 28% and 94%, respectively. A high prevalence of false-positive In-111 WBC-Tc-99m MDP scans may occur at periarticular sites of patients with associated traumatic arthropathy. This reduces the specificity of this technique for osteomyelitis, making culture confirmation of positive scans necessary. A negative scan is highly predictive of negative culture results at these sites.

Limitations of Indium Leukocyte Imaging the Diagnosis of Spine Infections for

The usefulness of indium-111 white blood cell (WBC) scintigraphy in the detection of spine sepsis was studied in 22 patients who had open or percutaneous biopsies for microbiologic diagnosis. The indium images in 18 patients with vertebral infection were falsely negative in 15 (83%) and truly positive in 3 (17%). All four patients with negative cultures and histology had true-negative scans. The indium-111 WBC imaging results yielded a sensitivity of 17%, a specificity of 100%, and an accuracy rate of 31%. Prior antibiotic therapy was correlated with a high incidence of false-negative scans and photon-deficient indium-111 WBC uptake. The usefulness of indium-111 WBC scintigraphy for the diagnosis of vertebral infection may be limited to those patients who have not been treated with antibiotics previously.