Accuracy of arterial spin labeling magnetic resonance imaging (MRI) perfusion in detecting the epileptogenic zone in patients with drug-resistant neocortical epilepsy: comparison with electrophysiological data, structural MRI, SISCOM and FDG-PET.

BACKGROUND AND PURPOSE: Locating the epileptogenic zone (EZ) in patients with neocortical epilepsy presents major challenges. Our aim was to assess the accuracy of arterial spin labeling (ASL), an emerging non-invasive magnetic resonance imaging (MRI) perfusion technique, to locate the EZ in patients with drug-resistant neocortical epilepsy. METHODS: Twenty-five consecutive patients with neocortical epilepsy referred to our epilepsy unit for pre-surgical evaluation underwent a standardized assessment including video-electroencephalography (EEG) monitoring, structural MRI, subtraction ictal single-photon emission computed tomography co-registered to MRI (SISCOM) and fluorodeoxyglucose positron emission tomography (FDG-PET) studies. An ASL sequence was included in the MRI studies. Areas of hypoperfusion or hyperperfusion on ASL were classified into 15 anatomic-functional cortical regions; these regional cerebral blood flow maps were compared with the EZ determined by the other tests and the strength of concordance was assessed with the kappa coefficient. RESULTS: Of the 25 patients [16 (64%) women; mean age 32.4 (±13.8) years], 18 (72%) had lesions on structural MRI. ASL abnormalities were seen in 15 (60%) patients (nine hypoperfusion, six hyperperfusion). ASL had a very good concordance with FDG-PET (k = 0.84), a good concordance with structural MRI (k = 0.76), a moderate concordance with video-EEG monitoring (k = 0.53) and a fair concordance with SISCOM (k = 0.28). CONCLUSION: Arterial spin labeling might help to confirm the location and extent of the EZ in the pre-surgical workup of patients with drug-resistant neocortical epilepsy.

Testing an Adapted Auditory Verbal Learning Test Paradigm for fMRI to Lateralize Verbal Memory in Patients with Epilepsy.

BACKGROUND AND PURPOSE: fMRI is a noninvasive tool for predicting postsurgical deficits in candidates with pharmacoresistant temporal lobe epilepsy. We aimed to test an adapted paradigm of the Rey Auditory Verbal Learning Test to evaluate differences in memory laterality indexes between patients and healthy controls and its association with neuropsychological scores. MATERIALS AND METHODS: We performed a prospective study of 50 patients with temporal lobe epilepsy and 22 healthy controls. Participants underwent a block design language and memory fMRI. Laterality indexes and the hippocampal anterior-posterior index were calculated. Language and memory lateralization was organized into typical and atypical on the basis of laterality indexes. A neuropsychological assessment was performed with a median time from fMRI of 8 months and was compared with fMRI performance. RESULTS: We studied 40 patients with left temporal lobe epilepsy and 10 with right temporal lobe epilepsy. Typical language occurred in 65.3% of patients and 90.9% of healthy controls (P = .04). The memory fMRI laterality index was obtained in all healthy controls and 92% of patients. The verbal memory laterality index was bilateral (24.3%) more frequently than the language laterality index (7.69%) in patients with left temporal lobe epilepsy. Atypical verbal memory was greater in patients with left temporal lobe epilepsy (56.8%) than in healthy controls (36.4%), and the proportion of bilateral laterality indexes (53.3%) was larger than right laterality indexes (46.7%). Atypical verbal memory might be associated with higher cognitive scores in patients. No relevant differences were seen in the hippocampal anterior-posterior index according to memory impairment. CONCLUSIONS: The adapted Rey Auditory Verbal Learning Test paradigm fMRI might support verbal memory lateralization. Temporal lobe epilepsy laterality influences hippocampal memory laterality indexes. Left temporal lobe epilepsy has shown a higher proportion of atypical verbal memory compared with language, potentially to memory functional reorganization.

Comparison of four prognostic scores in peripheral T-cell lymphoma.

BACKGROUND: To compare the usefulness of four prognostic scores in patients with peripheral T-cell lymphoma (PTCL) from a single institution. PATIENTS AND METHODS: One hundred twenty-one patients (77 male/36 female, median age 53 years) with PTCL [anaplastic large-cell lymphoma (ALCL) 21, PTCL not otherwise specified 56 and other 44)]. Complete response (CR) rate and 5-year overall survival (OS) were 41% and 31%, respectively. International Prognostic Index (IPI), Prognostic Index for T-cell lymphoma (PIT), International peripheral T-cell lymphoma Project score (IPTCLP) and modified Prognostic Index for T-cell lymphoma (mPIT) were calculated as in the original references. mPIT was only assembled to 41 patients in whom Ki-67 immunostaining was available. ALCL patients were analyzed separately. RESULTS: Concordance among IPI, PIT and IPTCLP was 52% for low-risk group, 27% for low/intermediate-risk group, 20% for high/intermediate-risk group and 14% for high-risk group. IPI, PIT and IPTCLP predicted CR, with IPI being the best score in logistic regression. Neither Ki-67 immunostaining nor mPIT predicted CR. Five-year OS (low-risk versus intermediate- or high-risk categories) according to IPI, PIT, IPTCLP and mPIT were 52% versus 45%, 75% versus 49%, 58% versus 20% and 39% versus 0%, respectively. IPTCLP was the best score for OS in multivariate analysis. CONCLUSION: All the scores demonstrated their usefulness to assess the outcome of patients with PTCL, with IPTCLP being the most significant to predict OS.

Detection of epileptogenic focus with two new methods of processing of SPECT and PET cerebral images: PET-Analysis and PISCOM. / Detección del foco epileptógeno mediante dos nuevos métodos de procesamiento de imágenes SPECT y PET cerebral: PET-Analysis y PISCOM.

Functional neuroimaging with positron emission tomography with 18F-fluorodeoxyglucose (PET-18F-FDG) and perfusion single photon emission computerized tomography (SPECT) are increasingly more essential for presurgically locating the epileptogenic focus. We present the case of an 18-year-old male with epileptic seizures refractory to antiepileptic treatment. Magnetic resonance (MR) showed dysplasia in the posterior right insular cortex. Subtraction of ictal SPECT co-registered to MR (SICOM) detected a focal increase of uptake in the left fronto-parietal cingulate and PET-FDG showed normal distribution of the radiotracer. The posterior right insula was resected with histopathological results of grade I ganglioglioma according to the World Health Organization classification. The patient made favourable post-surgical progress, and remains seizure-free after 5 years (Engel I). Retrospective analysis of this case with two new image processing methods (PET analysis and PET interictal subtracted ictal SPECT coregistered with MR [PISCOM]) correctly localized the epileptogenic focus in the posterior right insular cortex.

Localising imaging in secondary hyperparathyroidism.

Preoperative imaging has proved its use successful in the localization of solitary parathyroid adenomas in patients with suspected primary hyperparathyroidism. However, due to multiglandular disease at presentation patients with renal hyperparathyroidism need to be analyzed separately, making the usefulness of imaging techniques controversial. Recently, improved methods of functional imaging like parathyroid scan with 99mTc-sestamibi or positron emission tomography, especially when combined with computed tomography, can provide additional quantitative and qualitative information that has yet to be assessed. Nuclear medicine procedures could prove useful not only in preoperative diagnosis, but also in the selection of medical or surgical therapeutic alternatives in secondary hyperparathyroidism patients. There is evidence that 99mTc-sestamibi uptake in parathyroid hyperplasia or adenoma is related to biochemical markers of parathyroid function. We are only beginning to identify the factors involved in radiotracer uptake by parathyroid cells and how it can be modulated to obtain more accurate results. This review analyzes the current use of non-invasive imaging modalities in patients with secondary hyperparathyroidism, taking into account the latest trends in the field combining anatomic and functional modalities and the relevant factors linked to radiotracer uptake in abnormal hyperfunctioning parathyroid glands.

[Potential use of bone marrow scintigraphy in suspected prosthetic hip infection evaluated with 99mTc-HMPAO-leukocytes]. / Valor de la gammagrafía de médula macrofágica en el diagnóstico de infección de prótesis total de cadera estudiada con leucocitos Tc-HMPAO.

AIM: To evaluate the usefulness of (99m)Tc-Sulphur colloid when combined with leukocyte scintigraphy in suspected prosthetic hip infection, comparing the results with information from (99m)Tc-HMPAO-leukocyte scintigraphy alone. MATERIALS AND METHODS: Seventy patients (42 women, 28 men; mean age 68 +/- 13 years) with painful hip prostheses and suspicion of infection were evaluated prospectively. All patients had bone scintigraphy, (99m)Tc-HMPAO-labelled white blood cell scintigraphy and (99m)Tc-Sulphur colloid bone marrow scintigraphy. ESR and CRP levels were measured in all patients. The final diagnosis was made with microbiological findings or by clinical follow up of at least 12 months. RESULTS: Infections were diagnosed in 12 of the 70 patients (3 coagulase-negative Staphylococcus, 2 Staphylococcus aureus, 2 Staphylococcus epidermidis, 2 enterococcus and 3 polymicrobial agents). ESR and CRP values were higher in patients with infection than in patients without infection (51.8 +/- 29.4 vs. 25.4 +/- 16.4 and 2.8 +/- 2.2 vs. 1.1 +/- 1.3, respectively; p < 0.05). Bone scintigraphy did not show a characteristic pattern to differentiate infection from aseptic loosening. The pool phase of the bone scintigraphy was positive in only 3/12 patients with infection (25 %). Sensitivity and specificity of the leukocyte scintigraphy was 83 % and 57 %, respectively. When the results of the bone marrow scintigraphy were added, these values increased to 92 % and 98 %, respectively. CONCLUSION: Performing bone marrow scintigraphy significantly improves results when compared with leukocyte scintigraphy alone in the diagnosis of infected hip prostheses. Bone scintigraphy did not help to differentiate aseptic loosening from infection in this series.

A new era for Nuclear Medicine neuroimaging in Spain: Where do we start from in Spain? / Nuevos tiempos para la neuroimagen de Medicina Nuclear en España: ¿de dónde partimos?

OBJECTIVE: To determine the status of neuroimaging studies of Nuclear Medicine in Spain during 2013 and first quarter of 2014, in order to define the activities of the neuroimaging group of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). MATERIAL AND METHODS: A questionnaire of 14 questions was designed, divided into 3 parts: characteristics of the departments (equipment and professionals involved); type of scans and clinical indications; and evaluation methods. The questionnaire was sent to 166 Nuclear Medicine departments. RESULTS: A total of 54 departments distributed among all regions completed the questionnaire. Most departments performed between 300 and 800 neuroimaging examinations per year, representing more than 25 scans per month. The average pieces of equipment were three; half of the departments had a PET/CT scanner and SPECT/CT equipment. Scans performed more frequently were brain SPECT with 123I-FP-CIT, followed by brain perfusion SPECT and PET with 18F-FDG. The most frequent clinical indications were cognitive impairment followed by movement disorders. For evaluation of the images most sites used only visual assessment, and for the quantitative assessment the most used was quantification by region of interest. CONCLUSIONS: These results reflect the clinical activity of 2013 and first quarter of 2014. The main indications of the studies were cognitive impairment and movement disorders. Variability in the evaluation of the studies is among the challenges that will be faced in the coming years.

[Usefulness of 111In-oxine labelled platelets in the management of febrile syndrome in dialysis patients with non-functional renal allografts]. / Utilidad de la gammagrafía con plaquetas marcadas con 111In-oxina en el manejo del síndrome febril en pacientes en diálisis portadores de injerto renal no funcionante.

AIM: To evaluate the usefulness of 111In-oxine-labelled platelet scan in the therapeutic management of prolonged febrile syndrome in dialysis patients with a non-functional renal allograft. MATERIAL AND METHODS: One hundred and fifty-eight patients (94 men, 64 women; mean age 44 +/- 9 years) were studied. Duration of fever was 42 days (range 7-112). A total of 68 % of the patients (107/158) were on low doses of corticosteroids (<10 mg/day). Platelet scans were performed 48 hours after reinjection of 111In-ixone-labelled platelets. A platelet uptake index (PUI) was calculated by dividing the cpm/pixel in the allograft by the cpm/pixel in a mirror background. A PUI > or = 1.5 was considered as threshold for immunological fever. The final diagnosis of immunological fever was established when it disappeared after transplantectomy, embolization or high doses of corticosteroid therapy. Fever of non-immunological origin was established when it disappeared after antibiotic therapy. RESULTS: In 102/158 patients the fever was considered of immunological origin. In 56/158 patients the fever was considered of non immunological origin. Sensitivity and the specificity of the platelet scan was 80 % and 100 %, respectively. All those patients considered as having fever of immunological origin who had PUI <1.5 had been using corticosteroids during platelet scan. CONCLUSION: 111In-labelled platelet scintigraphy is a useful technique in the therapeutic management of prolonged febrile syndrome in dialysis patients with non-functional renal allograft. The use of corticosteroids can reduce the sensitivity of 111In- labelled platelet scan.

PET/MRI and PET/MRI/SISCOM coregistration in the presurgical evaluation of refractory focal epilepsy.

We aimed to investigate the usefulness of coregistration of positron emission tomography (PET) and magnetic resonance imaging (MRI) findings (PET/MRI) and of coregistration of PET/MRI with subtraction ictal single-photon emission computed tomography (SPECT) coregistered to MRI (SISCOM) (PET/MRI/SISCOM) in localizing the potential epileptogenic zone in patients with drug-resistant epilepsy. We prospectively included 35 consecutive patients with refractory focal epilepsy whose presurgical evaluation included a PET study. Separately acquired PET and structural MRI images were coregistered for each patient. When possible, ictal SPECT and SISCOM were obtained and coregistered with PET/MRI. The potential location of the epileptogenic zone determined by neuroimaging was compared with the seizure onset zone determined by long-term video-EEG monitoring and with invasive EEG studies in patients who were implanted. Structural MRI showed no lesions in 15 patients. In these patients, PET/MRI coregistration showed a hypometabolic area in 12 (80%) patients that was concordant with seizure onset zone on EEG in 9. In 7 patients without MRI lesions, PET/MRI detected a hypometabolism that was undetected on PET alone. SISCOM, obtained in 25 patients, showed an area of hyperperfusion concordant with the seizure onset zone on EEG in 7 (58%) of the 12 of these patients who had normal MRI findings. SISCOM hyperperfusion was less extensive than PET hypometabolism. A total of 19 patients underwent surgery; 11 of these underwent invasive-EEG monitoring and the seizure onset zone was concordant with PET/MRI in all cases. PET/MRI/SISCOM coregistration, performed in 4 of these patients, was concordant in 3 (75%). After epilepsy surgery, 13 (68%) patients are seizure-free after a mean follow-up of 4.5 years. PET/MRI and PET/MRI/SISCOM coregistration are useful for determining the potential epileptogenic zone and thus for planning invasive EEG studies and surgery more precisely, especially in patients without lesions on MRI.

Double-phase parathyroid 99mTc-Sestamibi scintigraphy in chronic haemodialysis patients: correlation with biochemical markers of parathyroid function.

99mTc-Sestamibi identifies the presence of hyperfunctioning autonomous parathyroid glands in patients with secondary hyperparathyroidism (SHP). The objectives of this study were: (i) to evaluate the interdependence between biochemical markers of SHP and 99mTc-Sestamibi uptake; and (ii) to determine whether 99mTc-Sestamibi uptake could be efficiently predicted by any combination of the former variables. Double-phase parathyroid 99mTc-Sestamibi uptake and total serum calcium, phosphorus, intact parathormone, 25-OH vitamin D and 1,25(OH) vitamin D determinations were performed simultaneously in 74 patients (36 female, 38 male) with SHP. Planar images of the neck and upper thorax were obtained in anterior view, 15 min (early phase) and 120 min (delayed phase) after the injection of 740 MBq of 99mTc-Sestamibi. In each patient, a final parathyroid/thyroid (P/T) activity index was obtained by adding the results of the P/T index of all parathyroid lesions. There was a significant correlation between intact parathormone levels and delayed 99mTc-Sestamibi uptake ( r=0.656; P<0.01). Of all the variables, intact parathormone was the only significant predictor of delayed 99Tc-Sestamibi uptake ( r=0.487; P<0.001). Calcium, phosphorus, vitamin D metabolites, age, gender, time spent on haemodialysis and cause of chronic renal failure displayed no significant correlation with 99mTc-Sestamibi uptake. It can be concluded that 99mTc-Sestamibi uptake is a potential predictor of parathyroid function in SHP patients. Hence, 99mTc-Sestamibi scintigraphy could be useful to assess parathyroid function and in the clinical follow-up of these patients.

Salivary scintigraphy for assessing the protective effect of pilocarpine in head and neck irradiated tumours.

Patients with head and neck cancers can develop salivary hypofunction after radiotherapy. The use of pilocarpine during radiotherapy treatment has been shown to be an effective treatment, although its usefulness is being discussed. The aim of this study was: (1) to determine the value of a semiquantitative scintigraphy method for measuring the uptake and excretory salivary function of patients with head and neck irradiated tumours; and (2) to study the usefulness of pilocarpine as a salivary gland protector during radiotherapy. We prospectively studied 49 patients (mean age 61 years, range 29-87 years) with head and neck cancer in need of radiotherapy. Patients were divided into two groups consecutively: group P (26 patients) received 5 mg of pilocarpine three times per day starting the day before radiation therapy, and group NP (23 patients) received radiotherapy without pilocarpine and were used as the control group. Salivary gland scintigraphy and a visual analogue scale (VAS) of mouth dryness were obtained from each patient before radiotherapy and during the first year after treatment. The most frequent finding after radiotherapy was a quick impairment in parotid and submaxillary excretion (P < 0.001). There were no statistical differences comparing the pilocarpine group against the non-pilocarpine group. Parotid and submaxillary uptake significantly decreased after radiotherapy in both groups (P < 0.001). However, a tendency to recover within the pilocarpine group was observed in both the parotids and the submaxillary glands at 12 months. No differences were found comparing the VAS results in both groups. Strikingly, VAS data did not correlate with salivary gland dysfunction observed by means of scintigraphy. In conclusion, salivary scintigraphy is a useful technique to evaluate objectively the salivary gland function of patients with head and neck irradiated tumours as well as to test the response to pilocarpine. However, despite better results on the salivary uptake at 12 months, pilocarpine did not significantly improve salivary gland function.

[Psoas abscess as cause of lumbar spine pain detected by scintigraphy with gallium in a patient with suspicion of spondylodiscitis]. / Absceso del psoas como causa de dolor lumbar detectado mediante gammagrafía con galio en un paciente con sospecha de espondilodiscitis.

A 56 year old man with fever and lumbar pain who underwent an abdominal CT scan that showed lumbar arthrosic changes, although it was not possible to rule out infectious disease in L5/S1. Bone scintigraphy was requested. It showed heterogeneous hyperuptake that did not make it possible to exclude a spondylodiscitis in this site. Scintigraphy with 67Ga-citrate excluded infectious diseases in the lumbar spine column. However, a pathological uptake was observed in the left iliac fossa suggestive of psoas abscess, which was confirmed by ultrasonography, isolating streptococcus viridans.

[Diagnosis and assessment of therapeutic response of bone metastases by bone scintigraphy and PET study]. / Diagnóstico y valoración de la respuesta terapéutica de las metástasis óseas mediante gammagrafía ósea y estudio PET.

Nuclear medicine plays an important role in staging and evaluation of the initial extension and response to treatment of bone metastases. In order to accurately read Bone Scintigraphy (BS) and Positron Emission Tomography scan (PET) procedures, it is essential to understand the different behavior of these studies. We present a case report of a woman treated for breast cancer, with suspicion of recurrent disease due to increase of tumor markers. Initial BS showed non-conclusive findings, whereas PET study was consistent with a spread of bone metastases. The patient underwent both procedures again after a course of chemotherapy. Post-treatment BS showed progression of bone lesions, while PET showed good therapeutic response. The PET demonstrates lesions earlier and more effectively than the bone scintigraphy in the evaluation of the therapeutic response of bone metastases.

[PET and SPECT in epilepsy]. / PET y SPECT en la epilepsia.

Epilepsy is one of the most frequent chronic neurological disorders, affecting 1-2% of the population. Patients with complex partial drug resistant episodes may benefit from a surgical treatment consisting in the excision of the epileptogenic area. Localization of the epileptogenic area was classically performed with video-EEG and magnetic resonance (MR). Recently, functional neuroimaging studies of Nuclear Medicine, positron emission tomography (PET) and single photon emission tomography (SPECT) have demonstrated their utility in the localization of the epileptogenic area prior to surgery. Ictal SPECT with brain perfusion tracers show an increase in blood flow in the initial ictal focus, while PET with (18)FDG demonstrates a decrease of glucose metabolism in the interictal functional deficit zone. In this review, the basic principles and methodological characteristics of the SPECT and PET in epilepsy are described. The ictal SPECT injection mechanism, different patterns of perfusion based on the time of ictal, postictal or interictal injection are detailed and the different diagnostic sensitivities of each one of these SPECT are reviewed. Different methods of analysis of the images with substraction and fusion systems with the MR are described. Similarly, the injection methodology, quantification and evaluation of the images of the PET in epilepsy are described. Finally, the main clinical indications of SPECT and PET in temporal and extratemporal epilepsy are detailed.

[Dual-time point images of the liver with (18)F-FDG PET/CT in suspected recurrence from colorectal cancer]. / (18)F-FDG PET/TC con imagen hepática en dos tiempos en la sospecha de recidiva del cáncer colorrectal

AIM: To analyze the potential improvement of (18)F-fluorodeoxyglucose (FDG) PET/CT using additional delayed images of the liver in operated colorectal cancer. MATERIAL AND METHODS: The study prospectively included 71 patients (22 women, 49 men) with mean age of 65 ± 11 years with clinical, analytic or radiological suspicion of current disease. A whole body PET/CT scan was performed at 60 min. (standard images) and after 2 hr (delayed images) post-injection of 4.07 MBq/Kg of (18)F-FDG. Visual and quantitative SUV analysis of PET/CT findings was done. All findings were confirmed by histopathology and/or at least 6 months follow-up. RESULTS: Thirty-seven out of 71 patients were diagnosed of liver metastases (79 metastases). In 38/71 cases there was extra-hepatic disease in the form of local recurrence (10), abdominopelvic (3) or mediastinal (3) lymph nodes, bone (1) or lung metastases (16) and carcinomatosis (10). Sensitivity and specificity in the diagnosis of liver metastases in a patient-by-patient basis in standard (81% and 91%) and in delayed images (95% y 97%) was calculated. The number of lesions detected in delayed images was significantly higher (66/79) than in standard images (57/79). Sensitivity and specificity for PET/CT in the diagnosis of extra-hepatic disease was 84% and 70%, contributing to the detection of synchronous tumors in 5 patients. CONCLUSIONS: PET/CT may be useful in the diagnosis of extra-hepatic disease in suspected recurrence of colorectal cancer. Delayed images on PET/CT may increase the sensitivity to identify liver metastases.