Biomedical subjects

R Linke

Publications and source records attributed to R Linke.

At least 55 records · Page 3Linked to original sources

PubMed1999

[Diagnosis and staging of liver metastases with imaging methods].

Liver metastases are much more common than primary hepatic malignancies and may occur in up to 80% of patients with extrahepatic malignancies. To optimize the patient's management, precise detection or exclusion of liver metastases, as well as assessment of their number and extent, is indispensable. For imaging of liver metastases, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), scintigraphy, and angiography can be utilized. All these methods have been technically improved with benefits for diagnostic utility. Biphasic contrast-enhanced spiral CT (SCT) and MRI with modern pulse sequences and tissue-specific contrast agents are superior to other imaging modalities in terms of diagnostic efficacy and reproducibility of results. With SCT and MRI sensitivities and specificities in the diagnosis of focal hepatic disease are in the range of 80-95%. Moreover, their non-invasiveness is a strong advantage. The diagnostic strategy in the assessment of liver metastases has to take into account both the strengths and limitations of the respective method. Additionally, the clinical situation of a particular patient has to be considered, and conclusive diagnostic results have to be achieved in a short time in order to ensure a favourable cost-effectiveness relation.

Colorectal Neoplasms↗

PubMed1999

Organization of projections to temporal cortex originating in the thalamic posterior intralaminar nucleus of the rat.

Thalamic nuclei surrounding the medial geniculate body, among which the posterior intralaminar nucleus (PIN) is one of the largest, have great importance in fear-potentiated emotional behavior. Due to limited knowledge of the distribution of the cortical projections of the PIN, the connections between the temporal neocortex and the PIN were investigated by means of axonal transport of Phaseolus vulgaris leucoagglutinin or Mini-ruby. After iontophoretic injections of either tracer, anterogradely labeled terminals showed a broad, but not a diffuse, distribution in temporal and adjacent cortices (perirhinal, secondary auditory, visceral, secondary somatosensory, agranular insular cortices). A common projection to all areas was found in the upper layer I except for perirhinal cortex, where this projection was confined to the basal layer I. In selected cortical fields (ectorhinal, perirhinal, visceral cortices), an additional projection to layers III/IV was found. The corticofugal projection to the PIN originated from pyramidal neurons in layer V and - in some regions - in layer VI. The present results demonstrate a distinct and selective projection of the PIN to several areas of the temporal neocortex, which may activate inter- and intra-areal cortical circuits during processing of auditory stimuli.

Animals↗

PubMed1999

Comparison of two sensitization paradigms of the acoustic startle response in Wistar and Sprague-Dawley rats.

An increase in general responsiveness after aversive stimulation has provided a most widely accepted and well-understood sensitization paradigm. According to a second paradigm (based on the dual process theory of habituation and sensitization), not only additional aversive stimuli, but also the response-eliciting stimuli themselves, induce sensitization. To relate these two sensitization paradigms, we compared the course of startle response parameters during repetitive acoustic stimulation with the change in startle amplitude after electric footshocks in outbred Wistar and Sprague-Dawley rats. Compared to the Wistar rats used, the Sprague-Dawley rats showed a lower response decrement and a shortened latency during repetitive stimulation, both of which are indicators of increased sensitization by the startle-eliciting stimuli. In addition, the Sprague-Dawley rats also demonstrated a reduced increase in startle amplitude following footshock. This was postulated to be a consequence of the strong sensitization by startle-eliciting stimuli, which interferes with sensitization elicited by footshock. Because our Wistar and Sprague-Dawley rats did not differ in initial startle amplitude, but mainly in susceptibility to sensitization, further comparisons of these genetically different stocks of rats seem to be of potential value in studying differences in fear-motivated behavior.

Acoustic Stimulation↗

PubMed1999

Differential projection patterns of superior and inferior collicular neurons onto posterior paralaminar nuclei of the thalamus surrounding the medial geniculate body in the rat.

The thalamic nuclei at the medial border of the medial geniculate body (i.e. the suprageniculate nucleus, the medial division of the medial geniculate nucleus, the posterior intralaminar nucleus and the peripeduncular nucleus) which relay sensory information to the amygdala are thought to receive convergent input from multiple sites. In order to delineate the organization of these multimodal thalamic nuclei, the locations of superior and inferior collicular neurons projecting to these nuclei were studied by means of retrograde transport methods. Small injections of the tracer Miniruby were made into single paralaminar thalamic nuclei. Injections of Miniruby into the suprageniculate nucleus labelled predominantly neurons in the stratum opticum of the superior colliculus, whereas injections into the medial division of the medial geniculate body, the posterior intralaminar nucleus and the peripeduncular nucleus labelled predominantly neurons in the deep layers of the superior colliculus. These injections also labelled neurons in the inferior colliculus. The majority of retrogradely labelled neurons were found in the external nucleus of the inferior colliculus and here predominantly in layer 2. Injections focused onto the medial division of the medial geniculate body additionally labelled magnocellular neurons in layer 3 of the external nucleus and a few neurons in the central nucleus. More ventrally located injections, focused onto the posterior intralaminar and peripeduncular nucleus, almost exclusively labelled neurons in layer 1 of the external nucleus and the dorsal part of the dorsal nucleus. After injections into the suprageniculate nucleus, only neurons in layer 2 were found. Neurons in the central nucleus of the inferior colliculus were only found after injections that involved the medial division of the medial geniculate body. The present results suggest that, despite a considerable degree of convergence in this thalamic region, each of these thalamic nuclei receives a unique pattern of projections from the superior and inferior colliculi. It appears that the thalamic nuclei may be concerned mainly, but not exclusively, with a single sensory modality, and give rise to parallel multimodal and unimodal pathways to the amygdala.

Animals↗

PubMed1998

Prevention of initial perfusion failure during xenogeneic ex vivo liver perfusion by selectin inhibition.

BACKGROUND: Endothelial cell activation triggered by xenoreactive antibodies and complement products is the main feature of discordant xenograft rejection. The contribution of early cell-mediated mechanisms to this rejection process is poorly understood, and the function of adhesion molecules in xenogeneic cell interactions in vivo is unclear. The aim of the study was to investigate the role of selectins in mediating cell-dependent initial perfusion failure and functional restrictions in xenoperfused guinea pig (GP) livers. METHODS: Isolated GP livers were hemoperfused in a flow-constant, recirculating perfusion system via the portal vein. Microhemodynamic parameters such as sinusoidal perfusion rate and leukocyte flux were analyzed using intravital fluorescence microscopy. Hepatic oxygen consumption and bile production, as well as liver enzymes, potassium level, and numbers of white blood cells and platelets in the perfusate, were determined. The GP livers were perfused either with GP blood (control perfusion), with unmodified rat blood (xenoperfusion), or with rat blood treated with the selectin-blocking polysaccharide Fucoidin. RESULTS: A significant sinusoidal perfusion failure was observed in the xenoperfusion group, which was accompanied by distinct signs of a functional restriction-like reduced oxygen consumption, bile production, and increased perfusion pressure. However, there were significantly fewer impairments in the Fucoidin group. Furthermore, fewer platelets were trapped and a smaller number of stagnant leukocytes were observed in this group. CONCLUSION: Fucoidin did not suppress complement activation during xenoperfusion. Considering that Fucoidin inhibits the selectin-dependent interactions among white blood cells, platelets, and sulfate-containing proteoglycans on the surface of vascular endothelium, these findings suggest an important role for early cellular interactions in the development of organ failure during xenogeneic rejection.

Animals↗

PubMed1998

Monitoring of microhemodynamic changes during ex vivo xenogeneic liver perfusion using intravital microscopy.

The main targets of xenogeneic rejection mechanisms are the endothelial cells of the graft. Their activation and the consequent alteration of the organ's microcirculation lead to the destruction of the xenograft. Microhemodynamic changes occurring during this process are still poorly characterized. The aim of this study was to analyze the microcirculation during xenogeneic ex vivo hemoperfusion of rat livers and to monitor the impact of treatment strategies using intravital fluorescence microscopy. In contrast to the isogeneic control group, blood flow almost completely stopped within the first minutes of xenoperfusion. Simultaneously, perfusion pressure increased and bile production was reduced. Acetylsalicylate (Aspisol) and the platelet-activating factor antagonist WEB 2170 improved the microcirculation and function of the xenoperfused liver. The combination showed a synergistic effect. After apheresis of preformed xenogeneic antibodies, the parameters measured were comparable with those seen in isogeneic experiments. Complement degradation with cobra venom factor revealed a minor improvement in perfusion. A rapid, extensive, and irreversible leukocyte accumulation in terminal portal vessels was observed in all xenogeneic experiments. Blood counts of the perfusate confirmed the early trapping of leukocytes and platelets in the xenoperfused liver, indicating nonimmunological, cellular involvement in this rejection process.

Animals↗

PubMed1998

Analysis of the microcirculation during xenogeneic liver perfusion in the guinea pig--rat model. The contribution of leukocytes to the rejection process.

Since the main feature of hyperacute rejection is a disturbance of the xenograft's microcirculation, we analyzed microhemodynamic parameters during xenogeneic hemoperfusion of the guinea pig (GP) liver and investigated the contribution of leukocytes to the rejection process using intravital fluorescence microscopy. Isolated GP livers were hemoperfused via the portal vein in a recirculating system with a constant flow of 1 ml/min per g liver. In contrast to isogeneic perfusion with heparinized GP blood, a disturbance in the microcirculation was observed during xenogeneic perfusion using heparinized rat blood, with significantly higher values of perfusion pressure, reduced sinusoidal perfusion rates, and a larger number of stagnant leukocytes. A complete breakdown of the microcirculation, with the highest values of perfusion pressure and the smallest perfusion index, was associated with 100% accumulated leukocytes when rat blood was anticoagulated with sodium citrate. Almost isogeneic perfusion values were obtained when fucoidin, which inhibits L-selectin-dependent cell interaction, was added to heparinized rat blood. These data indicate that leukocyte-endothelial cell interaction contributes to xenogeneic rejection.

Animals↗

PubMed1998

Modulation of mRNA expression of the neurotrophins of the nerve growth factor family and their receptors in the septum and hippocampus of rats after transient postnatal thyroxine treatment. I. Expression of nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin 4 mRNA.

Early postnatal application of thyroid hormones to rats results in morphological changes in septum and hippocampus. Modulation in the expression of either neurotrophins and/or their receptors is postulated to be responsible for these effects. In the present study we tested whether thyroxine administration leads to changes in the expression of neurotrophins of the nerve growth factor (NGF) family. Newborn rats were treated daily with subcutaneous injections of thyroxine until postnatal day (P) 12 at maximum. The pups were killed at defined intervals from P2 to 21. The septal area and the hippocampi were analyzed using the reverse transcriptase-PCR method for quantitation of NGF, brain-derived neurotrophic factor (BDNF), NT-3, and NT-4 messenger RNA (mRNA) levels. In hippocampus of hyperthyroid rats, as compared to controls, we found higher levels of BDNF and NT-3 mRNA over the total investigation period, whereas in the septum a thyroxine-dependent increase in NT-3 mRNA expression was observed. In addition, significant thyroxine-induced effects were found for all variables (except for NGF in the septum) at particular postnatal days. From these data we conclude that modulation of neurotrophin expression is a possible mechanism for the morphological modifications within the hippocampal mossy fiber system and the septohippocampal cholinergic system.

Animals↗

PubMed1998

Myocardial fatty acid metabolism during acute cardiac allograft rejection.

Fatty acids are promptly taken up, metabolised and eliminated by healthy cardiomyocytes. Cardiomyopathy, coronary heart disease and chronic rejection are known to be associated with an impaired fatty acid metabolism. It was the aim of this study to investigate fatty acid metabolism in a rat heart transplant model and to correlate scintigraphic findings with histological changes. After right-side nephrectomy of Lewis recipients Brown Norway cardiac allografts were anastomosed to the renal vessels. Animals were given no immunosuppression. The metabolism of carrier-free 17-123 jodo-heptadecanoic acid (123J-HDA) with a specific activity of > 2 x 10(17) Bq/ml was scintigraphically measured between days 1 and 11. An increase in the grade of rejection was observed over time. Fifty-six frames of 30 s duration each were recorded. For the region of interest (native heart, transplanted heart, left kidney) frames 10-56 were superimposed, time-activity curves generated and monoexponentially fitted. Furthermore, elimination half-life and intercepts were calculated. Following scintigraphic evaluation the animals were killed and graft as well as native hearts excised for histological examination. The uptake of the tracer identified severe grades of rejection. Elimination half-life of the tracer was twice as long from hearts with mild rejection and more than 14 times as long in severe rejection compared with no rejection. Elimination half-life and amplitude did not permit discrimination between grades 1, 2 and 3 a, but significantly decreased in groups 3 b and 4. This method therefore seems to be a valuable tool for the noninvasive detection of severe acute cardiac allograft rejection. Since fatty acid metabolism is clearly stress-dependent it remains to be seen whether this method allows detection of earlier rejection in loaded hearts.

Animals↗

PubMed1998

Xenogeneic rejection mechanisms shown by intravital microscopy.

The importance of this model is that it showed exactly where in the organ the xenogeneic damage occurred. The liver received the blood mainly via portal veins, which merge with the pulsatile arterioles in the Disse spaces. This periportal area is followed by the sinusoids and ends in the central or postsinusoidal vein. IVM enables us to differentiate between perfused and unperfused sinusoids and to calculate the ratio. Not all sinusoids are perfused at any time. It appears that 5% to 10% are unperfused. During xenoperfusion, only 65% of sinusoids show blood flow after a perfusion of 12 minutes. This is less than in hemorrhagic shock. Only the combined platelet inhibitors and apheresis resulted in remarkable improvement. The calculation of an index indicates the improvement of acinar perfusion. Thrombocytes and leukocytes remain, however, in the liver. In conclusion, the model used to analyze the dynamics of microvascular liver perfusion and sinusoidal perfusion is suitable for such investigations in a xenogeneic model. It has no major side effects, either on the perfusing blood or on the liver, as proved in the isogeneic control group. The important finding in our eyes is that the perfusion failure begins in the periportal fields, where the blood enters the foreign microvasculature and where the leukocytes first come in contact with the foreign endothelium. All previous manipulations had only a minor impact on this contact of cells with the foreign endothelium. The study indicates that the early events of xenogeneic hyperacute rejection are of unspecific character and involve leukocytes and thrombocytes to a major degree, thus being responsible for the dramatic decrease in the microcirculation in xenogeneic livers.

Animals↗

PubMed1998

Axotomy-induced c-JUN expression in young medial septal neurons is regulated by nerve growth factor.

In the present study we investigated the axotomy-induced expression of the proto-oncogene c-jun in young rat medial septal neurons and its regulation by nerve growth factor. First, medial septal neurons were retrogradely labelled by Fast Blue injection into the hippocampus at postnatal day 1 (P1). Rats of different developmental ages (P6, P9, P14, P21, P28 and P42) were then subjected to bilateral fimbria-fornix transection resulting in the axotomy of septohippocampal projection neurons. After the lesion, c-JUN immunoreactivity was observed in the nuclei of axotomized medial septal neurons of all stages examined, suggesting that c-JUN induction is an age-independent feature of axotomized medial septal neurons. Double immunolabelling for choline acetyltransferase and c-JUN or parvalbumin and c-JUN, respectively, revealed that both cholinergic and GABAergic septohippocampal projection neurons express c-JUN after axotomy. In addition, a co-localization of immunostaining for c-JUN and the neuropeptide galanin was found after lesion, as both proteins were induced in the same medial septal neurons following fimbria-fornix transection. Next, the regulation of c-JUN expression in axotomized medial septal neurons was studied in organotypic cultures of the medial septum. Axotomized medial septal neurons in culture did not express c-JUN in contrast to the in vivo situation. With the concept that nerve growth factor suppresses c-JUN expression, slice cultures of the medial septum were treated with antibodies against nerve growth factor. This treatment caused a dose-dependent increase in c-JUN-positive cells in these slice cultures. Simultaneous addition of nerve growth factor and antibodies against nerve growth factor resulted in the reversal of this effect. These data suggest an age-independent induction of c-JUN in axotomized medial septal neurons and its regulation by nerve growth factor.

Acetylcholine↗

PubMed1998

[Is there a correlation between sudden deafness and smoking?].

BACKGROUND: The etiology of sudden hearing loss is not yet known. The most common mechanism of sudden hearing loss would appear to be impaired cochlear blood circulation. Tobacco smoking causes changes in hemostasis and raises the body's need for oxygen because of carbon monoxide, one component of the smoke which blocks a part of the hemoglobin. PATIENTS AND METHODS: 297 patients (76 smokers, 99 former smokers, and 122 non smokers) who were treated because of sudden hearing loss in the hospital in the last 5 years were queried about their smoking habits. We asked the patients to complete a questionnaire in order to get more reliable answers. We explored the kind of tobacco, the number of cigarettes or cigars per day, the age at onset of smoking, the number and rate of recurrence of sudden hearing loss, the result of the treatment of a former sudden hearing loss (if there was one), the characteristics of tinnitus, the possibility of stopping smoking, and the significance of tobacco smoking as reflected in health policy. RESULTS: Tobacco smoking does not increase the overall risk of sudden hearing loss. The incidence of smokers in the population of the region and the incidence of smokers among patients with sudden hearing loss is equal. But the average age of the smoking patients is significantly lower than the average age of non smokers and former smokers. Smokers have a higher rate of recurrence of a sudden hearing loss. The result of treatment of former sudden hearing loss is worse in smoking patients. CONCLUSIONS: There is no obvious relation between the risk of sudden hearing loss and tobacco smoking.

Adult↗

PubMed1998

Limited value of scintimammography and contrast-enhanced MRI in the evaluation of microcalcification detected by mammography.

The aim of this study was to evaluate whether scintimammography using 99Tc(m)-sestamibi or contrast-enhanced magnetic resonance imaging (MRI) can improve the specificity of mammography for the differentiation of benign and malignant breast microcalcification. From 156 consecutive patients studied with SMM, 44 patients with microcalcification on mammograms were selected for this study. Forty patients in this group also had contrast-enhanced MRI of the breast. The intensity and patterns of sestamibi uptake for scintimammography and contrast enhancement for MRI were visually determined and graded on a 5-point scale for malignancy. The results of both techniques were compared and correlated with final histopathologic diagnoses. The sensitivity and specificity of scintimammography were 63% and 85% respectively, if only those cases classified as probable or definite malignancy were considered positive. If indeterminate findings were also considered positive, the sensitivity and specificity of scintimammography were 79% and 80% respectively. Using the latter classification for MRI revealed a comparable sensitivity of 82% but a markedly lower specificity of 56%. Excluding indeterminate findings from the group of positive MRI diagnoses resulted in a specificity of 94% and a sensitivity of 64%. In conclusion, scintimammography of the breast had a comparable sensitivity but a higher specificity than MRI. The sensitivity of both techniques, however, is probably too low for routine use in the evaluation of microcalcification detected by mammography.

Adult↗

PubMed1998

Intravital microscopic investigation of xenogeneic microcirculation and impact of complement depletion by cobra venom factor.

Discordant xenografts are hyperacutely rejected within minutes. Disturbances in the microcirculation are considered to be the central mechanisms of hyperacute xenogeneic rejection (HXR). In this study intravital fluorescence microscopy was applied to investigate the dynamics of microcirculatory alterations in a setting in which HXR was inhibited by complement (C) depletion. Blood flow was measured as rat livers were perfused with isogeneic rat or xenogeneic human blood to assess the pattern of either physiological isogeneic hemoperfusion or in the course of HXR. Next, the complement system of the perfusate was inactivated by cobra venom factor (CVF) in order to inhibit HXR. Liver sinusoids of the isogeneic group were homogeneously perfused (sinusoidal perfusion rate 93.6+/-0.3%), whereas in the xenogeneic group the sinusoidal perfusion rate dropped to 67.1+/-3%. The perfusion in the periportal zone of an acinus was significantly lower ( 59.0+/-3.3%) than in the pericentral zone (76.2+/-3.1%). Treatment with CVF improved the sinusoidal perfusion to a value of 85.6+/-2.3%, physiological perfusion, however could not be reached. In contrast to the isogeneic group, massive white blood cell (WBC) and platelet accumulation was found in the xenogeneic group, especially in the terminal portal vessels and in the periportal zone of liver acini. WBC and platelet counts show that the adherence of these cells appears rapidly in the first 5 min after reperfusion as firm adherence. CVF was not able to inhibit WBC and platelet accumulation, indicating that WBC endothelial interactions do not require an intact complement system. Bile flow, a parameter of liver function, decreased only slightly during isogeneic perfusion. The addition of CVF to the rat blood reduced the bile flow to one half of the untreated isogeneic flow, indicating a hepatotoxic side-effect of CVF. In xenogeneic perfusion the bile flow dropped to 62.6% and with the addition of CVF to 37.5% in the first 15 min after reperfusion. The bile flow of the CVF treated groups recovered during the perfusion but could not reach isogeneic values.

Acute Disease↗

PubMed1998

Dopaminergic deficit in amyotrophic lateral sclerosis assessed with [I-123] IPT single photon emission computed tomography.

Dopamine transporter imaging was performed in 18 patients with sporadic amyotrophic lateral sclerosis (ALS) and 11 age matched controls with [I-123] IPT (N-(3-iodopropen-2-yl)-2beta-carbomethoxy-3beta(4-chlorophen yl)-tropane), a new cocaine analogue that selectively binds to the dopamine transporter located on dopaminergic nerve terminals. Image analysis showed that striatal IPT binding was moderately but significantly reduced in the ALS group compared with controls (p<0.01). The reduction of IPT binding was similar for patients with bulbar onset compared with those with limb onset. There was no correlation between values for uptake of striatal IPT and the age of the patients or the duration of the disease. These data indicate that nigrostriatal dopaminergic neurons are subclinically affected in a subset of patients with sporadic ALS.

Adult↗

PubMed1998

Organs from animals for man.

In the following review some of the problems of xenotransplantation shall be discussed, based on the few experimental data available so far and on reports in the literature describing investigations which may be of importance for xenotransplantation. The impact of gravity on the upright posture of man versus almost all other mammals, the dysfunction between enzymes and hormones in different species and the lack of interactions between interleukins, cytokines and vasoactive substances will be taken into consideration. The question must be asked whether different levels of carrier molecules or serum proteins play a role in the physiological network. Even though the development of transgenic animals or other imaginative manipulations may lead to the acceptance of any type of xenografted organ, it has to be established for how long the products of the xenografts are able to act in the multifactorial orchestra. We are far from understanding xenogeneic molecular mechanisms involved in toxicity, necrosis and apoptosis or even reperfusion injury and ischemia in addition to the immediate mechanisms of the hyperacute xenogeneic rejection. Here, cell adhesion, blood clotting and vasomotion collide and bring micro- and macrocirculation to a standstill. All types of xenogeneic immunological mechanisms studied so far were found to have a more serious impact than those seen in allogeneic transplantation. In addition we are now only beginning to understand that so-called immunological parameters in allogeneic mechanisms act also in a true physiological manner in the xenogeneic situation. These molecular mechanisms occur behind the curtain of hyperacute, accelerated, acute or chronic xenograft rejection of which only some folds have been lifted to allow glimpses of part of the total scene. Other obstacles are likely to arise when long-term survival is achieved. These obstacles include retroviral infections, transfer of prions and severe side effects of the massive immunosuppression which will be needed. Moral, ethical and religious concerns are under debate and the species-specific production of proteins of the foreign donor species developed for clinical use suddenly appears to be a greater problem than anticipated.

Animals↗

PubMed1998

[Effect of high dosage immunoglobulins on the function of rat hearts in xenoperfusion with human blood].

The application of high-dose immunoglobulins during xenoperfusion of the isolated rat heart resulted in a significantly higher pressure and heart rate. The coronary flow was also elevated as compared to untreated controls. The heart function during xenoperfusion without treatment was reduced to 50% of the baseline values within 11 min. With immunoglobulin treatment the occurrence of this deficit was delayed to 30 min. A concentrate of immunoglobulins was able to reduce the early functional damage of xenoperfused hearts by interfering with complement related graft destruction.

ABO Blood-Group System↗

PubMed1998

Technetium-99m-sestamibi scintimammography for the detection of breast carcinoma: comparison between planar and SPECT imaging.

UNLABELLED: The purpose of our study was to compare the results of planar and SPECT scintimammography for the detection of breast carcinoma. In addition, our goal was to determine whether SPECT reconstructed with filtered backprojection (FBP) or with iterative algorithms (ISA) can improve the sensitivity and specificity of planar scintimammography (SMM). METHODS: One hundred thirteen patients with suspicious physical examinations and/or mammography underwent planar lateral and anterior breast imaging as well as SPECT imaging after injection of 99mTc-sestamibi. We used a blind evaluation, both separately and combined, for planar SMM, ISA-SPECT and FBP-SPECT. Scintigraphic findings were correlated with the final histopathological diagnoses. RESULTS: The sensitivity of planar SMM was 80% with a specificity of 83%. All ISA-SPECT studies were of diagnostic quality, while FBP-SPECT was considered nondiagnostic in 14 that were excluded for statistical calculation. Sensitivity of ISA-SPECT and FBP-SPECT were 71% and 69%, respectively. Specificity was 70% for ISA-SPECT and 66% for FBP-SPECT. Combined planar SMM plus ISA-SPECT sensitivity was 85% (81% for planar SMM plus FBP-SPECT) with a specificity of 72%. Three carcinomas indeterminate on planar SMM were correctly identified by combined planar SMM plus ISA-SPECT. ISA-SPECT and FBP-SPECT provided additional information to planar SMM with respect to localization of sestamibi uptake, tumor extent, improved diagnostic certainty and detection of axillary nodes in 40 and 14 patients, respectively. CONCLUSION: ISA reconstruction is the preferable approach to SPECT data. Combined with planar SMM, ISA-SPECT can improve sensitivity. SPECT is useful in cases of indeterminate and positive planar SMM.

Algorithms↗