Role of CT and MRI prior to redo sternotomy in paediatric patients with congenital heart disease.

AIM: To assess the value of computed tomography (CT) and magnetic resonance imaging (MRI) in the preoperative evaluation of congenital heart disease patients about to undergo redo sternotomy. MATERIALS AND METHODS: Forty-three patients (26 male, 17 female, median age 65 months) underwent contrast-enhanced CT and 24 patients (16 male, eight female, median age 89 months) underwent MRI prior to redo sternotomy for congenital heart disease. The informed consent requirement was waived by the institutional review board for this Health Insurance Portability and Accountability Act (HIPAA) compliant study. A standardized CT protocol utilizing a 64 section multidetector machine and an unenhanced and contrast-enhanced MRI multisequence protocol was used. Images were qualitatively graded and retrosternal distances were measured as part of a risk assessment score. RESULTS: There were no statistically significant differences between the observers' grades regarding most retrosternal structures at both CT and MRI, separately (p > 0.05); furthermore, both readers found CT to be superior to MRI in qualitative grading except one reader's grades for shunts/conduits (p = 0.107). κ-values were good to excellent (κ ≥ 0.61) for most structures in qualitative grading of cases and risk assessment scores. There were no significant differences between grades of important structures using the same technique based on Friedman's test (p > 0.05). Analysis showed no difference between risk scores given to CT and MRI patients (p > 0.05). CONCLUSION: The present findings demonstrate the value of imaging to evaluate retrosternal anatomy. CT could be more valuable than MRI and could play a pivotal role in the surgical planning of CHD patients prior to redo operations.

Comprehensive low-dose imaging of carotid and coronary arteries with a single-injection dual-source CT angiography protocol.

AIM: To assess the feasibility of a fast single-bolus combined carotid and coronary computed tomography angiography (CTA) protocol in asymptomatic patients. MATERIALS AND METHODS: Thirty-three consecutive patients (18 women and 15 men) with a median age of 61 ± 14 years old (range 37-87 years) with known or suspected atherosclerotic disease were enrolled in this prospective study. A single breath-hold, single biphasic injection protocol (50 ml at 3 ml/s, 50 ml at 5 ml/s, 50 ml saline flush at 5 ml/s) was used for combined CTA imaging of the supra-aortic (SAA) and coronary arteries (CA) on a 64-slice dual-source CT (DSCT) machine. Helical CTA acquisition of the SAA was followed by prospective electrocardiography (ECG)-triggered coronary CTA. Subjective (four-point scale) image quality and objective signal-to-noise (SNR) and contrast-to-noise (CNR) measurements were performed. Vascular disease was graded on a four-point scale (grade 1: absent; grade 2: mild, grade 3: moderate; grade 4: severe). The radiation dose was recorded for each patient. RESULTS: The average enhancement and subjective quality score of SAA and CA segments were 396 HU/358 HU and 1.2 ± 0.3/1.72 ± 0.4, respectively. The SNR was 27.1 ± 1.7 in the SAA and 21.6 ± 1.6 in the CA (p < 0.0001). The CNR was 18.1 ± 1.2 and 15.9 ± 1.8, respectively (p = 0.4). Four percent of SAA and 14% of CA segments (mostly due to peri-venous streak artefacts and small calibre, respectively) produced non-diagnostic images. SAA findings were as follows: 26/33 (79%) patients showed no disease and 6/33 (18%) had grade 2 and 1/33 (3%) had grade 3 disease. CA findings were as follows: 25/33 (76%) showed no disease and 6/33 (18%) patients had grade 2 and 2/33 (6%) had grade 3 disease. Five patients had disease in both districts. The average radiation dose for the combined CTA angiogram was 4.3 ± 0.6 mSv. CONCLUSION: A fast, low-dose combined DSCT angiography protocol appears technically feasible for imaging carotid and coronary atherosclerotic disease.

Cardiac dual-source CT for the preoperative assessment of patients undergoing bariatric surgery.

AIM: To assess the diagnostic value of coronary dual-source computed tomography (DSCT) as a comprehensive, non-invasive tool in the preoperative cardiac evaluation of patients undergoing bariatric surgery. MATERIALS AND METHODS: Thirty consecutive obese [average body mass index (BMI): 45 ± 7.6, range: 35-59] patients (24 women; six men; median age: 52 ± 15 years) were enrolled in this institutional review board (IRB)-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant prospective study. Calcium scoring (CaS) and electrocardiography (ECG)-gated images of the coronary arteries were obtained with a large body habitus protocol (120 kV; 430 mAs; 100 ml iodinated contrast medium at 7 ml/s injection rate) on a DSCT machine. Qualitative (four-point: 1 = excellent to 4 = not delineable) coronary segmental analysis, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) measurements were performed. The presence and degree of vascular disease (four-grade scale: mild to severe) was correlated with CaS and cardiovascular (CV) risk stratification blood tests. In patients with severe stenosis (>70%), findings were compared with cardiac nuclear medicine imaging (single photon-emission computed tomography; SPECT) imaging. RESULTS: The average HR, enhancement, and quality score were 64 ± 7 beats/min, 288 ± 66 HU and 1.8 ± .5, respectively. Ninety-three percent (417/450) of the coronary segments were rated diagnostic. The SNRs and CNRs were 17 ± 9 and 12 ± 7 for the right coronary artery; 17 ± 8 and 12 ± 7 for the left main coronary artery; 16 ± 9 and 11 ± 7 for the left anterior descending coronary artery; and 15 ± 7 and 10 ± 6 for the left circumflex coronary artery. Ten of the 30 patients (33%) demonstrated coronary artery disease (CAD) of which two (6%) showed three-vessel disease. Four (13%) patients showed severe disease: in three of which the presence of significant stenosis was confirmed by SPECT and by catheter angiography in the fourth patient. Neither the CaS, nor the CV risk stratification tests showed significant correlation with presence or degree of CAD (p > 0.05). CONCLUSIONS: Coronary DSCT is a robust alternative imaging tool in the preoperative assessment of patients undergoing bariatric surgery.

Dual-energy CT angiography of pelvic and lower extremity arteries: dual-energy bone subtraction versus manual bone subtraction.

AIM: To analyse the effect of dual-energy bone subtraction (DEBS) on the image quality of peripheral computed tomography (CT) angiograms. MATERIALS AND METHODS: Twenty patients underwent dual-energy CT angiography of the pelvic and lower extremity arteries using commercially available equipment. Two different methods of image processing were employed for each CT angiographic dataset: (1) DEBS, and (2) manual bone subtraction (MBS). Effects on vessel visibility and artificial vessel alterations were compared. RESULTS: Bone removal, and the resultant visibility of vessel segments, were significantly better with DEBS than with MBS (p=0.011). The overall frequency of vessel-related alterations was lower in MBS compared with DEBS (p=0.001). Specifically, in the 249 vessel segments with calcified plaques, MBS generated fewer vessel alterations than DEBS (p<0.001). In the 309 vessel segments without calcified plaques, there was no difference in vessel alteration between the two techniques (p=0.22). CONCLUSION: DEBS facilitates bone removal in peripheral CT angiography, but generates more vessel alterations, particularly in the presence of calcified plaque.

Bone-subtraction CT angiography: evaluation of two different fully automated image-registration procedures for interscan motion compensation.

BACKGROUND AND PURPOSE: Bone-subtraction techniques have been shown to enhance CT angiography (CTA) interpretation, but motion can lead to incomplete bone removal. The aim of this study was to evaluate 2 novel registration techniques to compensate for patient motion. MATERIALS AND METHODS: Fifty-four patients underwent bone-subtraction CTA (BSCTA) for the evaluation of the neck vessels with 64-section CT. We tested 3 different registration procedures: pure rigid registration (BSCTA), slab-based registration (SB-BSCTA), and a partially rigid registration (PR-BSCTA) approach. Subtraction quality for the assessment of different vascular segments was evaluated by 2 examiners in a blinded fashion. The Cohen kappa test was applied for interobserver variability, and the Wilcoxon signed rank test, for differences between the procedures. Motion between the corresponding datasets was measured and plotted against image-quality scores. RESULTS: Algorithms with motion compensation revealed higher image-quality scores (SB-BSCTA, mean 4.31; PR-BSCTA, mean 4.43) than pure rigid registration (BSCTA, mean 3.88). PR-BSCTA was rated superior to SB-BSCTA for the evaluation of the cervical internal and external carotid arteries (P<.001), whereas there was no significant difference for the other vessels (P=.157-.655). Both algorithms were clearly superior to pure rigid registration for all vessels except the basilar and ophthalmic artery. Interobserver agreement was high (kappa=0.46-0.98). CONCLUSION: Bone-subtraction algorithms with motion compensation provided higher image-quality scores than pure rigid registration methods, especially in cases with complex motion. PR-BSCTA was rated superior to SB-BSCTA in the visualization of the internal and external carotid arteries.

Magnetic resonance imaging of atherosclerotic plaque with ultrasmall superparamagnetic particles of iron oxide in hyperlipidemic rabbits.

BACKGROUND: Based on the observation that ultrasmall superparamagnetic particles of iron oxides (USPIOs) are phagocytosed by cells of the mononuclear phagocytic system, the purpose of this study was to evaluate their use as a marker of atherosclerosis-associated inflammatory changes in the vessel wall before luminal narrowing is present. METHODS AND RESULTS: Experiments were conducted on 6 heritable hyperlipidemic and 3 New Zealand White rabbits. 3D MR angiography (MRA) of the thoracic aorta was performed on all rabbits by use of a conventional paramagnetic contrast agent that failed to reveal any abnormalities. One week later, all rabbits except 1 of the hyperlipidemic animals were injected with a USPIO contrast agent (Sinerem, Guerbet) at a dose of 1 mmol Fe/kg. 3D MRA data sets collected over the subsequent 5 days showed increasing signal in the aortic lumen. Whereas the aortic wall of the control rabbits remained smooth and bright, marked susceptibility effects became evident on day 4 within the aortic walls of hyperlipidemic rabbits. Ex vivo imaging of aortic specimens confirmed the in vivo results. Histopathology documented marked Fe uptake in macrophages embedded in atherosclerotic plaque of the hyperlipidemic rabbits. Electron microscopy showed multiple cytoplasmic Fe particles in macrophages. No such changes were seen in control rabbits or in the hyperlipidemic rabbit that had not received Sinerem. CONCLUSIONS: USPIOs are phagocytosed by macrophages in atherosclerotic plaques of the aortic wall of hyperlipidemic rabbits in a quantity sufficient to cause susceptibility effects detectable by MRI.

The feasibility of spatial high-resolution magnetic resonance angiography (MRA) of the renal arteries at 3.0 T.

PURPOSE: To evaluate the feasibility of high-spatial resolution magnetic resonance angiography (MRA) of the renal arteries at 3.0 T. MATERIAL AND METHODS: Twelve healthy volunteers (mean age, 38.8 years) underwent renal MRA at 3.0 T. The application of parallel imaging with an acceleration factor of 3 allowed obtaining MR angiographic data with a voxel size of 0.9 x 0.8 x 0.9 mm in scan time of only 16 s. A dose of 0.2 mmol/kg body weight of 0.5-molar gadodiamide was administered at a flow rate of 2 ml/s. For image analysis, image quality, presence of artifacts, venous contamination and level of noise were rated by two radiologists in consensus. RESULTS: All examinations were of diagnostic quality. The image quality was rated good or very good in 91 % (11/12) of cases. Due to the high parallel imaging factor the level of noise was slightly increased without diagnostic impairment. Mild venous enhancement was found in 75 % (9/12) of the examinations. CONCLUSION: Renal MRA at 3.0 T is feasible with high spatial resolution and a short acquisition time.

[Diagnostic imaging in liver transplantation. Preoperative evaluation and postoperative complications]. / Bildgebende Diagnostik bei Lebertransplantationen. Präoperative Evaluierung und postoperative Komplikationen.

Complimentary to orthotopic liver transplantation (OLT), living donor liver transplantation (LDLT) is increasingly considered a therapeutic option in the therapy of end-stage liver disease. Accurate pre- and postoperative imaging is crucial for the transplantation success and represents an established part of the current evaluation algorithms. This article summarizes the most important requirements and the current imaging standards. Preoperative imaging is important for exclusion of transplantation contraindications in the recipient and for reliable assessment of anatomical variants in the donor. The main purpose of postoperative imaging is the early detection and characterization of complications. In both instances, multislice CT currently represents the most versatile and reliable imaging modality, still superior to MRI. For postoperative follow-up, the imaging modality of first choice is still bedside ultrasound; however, unclear findings usually need to be further assessed by CT.

Femoral head necrosis in three patients with relapsed ovarian cancer receiving high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation.

We report three patients with relapsed ovarian cancer who developed femoral head necrosis requiring endoprosthetic hip surgery 16-35 months after high-dose chemotherapy (HDC) with treosulfan (47 and 56 g/m(2) body-surface area (BSA)) given as 3-25 h infusions and followed by autologous peripheral blood stem cell (PBSC) transplantation. One woman received two courses of single agent treosulfan while the other two patients received one course of high-dose treosulfan either preceded or followed by high-dose carboplatin, etoposide and cyclophosphamide. A total of 30 women with ovarian cancer were treated with HDC at our unit and 21 of them received treosulfan-containing regimens. Femoral head necrosis was not observed in patients either receiving conditioning regimens without treosulfan (n=9) or when the total treosulfan dose was given over 3 consecutive days (n=3) or in patients with a diagnosis other than ovarian cancer and treated with high-dose treosulfan (n=10). We conclude that women with relapsed ovarian cancer receiving HDC with excessive single-dose treosulfan might be at an increased risk of developing bone necrosis.

Peripheral magnetic resonance angiography.

Peripheral vascular disease (PVD) is a common disorder in western society. Reflecting on the risks and costs of contrast arteriography, magnetic resonance angiography is a powerful noninvasive imaging modality for the diagnostic workup of patients with peripheral vascular disease. This article reviews the current state of the art of magnetic resonance angiography of the peripheral vasculature.

CT appearances of hepatic involvement in systemic varicella-zoster.

In a patient suffering from T-cell non-Hodgkin's lymphoma and systemic varicella-zoster, contrast enhanced CT showed multiple hypodense nodular lesions in the liver which corresponded to areas of focal liver necrosis. This appearance on CT may be characteristic of varicella-zoster involvement of the liver.

MR-angiography: the role of contrast agents.

Contrast-enhanced 3D MR angiography (MRA) permits comprehensive assessment of the supraaortic arteries as well as the arterial system in the chest, abdomen and lower extremities. 3D MRA combines intravenous injection of a non-nephrotoxic, paramagnetic, extracellular contrast agent that increases the signal intensity of blood by shortening its T1 value with the acquisition of a fast 3D data set. High contrast between the vascular lumen and surrounding tissues, inherent three-dimensionality and the ability to collect image data in the chest and abdomen under apnea conditions all contribute to excellent image quality. This review provides clinical applications of 3D MRA in the chest, abdomen and lower extremities based upon the available literature and several clinical examples.

[MR Angiography: First choice for diagnosis of the arterial vascular system]. / MR-Angiographie: Erste Wahl bei der Abklärung des arteriellen Gefässsystems.

Contrast medium-enhanced, 3D MR angiography enables an extensive and diagnostically accurate evaluation of arterial vessels in the neck, thorax, abdomen, and limbs. Advances in the field of MR apparatus technology and the introduction of contrast-medium enhanced MR angiographic techniques have made this development possible. Contrast medium-enhanced MR angiography combines the intravenous bolus administration of a paramagnetic contrast medium with the rapid acquisition of 3D datasets. The possibilities for obtaining data in the thorax and abdomen within one breath-hold, the resulting high contrast between vessel lumen and surrounding soft tissue as well as the inherent 3D nature of the images allow for diagnostically relevant image quality. In many centers contrast-enhanced 3D MR angiography has widely replaced the conventional digital subtraction roentgenography for the clarification of pathologies in arterial vessels. This review presents a survey of the technical background of contrast medium eýnhanced 3D MRA. In addition, the spectrum of indications is given and discussed on the basis of clinical examples.

[Value of pelvic MRI in the preoperative diagnosis of endometriosis]. / Wertigkeit der Magnetresonanztomographie (MRT) des Beckens in der präoperativen Diagnostik der Endometriose.

PURPOSE: To determine the value of magnetic resonance imaging (MRI) of the pelvis in the preoperative diagnosis of endometriosis. MATERIALS AND METHODS: Over a period of 8 months, preoperative MRI of the pelvis were obtained in 13 patients with suspected endometriosis (mean patient age 34.6 years; range 25 - 47 years). RESULTS: In 9 of 13 patients (69 %), the diagnosis of endometriosis was made by MRI and confirmed by laparoscopy in 8 cases. In 2 of 13 patients, endometriotic lesions were detectable by laparoscopy only. In the remaining 2 patients, no endometriosis was visible on MRI or by laparoscopy. MRI was able to visualize a total of 19 endometriotic lesions, with 14 (74 %) confirmed by histopathologic examination following laparoscopy. Five of these 19 lesions (26 %) visible on MRI were not seen by laparoscopy. Using laparoscopy and subsequent histopathologic examination, 27 endometriotic lesions were diagnosed, with 13 (48 %) not seen on the preoperative MRI. CONCLUSION: MRI and laparoscopy are complementary diagnostic tools that will best document the full extent of endometriosis when combined. MRI can visualize additional lesions inaccessible to laparoscopy. Thus, MRI of the pelvis should used preoperatively for surgical treatment planning.

[Magnetic resonance imaging in the diagnosis of benign and malignant pelvic tumors]. / Magnetresonanztomographie benigner und maligner Tumoren des weiblichen Beckens.

Magnetic resonance imaging (MRI) is an accepted imaging method for diagnosing diseases of the female pelvis. This review article describes the role of MR imaging for the diagnosis of benign and malignant pelvic tumors. Sagittal T2-weighted fast spin echo sequences can be effectively applied to diagnose leiomyomas of the uterus and provide exact pretreatment measurements of size and localization. In the diagnostic work-up of endometrial carcinoma, fat-saturated, T1-weighted gradient echo sequences make it possible to determine precisely how deep myometrial infiltration extends and what tissue should be included in preoperative treatment planning. In cervical cancer staging, MRI permits both assessment of local tumor extent and determination of tumor volume for planning and monitoring radiotherapy. The usefulness of MRI in cervical cancer staging is, however, limited since not all early-stage cancer (FIGO stage IA and small stage IB tumors) can be detected. Hence, it appears that the use of MRI as a screening method for cervical cancer cannot be recommended. MRI can distinguish between benign and malignant ovarian tumors with high sensitivity and specificity. Standard and fat-saturated T1-weighted sequences usually can diagnose teratomas with a specificity of 100 %. Axial fat-saturated, contrast enhanced T1-weighted spin echo sequences are useful in the staging of malignant ovarian tumors since they facilitate evaluation of their internal structure and will disclose peritoneal metastases. Besides staging of ovarian cancer, MRI can be applied for localization and for monitoring treatment response.

[Whole-body MRA on a rolling table platform (AngioSURF)]. / Ganzkörper-MRA auf einer rollenden Tischplattform (AngioSURF).

PURPOSE: Development of a technique for whole-body MR angiography based on a rolling table platform and integration of a surface coil. MATERIAL AND METHODS: The developed rolling table platform AngioSURF (System for Unlimited Rolling Field-of-view) with integrated surface coil can be mounted on top of the original patient table of a Siemens Symphony System. Data acquisition was performed with a standard body array surface coil. The system was tested on three volunteers and one patient with angiographically documented vascular pathology. Data acquisition was performed with a 3D-FLASH-sequence (TR/TE 2.1/0.7 ms, flip angle: 20 degrees, FOV 40 x 40 cm, 80 partitions, matrix 512 x 420 with zero interpolation). Five data sets were collected in immediate succession during continuous injection of a paramagnetic contrast agent. Time of acquisition per data set was 10 seconds. Table repositioning was performed manually within 3 seconds. Thus the total acquisition time amounted to 72 seconds. RESULTS: No problems with handling occurred in any of the four cases. The excellent image quality enables detailed assessment of the displayed vascular territories. CONCLUSIONS: The rolling table platform with integrated surface coil (AngioSURF) allows diagnostic display of the arterial vascular system from supraaortic vessels to the distal trifurcation arteries in only 72 seconds.

[Contrast-enhanced 3D MR venography of central thoracic veins: preliminary experience]. / Kontrastmittelverstärkte 3D-MR-Venographie der oberen Thoraxapertur: Erste Erfahrungen.

PURPOSE: To evaluate the usefulness of three-dimensional (3D) gadolinium-enhanced magnetic resonance (MR) venography for evaluation of thoracic central veins. MATERIALS AND METHODS: Over a 4-month period, 14 patients with suspected central venous abnormalities were examined on a 1.5 T scanner (Magnetom Sonata, SIEMENS, Germany) by means of MR venography. A FLASH-3D sequence using the following parameters was employed: TR 1.6 ms, TE 0.6 ms, TA 3.74 s, flip: 15 degrees, slab thickness 110 mm, effective slice thickness: 2.75 mm, 40 partitions, FOV 360 mm, matrix 140 x 256. 10 s prior to imaging 20 ml of Gd-DOPTA (Multihance, BRACCO, Italy) were automatically injected (MEDRAD, Pittsburgh, USA) flushed by 20 ml of normal saline (flow 4 ml/s). Six 3D data sets were acquired in immediate succession in under 24 s. Results were corroborated with findings from duplex sonography. RESULTS: MR venograms were of diagnostic quality for all 14 patients. Compared to duplex sonography thromboses, post-thrombotic changes as well as functional compressions were reliably detected. Unsuspected findings were found in two patients. CONCLUSION: The outlined strategy allows for dynamic diagnostic imaging of central thoracic veins. Gadolinium-enhanced breath-hold 3D MR venography is easy to perform, well tolerated and highly accurate in assessing central venous pathology.

Dark lumen MR-colonography: initial experience.

PURPOSE: The aim of this study was to assess a new strategy of MR colonography for the detection of colonic polyps/malignancy. The technique is based on a rectal enema with water in combination with the intravenous application of a paramagnetic contrast agent. METHODS: Twelve subjects were included in this study either due to suspected colorectal tumors or for screening purposes. For MR colonography the colon was filled with approximately 3000 ml of tap water while Gadobenate dimeglumine (0.2 mmol/kg) was injected intravenously. A T1w GRE sequence was acquired before and 75 sec after the contrast administration only in prone position. Three patient underwent the "bright lumen" MRC as well. All MR examinations were performed at least five days prior to conventional colonoscopy and the results of both modalities were compared. RESULTS: The colonic filling with water resulted in a homogeneously low signal throughout the colonic lumen in all twelve subjects. Intravenous injection of gadolinium caused avid enhancement of the colonic wall. Similarly lesions arising from the colonic wall enhanced avidly. Dark lumen MR colonography correctly identified five polyps in four patients. Bright lumen MRC showed in one patient false positive results. CONCLUSION: The new MR colonography concept based on a dark colonic lumen and a bright, contrast enhanced colonic wall turned out to be a promising alternative to the traditional MRC based on a bright lumen concept. The new technique suggests a higher accuracy in detecting polyps, a better evaluation of other parenchymal organs as well as a reduced time needed for data acquisition and analysis.

Detection of myocardial perfusion abnormalities: standard dual-source coronary computed tomography angiography versus rest/stress technetium-99m single-photo emission CT.

We compared coronary dual-source computed tomography angiography (corDSCTA) with technetium-99m single-photon emission computed tomography (SPECT) for the detection of myocardial perfusion abnormalities. Fifty-five consecutive patients underwent both gated myocardial perfusion SPECT and corDSCTA, the latter during a single arterial-phase injection of contrast agent. The perfusion defects visualised by corDSCTA correlated with the findings of rest/stress SPECT. Abnormal findings on stress SPECT, which were due to either ischaemia or infarct, were found in 24 patients. In comparison to SPECT at rest, corDSCTA detected perfusion defects with a sensitivity and specificity of 100% and 78%, respectively. Compared to SPECT at stress, the sensitivity and specificity values of corDSCTA were 83.3% and 90.3%, respectively. On corDSCTA , the average attenuation values of perfusion defects that corresponded to chronic infarcts (-8.5+/-22.2 HU) were significantly lower (p = 0.002) than those of non-infarct-related perfusion defects (43.1+/-17.5 HU). Using rest/stress SPECT is the gold standard for the diagnosis of myocardial ischaemia, corDSCTA was able to diagnose ischaemic disease (defined as the presence of high-grade stenotic CAD (>or=50% luminal narrowing)) with a sensitivity and specificity of 59% and 89%, respectively, in patients with no known history of myocardial infarction (n = 4). Thus, corDSCTA may serve as a diagnostic tool for the detection of perfusion abnormalities (first) visualised by SPECT. There appears to be a limited correlation between coronary stenotic disease and SPECT findings.