Anterior Oblique Images Research Articles

Combining conventional technique with fluoroscopy integration module in accessory pathway ablation.

Accessory pathway (AP) ablation is a straightforward approach with high success rates, but the fluoroscopy time (FT) is significantly longer in conventional technique. Electroanatomical mapping systems (EMS), reduce the FT, but anatomical and activation mapping may prolong the procedure time (PT). The fluoroscopy integration module (FIM) uses prerecorded fluoroscopy images and allows ablation similar to conventional technique without creating an anatomical map. In this study, we investigated the effects of combining the FIM with traditional technique on PT, success, and radiation exposure. A total of 131 patients who had undergone AP ablation were included in our study. In 37 patients, right and left anterior oblique (RAO-LAO) images were acquired after catheter placement and integrated with the FIM. The ablation procedure was then similar to the conventional technique, but without the use of fluoroscopy. For the purpose of acceleration, anatomical and activation maps have not been created. Contact-force catheters were not used. 94 patients underwent conventional ablation using fluoroscopy only. FIM into AP ablation procedures led to a significant reduction in radiation exposure, lowering FT from 7.4 to 2.8 min (p < .001) and dose-area product from 12.47 to 5.8 μGym² (p < .001). While the FIM group experienced a reasonable longer PT (69 vs. 50 min p < .001). FIM reduces FT regardless of operator experience and location of APs CONCLUSION: Combining FIM integration with conventional AP ablation offers reduced radiation exposure without compromising success rates and complication.

Evaluation of the effect of pelvis type in percutaneous acetabular column fixation: a computed tomography study.

This study aimed to evaluate the effect of pelvis type in percutaneous acetabular column fixation. What is the effect of pelvis type in percutaneous acetabular colon fixation? The available pelvic computed tomography (CT) scans which were obtained in the diagnostic imaging center with a 1 mm slice width were evaluated. The pelvic type was classified with the help of MPR (Multiplanar Reformat) and 3D (Three Dimensional) imaging modes. All evaluated bony pelvic structures were anatomically intact. 40 types of android, gynecoid, anthropoid, and platypelloid pelvis were determined. CT sections were created in MPR imaging mode. Anterior obturator oblique (AOO) and inlet images were created for anterior column evaluation, while iliac oblique (IO) and outlet images were created for posterior column evaluation. The possibility of obtaining a linear corridor for acetabular columns was investigated by measuring corridor width and lengthon images of pelvic CTs. A linear corridor could not be obtained between the pubic tubercle and the supraacetabular region of 12 (30%) CTs in the anterior column of gynecoid pelvis group. The diameter of the anterior column corridor was below 5.5 mm in 10 (25%) of Gynecoid pelvis group, 5 (12.5%) of Anthropoid pelvis group, and 10 of Platypelloid pelvis group, , and all those scans belonged to the female gender. There was a statistically significant difference between pelvis types in terms of anterior and posterior column diameters (p <0.001). While the android pelvis type had the highest diameter and corridor length in both anterior column and posterior column measurements, the gynecoid pelvic type had the lowest diameter and corridor length. In the evaluations made according to gender, both anterior and posterior column diameters were larger and longer in males than in females (p <0.001). Pelvis type is an important factor which can affect anterior and posterior column diameter and length of acetabulum. Pelvic typing before acetabular surgery can help the surgeon determining the most appropriate patient position, surgical approach, and implant selection. Level of Evidence: Level 2.

Fluoroscopy integration module reduces radiation exposure without affecting procedure time in accessory pathway ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Conventional Accessory Pathway (AP) ablation is a straightforward approach with high success rates, but the fluoroscopy time is significantly higher. Electroanatomical mapping systems (EMS), reduce the fluoroscopy time, but anatomical reconstruction and activation mapping prolong the procedure time. The Fluoroscopy Integration Module (FIM) uses prerecorded fluoroscopy images and allows ablation similar to conventional technique without creating an anatomical map. In this study, we investigated the effects of combining the FIM with the traditional technique on procedure time, success, and radiation exposure. Methods 112 patients who underwent AP ablation were included in our study. In 18 patients, right and left anterior oblique (RAO -LAO) images were recorded after the insertion of the catheters and integrated with FIM. Afterwards, ablation was performed similarly to the conventional technique but without using fluoroscopy. To accelerate the procedure anatomical and activation maps were not created. Contact-force catheters were not used. 94 patients were ablated conventionally using only fluoroscopy. Results Combining the FIM with the conventional method significantly reduced radiation exposure (Fluoroscopy time: 3,3±2,6 vs 11,5±11,6 sec, p: 0,001; Dose-area-product (DAP): 7,3±6,2 vs. 28,6±40,5 μGym2, p: 0,003) without affecting the total procedure time ( 64,4±15 vs. 62,6±28,7 sec, p: 0,272 ), time to successful ablation ( 33,2±13,9 vs. 29,7±29,5 sec p: 0,056) and radiofrequency application time ( 183,7±94,4 vs. 167,3±89,8 sec p: 0,336). Conclusion These findings suggest that FIM can be used for rapid and successful ablation of APs with reduced radiation exposure times.

Abstract B042: Sentinel lymph node detection in breast cancer: Comparison of blue dye and filtered Technetium 99m sulphur colloid radiotracer injection

Abstract Aim: This prospective study was performed to compare the identification rate, sensitivity and specificity of blue dye and filtered Technetium 99m labelled sulphur colloid (Tc99m SC), individually and in combination for the detection of sentinel lymph nodes in clinically node negative early-stage breast cancer. Materials and methods: Thirty-two women with biopsy-proven breast cancer (cT1N0M0-T2N0M0) were included in this prospective study over a period of 18 months (2019-2020). Four peri-areolar intradermal injections of filtered Tc99m SC were administered 2-3 hours before surgery. Sequential dynamic anterior images of the chest were acquired on a gamma camera, followed by anterior and anterior oblique static images and hybrid single photon emission computed tomography / computed tomography (SPECT/CT) of the affected breast and ipsilateral axilla. Pre-operatively, the sites of detected sentinel lymph nodes (SLNs) were marked on the skin surface using a hand-held gamma probe. SLNs were then identified intra-operatively after peri-tumoral methylene blue injection (blue nodes) and with the gamma probe (hot nodes). These SLNs were removed and sent for frozen section histopathology separately, labelled as hot only, blue only and hot and blue. All patients underwent axillary lymph node dissection (ALND). The final histopathology of all lymph nodes excised during ALND and SLN biopsy were analysed. Identification rate, sensitivity and specificity of both the methods for SLN detection individually and in combination were compared. Results: SLN data of 32 female patients aged 54.7±10.6 years with cT1N0M0-T2N0M0 was analysed. In 87.5% of patients (n=28) the same lymph node was identified by blue dye and filtered Tc99m SC and discordance was seen in 12.5% (n=3) patients. No SLN was detected by any method in one patient. Identification rate of filtered Tc99m SC alone, blue dye alone and combination techniques was 96.9% (n=31), 93.8% (n=30) and 96.9% (n=31) respectively. Of total 593 dissected lymph nodes including 78 SLNs (average 2.4±1.7 per patient), metastasis was found in 198 lymph nodes (12/32 patients). The sensitivity and specificity of the procedure considering only filtered Tc99m SC, blue dye alone and combination of the two tracers was found to be 83.3% (95% CI of 51.6-97.9) and 100% (95% CI of 82.4-100), 75% (95% CI of 42.8- 94.5) and 100% (95% CI of 81.5 -100) and 83.3% (95% CI of 51.6-97.9) and 100% (95% CI of 82.4-100) respectively. Conclusion: SLNB with filtered Tc99m SC using the intra operative gamma probe has better identification rate and sensitivity than blue dye in detecting SLN, while preoperative SPECT/CT helped the surgeon to locate the SLN during surgery. Blue dye has a complementary role in identifying the SLN due to ease of visualisation while operating. Citation Format: Anish Bhattacharya, Yamini Mathur, Ishita Laroiya, Amanjeet Bal, Sarika Sharma, Bhagwant R. Mittal. Sentinel lymph node detection in breast cancer: Comparison of blue dye and filtered Technetium 99m sulphur colloid radiotracer injection [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B042.

Parathyroid Imaging: The Importance of Dual-Radiopharmaceutical Simultaneous Acquisition with 99mTc-Sestamibi and 123I

Our objective was to compare the accuracy of 3 imaging protocols for the detection of parathyroid adenomas: single-tracer, dual-phase imaging with (99m)Tc-sestamibi; dual-tracer, single-phase imaging with simultaneous acquisition of (99m)Tc-sestamibi and (123)I images; and dual-tracer, dual-phase imaging with simultaneous acquisition of (99m)Tc-sestamibi and (123)I images. Thirty-seven patients with surgical proof of parathyroid adenomas were evaluated. Three different protocols were derived from a single study in each patient, resulting in an intrapatient intrastudy comparison. The first derived protocol was the conventional dual-phase protocol with (99m)Tc-sestamibi consisting of anterior and anterior-oblique pinhole images of the neck at 15 min and 3 h plus parallel-hole images of the neck and upper chest at both imaging times. The second derived protocol was a dual-tracer, single-phase protocol consisting of administration of (123)I followed 2 h later by (99m)Tc-sestamibi. Fifteen minutes later, anterior and anterior oblique pinhole images of the (99m)Tc-sestamibi and (123)I were acquired simultaneously, allowing generation of perfectly coregistered subtraction images. Parallel-hole images of the neck and upper chest were also obtained. The third protocol was the same as the second except that the same imaging protocol was repeated at 3 h. Two experienced nuclear medicine physicians indicated the location of any identified lesion and graded the certainty of diagnosis on a 3-point scale. Thirty-seven patients had 41 parathyroid adenomas. For the 2 observers combined, the localization success rate was 66% for the single-tracer, dual-phase protocol; 94% for the dual-tracer, single-phase protocol; and 90% for the dual-phase, dual-tracer protocol. Both dual-tracer protocols were significantly more accurate than the single-tracer protocol (P < 0.01); there was no significant difference between the 2 dual-tracer protocols. In addition, the degree of certainty of localization was greater with the 2 dual-tracer protocols than the single-tracer protocol (P < 0.001). A dual-tracer, single-phase parathyroid imaging protocol consisting of simultaneous acquisition of (99m)Tc-sestamibi and (123)I images with pinhole collimation at 15 min and perfectly coregistered subtraction results in a higher degree of accuracy and a greater degree of diagnostic certainty than the commonly used single-tracer, dual-phase protocol of imaging (99m)Tc-sestamibi alone at 15 min and 3 h. The addition of delayed imaging to the dual-tracer protocol did not improve results.

Coronary sinus fistula: A reason not to implant a transvenous left ventricular lead

A 40-year-old woman referred for biventricular implantable cardioverter-defibrillator (ICD) implantation with an ejection fraction of 30%, New York Heart Association class III symptoms, and left bundle branch block QRS duration of 160 ms (patient had nonischemic cardiomyopathy and no evidence of occlusive coronary artery disease by nuclear perfusion imaging). Occlusive venography (Figure 1) demonstrated a coronary artery‐to‐coronary venous fistula. The left anterior descending artery is seen anteriorly (along the interventricular septal region) in the right anterior oblique image. There is no evidence of coronary sinus dilation, and the proximal coronary sinus was a relatively narrow vessel with no significant lateral branches. A shunt assessment demonstrated no significant left-to-right shunt. Based on the findings, the decision was made not to place a coronary sinus lead due to risk of thrombus formation and embolization to the coronary arteries. Additionally, there was a lack of suitable lateral branches to provide an optimal pacing vector. A decision to consider a surgically implanted lead was made. A follow-up coronary computed tomography (CT) scan interestingly did not document a fistula, likely because the image resolution of the 64-slice CT was not sufficient to visualize a small fistula.

Novel software package for quantifying local circumferential myocardial stress

Local myocardial stress is an important index of ventricular loading conditions. We developed a novel software package to provide estimation of local circumferential stress in the entire left ventricle (LV) based on Janz's method using contemporary LV imaging techniques. The aim of this study was to confirm the validity of our novel software by comparing local circumferential stress (local σ) with global equatorial stress (global σ) values. We acquired 30° right anterior oblique LVG images in 74 patients (aortic regurgitation; n = 48, aortic stenosis; n = 26) and 26 healthy subjects, then analyzed them using Janz's method to elucidate local σ in segment #12 (mid-anterolateral) based on AHA/ASE segmentation criteria. Global σ was obtained using Mirsky's formula. A highly significant correlation was found between local σ and global σ (r = 0.99, p < 0.001). Bland-Altman analysis also showed good agreement between the two methods (mean bias 2.4 kdyn/cm(2), limits of agreement 9.3 kdyn/cm(2)/-4.6 kdyn/cm(2)). There were good correlations for both intra-observer and inter-observer agreement. Our novel software package was shown useful to assess local circumferential stress with contemporary cardiovascular imaging techniques.

Supravalvular Arrhythmia

Supravalvar ablation has now been well documented to be the ideal mode for ablating specific forms of ventricular tachycardia, atrial tachycardia, and accessory pathways. A studied appreciation of the anatomy of the supravalvar region is a prerequisite for electrophysiologists to safely and effectively approach these arrhythmias. In addition, the consistent ability to correlate the recorded electrograms with fluoroscopic anatomy and intracardiac ultrasound images enhances the chance of successful elimination of supravalvar arrhythmias.

Comparison of pinhole and SPECT 99mTc-MIBI imaging in primary hyperparathyroidism

This study aims to compare dual tracer, dual phase pinhole technetium-99m labelled 2-methoxyisobutylisonitrile (Tc-MIBI) imaging (including oblique imaging), with single photon emission computed tomography (SPECT) and dual phase planar Tc-MIBI images, and combined SPECT, dual phase planar Tc-MIBI images and anterior pinhole thyroid images for the localization of parathyroid adenomas in the neck in primary hyperparathyroidism. Sixty-two patients underwent Tc-MIBI dual phase, anterior and anterior oblique pinhole images of the neck, anterior planar images of the neck and chest and early phase neck/chest SPECT followed by [Tc] pertechnetate anterior and anterior oblique pinhole thyroid images. Images were reviewed by consensus in three combinations - dual phase anterior and anterior oblique pinhole Tc-MIBI images and pinhole thyroid images; SPECT and dual phase planar Tc-MIBI images and combined SPECT, dual phase planar Tc-MIBI images and anterior pinhole thyroid images. For 52 parathyroid adenomas in 50 patients, the sensitivity of dual phase anterior and anterior oblique pinhole Tc-images and pinhole thyroid images was 81%. Significantly lower sensitivities were observed with SPECT and dual phase planar Tc-MIBI images (54%, P=0.0005) and combined SPECT, dual phase planar Tc-MIBI images and anterior pinhole thyroid images (65%, P=0.0209). The positive predictive value for all imaging combinations was 88-92%. Dual phase anterior and anterior oblique pinhole Tc-MIBI images and pinhole thyroid images are significantly more sensitive than imaging combinations that included SPECT and remains the optimal imaging protocol for the localization of parathyroid adenomas in the neck in primary hyperparathyroidism.

New Endoscopic Technique to Analyze Various Modern Specialized Intraocular Lenses in Research Eyes and Human Eyes Obtained Postmortem

To describe a new modification of the Miyake-Apple posterior video photographic technique and its 2 variations. We have developed a new endoscopic technique that is especially amenable for observation of modern specialized intraocular lenses (IOLs). Laboratory study. Three cadaver eyes obtained postmortem. Human eyes obtained postmortem were prepared according to our modified preparation technique used for analyses of whole globes. An intraocular endoscope was utilized to demonstrate all aspects of the interior of an experimentally implanted IOL, with specialized reference to anterior segment structures, obtaining posterior, oblique, and side view images. Different interior dynamic views of the anterior segment structures before and after implantation of an IOL. High-magnification images of different intraocular structures both before and after device insertion as well as the device itself were obtained. Oblique and side view images from different locations were also available and informative. These images helped to create a 3-dimensional view of these objects and their relations to the surrounding structures. The combination of the intraocular endoscope with the closed-system technique is a useful addition to our 3 previously described techniques: (1) the original Miyake-Apple posterior video/photograph technique and the (2) closed system and (3) side/oblique view (keyhole technique) modifications.

Perspectives on the development of a magnetic navigation system for remote control of electrophysiology catheters The opinions expressed in this article are not necessarily those of the Editors of Europace , the European Heart Rhythm Association or the European Society of Cardiology.

Development of the magnetic navigation system was motivated by the need for accurate catheter manipulation during complex ablation procedures that may include targets that are difficult to reach. The first step in the development of this technology was to demonstrate the feasibility of catheter navigation without affecting the stability of diagnostic catheters, the quality of intracardiac and surface recordings, or the ability to perform diagnostic pacing manoeuvres. Preliminary studies confirmed the safety and efficacy of the magnetic navigation system for these basic requirements.1 The next step demonstrated the feasibility of this system for cardiac mapping and ablation in patients with supraventricular tachycardia.2 The ability to perform remote navigation was not a primary objective, but it is a very attractive attribute for prolonged studies because it reduces operator fatigue and radiation exposure. Innovative technologies develop incrementally because experience inevitably identifies problems that require improvement on the original design of the system. The initial prototype of the magnetic navigation system, which was only used in animal studies, had an orthogonal array of electromagnets that were inactive when the power was deactivated. The array encircled the torso in a configuration that was too small for human subjects. The fluoroscopy system was built by Stereotaxis using an early version of flat plate technology, but the images did not have the quality required for clinical use. During mapping procedures, a computer interface was used by the operator to set vectors in the right anterior oblique and left anterior oblique radiographic images. The software was rudimentary by today's standards. The …

Heart-Shaped Tumor in Pulmonary Trunk

A 59-year-old woman had a six-month history of increasing shortness of breath. Echocardiography showed an abnormal mass in the right ventricle. Surgical resection was performed because of hemodynamic instability, and histologic evaluation revealed a myxosarcoma. Five months later, the patient again had dyspnea, and enhanced computed tomography (CT) showed a defect extending from the right ventricle through the pulmonary trunk to the right pulmonary artery (arrow in Panel A). A left anterior oblique CT image showed a heart-shaped defect in the pulmonary trunk (arrow in Panel B). Recurrent myxosarcoma was diagnosed. Surgical resection was again performed. However, three months later, . . .

Detecting the sentinel lymph node in patients with differentiated thyroid carcinoma.

The aim of this study was to evaluate sentinel lymph node mapping in patients with differentiated thyroid carcinoma. Nine patients with suspected thyroid carcinoma who were scheduled to undergo thyroidectomy underwent scintigraphic localization of sentinel lymph nodes (SLNs). On the day of surgery we injected 37 MBq technetium-99m nanocolloid intratumourally. Dynamic data up to 10 min followed by planar anterior and lateral oblique images up to 1 h after tracer administration were recorded. At surgery the primary tumour was excised first, then the SLNs were removed using a gamma probe. Four patients had papillary carcinoma, two follicular carcinoma, one an oncocytic tumour and two benign tumours. An SLN was identified in all four patients with papillary carcinoma. In the two patients with follicular carcinoma, SLN detection failed. Five patients had one radioactive node, one had three and one had four. In one patient, no SLN was visible with scintigraphic imaging but at surgery three SLNs could be clearly identified using the gamma probe after removal of the primary tumour. There were no false-negative findings. This initial study indicates that in patients with papillary thyroid carcinoma detection of the SLN is possible, whereas the technique failed in two patients with follicular carcinoma. A study on a larger patient sample is now warranted.

Effects of surgery for postinfarction ventricular tachycardia on parameters of left ventricular function

Heart failure is the leading cause of death in patients after surgery for ventricular tachycardia. This study examines the effects of antiarrhythmic surgery on 4 parameters of left ventricular (LV) function. Global ejection fraction, segmental wall motion score, homogeneity of contraction, and diastolic function were measured in 32 patients by technetium-99m radionuclide ventriculography. Ejection fraction was measured from the left anterior oblique image. Wall motion score was assessed semiquantitatively for 11 LV segments from 3 projections. Homogeneity of contraction was expressed as the SD of the LV phase analysis curve during systole from the left anterior oblique image. Diastolic function was expressed in terms of peak and mean first time derivative of the action potential (dV/dt) of the LV function curve. Subgroup analyses were performed to distinguish the effects of aneurysmectomy, coronary artery bypass grafting, and changes in angiotensin converting enzyme inhibitor therapy. Mean systolic function improved after surgery (ejection fraction 22% vs 32%, p <0001; wall motion score 20 vs 13, p <0.0001; phase analysis 18 vs 12, p <0.03). Mean diastolic function also improved (peak dV/dt 0.83 ± 0.32 vs 1.49 ± 0.39, p = 0.006; mean dV/dt 0.41 ± 0.15 vs 0.76 ± 0.27, p = 0.006). Improvements were not confined to those who had aneurysmectomy or coronary bypass grafting and were not explained by changes in vasodilator therapy. Thus, antiarrhythmic surgery does not inherently damage LV function. Significant improvements were observed in most patients. Failure to improve indicated a poor longer term prognosis.

Improved assessment of inferior left ventricular wall motion using biplane equilibrium radionuclide ventriculography.

Equilibrium radionuclide ventriculography is often restricted to the left anterior oblique projection. The differential sensitivity of left anterior oblique amplitude and phase images for anterior and inferior infarction was evaluated using quantitative analysis, and the role of left posterior oblique images assessed. Twenty anterior infarcts, 20 inferior infarcts and 20 normal controls were studied. Left anterior oblique amplitude and phase abnormalities were seen in 100% (20) and 85% (17) of anterior infarcts but only 55% (11) and 50% (10) of inferior infarcts. Left posterior oblique amplitude and phase abnormalities were seen in 95% (19) of anterior infarcts and 75% (15) and 85% (17) of inferior infarcts. Left anterior oblique standard deviation of phase differed from normal only for anterior infarction (P < 0.01); both anterior and inferior (P < 0.05) infarction differed from normal in the left posterior oblique projection. Left anterior oblique images are therefore insensitive for inferior infarction. An accurate description of regional ventricular wall motion requires biplane radionuclide ventriculography.

5107838 Method of left ventricular volume evaluation using nuclear magnetic resonance imaging

A method of left ventricular volume evaluation capable of obtaining an accurate evaluation of the left ventricular volume for a heart in an unaffected state. In the method, right anterior oblique image and 4-chamber image of the heart are obtained; using a nuclear magnetic resonance imaging, contours of the left ventricle in the right anterior oblique image and the 4-chamber image are determined; prescribed sets of sizes for the left ventricle are measured from the determined contours; and the volume of the left ventricle is evaluated by using an orthogonal biplane Simpson's method and the measured sizes.

Assessment of left ventricular dysfunction in acromegalic patients using radionuclide ventriculography parameters.

The left ventricular function of 14 acromegalic patients was investigated using radionuclide ventriculography. After labeling the red blood cells with 750-1,000 MBq 99mTc-pertechnetate, ECG-triggered left anterior oblique images were recorded. Fourier analysis was then performed on the time-activity curve of the left ventricle. The ejection fraction (EF), peak ejection rate, time to peak ejection (TPE), time to end-systole (TES), peak filling rate (PFR), time to peak filling (TPF), 1/3 EF, 1/3 filling fraction (FF), TPE/T, TPF/T and TES/T values (T: time interval for one heart beat) were calculated for each patient. Five patients (35.7%) had clinical cardiovascular symptoms. A decreased EF was observed in 28.5% of the patients. In comparison to the control group, the EF (53.5 +/- 5.5 vs. 60.8 +/- 5% p less than 0.009), 1/3 EF (14.45 +/- 3 vs. 20 +/- 4%, p less than 0.001), 1/3 FF (28.5 +/- 10.6 vs. 41 +/- 11%, p less than 0.02), TPE (158 +/- 33 vs. 132 +/- 35 ms, p less than 0.01), TPE/T (20.2 +/- 5 vs. 16 +/- 3.7, p less than 0.01) and PFR (2.4 +/- 0.5 vs. 2.9 +/- 0.4 EDC/s, p less than 0.005) were significantly different. It was found that TPE was prolonged and the early ejection function was decreased. Diastolic dysfunction was found in 5 (35.7%) patients; 21.4% of the patients had decreased PFR values although they had no cardiac symptom, hypertension and/or cardiomegaly. Scintigraphic parameters did not correlate with the presence of hypertension, cardiomegaly or cardiovascular symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Early Indium-111 antimyosin scintigraphy for assessment of regional wall motion asynergy on discharge after myocardial infarction

To assess the relation between early Indium-111 monoclonal antimyosin antibody scintigraphy and degree of regional asynergy on discharge, 38 patients with a first acute myocardial infarct were studied (18 anterior, 20 inferoposterior infarctions). In 21 patients thrombolytic therapy was administered. On the first day of myocardial infarction, 80 MBq Indium-111 Antimyosin was injected. Planar images, anterior, lateral and left anterior oblique, were made 24 hours later. Localized myocardial uptake was present in 37/38 patients, and was evaluated for Count Density Index (count density of infarct zone/left lung count density) in the left anterior oblique images, which displayed the infarct zone well. Regional asynergy on discharge was evaluated by cross-sectional echocardiography and defined mild (hypokinesia) or severe (akinesia or dyskinesia). Count density index was significantly lower in 15 patients with mild asynergy, compared with 22 patients with severe asynergy (1.61 +/- 0.25 vs. 2.42 +/- 0.40, p less than 0.001). This difference was present in both patient groups treated with or without thrombolysis. We conclude that early count density index, reflecting the amount of local necrosis, is highly correlated to the ultimate degree of wall motion impairment.

Quantitative analysis of myocardial ischaemia on end-diastolic thallium 201 perfusion images

ECG gating of images with thallium 201 (201Tl) may improve the representation of myocardial perfusion by allowing isolation of the end-diastolic (ED) portion of the cardiac cycle. To characterize this phenomenon, circumferential distribution profiles for ED and conventional total-cycle images (TC) with 201Tl were analysed after summing ECG gated acquisitions; redistribution was defined as net washing of 201Tl for specific myocardial segments visualized on the left anterior oblique images. Scintigraphic data were compared with the presence of coronary stenoses in 150 patients. ED images had relatively less activity in the inferoseptal and inferoapical region than TC profiles. The ED mode of washout analysis provided more frequent confirmation of visually suggested redistribution than did the TC mode (84% incidence of net wash in for ED, 69% for TC). ED analysis showed a higher incidence of net 201Tl wash in in relation to critical circumflex and left anterior descending artery lesions, but yielded a similar overall performance to TC analysis in distinguishing patients with diseased coronary arteries from normal subjects. Thus, in selected cases, analysis of ED images could assist in confirming 201Tl redistribution.

Oblique views in thyroid imaging

To assess the value of oblique thyroid views during routine thyroid scanning 73 sequential euthyroid patients with focal or diffuse thyroid pathology were studied. Oblique thyroid images did not alter the scan report in 37 patients shown to have a multinodular goitre on the anterior image. However, in the remaining 36 patients oblique thyroid images altered scan category in 30% of patients, mainly demonstrating multiple nodules in thyroids which would have been reported as having a solitary nodule on the anterior image alone. Despite the extra imaging time required, both anterior oblique thyroid images should be obtained in all euthyroid patients presenting with focal or diffuse thyroid pathology in whom the anterior image does not clearly demonstrate a multinodular goitre.