Intérêt de l’imagerie hybride TEMP-TDM dans l’exploration des infections

Single-Photon Emission Computed Tomography-Computerized Tomography (SPECT-CT) is a new hybrid technique which offers new diagnostical capabilities in daily nuclear medicine practice. This technique not only allows to acquire fusioned anatomic and functional images in the same time, but also, it increases sensitivity and accuracy of SPECT thanks to attenuation and scattering corrections got from transmission data. Until now, SPECT-CT data have been mainly obtained in oncology and cardiology, but now, many authors use it in many scan studies and particularly for infectious diseases. In inflammatory bowel diseases, SPECT-CT seems to increase diagnostical performances and to modify management of many patients. In suspected vascular sepsis, SPECT-CT could increase sensitivity of white blood cell scintigraphy but also its specificity thanks to spatial resolution of CT. In osteoarticular sepsis, SPECT-CT has the advantage to distinguish osteomyelitis from soft tissue infection and to guide biopsies. Nevertheless, in the light of PET-CT works, SPECT-CT development will probably modify nuclear medicine practice and many studies have to be conducted to highlight consensual procedure guidelines.     

Intérêt de l’imagerie hybride TEMP/TDM pour la scintigraphie des récepteurs de la somatostatine dans le bilan des tumeurs endocrines gastro-entéro-pancréatiques

In this work, we have evaluated the potential of image fusion and attenuation correction (AC) of SPECT-CT imaging for the assessment of gastro-entero-pancreatic endocrine tumors by somatostatin receptor scintigraphy (SRS).MethodAfter optimisation of acquisition and reconstruction parameters, we have evaluated, in a prospective study, SRS performed over a period of one year. We have compared visual interpretations of planar and tomographic images versus SPECT/CT images to determine if anatomical localisation and diagnostic contributions are improved. In a semi-quantitative analysis of pathological foci, we have measured maximal intensity values (T_max), tumour to background ratios (T/B) and tumour contrasts (Ct) with and without AC.ResultsIn 25 SRS, visual analysis has shown anatomical localisation improvements in 60% of cases (CI95%, 39–79) and diagnostic improvements in 64% of cases (CI95%, 43–82). Doubtful foci proportion changed from 44 to 11%. In the semi-quantitative analysis of 41 pathological foci, Wilcoxon matched-pairs tests showed significantly higher T_max, T/B and Ct values after AC.ConclusionSPECT/CT imaging improves diagnostic quality of SRS thanks to a better foci localisation and a better lesional contrast in the image.     

Intérêt de l’imagerie hybride TEMP-TDM dans l’histiocytose langerhansienne osseuse. À propos d’un cas

Langerhans’ cell histiocytosis is a non-malignant proliferative disease of unknown etiology. It is a rare illness affecting mainly children and young adults with a male predominance. It can affect one or many organs. The bone locations are the most frequent. We present one case of multifocal Langerhans’ cell histiocytosis in a 22-year-old male patient followed for diabetes insipidus with an enlargement of the pituitary stalk at the magnetic resonance imaging (MRI), and a lytic bone lesion revealed in lumbar spine (L2) by ^99mTc-HMDP scintigraphy conducted in planar mode, and then in Single Photon Emission Computed Tomography coupled to Computed Tomography (SPECT/CT) in hybrid mode. To this end, we propose to highlight diagnostic gain of SPECT/CT compared with SPECT and planar scintigraphy to characterize radiotracer uptake abnormalities in bone in Langerhans’ cell histiocytosis.     

Intérêt de la scintigraphie parathyroïdienne de soustraction dans la prise en charge de l’hyperparathyroïdie secondaire. À propos de 33 cas

Aim^99mTc-Sestamibi is used in the imaging of hyperparathyroidism in order to guide the surgical procedure and to propose methods of less invasive surgery. The aim of our study was to evaluate the efficiency of preoperative subtraction parathyroid scintigraphy (Sestamibi-^99mTc/Pertechnetate) in the management of secondary hyperparathyroidism.Patients and methodsThe records of 33 patients with renal impairment consecutively operated from 2009 to 2011 for secondary hyperparathyroidism were retrospectively reviewed. We collected data on parathyroid function, results of parathyroid scintigraphy, intraoperative findings and pathological findings.ResultsScintigraphy was positive in 32 patients by disclosing a total of 75 hyperplastic parathyroid glands. The surgical exploration of all parathyroid glands revealed 99 hyperplastic glands confirmed by histological analysis. The sensitivity of parathyroid scintigraphy was 70.7% with a specificity of 85%. Positive predictive value was 93.3%, while negative predictive value was 50%. No correlation was found between the values of parathyroid hormone (PTH) and calcemia measured preoperatively and scintigraphic results.Discussion and conclusionIn our study, the correlation of scintigraphic data with PTH and serum calcium is not statistically significant. However, owing to a high positive predictive value, the parathyroid scan should be indicated. Value of parathyroid scintigraphy extends to searching ectopic or supernumerary glands and especially in cases of persistent or recurrent hyperparathyroidism.     

Intérêt de l’imagerie scintigraphique, à Madagascar,dans le diagnostic de l’adénome parathyroïdien ectopique – à propos d’un cas

This study reports the first case of ectopic parathyroid adenoma, diagnosed in the Department of Nuclear Medicine in Antananarivo. This clinical vignette illustrates the interest of the MIBI-Tc-99 m scan in locating this adenoma and its diagnostic confirmation after six years of erratic diagnosis. A whole body bone scintigraphy has also allowed to assess the state of bone metabolism and study outbreaks of fracture. The parathyroid scintigraphy was carried out after intra-venous administration of 666 MBq of MIBI-Tc99m. Dynamic images, static early and late static were acquired with a gamma camera E-Cam Siemens. The whole body bone scan was carried out after administration of 555 MBq of MDP-Tc-99 m. The results evidenced the presence of an para-aortic increased uptake area pointing to a left parathyroid adenoma. The persistence of a late left submaxillary increased uptake area raises, however, a reservation about the existence of a second adenoma. The bone scan displayed global skeletal remodeling, non suggestive of metastases, as it was mentioned with the CT-scan. In a diagnostic tools limited environment, skeletal pain refractory to painkillers, a chronic hypercalcemia associated with an increased parathyroid hormone level, should trigger the scintigarphic exploration in order to avoid bone and renal complications.     

Intérêt de l’imagerie hybride TEMP/TDM pour la détection de l’ectopie parathyroïdienne. Expérience du service de médecine nucléaire – CHU Mohammed VI,Marrakech

IntroductionHyperparathyroidism due to a parathyroid ectopia is a rare disease; it is the most common cause of persistent or recurrent hyperparathyroidism. Its treatment is exclusively surgical and the results of the surgery benefit from the contribution of preoperative imaging techniques. The aim of this work is to illustrate the interest of the single photon emission computed tomography/computed tomography (SPECT/CT) in the detection and treatment of ectopic parathyroid orientation.Case reportClinical case 1: a 41-year-old patient was followed for persistent primary hyperparathyroidism revealed by brown tumors at the level of the lower extremity of the right femur and tibia. The rate of parathormone was 1987.4 pg/mL. The cervical echography and the scanning were not decisive. The SPECT/CT, performed during a ^99mTc-MIBI scintigraphy and the same for the 2nd clinical case, has showed an area of high uptake projecting behind the left sternoclavicular joint. The diagnosis of ectopic parathyroid localization was retained. Resection and pathologic examination of the surgical specimen revealed parathyroid adenoma tissue. The evolution was marked by a normalization of the rate of parathormone. Clinical case 2: a 71-year-old patient who presents a clinico-biological board of primitive persistent hyperparathyroidism. A first scintigraphy (^99mTc-MIBI) realized in 2010 was negative. The rate of parathormone was 969 ng/L, the rate of calcium was 2.90 mmol/L. Two cervical ultrasound were normal. The SPECT/CT has objectified an area of high uptake in projection at the upper floor of the middle mediastinum. The diagnosis of ectopic parathyroid localization was retained. Surgical resection and histological study revealed a parathyroid adenoma tissue. The evolution was marked by a normalization of the rate of parathormone.DiscussionThe SPECT/CT has an important role in the management of patients with persistent or recurrent hyperparathyroidism. It can usually visualize ectopic parathyroid injury, specify its size and anatomic relationships to optimize surgical management.     

Impact de l’imagerie hybride TEMP/TDM dans le diagnostic et la prise en charge de l’ostéome ostéoïde

IntroductionThe osteoid osteoma is a major bone benign tumors in children. It is more common in boys. The femoral and tibial locations account for 50% of cases. Clinically, it is revealed by nocturnal pain relieved by aspirin. The pain may precede by several months the radiographic abnormality. The purpose of our work is to elucidate the contribution of SPECT/CT in addition to the planar bone scintigraphy in the diagnosis and treatment of osteoid osteoma about two cases.Case reportClinical case No. 1: a 10-year-old child who presented a limp nocturnal pain in the left hip evolving for 4 months. The radiograph of the pelvis showed bone condensation subtrochanteric left femur. SPECT/CT showed an image for an osteoid osteoma. Surgical resection of the home revealed in the histological study an osteoid osteoma of the left femoral neck. The evolution was marked by an immediate pain relief and full recovery of the left lower limb mobility. Clinical case No. 2: an 11-year-old child who had a limp nocturnal pain at the upper end of the left femur evolving for 2 months. The pain was paroxysmal, relieved by salicylates. The X-ray of the pelvis showed a metaphyseal image with peripheral condensation and thickening of the cortex. SPECT/CT showed an image for an osteoid osteoma. The intervention was a tumor excision resection. Histopathological examination revealed a small nidus consistent with an osteoid osteoma. The evolution was marked by an immediate pain relief and normalization of the mobility of the left lower limb.DiscussionThe SPECT/CT can increase the sensitivity and specificity of planar bone scintigraphy. It confirms the location of osteoid osteoma and defines its anatomical relationships in order to optimize surgical management.ConclusionThe SPECT/CT contributes significantly to the diagnosis of osteoid osteoma when radiological images are atypical or unusual clinical expression.     

L’apport de l’imagerie hybride TEMP/TDM dans la prise en charge du cancer différencié de la thyroïde

IntroductionSingle photon emission computed tomography combined with a low dose computed tomography (SPECT/CT), is a hybrid imaging integrating functional and anatomical data. The purpose of our study was to evaluate the contribution of the SPECT/CT over traditional planar imaging of patients with differentiated thyroid carcinoma (DTC).MethodsPost-therapy iodine 131 (¹³¹I) whole-body scan followed by cervico-thoracic SPECT/CT, were performed in 100 patients with DTC.ResultsAmong these 100 patients followed for a predominantly papillary DTC, planar imaging and SPECT/CT, were perfectly concordant in 70% of patients and discordant in the remaining 30%. The use of fusion imaging SPECT/CT compared to conventional planar imaging allowed us to correct our therapeutic approach in 27% (27/100 patients), according to the protocols of therapeutic management of our institute.ConclusionSPECT/CT is a hybrid imaging modality which provides better identification and more correct anatomic localization of the foci of radioiodine uptake with impact on therapeutic management.     

Intérêt de la TEP-FDG dans le syndrome d’hyper-IgG4 : à propos d’un cas et revue de la littérature

Hyper-IgG4 syndrome, or IgG4-related systemic disease (IgG4-RSD), is a recently described entity of fibro-inflammatory systemic damage. Multiorgan lesions can occur synchronously or metachronously in a same patient. The common histological features include a lymphoplasmacytic infiltration (especially to IgG4), and fibrosis. Elevated serum level of IgG4 is also often present. The main concerned organs are: pancreas, biliary ducts, mediastinal lymph nodes, peritoneum, lacrimal and salivary glands. We report a case of an unusual location of this disease at the nasophyrnx in a patient of 84 years for which the diagnosis was made through immunolabelling with IgG4 in lesions biopsied, and we illustrate the potential role of PET-FDG in this systemic disease.     

Intérêt de l’imagerie hybride TEMP-TDM pour la détection du ganglion sentinelle dans les cancers du sein

IntroductionSingle-Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) is an hybrid technique which associates functional and morphological images. The aim of this study was to assess the role of SPECT-CT lymphoscintigraphy in sentinel node identification in patients with breast cancer.MethodsTwelve months prospective study was undertaken. Lymphoscintigraphy comprising planar and SPECT-CT acquisition was performed in 51 consecutive patients with breast cancer (mean age: 62 ± 11.3, range: 33–83 years). Planar and SPECT-CT images were interpreted separately and the two imaging techniques were compared with respect to their ability to identify sentinel node.ResultsAn add-value of SPECT-CT images was evidenced in 31% of cases: a more accurate anatomic localization in 21% of cases and identification of undeterminate sites of uptake in 10% of cases. Furthermore, SPECT-CT detected intramammary (4% of cases) and retromammary (2% of cases) sentinel nodes missed by planar imaging. SPECT-CT was more sensitive for internal mammary drainage detection (6% of cases). The added value proved higher in obese patients. Finally, functional and anatomical images fusion and three-dimensional overview provided clear and readily usable informations to the surgeon.ConclusionHybrid SPECT-CT imaging improves the preoperative localisation of sentinel nodes in patients with breast cancer, in particular in obese patients. SPECT-CT provides readily usable informations to the surgeon.     

Intérêt de la TEP/TDM dans le diagnostic de la carcinose péritonéale : à propos d’une observation

PET/CT is a significant examination recognized in the detection of tumors and their metastases. Through a rare case of peritoneal carcinomatosis complicating an endometrial carcinoma, the authors discuss utility of FDG-PET/CT in the diagnosis and follow-up of this disease.     

Intérêt de la scintigraphie au 99mTc-DMSA dans l’exploration des reins étiquetés muets à l’urographie intraveineuse: À propos de 20 cas

IntroductionThe renal scintigraphy using 99mTc-DMSA constitutes a non-invasive and functional method that is of appreciable interest in the qualitative study of renal parenchyma and the evaluation of the separate renal function.Materiel and methodsWe report, through this work, the observation of 20 patients presenting a unilateral renal muteness to the intravenous urography (IVU). A 99mTc-DMSA scintigraphy was carried out among all our patients by means of a gamma-camera with large field equipped with a parallel collimator of weak energy and high-resolution. The evaluation of images obtained consisted of a qualitative study of parenchyma as well as an estimate of the functional value separated from the two kidneys obtained by the calculation of geometric mean.ResultsOn the 20 studied cases, the sex-ratio was equal to 1.16; the average age was 29.72 years with extremes spanning from 18 months to 70 years. The renal muteness reported on intravenous urography was due among 12 patients (60% of cases) to a lithiasic origin, in six patients (30% of cases), to an ureteral-pelvic junction, in one patient (5% of cases), to a chronic pyelonephritis and in another patient (5% of cases) to a megauretera. The separated renal function of the non functional kidneys to the IVU, obtained from the renal 99mTc-DMSA scintigraphy varied from 11% to 31% with an average of 20.6%.DiscussionThrough our series, 99mTc-DMSA scintigraphy allowed to alleviate the limits of IVU in the evaluation of the precise functional value of pathologic kidneys. Indeed, in the 20 studied cases where the IVU had reported a renal muteness, the 99mTc-DMSA scintigraphy allowed a better appreciation of the renal function which varied from 11% to 31% thus calling into question the accuracy of IVU in the exploration of renal function at an advanced stage of uropathy.     

Intérêt de l’introduction à la nomenclature du test de détection des HPV

Le cancer du col de l’utérus reste un problème de santé publique puisque 900 000 nouveaux cas sont diagnostiqués chaque année de par le monde [Luthra] et il est responsable en France de plus de 1600 décès par an. Pourtant, depuis plus de 40 ans, le dépistage de masse des précurseurs du cancer invasif est tout à fait réalisable et le traitement des anomalies cervicales pré-invasives amène généralement à la guérison.     

Intérêt de la scintigraphie rénale dynamique dans le diagnostic de l’hypertension orthostatique (à propos d’un cas)

Orthostatic hypertension (HTO) is a well-known clinical entity and is sometimes associated with excessive renal mobility. During nephroptosis, dynamic renal scintigraphy (SRD) allows the identification of scintigraphic abnormalities suggestive of HTO guiding therapeutic by nephropexy. The authors report a case of HTO combined with a mobile right kidney, treated favourably by nephropexy and whose diagnosis was suggested by DTPA-Tc99m dynamic renal scintigraphy results.