How to diagnose splenic abscesses?

Splenic abscess is a rare but potentially fatal entity, occurring mainly in patients with underlying risk factors. Mortality of the disease depends on the time of diagnosis and treatment. Due to low sensitivity and specificity of clinical symptoms and laboratory markers, imaging plays the vital role in the diagnostic work-up. The aim of this article is to give a concise overview of the methods of splenic abscess diagnosis.

Is eye lens dosimetry needed in nuclear medicine?

INTRODUCTION: The exact level of exposure experienced by nuclear medicine personnel, whose work often requires performing manual procedures involving radioactive isotopes, is associated with the form of radiation source used. The variety of radionuclides and medical procedures, and the yearly increase in the number of patients, as well as the change of the individual dose limit for the lens of the eye from a value of 150 mSv yr-1 to 20 mSv yr-1, mean that issues of eye lens routine dosimetry become interesting from the radiation protection point of view. OBJECTIVE: This paper presents an analysis of the exposure of the eye lenses of nuclear medicine department personnel, as well as those of personnel in the facilities that produce radiopharmaceuticals for the purpose of diagnosis by positron emission tomography, from the viewpoint of the advisability of routine eye lens exposure monitoring, taking into account changes in the dose limit for the lens of the eye. MATERIALS AND METHODS: The paper considers the two most commonly used radionuclides for diagnostic purposes 99mTc, 18F, and-for therapeutic purposes-131I. Dose measurements were made using thermoluminescent detectors. RESULTS: The estimated exposure analysis identifies the cases when the maximum annual value of the personal dose equivalent, in terms of Hp(3), exceeds threefold the new limit value (20 mSv yr-1). CONCLUSIONS: It is recommended that Hp(3) doses be routinely monitored in the group of radiopharmacists who label pharmaceuticals with the radionuclide 99mTc and in chemists working in 18F-FDG quality control departments in production units, where this is carried out manually.

Late onset GM2 gangliosidosis mimicking spinal muscular atrophy.

A case of late onset GM2 gangliosidodis with spinal muscular atrophy phenotype followed by cerebellar and extrapyramidal symptoms is presented. Genetic analysis revealed compound heterozygous mutation in exon 10 of the HEXA gene. Patient has normal intelligence and emotional reactivity. Neuroimaging tests of the brain showed only cerebellar atrophy consistent with MR spectroscopy (MRS) abnormalities. (18)F-fluorodeoxyglucose positron emission tomography (18)F-FDG PET/CT of the brain revealed glucose hypometabolism in cerebellum and in temporal and occipital lobes bilaterally.

Emotionally negative stimuli can overcome attentional deficits in patients with visuo-spatial hemineglect.

Left unilateral spatial neglect resulting from right brain damage is characterized by loss of awareness for stimuli in the contralesional side of space, despite intact visual pathways. We examined using fMRI whether patients with neglect are more likely to consciously detect in the neglected hemifield, emotionally negative complex scenes rather than visually similar neutral pictures and if so, what neural mechanisms mediate this effect. Photographs of emotional and neutral scenes taken from the IAPS were presented in a divided visual field paradigm. As expected, the detection rate for emotional stimuli presented in the neglected field was higher than for neutral ones. Successful detection of emotional scenes as opposed to neutral stimuli in the left visual field (LVF) produced activations in the parahippocampal and anterior cingulate areas in the right hemisphere. Detection of emotional stimuli presented in the intact right visual field (RVF) activated a distributed network of structures in the left hemisphere, including anterior and posterior cingulate cortex, insula, as well as visual striate and extrastriate areas. LVF-RVF contrasts for emotional stimuli revealed activations in right and left attention related prefrontal areas whereas RVF-LVF comparison showed activations in the posterior cingulate and extrastriate visual cortex in the left hemisphere. An additional analysis contrasting detected vs. undetected emotional LVF stimuli showed involvement of left anterior cingulate, right frontal and extrastriate areas. We hypothesize that beneficial role of emotion in overcoming neglect is achieved by activation of frontal and limbic lobe networks, which provide a privileged access of emotional stimuli to attention by top-down modulation of processing in the higher-order extrastriate visual areas. Our results point to the importance of top-down regulatory role of the frontal attentional systems, which might enhance visual activations and lead to greater salience of emotional stimuli for perceptual awareness.

DNA damage and its repair in lymphocytes and thyroid nodule cells during radioiodine therapy in patients with hyperthyroidism.

Radioiodine treatment of hyperthyroid patients with autonomous thyroid nodule leads to cellular DNA damage not only in thyrocytes but also in peripheral blood lymphocytes. The purpose of this study was to evaluate DNA breakage and base damage in thyrocytes and lymphocytes in patients treated with 131-I. In all the patients thyroid scintiscan was performed using 131-I. Damage to DNA was estimated by comet assay. Samples were taken before radioiodine treatment, and 12 and 54 days afterwards. Our results indicate high diversity in the level of DNA damage among the individual patients. However, in all cases, after 54 days the level of DNA damage in lymphocytes was similar or even lower than that in the controls. In contrast, in hot nodule the DNA damage persisted until the 54th day after 131-I application. Differences in the type of DNA damage between thyrocytes and lymphocytes were also observed. In lymphocytes there was more base damage, whereas in thyrocytes single strand breaks prevailed. This may indicate different mechanisms of DNA damage induction and/or DNA repair.

[Proton MR spectroscopy studies of the brain in ALS patients]. / Badanie metoda spektroskopii rezonansu magnetycznego u chorych na stwardnienie boczne zanikowe.

Nuclear magnetic resonance spectroscopy (MRS) has an ability to measure brain metabolites noninvasively in vivo. The content of N-acetyl-aspartate (NAA) is used as a biochemical marker of neuronal integrity and viability. In amyotrophic lateral sclerosis (ALS) patients the degeneration and neuronal loss of motor cortex was reported. The presence of these changes can lead to the decrease of NAA. The aim of this study was to evaluate the neurochemical status of motor cortex (by using 1H-MRS) in 11 patients with clinically definite or probable forms of ALS (according to the El Escorial criteria). These data were compared with MRS results from 4 healthy controls. The mean NAA/(Cr + PCr) values were decreased by 19% (p < 0.05) when compared with controls. In 4 ALS patients the NAA/(Cr + PCr) ratio was decreased by 31% (p < 0.05) and these patients had rapidly progressing disease. In other 7 ALS patients, we found that NAA/(Cr + PCr) was decreased by 10% (p < 0.05) and they showed less advanced neurological symptoms. 1H-MRS of the motor cortex can be a new diagnostic tool in ALS and it might help to monitor the progress of the disease.

New therapeutic options of carcinoid syndrome metastatic to the liver.

Carcinoid syndrome is a relatively rare disease, generally associated with poor prognosis. Conventional diagnostic and therapeutic methods often prove inadequate and ineffective. New therapeutic options have recently been provided by Radiolabeled long-acting somatostatin analogs (Octreotide), alpha interferon, 131 MIBG and non-pharmacological methods--embolization of the hepatic artery, gene therapy, and combined therapies.

Radioisotope examination in the evaluation of complications followed the implantation of joint prostheses.

Advances in orthopedic reconstructive and reparative techniques have resulted in a new population of patients suffering complications from these surgical procedures. Radionuclide examinations play an important role in the diagnosis of various types of complications following prosthesis implantation. Orthopedists can now choose from among several different radiopharmaceutic media: diphosphonates, gallium or labeled leukocyte. Diphosphonate radionuclide bone scintigraphy is quite sensitive in detecting changes in osseous metabolism. Gallium or leukocyte scans are best suited for the evaluation of inflammatory processes. Nuclear medicine techniques are generally accepted as complementary methods in the evaluation of complications after prosthesis implantation.

The evaluation of articular cartilage in magnetic resonance imaging.

MR imaging is now the method of choice in the evaluation of articular cartilage, revealing its structure and thickness, as well as any changes occurring within the cartilage in all joint surfaces and bones, and in the soft tissues of the joints. The present study describes a method for examining cartilage and examples of pathological images.

Discriminatory power of MRI for differentiation of adrenal non-adenomas vs adenomas evaluated by means of ROC analysis: can biopsy be obviated?

The purpose of our study was to evaluate the discriminatory power of MRI in high-field magnet (1.5 T) for differentiation of adrenal non-adenomas vs adenomas assessing the following parameters separately and in combination: mean diameter of adrenal mass; previously described and new ratios as well as index calculated from signal intensity (SI) on SE T2-weighted images, chemical shift imaging (CSI), and Gd-DTPA-enhanced dynamic studies. One hundred eight adrenal masses (36 non-hyperfunctioning adenomas, 27 pheochromocytomas, 23 aldosterone-secreting adenomas, 20 malignant masses and 2 cortisol-secreting adenomas) in 95 patients were evaluated with SE sequences, CSI and Gd-DTPA dynamic studies. Indices and ratios of SI for all examined MRI methods were calculated and examined retrospectively for significance of differences between the groups with calculation of sensitivity and specificity. Receiver operating characteristics (ROC) analysis of calculated parameters in combination was performed. The multifactorial analysis of all four parameters, including size of the tumor, T2(liver) index, CSI ratio reflecting lipid content in the tumor and Wo(max/last) ratio reflecting maximal washout of contrast agent from the tumor had 100 % sensitivity and 100 % specificity in characterization of adrenal non-adenoma. The best performance of combination of mean tumor diameter with single MRI SI parameter was achieved in combination with T2(liver) index for all adrenal masses (area under ROC 0.987) and CSI ratio for non-hyperfunctioning adrenal masses (area under ROC 0.991). Magnetic resonance imaging enables sensitive and specific diagnosis of adrenal non-adenoma.

[Anaplastic oligoastrocytoma of the spinal cord: diagnostic difficulties. Case report]. / Oligoastrocytoma anaplasticum rdzenia kregowego: trudnosci diagnostyczne. Opis przypadku.

The authors report a rare case of 49-years old woman with rapidly progressing anaplastic oligoastrocytoma primarily localized in the spinal cord. Increasing spastic paresis of the right lower limb was concomitant with decrease in superficial sensibility in this limb and the right side of the trunk below Th10 level, suggested a lesion within the spinal cord. However, it was the difficult confirming the diagnosis by spinal MR imaging, and the negative result of the first MR examination (performed 5 weeks after manifestation of first clinical symptoms of the disease) delayed surgical treatment. During the next 3 weeks the neurological syndrome increased to spastic paraparesis with sphincters dysfunction and decrease in superficial and vibratory sensibility within the lower limbs and the trunk below the Th10 level. The second MR examination of the spine revealed an intraspinal tumour at Th8-Th10 levels. Surgical (partial excision of the tumour) and radiation treatment was given. Histopathological examination of tumour tissue showed the presence of anaplastic oligoastrocytoma. During the follow-up of our patient we found cerebral foci, probably of metastatic origin ascending with cerebrospinal fluid. More than 5 months after the diagnosis was established the patient died of primary disease. The imaging parameters of both spinal MR examinations were similar, however, on second examination narrower field of vision was used. In both cases Magnevist was administered. Discussing factors which might be responsible for the false-negative result of spinal MR examination--the examination of choice for detection of proliferative transformation--the authors take artefacts connected with respiratory and circulatory function, peristaltic movements, and with field of vision into consideration.

MR examinations in the diagnostics of disorders in the cervical segment of the vertebral canal.

MR imaging technology has made it possible to detect and characterize a number of pathological changes in the vicinity of the vertebral canal a noninvasive manner. The method is characterized by high sensitivity and specificity. It has two basic advantages in comparison to computer-assisted X-ray tomography (CT):
- the ability to image the structure of the vertebral canal directly along planes selected by the operator.
- signal intensity in the constituent structures of the vertebral canal, structures adjacent to the vertebral canal, and pathological changes sufficiently differentiated that the injection of contrasting media into the fluid spaces is not necessary.
These two features of the MR technique have made it the technology of choice in the diagnostics of disorders in the vertebral canal.

Posttraumatic epilepsy risk factors: one-year prospective study after head injury.

PURPOSE: Prospective evaluation of risk factors for posttraumatic epilepsy (PTE) by using clinical, EEG, and brain computed tomography (CT) data in four assessments from the head injury (HI) acute phase to 1 year later; and evaluation of the possible epileptogenic role of hemosiderin as shown by brain magnetic resonance imaging (MRI). METHODS: Risk factors for PTE were evaluated by using Kaplan-Meier curves, log-rank test, and the Cox model in 137 consecutively enrolled adult inpatients. Percentage differences of patients with brain hyperintense and/or hemosiderin areas shown by MRI 1 year after HI were statistically evaluated by univariate tests considering two subgroups [e.g., patients with (PTE) and without (WLS) late seizures]. RESULTS: The PTE subgroup included 18 patients with at least two seizures between the second and twelfth months. Kaplan-Meier curves demonstrated that Glasgow Coma Scale low score, early seizures, and single brain CT lesions are PTE risk factors, as is the development of an EEG focus 1 month after HI. No significant percentage difference was found between PTE and WLS patients with hemosiderin spots shown by MRI 1 year after HI. CONCLUSIONS: the Cox model indicates that, for HI patients with early seizures and brain CT single temporal or frontal lesions in the acute phase, the PTE risk is 8.58 and 3.43 times higher, respectively, than for those without. An EEG focus 1 month after HI is a risk factor 3.49 times higher than for patients without such EEG changes. One year after HI, a higher percentage of PTE than WLS patients had cortical MRI hyper-intense areas including hemosiderin.

[False aneurysms of lower extremity arteries: noninvasive preop diagnosis with magnetic resonance angiography and Doppler ultrasonography]. / Pseudotetniaki tetnic konczyn dolnych--nieinwazyjna diagnostyka przedoperacyjna z zastosowaniem angiografii rezonansu magnetycznego i ultrasonograficznych badan dopplerowskich.

The purpose of this study was to work out a diagnostic algorithm to be used in patients surgically treated because of a false aneurysm of arteries supplying the lower limb. The study includes preoperative vessel evaluation as well as treatment results assessment with MRA and US methods. Examinations included until now 16 patients with clinical false aneurysm suspicion. Most cases presented false aneurysms being complications after arterial graft implantation, in two patients, who were not previously operated, diagnosed false aneurysms were the result of injury. We performed 23 examinations (7 of which were postoperative treatment result evaluation examinations). Examinations were performed on MR equipment with a 1.5 T field induction. The 2D TOF with traveling presaturation method was used. Primary data and reconstructed (MIP) angiograms were analyzed by a radiologist having no access to clinical information and previous examination results. Ultrasound duplex doppler examinations were performed with 7 MHz linear probe. The MRA examinations visualized 7 false aneurysms of the lower Y-graft junction. Clinical verification, ultrasonography examinations and surgery confirmed the existence of 6 aneurysms of the Y-graft as well as 5 out of 6 diagnosed in the ileofemoral graft junctions area. The post-traumatic aorta aneurysm and the postarteriographic femoral aneurysm were also confirmed. Two false positive MRA diagnoses were due to dilatation of the artery below the graft junction, in one case it was a dilatation of the vessel below a stenosis. Furthermore, the MRA helped diagnosing stenoses and occlusions in femoral arteries and common iliac artery.

[Magnetic resonance arteriography as a method for diagnosing arteriosclerosis of the lower extremities]. / Arteriografia rezonansu magnetycznego jako metoda diagnostyki w miazdzycy zarostowej tetnic konczyn dolnych.

The purpose of our study was the evaluation of usefulness of Magnetic Resonance Angiography in diagnostic process in patients with arteriosclerosis of lower extremities and complications such as aneurysms and pseudoaneurysms. 105 patients were examined using 2D TOF method. We concluded the results were very similar as in radiological examinations. The MRA is a very helpful method in evaluation of constriction and occlusion of iliac and femoral arteries and aorta.

[Examination of veins with magnetic resonance imaging and it's place in the diagnostic algorithm of patients with deep venous thrombophlebitis]. / Badania naczy zylnych metod rezonansu magnetycznego i ich miejsce w algorytmie postepowania diagnostycznego u chorych z zakrzepowym zapaleniem zyl glbokich.

The aim of our study was to show the results of the Magnetic Resonance Angiography of pelvis and lower extremities. 21 patients with clinical signs of venous thrombosis were examined. The obtained results show the MRA is very useful in evaluation of venous flow.

Multilocular cysticeral and hydatid cysts of the brain: a report of three cases.

Three cases of multilocular parasitic brain cysts are presented; two cases of specific form of neurocysticercosis and one case of multilocular hydatid cyst. MRI shows features seen in other cystic lesions of the CNS. In all cases the diagnosis was established by neurosurgical brain biopsy. The authors indicate that the parasitic disease should be taken into consideration in differential diagnosis of tumor-like cystic brain lesions.