[Novel approaches to control the rise in pertussis cases]. / Nové prístupy v kontrole vzestupu poctu onemocnení pertusí.

UNLABELLED: Pertussis is a respiratory disease caused by the Gram-negative encapsulated bacterium Bordetella pertussis. Despite the high vaccination coverage rate and addition of new booster doses to the immunisation scheme (in response to the epidemiological situation), pertussis is on the rise not only in the Czech Republic but also in many other countries. The age groups at highest risk are infants and, to a lower extent, newborns who can get infected before receiving the first dose of vaccine and develop a severe course of the disease, often requiring admission to hospital. The most common source of infection are adults or adolescents from the childs close environment who experience a mild course of the disease because of the previous vaccination. The immune response induced by the currently available acellular vaccines does not last. It can be reasonably assumed that pertussis has been underreported. Multiple studies have shown mutations in the causative bacterium that confer higher pathogenicity to it, either as a result of enhanced production of pertussis toxin or loss of some antigens. Possible strategies to control these negative trends are to develop novel more effective vaccines using new adjuvants or to use whole-cell vaccines. Maternal vaccination in pregnancy trimester 3 also turned out to be effective. KEY WORDS: pertussis - vaccination - epidemiology - diagnosis - newborns.

Histological analysis of retraction pocket pars tensa of tympanic membrane in children.

AIMS: Histological and histochemical analysis of retraction pocket of pars tensa of tympanic membrane in children. Identification of morphological abnormalities in comparison with a healthy tympanic membrane as it is described in standard textbook. Identification of signs typical for cholesteatoma and support for a retraction theory of cholesteatoma formation. STUDY DESIGN: A prospective study analysing 31 samples of retraction pockets taken during surgery. DEPARTMENTS: University Hospital, Children's Medical Centre METHODS: Samples of retraction pockets were processed by a standard process for light microscopy, stained by haematoxylin-eosin. Van Gieson's stain was used for differential staining of collagen, Verhoeff's stain for elastic fibre tissues, Alcian blue for acidic polysaccharides and PAS (Periodic Acid Schiff) method for basement membrane polysaccharides. RESULTS: The following findings were observed in the samples of retraction pockets: hyperkeratosis (100%), hypervascularisations (100%), subepithelial fragmented elastic fibres (96%), myxoid changes (87%), subepithelial inflammatory infiltration (84%), rete pegs (71%), papilomatosis (71%), intraepithelial inflammatory cellularizations, (48%), intraepithelial spongiosis (16%) and parakeratosis (3%). No basement membrane continuity interruptions were observed. Thickness of retraction pocket, thickness of epidermis, occurrence of rete pegs and frequency of fragmented elastic fibres was higher in a Grade III stage RP than Grade II stage RP (according to Charachon). CONCLUSION: Morphological abnormalities in the structure of retraction pockets in comparison with a healthy tympanic membrane were described. The changes are typical for a structure of cholesteatoma (these changes are common in matrix and perimatrix), supporting retraction theory of its origin. Our observations show that it is inflammation that probably plays a key role in the pathogenesis of retraction pocket. The frequency of some of the changes increases with the stage of retraction pocket (II-III according to Charachon). Basement membrane continuity interruptions are not typical for retraction pockets.

[Ovaria borderline tumor - fertility-sparing surgery; case report]. / Fertilitu zachovávající lécba borderline tumoru ovaria - kazuistika.

The borderline tumors are known as low malignant potential tumors. Usually younger women suffer for them, than by the invasive ovarian carcinoma. They often which to be pregnant. The fertility-sparing surgery is posile but contain higher risk of the new disease on contralateral ovary.

Dopamine 2 and somatostatin 1-5 receptors coexpression in clinically non-functioning pituitary adenomas.

This study investigated quantitated expression of dopamine 2 receptor (D2R) and somatostatin receptors of the five types (SSTR1-SSTR5) in a large series of clinically non-functioning pituitary adenomas (CNFAs). Co-expression of these receptors in individual adenomas was studied as well as correlation between receptor types. Adenoma tissue from 198 patients who underwent surgery for CNFAs was analyzed by immunohistochemistry and quantitative real-time PCR. D2R and SSTR1-3 mRNA was expressed in all 198 adenomas. SSTR4 and SSTR5 were detectable in 85 % and 61 % of adenomas, respectively. Expression of D2R was significantly higher than that of the somatostatin receptors. The median relative expressions were as follows from highest D2R >> SSTR3 > SSTR2 > SSTR1 > SSTR5 > SSTR4. High relative expression (ratio to beta-glucuronidase mRNA > 1) of D2R was found in 60 % of tumors, high expression of SSTR1 in 7.5 %, SSTR2 in 7 %, SSTR3 in 4 % and SSTR5 in 0.5 %. The quantity of D2R correlated positively with expression of SSTR2 and SSTR3, and negatively with SSTR1 and SSTR5. Among histological adenoma types, SSTR1 was significantly higher in null-cell adenomas and SSTR3 was lower in silent corticotroph adenomas. In conclusions, in CNFAs, high expression of somatostatin receptors is much less common than that of D2R, and co-expression of both these receptors is exceptional. D2R and SSTR3 seem to be the most promising targets for pharmacological treatment.

Tauopathy PET and amyloid PET in the diagnosis of chronic traumatic encephalopathies: studies of a retired NFL player and of a man with FTD and a severe head injury.

Single, severe traumatic brain injury (TBI) which elevates CNS amyloid, increases the risk of Alzheimer's disease (AD); while repetitive concussive and subconcussive events as observed in athletes and military personnel, may increase the risk of chronic traumatic encephalopathy (CTE). We describe two clinical cases, one with a history of multiple concussions during a career in the National Football League (NFL) and the second with frontotemporal dementia and a single, severe TBI. Both patients presented with cognitive decline and underwent [(18)F]-Florbetapir positron emission tomography (PET) imaging for amyloid plaques; the retired NFL player also underwent [(18)F]-T807 PET imaging, a new ligand binding to tau, the main constituent of neurofibrillary tangles (NFT). Case 1, the former NFL player, was 71 years old when he presented with memory impairment and a clinical profile highly similar to AD. [(18)F]-Florbetapir PET imaging was negative, essentially excluding AD as a diagnosis. CTE was suspected clinically, and [(18)F]-T807 PET imaging revealed striatal and nigral [(18)F]-T807 retention consistent with the presence of tauopathy. Case 2 was a 56-year-old man with personality changes and cognitive decline who had sustained a fall complicated by a subdural hematoma. At 1 year post injury, [(18)F]-Florbetapir PET imaging was negative for an AD pattern of amyloid accumulation in this subject. Focal [(18)F]-Florbetapir retention was noted at the site of impact. In case 1, amyloid imaging provided improved diagnostic accuracy where standard clinical and laboratory criteria were inadequate. In that same case, tau imaging with [(18)F]-T807 revealed a subcortical tauopathy that we interpret as a novel form of CTE with a distribution of tauopathy that mimics, to some extent, that of progressive supranuclear palsy (PSP), despite a clinical presentation of amnesia without any movement disorder complaints or signs. A key distinguishing feature is that our patient presented with hippocampal involvement, which is more frequently seen in CTE than in PSP. In case 2, focal [(18)F]-Florbetapir retention at the site of injury in an otherwise negative scan suggests focal amyloid aggregation. In each of these complex cases, a combination of [(18)F]-fluorodeoxyglucose, [(18)F]-Florbetapir and/or [(18)F]-T807 PET molecular imaging improved the accuracy of diagnosis and prevented inappropriate interventions.

[Percutaneous interspinous dynamic stabilization (in-space) in patients with degenerative disease of the lumbosacral spine - a prospective study]. / Perkutánní interspinózní dynamická stabilizace (In-Space) u nemocných s degenerativním onemocnením lumbosakrální pátere - prospektivní studie.

INTRODUCTION: Interspinous spacers are supposed to reduce the segmental extension with a decrease in the expansion of yellow ligaments into the spinal canal, thus avoiding the dynamic narrowing of the spinal canal and compression of nerve roots. The aim of this study was to evaluate clinical outcomes and post-operative complications during one year in patients mostly having suffered from spinal stenosis and treated by In-Space interspinous spacer (Synthes, USA). MATERIAL AND METHODS: A total of 25 patients aged between 25 and 73 (average age 52.6) years, including 18 males and 7 females, with degenerative disease of the lumbosacral spine were indicated for surgery and prospectively followed up. The patients were operated on under general anaesthesia in the prone position, using a minimally invasive lateral percutaneous approach, under fluoroscopic control. The ODI and VAS values as well as X- rays (Range Of Motion and Sagittal angle of the operated segment) 6 and 12 months after the surgery were compared to each other and to those before surgery. The results were statistically analyzed. RESULTS: The average ODI of the group was 47.2% before surgery and 17.48% 6 months (22.76% 12 months) after surgery, showing a statistically significant improvement by 63% (52% after 12 months). The average VAS of the group was 6.64 points before surgery and 2.96 points 6 months (2.8 points 12 months) after surgery, which showed a statistically significant improvement by 55.4% after 6 months (57.8% after 12 months) when compared to preoperative status. After surgery the lordotic sagittal angle remained in all cases; one year after surgery the angle increased due to the slight sinking of some implants. The extent of segmental motion was minimally changed (6.1° 6 months and 7.24° 12 months after surgery). No serious complications occurred. The effect of interspinous implants proved insufficient in two cases (one year and two years after surgery) and conversion to arthrodesis or decompression was performed. CONCLUSIONS: 1. Percutaneous, minimally invasive insertion of an In-Space interspinous spacer is an effective and safe method of dynamic stabilization not accompanied by any serious complications. 2. ODI improved by 63% 6 months after surgery with a decrease in this effect 12 months after surgery. VAS for axial and radicular pain, as reported by patients, improved on average by 55.4% 6 months and by 57.8% 12 months after surgery. 3. In all cases, the lordotic sagittal angle remained after surgery and the extent of segmental motion from flexion to extension was minimally changed.

Fishnet metamaterials--rules for refraction and limits of homogenization.

The perfectly conducting stacked fishnet metamaterial is studied in this paper. The analysis is based on a combination of the mode matching method together with the generalized eigenvalue problem, and takes into account wave propagation along all three Cartesian axes. The analysis has been developed for a fishnet of square lateral periodicity and for two particular polarizations, namely TE and TM, corresponding to the two most common excitations. The 1D and 2D dispersion characteristics are calculated for both polarizations, showing that the TM waves undergo negative refraction in a narrow frequency band just below Wood's anomaly, whereas TE polarized waves exhibit ordinary positive refraction. Finally, possible homogenization of the fishnet metamaterial is considered, showing that only for small angles of incidence and in the immediate vicinity of Wood's anomaly can the fishnet be seen as homogenizable uniaxial medium.

[The DIAM spinal stabilisation system to treat degenerative disease of the lumbosacral spine]. / Implantace interspinózní rozperky DIAM u pacientu s degenerativním onemocnením lumbosakrální pátere.

PURPOSE OF THE STUDY: Each dynamic stabilisation should preserve motion at the operated segment as well as reduce a load on the disc and intervertebral joints. One of the methods to achieve this is the implantation of interspinous spacers between lumbar spinous processes. In this study, the patients treated with the DIAM interspinous spacer (Medtronic, USA) were prospective- ly followed up with the aim to evaluate clinical outcomes and post-operative complications. MATERIAL: Patients with a degenerative disease of the lumbosacral spine were indicated for the operation. They suffered from axial pain with signs of nerve root involvement due to disc hernia, foraminal stenosis or disc herniation recurrence A total of 68 patients aged 23 to 75 (average age, 50.01) years, including 39 men (average age, 50.44) and 29 women (average age, 49.45), were followed up for 1 to 3 years and evaluated. METHODS: All patients underwent a standard pre-operative clinical and neurological examination. Each patient assessed pain intensity using a Visual Analogue Scale (VAS) and, with an Oswestry Disability Index (ODI) questionnaire, evaluated their functional state. In the case of disc hernia or disc herniation recurrence, a sequester was removed; for foraminal stenosis, foraminotomy and partial medial facetectomy was performed. After this decompression of nerve structures, a spacer was implanted. Follow-up included clinical and neurological examination at 6 weeks, 6 months and 1 - 3 years post-operative- ly. At 6 months and between 1 and 3 years after surgery, pain intensity and functional outcome using VAS and ODI assessments were measured by the patients, and antero-posterior and lateral skiagrams of the lumbosacral spine were made. The X-ray examination was made to reveal a potential implant dislocation. The VAS and ODI values at 1-3 post-operative years were compared with those before surgery and the results were statistically analysed. The surgeon evaluated the outcomes at 1-3 years of follow-up according to the Odom criteria. RESULTS: The average ODI of the group was 60.44 % before and 21.85 % after surgery, which showed an improvement by 63.85%. The average VAS was 7.18 points before and 2.10 points after surgery, showing an improvement by 70.75 %. A comparison of the pre- and post-operative results showed, in the average ODI differences of 38.24 % and 39.44 % in women and men, respectively; and in the average VAS value, 5.00 in women and 5.19 in men. The results evaluated according to indication for surgery were as follows: in patients with disc hernia, the difference in ODI was 39.62 % on average, and in VAS it was 5.42 points on average. In patients with disc herniation recurrence, the differences between pre- and post-operative average values were 41.50 % for ODI and 5.00 points for VAS. In patients treated for foraminal stenosis, these differences were 39.79 % for ODI and 5.18 points for VAS. The results for the level treated showed that at L5/S1 the average difference for ODI was 46.75 % and 4.50 points for VAS ; at L4/5 it was 35.52 % for ODI and 5.12 for VAS; at L3/4 it was 48.00 % for ODI and 5.78 for VAS; and at L2/3 it was 39.00 % for ODI and 4.50 for VAS.The results related to the method of nerve root decompression included the average differences of 40.00 % in ODI and 5.17 in VAS for removal of a disc sequester; and average differences of 32.89 % in ODI and 4.78 in VAS for foraminotomy and partial medial facetectomy. The results evaluated for the duration of pre-operative complaints were as follows: surgery by 3 months, average ODI, 44, 53 % and average VAS, 5.25; surgery between 3 and 6 months, average ODI, 37.65 % and average VAS, 4.71; and surgery after 6 months, average ODI, 35.60 % and average VAS, 5.28. The Odom criteria showed results as excellent in 41 %, good in 51.5 % and fair in 7.5 % of the patients. No poor result was recorded. There were no early complications such as haematoma, wound seroma or deep subfascial infection, and no implant dis- location. One patient had to undergo repeat surgery for subcutaneous infection without affecting the implant. Until the end of the study, no signs of herniation recurrence at the segment stabilised with a Diam interspinous spacer had been found. DISCUSSION: The fact that none of the patients in this study required revision surgery or had a recurrence of disc herniation provides evidence for the effectiveness of the DIAM interspinous spacer.This also suggests that the implant protects the whole operated spinal segment, i.e., both intervertebral joints and discs, from being overloaded. Lesser mechanical stress applied to intervertebral facets may slow down degenerative processes and reduce their signs. CONCLUSIONS: The implantation of a DIAM interspinous spacer is a less invasive and safe method of dynamic stabilisation of the spi- ne without intra- or post-operative complications that is well tolerated by the patient. At 3-year follow-up the patients reported improvement in their functional state, as measured with an ODI, by 64 % on the average. Their axial and nerve root pain was reduced by 71 % on the average. All patients showed improved clinical conditions and the outcomes were evaluated as excellent in 41 %, good in 51 % and fair in 7.5 % of the patients. The results of implantation were not significantly related to age, gender, operative indications, operated lumbosacral level, method of nerve root decompression or duration of pre-operative problems. No patient treated by the DIAM spacer had any recurrence of disc herniation.

[The management of uterine fibroids: Czech and Slovak Gynecologic Endoscopy Working Group (CSGE) clinical practice guidelines]. / Management delozních myomu: CSGE doporucení k provádení spráivné klinické praxe.

OBJECTIVE: The objective of this paper is to give a guideline to the management of uterine fibroids. DESIGN: Review. SETTING: Czech Society Gynecological Endoscopic Working Group. MATERIAL AND METHOD: The bibliographic data from Medline were reviewed from 2003-2004 using the key words: fibroid--leiomyoma--uterine artery occlusion--hysterectomy--myomectomy. CONCLUSION: The clinical guideline was prepared after the analysed data were supplied using the material and criteria of Society of Obstetricians and Gynaecologists of Canada (SOGC) for the management of uterine fibroids.

Reverse echelon node and a lymphatic ectasia in the same patient during breast lymphoscintigraphy: the importance of injection and imaging technique.

Lymphoscintigraphy, along with triangulated patient body marking, can serve as a guide for surgeons during sentinel lymph node harvesting. Unique drainage patterns have been noted, especially with areolar or intradermal based injections, which are becoming increasingly popular. The images lymphoscintigraphy provide have been invaluable in delineating these patterns. The authors present a case that simultaneously illustrates two separate points in the same patient, a reverse echelon node and a lymphatic ectasia. To our knowledge, this combination has never been described in the same patient. Perilesional and areolar-cutaneous junction injections were performed sequentially and generated these patterns that could potentially have resulted in added morbidity and a false-negative sentinel node if not realised before surgery. Lymphoscintigraphy added valuable information in the management of this patient, which can occasionally present with complex patterns of activity during sentinel node harvesting.

Solitary intracranial metastasis of follicular carcinoma of the thyroid gland clinically mimicking a meningioma.

We describe a rare case of solitary metastasis of follicular carcinoma of the thyroid gland into the petroclival region in a 58-year-old woman. The metastasis was the first and only manifestation of the disease. The histology of the tumor, differential diagnosis and clinical course are discussed. In a few similar cases described so far the tumor was always a well or moderately differentiated follicular carcinoma located in the petroclival region. As in this presentation, these cases also clinically mimic a meningioma. The differential diagnosis includes adenoma of the thyroid gland and thyroid gland dystopia. We demonstrated the primary focus of carcinoma within the thyroid after its detailed examination initiated by our finding. The clinical outcome of such rare cases is usually excellent, much better than in metastases of papillary carcinoma into the brain.

Validation in the canine model of a new non-invasive method of measuring coronary blood flow reserve: split dose thallium-201 rest/stress imaging.

Diffusely impaired coronary blood flow reserve is difficult to measure non-invasively. We developed and tested a quantitative non-invasive method of measuring coronary blood flow reserve using thallium-201 perfusion imaging. Ten anesthetized dogs were injected simultaneously at rest with thallium-201 and either Ru-103 or Sn-113 microspheres. SPECT images were obtained followed by varying doses of intravenous adenosine, and a second thallium-201 dose was injected simultaneously with either Nb-95 or Sc-46 microspheres. SPECT images were then repeated. The heart was removed, sectioned and counted, along with arterial blood samples. Blood flow was calculated at rest and stress. Peak resting counts in four regions in each of three SPECT slices were subtracted from stress values and stress/rest thallium-201 count ratios (coronary flow reserve (CFR)) were calculated and correlated with the corresponding microsphere flow ratios. Overall correlation of the imaging and microsphere flow ratios was 0.77 (p = 0.0001). Regional correlation coefficients ranged from 0.65-0.86 (p = 0.0001). Coronary blood flow reserve ratios by the microsphere method ranged from 0.7 to 5.3, and by thallium-201 imaging from 0.33-2.45. The non-invasively measured coronary blood flow reserve with thallium-201 imaging and adenosine stress correlates well with microsphere-measured coronary blood flow reserve over a wide range of coronary flows, and should be useful in clinical studies of CFR impairment.

Incidental recognition of left subclavian vein obstruction on renal scintigraphy.

In a renal transplant recipient with persistently poor graft function, the flow phase of a renal scan incidentally revealed multiple venous collaterals with focally increased vascular activity near the left lobe of the liver (quadrate lobe). This was initially assumed to represent superior vena cava (SVC) obstruction. A renal biopsy was contemplated to exclude acute rejection because of a nondiagnostic flow phase (loss of a bolus effect). However, because the possibility of venous obstruction at the level of the subclavian and/or brachiocephalic veins (without involving the SVC) also existed, another renal scan was performed, with injection of radiotracer into the contralateral arm. This showed a patent SVC and reasonably preserved renal perfusion consistent with acute tubular necrosis. Subsequently, left subclavian vein obstruction was identified. The graft function improved with conservative management for acute tubular necrosis. These findings illustrate the danger of considering only SVC obstruction when collateral flow patterns and focal hot spots in the liver are present.

A normal variant on Tl-201 and Tc-99m MIBI whole-body imaging: the superior right atrial wall (auricle) and superoanterior right ventricular wall are often seen as mediastinal lesions.

PURPOSE: The authors have often observed on Tl-201 and Tc-99m sestamibi (MIBI) scans in patients with thyroid cancer a small focus of increased uptake in the right midparasternal region (focus A) or sometimes in the lower mid chest at the level of the lower sternum (focus B) just inferomedial to focus A. The objective of this study was to assess the frequency of this finding on Tl-201 MIBI studies, to assess the incidence of true pathologic lesions corresponding to these foci, and to identify their nature. MATERIALS AND METHODS: One hundred ten whole body Tl-201 studies using 4 mCi (148 MBq) and 84 MIBI studies using 20 mCi (740 MBq: first-pass, planar, and SPECT images) were reviewed. The appearance of either focus A or focus B on three orthogonal SPECT images was correlated with an atlas of cross-sectional anatomy and computed tomography. If focus A was seen on the immediate static image (obtained at the end of the first-pass acquisition without moving the patient), this image was coregistered with a selected image from the first-pass study showing the superior vena cava and also with another selected image showing the ascending aorta. RESULTS: Focus A was seen in 40% of Tl-201 scans and in 49% of MIBI scans, whereas focus B was seen in 20% of Tl-201 scans and 39% of MIBI scans. On correlation of the SPECT images with a cross-sectional anatomy atlas, focus A and focus B invariably corresponded to the superior portion of the right auricle and basal superoanterior right ventricular wall, respectively. These myocardial regions are prominent and sometimes appear as discrete foci because they are considerably thicker than other parts of the right atrial and right ventricular muscle, respectively, and because they are seen partly end-on in the anterior projection. CONCLUSIONS: The superior portion of the right auricle and basal superoanterior right ventricular myocardium often appear as isolated foci on whole-body Tl-201 and MIBl scans. Neither focus should be interpreted as a metastatic lesion in patients with possible cancer or as an ectopic parathyroid adenoma in patients with hyperparathyroid disease.

Comparison of two calcium blockers on hemodynamics, left ventricular mass, and coronary vasodilatory in advanced hypertension.

Dihydropyridine and nondihydropyridine calcium channel blockers (CCB) differ in pharmacologic characteristics. Few clinical studies distinguish effects of CCB as monotherapy. We conducted a comprehensive comparison of two CCB on patients with moderate to severe hypertension. Thirty patients with pretreatment diastolic blood pressures > or = 100 mm Hg were randomly assigned to either nifedipine-GITS or verapamil-SR. Dose titration achieved a diastolic blood pressure of < or = 95 mm Hg or a decrease of > or = 15 mm Hg over 4 weeks. Clinic blood pressure (BP), 24-h ambulatory BP, exercise BP, left ventricular mass, systolic and diastolic function by echocardiography, and coronary flow reserve by split-dose thallium-201 imaging with adenosine were assessed at baseline, end of titration, 3 months and 6 months of treatment. Plasma renin activity, atrial natriuretic peptide, norepinephrine, and epinephrine were assayed. Both drugs caused similar reductions in clinic and 24-h ambulatory BP and similar reductions in left ventricular mass index. Compared to nifedipine-GITS, verapamil-SR produced a significantly lower resting and peak exercise heart rate. Nifedipine-GITS elicited a lower peak exercise systolic BP. At end titration nifedipine-GITS produced lower plasma atrial natriuretic peptide levels, no longer apparent by 6 months. Plasma norepinephrine was lower with verapamil-SR, also at end titration and at 3 months, but not at 6 months. Plasma epinephrine and plasma renin activity were unchanged by either drug. There was no difference for systolic or diastolic left ventricular function or coronary flow reserve between the two treatments. Once daily nifedipine-GITS and verapamil-SR are equally effective for reduction of arterial pressure in moderate to severe hypertension. Differences in their hemodynamic profiles and neurohormonal responses are consistent with preclinical pharmacologic characteristics. The clinical implications of their similarities and differences remain to be fully evaluated in outcome studies.

Comparison of four echocardiographic techniques for measuring left ventricular ejection fraction.

Accurate quantitative measurement of left ventricular (LV) ejection fraction (EF) by 2-dimensional echocardiography is limited by subjective visual endocardial border detection. Both harmonic and precision contrast microbubbles provide better delineation of endocardial borders than fundamental imaging. The aim of this study was to correlate 2-dimensional echocardiographic quantification of LVEF measured by 4 currently available techniques with radionuclide angiography. A total of 50 patients who underwent radionuclide (EF) measurement (47 of 50 had technically difficult echocardiograms by fundamental imaging) underwent echocardiography by 4 methods: fundamental alone, fundamental with contrast, harmonic alone, and harmonic with contrast. Three echocardiologists measured the biplane 2-dimensional echocardiographic LVEF independently and were blinded to radionuclide angiography. The correlation of echocardiographic EF with radionuclide EF improved incrementally with each method. However, contrast with harmonic imaging provided the closest correlation (r = 0.95, 0.96, and 0.95 as assessed by the 3 independent analysts.

Comparison of correction techniques for simultaneous 201Tl/99mTc myocardial perfusion SPECT imaging: a dog study.

We compared two correction methods for simultaneous 201Tl/99mTc dual-isotope single-photon emission computed tomography (SPECT). Both approaches use the information from the third energy window placed between the photopeak windows of the 201Tl and 99mTc. The first approach, described by Moore et al, corrects only for the contribution of the 99mTc to the 201Tl primary 70 keV window. We developed the three-window transformation dual isotope correction method, which is a simultaneous cross-talk correction. The two correction methods were compared in a simultaneous 201Tl/99mTc sestamibi cardiac dog study. Three separate acquisitions were performed in this dog study: two single-isotope and one dual-isotope acquisition. The 201Tl single-isotope images were used as references. The total number of counts, and the contrast between the left ventricular cavity (LVC) and the myocardium, were used in 70 keV short axis slices as parameters for evaluating the results of the dual-isotope correction methods. Three consecutive short-axis slices were used to calculate averaged contrast and the averaged total number of counts. The total number of the counts was 667000+/-500 and 414500+/-400 counts for the dual isotope (201Tl+/-99mTc) and single-isotope (201Tl-only) 70 keV images, respectively. The corrected dual-isotope images had 514700+/-700 and 368000+/-600 counts for Moore's correction and our approach, respectively. Moore's method improved contrast in the dual isotope 70 keV image to 0.14+/-0.03 from 0.11+/-0.02, which was the value in the 70 keV non-corrected dual-isotope image. Our method improved the same contrast to 0.22+/-0.03. The contrast in the 201Tl single-isotope 70 keV image was 0.28+/-0.02. Both methods improved the 70 keV dual-isotope images. However, our approach provided slightly better images than Moore's correction when compared with 201Tl-only 70 keV images.