The role of nuclear medicine in the diagnosis of spondylodiscitis.

BACKGROUND: The diagnosis of spondylodiscitis can be difficult, because the patients history, subjective symptoms and physical findings are often inconclusive, particularly in the early stages. AIM: To perform an overview on the role of nuclear medicine procedures with single photon emission tomography (SPET) and positron emission tomography (PET) tracers in the diagnosis of spondylodiscitis. MATERIALS AND METHODS: A literature review about bone scintigraphy, Gallium-67-citrate scintigraphy, labeled leukocytes scintigraphy and PET was performed. Main findings of the literature were reported. RESULTS: Bone scintigraphy is a sensitive and widely available nuclear medicine technique, but it is characterized by low specificity. Gallium-67-citrate scintigraphy is often used as a complement to bone scintigraphy to enhance the specificity of the study and to detect extra-osseous sites of infection. Labeled leukocytes scintigraphy is not a useful method in the diagnosis of spondylodiscitis. Fluorine-18-fluorodeoxyglucose positron emission tomography is a sensitive method and could potentially be useful in the diagnosis of spondylodiscitis and in the evaluation of treatment response. Nevertheless, scientific literature about this topic is still limited. CONCLUSIONS: Overall, nuclear medicine procedures play a useful role in the diagnosis of spondylodiscitis identifying functional abnormalities which precede morphological changes. Therefore, nuclear medicine procedures may complement or integrate morphological imaging findings in patients with suspected spondylodiscitis.

Dopamine transporter binding in depressed patients with anhedonia.

Central dopaminergic dysfunction has been widely proposed as a common neurobiological correlate of the psychopathological expression of anhedonia. The dopamine transporter (DAT) is a predominantly presynaptic receptor that may play a critical role in the pathophysiology of dopaminergic transmission. The aim of our study was to evaluate DAT binding in a population of depressed patients with anhedonia. Single photon emission computed tomography (SPECT) with the radiotracer DATSCAN was used to evaluate DAT binding in 11 depressed patients with anhedonia and 9 healthy comparison subjects. Compared with healthy subjects, patients showed significantly lower DAT binding. No significant correlation was found between DAT binding ratios and scores on administered psychometric tests. These findings suggest an alteration in DAT density in depressed patients with anhedonia that may be a primary susceptibility factor or a secondary phenomenon to reduced dopamine concentration in the synaptic cleft.

Nuclear medicine in primary bone tumors.

INTRODUCTION: Conventional radiography is the method of choice to diagnose a primary bone tumor but in many cases it is necessary to integrate it with nuclear medicine scintigraphy using several radionuclides, including 67Ga, 201Tl, 99mTc-MIBI and especially 99mTc-diphosphonates. Recently a new technique has been recently introduced, that is positron emission tomography with 2(18F) fluoro-2 deoxy-D-glucose as radiopharmaceutical. OBJECTIVE: The specific purpose of this work is to show that nuclear medicine bone scanning is a very important method in the detection and diagnostic management of primary bone tumors. DIAGNOSIS, STAGING AND FOLLOW-UP: Three-phase bone scintigraphy, integrated with SPECT, is clinically useful to confirm the radiologic diagnosis of bone tumor. These techniques conveniently related to each other and to radiographic findings, can evaluate the tumor's local aggressiveness, often differentiating benign from malignant lesions, to monitor treatment efficacy, to permit total body scanning for the detection of recurrences. Nuclear medicine diagnostic techniques are not in competition with radiographic tools as CT and MRI which are highly sensitive in detecting even small lesions thanks to their excellent anatomical resolution. In questionable cases, we can integrate radiologic imaging with dynamic studies, in particular with FDG-PET, increasing the specificity of diagnosis and permitting more accurate follow-up. CONCLUSIONS: Patient management optimization needs the integration between dynamic nuclear medicine findings and the anatomical patterns provided by conventional radiology to increase imaging sensitivity and specificity. Equipe work is determinant to customize the diagnostic work-up to the individual patient's needs to reduce the cost of patient management avoiding useless examinations.

[Radioisotope study of urinary deformity pathology in childhood]. / Lo studio radioisotopico della patologia malformativa urinaria in età pediatrica.

The role of radionuclide investigation of urinary tract pathology in pediatric patients (computerized radionuclide urography and radionuclide cystogram) is discussed. Advantages of reliable morphological and functional study with a non invasive, low radiation procedure are emphasized.

A computer-assisted method for semi-quantitative assessment of salivary gland diseases.

The authors report on a computer-assisted method that allows a semi-quantitative assessment of salivary gland function under normal and pathologic conditions. They illustrate some mathematical procedures suitable for this purpose and the results achieved in various salivary gland diseases.

[Usefulness of radioisotopic methods in the study of the salivary glands]. / Utilità dei metodi radioisotopici nello studio delle ghiandole salivari.

The results achieved by dynamic and static salivary gland scintigraphy in 272 patients over a ten year time (January 1976-December 1985) are reported. On the basis of a semi-quantitative assessment of time/activity curves, dynamic studies prove to be the most suitable method for studying functional disorders (phlogosis, facial paralysis, etc.). Harmlessness, easy execution and functional results are the main advantages of radioisotope techniques. Salivary gland scintigraphy has some limits in the study of space occupying lesions (SOL): however, ultrasounds, CT and sialography represent the methods of choice in this field of salivary gland pathology.

[The tolerance of the hip prosthesis evaluted through scintigraphic studies (author's transl)]. / Die Toleranze bei Hüftgelenkprothesen bewertet durch szintigraphische Studien

The authors assert the usefulness of the scintigraphy in the early diagnosis and/or for the confirmation of the main complications connected with the artroprosthesis of the hip. Such investigation is effective only if it is carried out at a distance of at least six months from the operation and must be completed by clinical, bio-humoral and radiographic tests. This study is based on the observation of 40 cases, of which 20 represent the control group. The isotope used is the Tc99m-pyrophosphate.

Scintigraphy in osteoid osteoma: problems related to differential diagnosis.

Scintigraphy is currently the most widely used and most reliable diagnostic instrumental test for the diagnosis of osteoid osteoma. Indications for its use are based on two considerations: 1) the need for preoperative confirmation of a suspected diagnosis based on clinical and radiographic findings; 2) the preoperative differential diagnosis from lesions which, either due to site or to atypical features, can mimic osteoid osteoma and are not easily identified. However, the high sensitivity of the test is associated with low specificity. In order to increase the specificity, the authors use angioscintigraphy and illustrate some cases where this method permitted differential diagnosis with other bone lesions that simulate the clinical and radiographic features of osteoid osteoma.

Functional study with 131I-rose bengal in chronic active hepatitis and nonactive cirrhosis using a three-compartment model.

The authors, using 131I-Rose Bengal, determined the fractional transfer constants of a three-compartmental model in 30 patients divided into two groups (chronic active hepatitis and nonactive cirrhosis) on a histological basis. Other functional indexes were also taken into consideration. In nonactive cirrhosis, the results show a greater impairment of Rose Bengal transfer from plasma to liver. In chronic active hepatitis K32 (fractional transfer coefficient from the second to the third compartment) appears significantly lower than in nonactive cirrhosis. No significant differences have been found for K12 and K03. The best differentiation between the two groups (consistent with histological data in 29 of 30 cases) was obtained by grouping K21, retention index (RI) and SGOT in the discrimination function: L=4.88 K21-0.016RI+0.0034SGOT. The ratio K12/K21 seems meaningful for diagnostic purposes and in the evaluation of the hepatocellular damage in single cases.

The particular usefulness of radioisotope methods in some benign bone diseases.

The authors have performed radioisotope examinations in 271 patients with various non-neoplastic bone diseases. According to their opinion, early diagnosis and follow-up of therapeutic results are the main characteristics which allow radioisotopes to play an important and irreplaceable role. They particularly emphasize the usefulness of radioisotope methods in femoral aseptic necrosis and Paget's disease.

[Scintigraphic diagnosis of Meckel's diverticulum using Tc-99m-pertechnetate]. / La diagnosi scintigrafica del diverticolo di Meckel con il 99mTc-pertecnetato.

Meckel's diverticulum (MD) is a well-known cause of lower gastrointestinal hemorrhage, particularly in the pediatric age group. The radionuclide 99mTc-pertechnetate has been found useful in visualizing MD which contain gastric mucosa. This test is predicated of the affinity of the isotope for the parietal cells of the gastric glands. In an attempt to evaluate the sensibility and specificity of pertechnetate, the clinical data and scintigrams of 27 patients with suspected MD were reviewed. The scintigram correctly identified MD before operation in 6 of 7 patients. The false negative study occurred in a MD without gastric mucosa.

Surgical indications in normotensive hydrocephalus. A retrospective analysis of the relations of some diagnostic findings to the results of surgical treatment.

Twenty two of fifty five patients initially suspected of suffering from normotensive hydrocephalus were surgically treated (CSF ventriculoatrial shunt). The results of surgery were related to the findings of the different diagnostic examinations (pneumoencephalography, isotope cisternography, transfer fron CSF to blood of isotope labelled serum albumin, constant infusion manometric test, long lasting intraventricular pressure recording). 1.Pneumoencephalography, intraventricular pressure recording, and, above all, isotope cisternography provided the most reliable data for diagnosis and surgical prognosis. 2. The combined use of pneumoencephalography and isotope cisternography was sufficient for a correct diagnosis and surgical prognosis in about 50% of the patients examined. 3. When the diagnostic information given by the combined results of the two above examinations was not sufficient, intraventricular pressure recording proved to be the most useful examination to supplement it. 4. The relation of the results of the study of transfer of istope labelled serum albumin from CSF to blood and of the constant infusion manometric test to the surgical outcome was uncertain.

[Long-term scintigraphic follow-up study of the hip prosthesis]. / L'indagine scintigrafica nel controllo a distanza delle protesi d'anca.

The authors emphasize the importance of the bone scan in long-term follow-ups of total hip arthroplasty and describe some technical details of the examination. The changes revealed in the bone scan are confirmed by the operative report. Even though the number of patients in the study was relatively small, the fact that the bone scan taken of patients with cementless total hip replacements revealed no pathological changes is considered significant.

Impaired clearance of cholephilic anions in Rotor syndrome.

The behaviour of some cholephilic anions has been studied in three male patients (two of whom are brothers) affected with Rotor syndrome. The unconjugated bilirubin clearance was markedly reduced with impairment of the plasma-liver transfer constant rate (uptake defect). BSP retention at 45 min. was elevated without late rise of the anion. Transport maximum ("Tm") of BSP was slightly reduced; relative hepatic storage capacity of BSP ("S") was significantly impaired. Plasmatic retention of 131-I-Rose Bengal was increased with a diminished hepatic uptake of the compound. The hepatic excretion of IDA-derivatives was impaired, but less for parabutyl-IDA than for diethyl-IDA. It is concluded that in Rotor syndrome there exists an alteration of uptake and storage of several cholephilic organic anions: the alteration is common not only to substances that undergo intracellular conjugation--such as bilirubin and BSP--but also to substances that are not metabolized--such as Rose Bengal and IDA--derivatives. Finally the authors suggest that the Rotor syndrome and so--called "Hepatic storage disease" are the same condition.

The hepatic excretion of 131I-rose bengal and 99mTc-IDA derivatives in Rotor's syndrome.

Bilirubin kinetics and hepatobiliary excretion of some exogenous anions (BSP, 131I-rose bengal, diethyl and parabutly-IDA labeled with 99mTc) were studied in three patients presenting with Rotor's syndrome. Two were brothers; a nonjaundiced fraternal twin of one of them was also evaluated. The hepatic clearance of the radiopharmaceuticals was impaired in the affected patients but the degree of impairment was different among the tested anions, i.e., maximal for 99mTc-diethyl-IDA and minimal for 131I-rose bengal. Parabutyl-IDA was cleared better than the diethyl derivative. The metabolic derangement seems to be at the level of transfer from plasma to liver and of the hepatic storage, rather than at the level of hepatocyte excretory pathways, as in the case of Dubin-Johnson syndrome.