18F-FDG-PET/CT.

[18F]FDG has been the first radiopharmaceutical used for human brain PET studies and still is the most used radiotracer worldwide for PET and PET/CT oncologic applications. In the assessment of brain tumors, in spite of its low sensitivity in some histological exams, chiefly low-grade lesions, its prognostic value remains of high clinical impact. Moreover, the reliability of [18F]FDG in examining not only the tumor itself, but also the functional state of the whole brain, makes this tracer a valuable tool for treatment decisions and patient management, even nowadays when new tracers (especially amino-acids) are available. In addition, [18F]FDG has a role in the differential diagnosis between relapse and necrosis when assessing aggressive tumors and to establish dedifferentiation in low-grade lesions. With the growing of available therapies, another emerging application of [18F]FDG is the monitoring of response to treatment, even though more evidence is needed to assess the best scanning time. Finally, the implementation of CT in PET devices most likely will improve the sensitivity and specificity of [18F]FDG, even though more data are needed to better understand which is the real advantage of PET/CT with respect to multimodality imaging. Currently, the possible added value of PET/CT is in the study of secondary brain lesions. It is believable that in the future we will keep on speaking about this "old" radiotracer, still alive.

Retrospective study on PET-SPECT imaging in a large cohort of myotonic dystrophy type 1 patients.

The aim was to study brain involvement in myotonic dystrophy type 1 by single photon emission tomography (SPECT) and positron emission tomography (PET). 58 DM1 patients were subjected to SPECT; 17 to both SPECT and PET. SPECT patients were grouped as 'normally perfused' and 'abnormally perfused'; PET patients as 'normal performers' and 'abnormal performers'. To quantify hypoperfusion and/or hypometabolism, we used a semi-quantitative scale. To localize focal hypoperfusion/hypometabolism, nine cerebral areas of involvement were identified. The Chi-square, Wilcoxon, McNemar tests were used for statistics. SPECT showed abnormalities in 52/58 patients. PET showed an abnormal glucidic uptake in 15/17. Hypoperfusion was mild/moderate in 50/58 patients, mostly involving the left supratentorial areas. Abnormal glucidic uptake was mainly observed in the left frontal lobe. Abnormalities in blood perfusion and/or glucose metabolism are frequent in DM1. These abnormalities involve the left more often than the right hemisphere, the frontal lobe more than other lobes. Such abnormalities are more often cortical than subcortical.

Long-term evaluation of cognitive function and cerebral metabolism in liver transplanted patients.

INTRODUCTION: Patients with liver cirrhosis without overt hepatic encephalopathy (OHE) show alterations of cognitive function and metabolism which seem to not be fully reversible after liver transplantation (OLT), but the long-term outcomes have not be studied. METHODS: Fourteen cirrhotic subjects including alcoholic (n = 4), viral (n = 4), mixed (n = 5), and cholestatic (n = 2) without OHE were evaluated for OLT as well as 8 age-matched normal controls. All subjects underwent cerebral positron emission tomography (PET) with 18F-fluorodeoxyglucose to quantify cerebral glucose metabolism and neuropsychological evaluation to test memory, intelligence, and cerebral frontal functions. Transplanted patients underwent repeat evaluations at 1 and 10 years after liver transplantation. RESULTS: Compared with the controls patients with liver cirrhosis showed significantly reduced cerebral glucose metabolism in all cerebral cortical and subcortical regions. This observation correlated with the presence of alterations in neuropsychological tests evaluating memory, frontal tasks, and visuospatial memory. Among 12 patients who were transplanted, 10 underwent repeat neuropsychological evaluation at 1 year; in addition 5 underwent PET). At 10 years the 7 living patients had repeat neuropsychological evaluation. One year after OLT, transplanted patients showed significant amelioration of cerebral glucose metabolism in all cerebral regions with significant improvements in neuropsychological tests, despite 20% of patients showing residual defects in frontal tasks. The cognitive function did not further improve at 10 years after OLT. CONCLUSION: Patients with liver cirrhosis show altered cerebral function and metabolism that revert after successful liver transplantation, but with residual mild deficits in cerebral frontal functions, which seem to not improve in the long term.

[Intraoperative transesophageal echocardiography in the endovascular treatment of thoracic aortic aneurysms]. / L'utilizzo intraoperatorio dell'ecocardiografia transesofagea nel trattamento endovascolare degli aneurismi dell'aorta toracica.

AIM: Endovascular surgery is an efficacious alternative to conventional surgery in the treatment of descending thoracic aorta aneurysms. However, primary and delayed endoleaks are some endovascular technology's weak points. They are usually detected by angiography or angio CT, but many information may be obtained by transesophageal echocardiography (TEE) both as to endoleaks and to endograft's correct placement. Our purpose is to confirm, on the basis of our experience, the validity of this technique chosen both by us and by other groups with a wider casuistry. METHODS: We positioned endografts for the treatment of degenerative or post-traumatic aneurysms of the descending thoracic aorta using TEE, together with angiography, during surgery in 8 out of 9 patients. TEE was carried out on the same 8 patients also before surgery, and for some patients even in the follow-up together with angio CT, after 6 and 12 months. RESULTS: In the situations where TEE was used we found 5 cases of endoleaks and 1 of these was not detected by angiography because of its small dimensions. All of these endoleaks were immediately corrected with more angioplasty or graft extensions; in a case, where we could not utilize the TEE, the problem solved spontaneously after 30 days as it was confirmed both by angiography and angio TC. The statistical analysis with the Student t test is significant for P < 0.005. CONCLUSIONS: We think that using TEE during the placement of an endograft on the descending thoracic aorta may help to obtain useful information in addition to those that we can obtain with angiography. Therefore, this may lead to improve the technique and to reduce possible both immediate or delayed complications.

[Positron emission tomography with fluorodeoxyglucose in gastro-entero-pancreatic tumors: diagnostic role and prognostic implications]. / La tomografia ad emissione di positroni con fluorodesossiglucosio nei tumori neuroendocrini gastro-entero-pancreatici: ruolo diagnostico e implicazioni prognostiche.

From November 1994 to November 2004, seventy-seven patients with neuroendocrine gastro-entero-pancreatic tumor (71% pancreatic) were investigated with 18-fluorine-deoxi-glucose positron emission tomography (FDG-PET). PET results were compared with CT-scan, MRI and octreoscan scintigraphy and clinico-pathologic features of patients and survival. Overall PET sensitivity was 57%; 78% of malignant tumors, 67% of borderline and 17% of benign tumors were detected by FDG-PET. No duodenal tumor was detected by PET scan. Only 16% of primary less than 2 cm in size was localized. In 16% of cases PET scan provided new information able to change therapeutic management. In PET positive patients the addictive information obtained by PET scan when compared with octreoscan, MRI and CT scan were respectively 50% more, 26% more and 30% more. In malignant neuroendocrine tumors PET positivity was related to short survival. No patient with malignant tumor died for disease progression in the follow-up when PET was negative, while 13/35 PET positive patients died (p <0.003). FDG-PET proved to be a second line technique in neuroendocrine digestive tumors. PET results improve clinical staging of disease and is related to survival in malignant cases; in 16% of cases may change the therapeutic option.

Thiethylperazine-induced parkinsonism: in vivo demonstration of dopamine D2 receptors blockade.

Thiethylperazine (Torecan) is a piperazine phenothiazine employed to relieve vertigo. Its use may be associated with extrapyramidal side effects (dystonia, akathisia, tardive dyskinesia) (Sulkava, 1984), but parkinsonism has rarely been described. We describe a woman who, 1 month after the onset of thiethylperazine treatment, developed parkinsonism that disappeared 2 months after withdrawal of the drug. However, cerebral single-photon emission computed tomography (SPECT) with the dopamine (DA) D2 receptors ligand 123I-iodobenzamide (123I-IBZM) revealed a persistent reduced DA D2 receptors activity (by 45%) in the basal ganglia (BG), which may be clinically not effective.

Does liver-disease aetiology have a role in cerebral blood-flow alterations in liver cirrhosis?

BACKGROUND: Studies using brain-imaging techniques have shown changes in regional blood flow (rCBF) in patients with liver cirrhosis. It remains unknown whether the aetiology of liver disease accounts for these changes. AIMS: To evaluate whether the aetiology of liver cirrhosis is associated with different patterns of rCBF. MATERIALS AND METHODS: A total of 50 patients with end-stage liver disease and no overt encephalopathy were studied. Thirteen age-matched subjects admitted to the neurology department for headache were used as controls. Exclusion criteria were focal brain lesions, severe brain atrophy and any abnormalities found on computed tomography scan suggesting other central nervous system diseases, alcohol intake or use of neuroactive drugs for at least 6 months. rCBF was assessed using single-positron-emission tomography (SPECT) with 99mTc-hexamethylpropylene amine oxime (99mTc-HM-PAO) as a tracer in all patients and controls. The Mann-Whitney U test was used for statistical analysis. RESULTS: The liver-disease aetiology was as follows: alcoholic (A) in 19 patients; viral (V) (hepatitis B virus, hepatitis D virus, hepatitis C virus) in 14 patients; alcoholic with concomitant viral (A + V) in five patients; and cholestatic (C) (primary biliary cirrhosis, primary sclerosing cholangitis) in 12 patients. SPECT showed significantly lower rCBF in cirrhotic patients than in controls for most cortical and subcortical regions and in alcoholic and viral patients than in cholestatic liver disease patients for some cortical regions. When patients were grouped according to previous alcohol abuse (including cases with a concomitant viral aetiology), rCBF was significantly lower in the frontal superior, medial and temporal inferior regions in the alcoholic group. CONCLUSIONS: Cerebral blood flow is significantly lower in patients with liver cirrhosis than in controls and, among cirrhotics, it is lower in alcoholic and viral cirrhosis than in cholestatic liver disease. In patients with previous alcohol abuse, cerebral blood flow was significantly more reduced in the frontal and temporal regions compared with patients without previous alcohol abuse.

Advantages of positron emission tomography (PET) with respect to computed tomography in the follow-up of lymphoma patients with abdominal presentation.

For abdominal lymphoma patients, fluorine-18 fluorodeoxyglucose positron emission tomography (PET) provides unique information on the presence of residual active disease. We provide an update on the largest reported cohort of patients whose management following induction therapy was based on routine PET and computed tomography (CT) restaging. Fifty-nine patients with Hodgkin's disease or aggressive non-Hodgkin's lymphoma presenting abdominal involvement (35% with bulky disease) were studied with both PET and CT following combined chemotherapy/radiation treatment. After treatment, 3/3 (100%) patients who were PET+/CT- relapsed, compared with 0/7 patients in the PET-/CT- subset. Among the 49 patients who were CT+, six of the 10 (60%) who were PET+ relapsed, as compared with only two of the 39 (5%) who were PET-. The actuarial relapse-free survival (RFS) rates were 0 and 100% in the PET+/CT- and PET-/CT- subsets, respectively. In the PET+/CT+ subset, RFS was 94% at 5 years. PET restaging is very valuable for the identification of patients who would need appropriate second-line therapy because of the presence of residual active abdominal disease and should be made widely available in combination with CT.

Treatment of Buerger's disease with electrical spinal cord stimulation--review of three cases.

Buerger's disease or obliterating thromboangiitis is an inflammatory pathologic condition affecting the distal vascular segments; it strikes young adults, especially males and heavy smokers. Medical and surgical treatment often fail to heal these patients, especially considering the frequent relapse of this disease linked with tobacco abuse--definitive healing often involves limb amputation. Electrical spinal cord stimulation is evaluated in this study with an analgesic aim and for improvement in skin microcirculation, with the goal of long-term healing of diseased limbs.

Value of 18-fluorodeoxyglucose positron emission tomography in the management of patients with cystic tumors of the pancreas.

OBJECTIVE: To assess the reliability of 18-fluorodeoxyglucose positron emission tomography (18-FDG PET) in distinguishing benign from malignant cystic lesions of the pancreas. SUMMARY BACKGROUND DATA: The preoperative differential diagnosis of cystic lesions of the pancreas remains difficult: the most important point is to identify malignant or premalignant cysts that require resection. 18-FDG PET is a new imaging procedure based on the increased glucose metabolism by tumor cells and has been proposed for the diagnosis and staging of pancreatic cancer. METHODS: During a 4-year period, 56 patients with a suspected cystic tumor of the pancreas underwent 18-FDG PET in addition to computed tomography scanning, serum CA 19-9 assay, and in some instances magnetic resonance imaging or endoscopic retrograde cholangiopancreatography. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value. The accuracy of 18-FDG PET and computed tomography was determined for preoperative diagnosis of a malignant cyst. RESULTS: Seventeen patients had malignant tumors. Sixteen patients (94%) showed 18-FDG uptake with a standard uptake value of 2.6 to 12.0. Twelve patients (70%) were correctly identified as having malignancy by computed tomography, CA 19-9 assay, or both. Thirty-nine patients had benign tumors: only one mucinous cystadenoma showed increased 18-FDG uptake (standard uptake value 2.6). Five patients with benign cysts showed computed tomography findings of malignancy. Sensitivity, specificity, and positive and negative predictive values for 18-FDG PET and computed tomography scanning in detecting malignant tumors were 94%, 97%, 94%, and 97% and 65%, 87%, 69%, and 85%, respectively. CONCLUSIONS: 18-FDG PET is more accurate than computed tomography in identifying malignant pancreatic cystic lesions and should be used, in combination with computed tomography and tumor markers assay, in the preoperative evaluation of patients with pancreatic cystic lesions. A positive result on 18-FDG PET strongly suggests malignancy and, therefore, a need for resection; a negative result shows a benign tumor that may be treated with limited resection or, in selected high-risk patients, with biopsy, follow-up, or both.

Identificaiton of chlamydia penumoniae DNA in caroitd plaques.

Chlamydia pneumoniae (CP) is a bacterium that in recent years has been investigated as an etiologic agent for atherosclerosis. It is a ubiquitous microorganism that has been isolated in various regions of the vascular system and its prevalence is about 10% in the patient population. This study involved a group of 43 patients (27 men, 16 women, mean age 68 years) who underwent carotid endarterectomy. About 9.3% of the patients yielded plaques that tested positive for the DNA genome of Chlamydia pneumoniae.

Cerebral perfusion in hypertensives with carotid artery stenosis: a comparative study of lacidipine and hydrochlorothiazide.

Focal cerebral hypoperfusion is a common finding in uncomplicated hypertensives even in the absence of large vessel atherosclerosis, and neuropsychological deficits correlate with cerebral hypoperfusion in hypertensive patients with cerebral microangiopathy. We investigated the effects on cerebral perfusion of the dihydropiridine calcium antagonist lacidipine and of hydrochlorothiazide (HCTZ) in asymptomatic hypertensive patients with concomitant atherosclerosis of the carotid arteries. Fifteen essential hypertensives (including 13 males, aged 55-75 years) with at least one 30-60% stenosis of the internal carotid artery at echo-color Doppler examination were treated in a double-blind, randomized, parallel study with lacidipine (4-6 mg od) or HCTZ (25-50 mg od) for 3 months after a 4-week single-blind placebo period. Regional cerebral perfusion was assessed at baseline and at the end of the treatment period with HMPAO-SPECT. Relative perfusion of cortical and subcortical areas was calculated as the ratio between their tracer activity and that of the cerebellum. At baseline, mean relative perfusion (MRP) of the cortical and subcortical areas was similar in the stenotic and the contralateral side. Despite the fall in pressure, lacidipine increased MRP both in the cortical and in the subcortical areas, whereas HCTZ increased MRP only in the cortical areas. The mean change in local vascular resistance, adjusted for initial perfusion value, was -20 A.U. (arbitrary unit) with lacidipine and -12 A.U. with HCTZ (p < 0.001). These differential effects of antihypertensive drugs on subcortical perfusion may be of benefit in the long-term prevention of vascular dementia in hypertensive patients.

Cerebral perfusion in hypertensive patients: effects of lacidipine and hydrochlorothiazide.

Previous studies have shown areas of cerebral hypoperfusion in the frontal and parietal lobes of asymptomatic hypertensives, in the absence of extracranial carotid artery stenosis. The aims of the present study were: (a) to correlate the presence of focal cortical hypoperfusion with the presence of white matter lesions (WML), lacunae and extracranial carotid artery stenosis; and (b) to compare the effects on cerebral perfusion of the dihydropyridine calcium entry blocker lacidipine and of hydrochlorothiazide (HCTZ) in hypertensive patients with carotid artery stenosis. Forty-one patients (30 males, aged 40-75) with mild to moderate essential hypertension and with negative history for cerebrovascular diseases were investigated. Twenty-four had normal extracranial carotid arteries at echo-colourDoppler examination, while 17 had at least one 50-70% stenosis of the internal carotid artery (ICA). At computed tomography (CT) scan, five patients had one or more lacunar infarctions, four WML, three lacunar infarctions and WML, and 26 a normal CT scan. Three, with old cortical infarctions, were excluded from further analysis. The prevalence of lesions was significantly higher among the patients with carotid artery stenosis (44% vs. 29%; p < 0.05). Distribution of mean relative cortical perfusion (MRCP) of regions of interest [hexamethyl-propileneamine oxime-single photon emission tomography (SPET)] was not normal, with a negative skewness in patients with lacunae. MRCP was slightly but significantly reduced in patients with lacunae in comparison with hypertensives with normal CT scan and with WML. The asymmetry index of tracer distribution was significantly greater in the patients with lacunar infarctions and WML than in the hypertensive patients with normal CT scan, irrespective of the presence of internal carotid artery stenosis. Fifteen hypertensives (13 males, aged 55-75 years) with at least one moderate stenosis of ICA at duplex scanning were treated in a double-blind, randomised, parallel study with lacidipine (4-6 mg o.d.) or HCTZ (25-50 mg o.d.) for 3 months after a 4-week single-blind placebo period. At baseline, perfusion of the cortical and basal areas was similar in the stenotic and the contralateral side. Despite the fall in pressure, both treatments increased MRCP in the stenotic side and in the contralateral side. The lower the baseline perfusion, the larger its increase with treatment. The decrease of local cerebral vascular resistance was significantly greater with lacidipine than with HCTZ. We conclude that in hypertensive patients, the distribution of cerebral flow is uneven, mostly in the presence of small asymptomatic subcortical lesions and independently from internal carotid artery stenosis. Antihypertensive treatment with lacidipine and HCTZ reduces local cerebral resistance and corrects focal hypoperfusion without inducing steal effects in patients with ICA stenosis.

The role of positron emission tomography (PET) in the management of lymphoma patients.

BACKGROUND: Treatment of both Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL) with abdominal presentation at the time of diagnosis is often followed by detection of residual masses by computed tomography (CT). However, CT is usually unable to discriminate between residual tumor and fibrosis/necrosis. We investigated the ability of fluorine-18 fluorodeoxyglucose positron emission tomography (PET) to differentiate between residual active tumor tissue and fibrosis. PATIENTS AND METHODS: Forty-four patients with HD or aggressive NHL presenting abdominal involvement (41% with bulky mass) were studied with CT and PET at the end of chemotherapy +/- radiation therapy. RESULTS: After treatment, seven patients had negative PET and CT, and none of them relapsed. The remaining 37 patients all had positive CT (abnormalities < or = 10%). All of the 13 who also had positive PET relapsed (100%). By contrast, there was only 1 (4%) relapse among the 24 patients who were positive at CT but negative at PET. The two-year actuarial relapse-free survival rate was 95% for those with negative PET compared with 0% for positive PET patients (P < 0.000000). CONCLUSIONS: In lymphoma patients with abdominal masses who present CT positivity at restaging, PET should be considered the noninvasive imaging modality of choice for differentiating early recurrences or residual disease from fibrosis.

PET supports the hypothesized existence of a male sexual brain algorithm that may respond to treatment combining psychotherapy with virtual reality.

Could a brain circuit exist, verifiable using positron emission tomography (PET), that links coitus and its dysfunctions, such as impotence? Could re-establishing normal sexual functioning be linked with the normalization of some sort of altered brain metabolism utilizing a therapeutic project that uses psychodynamic psychotherapy integrating virtual reality (VR)? A Brain PET Scan and a self-administered sexual activity questionnaire were given to 11 heterosexual patients affected by impotence due to psychological causes, both before and approximately 6 months after a cycle of psychodynamic psychotherapy. Seven randomly-selected patients received psychotherapy with VR technology using the Optale Method. PET data, used to indicate glucose consumption in various brain areas, were compared with data from normal patients, and a statistical analysis was run. Alterations in cerebral metabolic functioning were displayed in the following areas: frontal cortex, nucleus caudatus, and thalamus. The seven patients who received psychotherapy with VR technology "normalized" in these same areas and attained satisfactory sexual performance. The existence of a male sex algorithm may be hypothesized that links the frontal cortex, nucleus caudatus, and thalamus, and explains its action on cortical motor areas and/or on the medial preoptic area of the hypothalamus, which may respond to treatment combining psychotherapy with VR.

Brain positron emission tomography (PET) in chronic fatigue syndrome: preliminary data.

Chronic fatigue syndrome (CFS) has been widely studied by neuroimaging techniques in recent years with conflicting results. In particular, using single-photon emission computed tomography (SPECT) and perfusion tracers, hypoperfusion has been found in several brain regions, although the findings vary across research centers. The objective of this study was to investigate brain metabolism of patients affected by CFS, using [18F]fluorine-deoxyglucose (18FDG) positron emission tomography (PET). We performed 18FDG PET in 18 patients who fulfilled the criteria of the working case definition of CFS. Twelve of the 18 patients were females; the mean age was 34 +/- 15 years (range, 15-68) and the median time from CFS diagnosis was 16 months (range, 9-138). Psychiatric diseases and anxiety/neurosis were excluded in all CFS patients. CFS patients were compared with a group of 6 patients affected by depression (according to DSM IV-R) and 6 age-matched healthy controls. The CFS patients were not taking any medication at the time of PET, and depressed patients were drug-free for at least 1 week before the PET examination. The PET images examined 22 cortical and subcortical areas. CFS patients showed a significant hypometabolism in right mediofrontal cortex (P = 0.010) and brainstem (P = 0.013) in comparison with the healthy controls. Moreover, comparing patients affected by CFS and depression, the latter group showed a significant and severe hypometabolism of the medial and upper frontal regions bilaterally (P = 0.037-0.001), whereas the metabolism of brain stem was normal. Brain 18FDG PET showed specific metabolism abnormalities in patients with CFS in comparison with both healthy controls and depressed patients. The most relevant result of our study is the brain stem hypometabolism which, as reported in a perfusion SPECT study, seems to be a marker for the in vivo diagnosis of CFS.

Regional cerebral blood flow changes in patients with cirrhosis assessed with 99mTc-HM-PAO single-photon emission computed tomography: effect of liver transplantation.

BACKGROUND/AIMS: Previous studies showed contrasting results with regard to alterations of regional cerebral blood flow/metabolism in subjects with liver cirrhosis. The aim of the study was to extend these findings in a larger series of patients. In addition, we wanted to determine whether such alterations are reversed by successful liver transplantation. METHODS: The study group comprised 23 patients with liver cirrhosis and 13 normal controls. At entry to the study, all subjects underwent a complete neurological examination, EEG recordings and SPECT scanning. The severity of liver disease was determined according to the Child-Pugh score. Fourteen patients underwent a second SPECT examination 1 year after liver transplantation. RESULTS: Significant rCBF reductions, ranging from 6% to 7%, were found in the majority of the cortical regions of the whole group of patients with cirrhosis, as compared to controls. These reductions were more diffuse in patients with alcoholic liver disease, comprising almost all the assayed regions. Liver transplantation normalized cortical rCBF deficits so that postoperative perfusion indexes were superimposable on control values. However, the frontal cortex remained significantly more impaired in patients with alcoholic cirrhosis than in those with non-alcoholic cirrhosis. The differences in frontal rCBF between the two groups of patients ranged from 6 to 11%. CONCLUSIONS: Liver cirrhosis was associated with rCBF defects that depend upon the etiology of liver disease and that subsided after successful liver transplantation. The frontal defects in alcoholic cirrhosis either before or after surgery may imply a neurotoxic, possibly irreversible, action of ethanol.