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Long waiting list times in liver transplant programs in Saudi Arabia and unavailability of deceased donor transplantation in Egypt have led several patients to seek transplantation in China. All patients who received transplants in China and followed in three centers from January 2003-January 2007 were included. All patients' charts were reviewed. Mortality and morbidity were compared to those transplanted in King Faisal Specialist Hospital & Research Centre (KFSH&RC) during the same period. Seventy-four adult patients were included (46 Saudi nationals; 28 Egyptians). One-year and 3-year cumulative patient survival rates were 83 and 62 respectively compared to 92 and 84 in KFSH&RC. One-year and 3-year cumulative graft survival rates were 81 and 59 respectively compared to 90 and 84 in KFSH&RC. Compared to KFSH&RC, the incidence of complications was significantly higher especially biliary complications, sepsis, metastasis and acquired HBV infection posttransplant. Requirements of postoperative interventions and hospital admissions were also significantly greater. Our data show high mortality and morbidity rates in Saudi and Egyptian patients receiving transplants in China. This could be related to more liberal selection criteria, use of donation after cardiac death (DCD) donors or possibly more limited posttransplant care.

Long waiting list times in liver transplant programs in Saudi Arabia and unavailability of deceased donor transplantation in Egypt have led several patients to seek transplantation in China. All patients who received transplants in China and followed in three centers from January 2003–January 2007 were included. All patients’ charts were reviewed. Mortality and morbidity were compared to those transplanted in King Faisal Specialist Hospital & Research Centre (KFSH&RC) during the same period. Seventy-four adult patients were included (46 Saudi nationals; 28 Egyptians). One-year and 3-year cumulative patient survival rates were 83% and 62%, respectively compared to 92% and 84% in KFSH&RC. One-year and 3-year cumulative graft survival rates were 81% and 59%, respectively compared to 90% and 84% in KFSH&RC. Compared to KFSH&RC, the incidence of complications was significantly higher especially biliary complications, sepsis, metastasis and acquired HBV infection posttransplant. Requirements of postoperative interventions and hospital admissions were also significantly greater. Our data show high mortality and morbidity rates in Saudi and Egyptian patients receiving transplants in China. This could be related to more liberal selection criteria, use of donation after cardiac death (DCD) donors or possibly more limited posttransplant care.

We present SPET brain perfusion findings in 32 patients who suffered mild traumatic brain injury without loss of consciousness and normal computed tomography. None of the patients had previous traumatic brain injury, CVA, HIV, psychiatric disorders or a history of alcohol or drug abuse. Their ages ranged from 11 to 61 years (mean = 42). The study was performed in 20 patients (62) within 3 months of the date of injury and in 12 (38) patients more than 3 months post-injury. Nineteen patients (60) were involved in a motor vehicle accident, 10 patients (31) sustained a fall and three patients (9) received a blow to the head. The most common complaints were headaches in 26 patients (81), memory deficits in 15 (47), dizziness in 13 (41) and sleep disorders in eight (25). The studies were acquired approximately 2 h after an intravenous injection of 740 MBq (20.0 mCi) of 99Tcm-HMPAO. All images were acquired on a triple-headed gamma camera. The data were displayed on a 10-grade colour scale, with 2-pixel thickness (7.4 mm), and were reviewed blind to the patient's history of symptoms. The cerebellum was used as the reference site (100 maximum value). Any decrease in cerebral perfusion in the cortex or basal ganglia less than 70, or less than 50 in the medial temporal lobe, compared to the cerebellar reference was considered abnormal. The results show that 13 (41) had normal studies and 19 (59) were abnormal (13 studies performed within 3 months of the date of injury and six studies performed more than 3 months post-injury). Analysis of the abnormal studies revealed that 17 showed 48 focal lesions and two showed diffuse supratentorial hypoperfusion (one from each of the early and delayed imaging groups). The 12 abnormal studies performed early had 37 focal lesions and averaged 3.1 lesions per patient, whereas there was a reduction to an average of 2.2 lesions per patient in the five studies (total 11 lesions) performed more than 3 months post-injury. In the 17 abnormal studies with focal lesions, the following regions were involved in descending frequency: frontal lobes 58, basal ganglia and thalami 47, temporal lobes 26 and parietal lobes 16. We conclude that: (1) SPET brain perfusion imaging is valuable and sensitive for the evaluation of cerebral perfusion changes following mild traumatic brain injury; (2) these changes can occur without loss of consciousness; (3) SPET brain perfusion imaging is more sensitive than computed tomography in detecting brain lesions; and (4) the changes may explain a neurological component of the patient's symptoms in the absence of morphological abnormalities using other imaging modalities.

Thallium-201 is known to accumulate in malignant tumours. In this work we are evaluating the role of thallium in differentiating benign from malignant solitary bone lesions in 28 patients with solitary bone lesions on 99Tcm-MDP bone scans. Lesions' uptake of 201T1 was evaluated using visual assessment and lesion to background ratio. We found significant uptake with a mean lesion to background ratio of 4.27 in malignant lesions and no or faint uptake with a mean lesion to background ratio of 1.37 in benign lesions.

To investigate the potential uses of right and left ventricular systolic and diastolic rate indices in identifying patients with ischaemic heart disease (IHD), gated blood-pool imaging was performed for 19 normal subjects (group 1) and 56 patients, of whom 31 had resting LVEF ≥50 (group 2) and 25 had resting LVEF ≤50 (group 3). The peak ejection rate (PER) and peak filling rate (PFR), their timing and the mean filling rate (MFR) were derived from the time-activity curves analysis. Group 2 patients had significantly reduced LV PER and PFR (3.00±0.58 EDV/s, p<0.005, 2.29±0.54 EDV/s, p<0.0009) as compared to normal (3.90±0.70 EDV/s and 3.35±0.80 EDV/s respectively). Patients with profoundly depressed LVEF had significantly low PER and PFR (1.96±0.50 EDV/s, 1.46±0.27EDV/s respectively). However, there was considerable overlap in values between groups. Therefore, we conclude that there is no single parameter more sensitive than LVEF in identifying IHD patients with normal LVEF at rest.

Accurate assessment of the severity of soft tissue damage particularly skeletal muscle associated with fractures in trauma patients is important in determining the plan of management and prognosis. We used Indium-Ill labelled anti-myosin to determine the extent of skeletal muscle injury in five patients involved in traumatic accidents. We found abnormal uptake in all 20 sites of muscle injury in four patients, 13 at the sites of fractures and seven away from fracture sites. There was good correlation between the degree of uptake and the extent of muscle injury. No uptake was seen in a case with no fracture and no muscle injury. At surgery this case proved to be haemarthrosis of the left knee. Indium-Ill anti-myosin scanning is a potentially sensitive and useful technique in assessing extent of acute muscle injury in trauma patients.

Changes in left ventricular (LV) performance between rest (Re) and exercise (Ex) in normal hearts has been analysed in great detail using various parameters (P) of radionuclide MUGA studies. Little attention was given in this regard to right ventricular (RV) performance. We developed a program on the Informatik Sims V Computer applying the first derivative technique to analyse the time activity curve of both R and LV to study the changes in the following (P) between Re and Ex. 1. Ejection fraction (EF) 2. Peak ejection rate (PER) 3. Time to peak ejection rate (TPER) 4. Normalized TPER to the ejection period (EP) 5. Peak filling rate (PFR) 6. Time to peak filling rate (TPFR) 7. Normalized TPFR to the filling period (FP) 8. The time from peak filling rate to peak ejection rate (TPFR-TPER). Nineteen volunteers performed gated blood pool studies at Re and Ex in the semi-supine bicycle position.

To evaluate 201Tl in the detection of the primary tumour, lymph node involvement and mediastinal spread we have studied a total of 188 patients with histologically proven lung cancer, breast cancer or malignant lymphorna. Ten patients with benign lung disease were also examined.

The relationship between the concentration of tissue glutathione (GSH) content and uptake of 99TcmHMPAO in Sprague Dawley rats was investigated. The GSH content of rat tissue was depleted with diethyl-maleate (DEM) and the ratio of GSH in control to GSH depleted rat was approximately twice that in the brain, liver, kidney, spleen and lung. The GSH content in all the organs studied except the liver had no statistically significant relationship with the uptake of 99TcmHMPAO. The apparent increase of radioactivity in the liver was due to longer retention of 99TcmHMPAO. This longer retention was due to stasis of bile flow as confirmed by subsequent experiments in which cholecystokinin (CCK).was administered to GSH depleted rats and compared to the uptake of GSH depleted rats without injection of CCK.

The aim of this study was to compare 201Tl-chloride and 99Tcm-sestamibi (MIBI) SPET brain imaging for differentiating brain lymphoma from other intracranial lesions in AIDS patients. Both studies were performed on the same day in 17 AIDS patients with intracranial enhancing lesions on either CT or MRI. Eleven patients underwent brain biopsy and six patients were followed clinically. We calculated the radiopharmaceutical uptake ratio of the lesion to that on the contralateral side with the guidance of CT or MRI findings. Ratios of 1.5 or more were considered to represent malignant lesions and ratios < 1.5 were considered to represent benign lesions. Biopsy revealed four cases of lymphoma, four cases of toxoplasmosis and two cases of progressive multi-focal leukoencephalopathy; one biopsy yielded necrosis. Both the MIBI and 201Tl studies yielded no false-negative cases of lymphoma (sensitivity 1007c). Of the 13 non-lymphoma cases, the 201T1 studies showed seven true-negative cases (specificity 54) and the MIBI studies showed nine true-negative cases (specificity 69). The biopsies of the false-positive cases (toxoplasmosis) showed a pattern of healing after medical treatment. We conclude that MIBI is more helpful than 201Tl because of higher specificity and equal sensitivity. The medical treatment of toxoplasmosis is a cause of false-positive 201Tl and MIBI studies.

Chrome fatigue syndrome is a clinically defined condition of uncertain aetiology. We compared 99Tcm-HMPAO single photon emission tomography (SPET) brain perfusion with dual-head 18F-FDG brain metabolism in patients with chronic fatigue syndrome. Eighteen patients (14 females, 4 males), who fulfilled the diagnostic criteria of the Centers for Disease Control for chronic fatigue syndrome, were investigated. Thirteen patients had abnormal SPET brain perfusion scans and five had normal scans. Fifteen patients had normal glucose brain metabolism scans and three had abnormal scans. We conclude that, in chronic fatigue syndrome patients, there is discordance between SPET brain perfusion and 18F-FDG brain uptake. It is possible to have brain perfusion abnormalities without corresponding changes in glucose uptake. (© 1998 Lippincott Williams & Wilkins)

Technetium-99m DTPA is a good agent for detecting sites of acute gastrointestinal bleeding due to its rapid clearance by the kidneys and its stability in the bowel achieving a good target to nontarget ratio. It has been successfully tried for a pilot study. Further evaluation is in progress for its sensitivity. In cases where there is a slow rate of bleeding, we are currently evaluating injection of the dose by infusion, slowly over 15 min instead of the rapid i.v. injection.

During the evaluation of 99Tcm-DTPA for localization of acute gastrointestinal bleeding in 81 studies (78 patients), it was observed that there was an increased 99Tcm-DTPA at sites of inflammatory and malignant lesions of the GI tract in 18 studies. Active bleeding was detected only in 10 and no bleeding was detected in the remaining eight studies. In all the increased DTPA uptake helped to localize the site of bleeding. Image subtraction of early from delayed images according to a predefined acquisition and processing protocol helped to differentiate bleeding from non bleeding lesions. We conclude that increased 99Tcm-DTPA uptake in malignant and inflammatory lesions of the bowel is an additional advantage for its use in localizing the site of acute GI bleeding.

Stress thallium-201 myocardial studies in 29 patients with chest pain were performed. The findings of digital display (DD) and quantitative segmental washout curves (QSWC) were compared independently and jointly with coronary angiography. It was found that QSWC is more sensitive (71) than DD (55) but is less specific (58) than DD (98). Taking both approaches together the sensitivity rises to 94 and the specificity falls to 61. Using both DD and QSWC for interpretation of thallium studies improves the agreement ratio with coronary angiography by 25 more than when using DD only.

99Tcm-DTPA has been evaluated in our clinical and experimental programme for the detection of acute gastrointestinal bleeding. As an adjunct to this programme, a protocol for image subtraction has been developed. The patient remains still while sequential static images I(i) (i= 1, . . ., N) are taken. They are first normalized to equal total counts and then subtracted images are produced according to the following three methods

Extracorporeal piezoelectric lithotripsy (EPL) has been recently introduced as a non-invasive method for treatment of renal and gall bladder stones. Thirty seven patients treated with EPL for renal calculi were the subjects of radionuclide renal studies. The aim was to evaluate the effects of EPL as a new technology by radionuclide renography. 99Tcm-DTPA and 99Tcm-DMSA studies were performed pre-EPL and one day and one week post-EPL.

First-pass radionuclide angiography (FPRA) in the 30° right anterior oblique and equilibrium gated radionuclide angiography (EGNA) in the 45° left anterior oblique were used for quantitative measurements of left ventricular ejection fraction (LVEF). Equipment used was a 400T gamma-camera interfaced with a Simis III Informatek computer. The results were compared with contrast angiography (CA). The aim of this study was to determine the sensitivity of both radionuclide techniques. The present data are based on 65 patients in whom CA and EGNA were performed. In 47 patients both FPRA and EGNA were performed. Results suggested that in ischemic heart disease (IHD) and valvular heart disease (VHD) the EGNA technique is well correlated with CA (r=0.9 and 0.73, respectively). FPRA correlated well only with CA in IHD (r=0.86), but not in VHD (r=0.18). This study indicates that both FPRA and EGNA are sensitive, noninvasive techniques for measuring ejection fraction in IHD, while in VHD, EGNA is more sensitive technique than FPRA.

Retrospective analyses of the stress thallium studies of 51 patients with a history of previous infarctions or definite stable angina were performed in order to determine the extent of the coronary-artery disease (CAD). The results were correlated with recent coronary-angiography findings in order to assess the effect of including rightventricule (RV) visualization on the accuracy of the detection of right coronary-artery (RCA) disease, as well as the effect of graded stenosis or occlusion of the RCA and the presence of disease of the other coronary vessels on the visualization of the RV. Eight patients had normal coronary arteries. The other 43 patients had CAD, only 5 of whom had single-vessel RCA disease. With regard to the RV, 6 patients had nonvisualization, 30 had patchy visualization, and 15 had normal visualization in the stress thallium studies. Nonvisualization indicated 100% occlusion of RCA in 6 out of 6 patients. Patchy visualization indicated significant occlusion of the RCA in 25 out of 30 patients (83%), while normal visualization indicated a normal RCA in 13 out of 15 patients (86%). Normal visualization did not mean that the possibility of RCA disease could be excluded. When RV visualization data were added to LV images, the sensitivity for detecting RCA increased from 66% to 94% (P<0.05), the specificity decreased from 89% to 72% (P<0.1), and the predictive accuracy increased from 75% to 86% (P>0.1).

Acute pancreatitis is a serious surgical problem with a high incidence of mortality. Both ultrasound and X-ray CT have problems in identifying the extent and severity of the disease and the response to therapy. 67Ga-citrate has been used in 21 patients with clinically diagnosed acute pancreatitis:9 patients had X-ray CT and 15 had US examination. Gallium scans were more sensitive than X-ray CT and US in detecting the extent and severity of acute pancreatitis. In addition, gallium was helpful to monitor the response to therapy when the scan was repeated at various intervals in three patients. A subtraction technique using 99mTc-tin colloid and 67Ga-citrate was helpful to mask the liver uptake of gallium and clearly identify the extent of acute pancreatitis.

A dual gated tomography (DGT) program for end systolic and end diastolic acquisition and subsequent processing for calculation of LVEF, end diastolic and end systolic volumes (EDV, ESV) has been evaluated in 20 healthy volunteers (25 years–40 years) and 45 patients (25 years–60 years): 20 with ischaemic heart disease and 25 with valvular heart disease (VHD). All had biplane multigated blood pool (MUGA) studies in the 40° LAO projection using in vivo 99mTc- RBCs, immediately followed by DGT. The results in the patients group were correlated with contrast ventriculography (CV). In the volunteer group, the normal values for LVEF, EDV and ESV measured with DGT were found to be 63%±10%, 91 ml±6 ml and 30 ml±6 ml and r value for the LVEF=0.91 compared with MUGA. In the IHD group, r values compared with CV were 0.915 and 0.97 for the EDV and ESV and 0.934 for the LVEF. Compared with the MUGA, the r value for LVEF was 0.883. In the VHD group, r values were 0.98 for both the EDV and ESV and 0.948 for the LVEF (P<0.002) compared with CV and 0.789 for the LVEF compared with the MUGA. We feel that DGT is an accurate and reproducible technique for LV function measurements.

Pulmonary hypertension (PH) produces strain followed by hypertrophy and later dilatation of the right ventricle (RV) and pulmonary artery. The signs and symptoms are nonspecific. There is a need for a noninvasive sensitive way to diagnose PH. The purpose of this study is to evaluate phase abnormalities in radionuclide MUGA studies of patients with referred diagnosis of PH. In a retrospective analysis of 44 patients who had a radionuclide multigated study (MUGA) and contrast ventriculography (CV), 19 had high mean pulmonary pressure (over 20 mmHg) and a high pulmonary vascular resistance index (over 2.0). In 15 patients, a delayed phase segment in the RV corresponding to the pulmonary infundibulum and pulmonary conus was noted “The Pulmonary Tongue” sign (PT), 12 had PH (True positive) and 3 did not (false positive) on CV. No PT was seen in the remaining 29 patients, only 7 of them had PH (False negative). The sensitivity, specificity and accuracy of the PT sign in detecting PH was 80%, 72% and 77% respectively. The number of patients was too small to calculate the correlation of the grade of PT with the severity of PH. We conclude that “The Pulmonary Tongue” sign on a MUGA study is clinically useful in detecting PH.

We have studied the mechanism of tumour uptake of 201Tl by in vivo and in vitro studies. In a series of patients with breast cancer (n=26), lung cancer (n=56) and lymphoma (n=15), the time course of tumour uptake of 201Tl paralleled that in the myocardium with almost identical times of peak uptake being obtained in tumours and myocardium. In a patient with hepatic metastases from colonic cancer undergoing laparotomy, 99mTc labelled microspheres and 201Tl were injected into the hepatic artery and biopsies of metastatic and normal liver tissue obtained. The tumour to normal liver activity ratios for 201Tl were one tenth of those for 99mTc microspheres. In the final part of the study, cells from a lung cancer tissue culture line were incubated for 30 min with 201Tl with and without the addition of cardiac glycoside, which acts a sodium potassium pump blocker. The cells exposed to the cardiac glycoside showed markedly decreased uptake of 201Tl compared to the cells not so exposed (0.6%±0.1% vs 11.8±0.7.2% of the administered dose). The mechanism of 201Tl uptake of tumours is similar to that in the myocardium. Sodium potassium pump activity appears to be more important than tumour blood flow. 201Tl uptake may provide a useful means of studying tumour viability.

To study the potential usefulness of99mTc-methoxy isobutyl isonitrile (99mTc-MIBI) as a substitute for201Tl in assessing patients with ischaemic heart disease, 24 patients underwent 1 day rest and exercise99mTc-MIBI single photon emission computerised topography (SPECT) 1 week after SPECT exercise201Tl. All patients were catheterized within 1 month after myocardial imaging. In 17 patients, resting first pass radionuclide angiography (FPRNA) was performed with99mTc-MIBI. The heart to lung ratio for99mTc-MIBI and201Tl was calculated both at rest and exercise. The segmental analysis for myocardial perfusion reveals that 87/96 segments (91 %) were correctly classified by SPECT201Tl and 84/96 segments (88%) were correctly classified by99mTc-MIBI. A significant correlation was present between LVEF measured by99mTc-MIBI FPRNA and contrast ventriculography (r = 0.85,P < 0.0001). The heart to lung ratio both at rest and exercise for99mTc-MIBI is significantly higher than201Tl (P < 0.01 and <0.001 respectively). We conclude that99mTc-MIBI is a promising agent for simultaneous evaluation of myocardial perfusion and cardiac function.

Following the intravenous injection of 75 MBq 201Tl-chloride we have assessed the uptake kinetics in the myocardium and in the primary tumour in 56 patients with lung cancer, 26 with breast cancer and 13 with mediastinal lymphoma. The time of maximal tumour uptake ranged from 8–20 min post-injection and did not differ significantly between lung cancer (mean±SD=11.9±3.34 min), breast cancer (11.21±1.88 min) and lymphoma (11.76±3.25 min). The time of maximum cardiac uptake of 201Tl was 11.61±3.25 min. There was no significant washout of 201Tl from the tumours in the first hour after injection in the various malignant lesions studied. The time of maximal tumour to background activity was 18.3±0.59 min for lung cancer, 13.0±1.16 min for breast cancer and 16.7±1.04 min for lymphoma.