PubMed Health⌕ Search

Biomedical subjects

A Al-Kutoubi

Publications and source records attributed to A Al-Kutoubi.

12 recordsLinked to original sources
PubMed1999

Ultrasonic plaque character and outcome after lower limb angioplasty.

PURPOSE: The value of ultrasonic plaque characteristics in identifying patients at "high-risk" of restenosis after percutaneous transluminal angioplasty (PTA) was studied. METHODS: Thirty-one arterial stenoses (6 common iliac, 2 external iliac, 1 profunda femoris, 21 superficial femoral, and 1 popliteal) in 17 patients who underwent angioplasty were studied by means of duplex scanning. With a computer-based program, B-mode images were digitized and normalized using 2 reference points, blood and adventitia. A grey level of 0 to 5 was allocated for the lumen (blood) and 180 to 190 for the adventitia on a linear gray scale of 0 to 255 (0 = absolutely black; 255 = absolutely white), and the overall plaque gray-scale median (GSM) of the pixels of the plaque was used as a measure of plaque echodensity. After PTA, follow-up of stenoses was done on day 1, weekly for 8 weeks, at 3 months, 6 months, and 1 year. The total plaque thickness (sum of anterior and posterior components), minimal luminal diameter (MLD), and peak systolic velocity ratio (PSVR) were measured for all stenoses. An increase of more than 2 in the PSVR was the duplex criterion used to signify restenosis. RESULTS: The GSM of the stenoses before angioplasty ranged from 6 to 71 (mean, 31.3 +/- 17.9); 17 stenoses had a GSM less than 25 (mean, 18.7 +/- 5.3), and 14 had a GSM more than 25 (mean, 46.4 +/- 15.8). When the GSM was less than 25, the absolute reduction in plaque thickness on day 1 post-PTA was 3.3 +/- 1.8 mm, in contrast to 1.8 +/- 1.6 mm when GSM was more than 25 (P <.03). The restenosis rate (PSVR more than 2) was 41% at 6 months and remained unchanged at 1 year. When the GSM was less than 25, restenosis occurred in 11% of lesions, in comparison with 78% when the GSM was more than 25 (P <.001). CONCLUSION: Plaque echodensity can be used to evaluate stenoses before PTA, to predict initial success and identify a subgroup that has a high prevalence of restenosis. The identification of a group at "high-risk" of restenosis can improve the selection of patients for the procedure and also be used in prospective studies on the prevention of restenosis.

Angioplasty, Balloon↗
PubMed1999

Angioplasty of lower limb arterial stenoses under ultrasound guidance: single-center experience.

PURPOSE: To examine the feasibility and utility of ultrasound-guided angioplasty for treating lower limb stenoses. METHODS: Duplex ultrasonography was employed to guide 55 balloon dilation procedures (27 iliac, 26 superficial femoral, 1 profunda, and 1 vein graft) with the help of a special ultrasound catheter (EchoMark). Ultrasound was used to determine balloon size, monitor guidewire passage, direct the dilation, and judge procedural success. Angiography was performed prior to the procedure to confirm preprocedural ultrasound findings and afterward to compare with duplex visual and hemodynamic parameters of success (peak systolic velocity ratio < 2.0). RESULTS: The balloon size determined from duplex measurements correlated in all cases with sizes selected based on the angiographic image. Guidewire visualization was possible in 95% of the cases. Angioplasty using ultrasound alone was feasible in 84%; inability to obtain a satisfactory image owing to vessel tortuosity, calcification, and bowel gas accounted for the failures. Against the duplex success criterion, initial completion angiograms had an accuracy of 76%, sensitivity of 76%, and specificity of 100%. The additional time for ultrasound guidance averaged 42 +/- 12 minutes for all cases. CONCLUSIONS: Our results show that ultrasound guidance is feasible in routine clinical practice. In this series of well-selected cases of arterial stenoses, angioplasty was performed safely using ultrasound guidance alone in over 80% of the cases. Fluoroscopic monitoring is needed when ultrasound visualization is suboptimal.

Aged↗
PubMed1998

Would thyroid and breast shielding be beneficial in CT of the head?

Contrary to common perception, the advent of third- and fourth-generation scanners has lead to a significant increase in radiation dose to the patient per computed tomography (CT) head scan. With that in mind, a pilot study was designed with the objective of assessing the effectiveness of a dental-style protective bib in reducing the dose to the radiosensitive organs of the neck and thorax. Radiation doses over the thyroid gland and breast were measured with thermoluminenscent dosemeters and an ionization chamber respectively in 110 patients undergoing routine head scans. Half the patients wore the protective bib and collar. With lead protection, the thyroid measurements were reduced by an average of 45 % and the breast measurements by an average of 76 %. Similar results were seen in phantom measurements.

Breast↗
PubMed1998

Peter B. Samuels Award. Restenosis after percutaneous transluminal angioplasty.

BACKGROUND: Determine the feasibility of studying the natural history of the atherosclerotic plaque following percutaneous transluminal angioplasty (PTA), using duplex scanning. METHODS: Twenty-three patients with 40 stenoses (>70% and <5 cm in length) in the iliac and femoro-popliteal segments were studied by duplex scanning before PTA, on day 1, weekly for 8 weeks, and at 3 months, 6 months, and 1 year. The following measurements were made: thickness of the plaque, minimal lumen diameter (MLD), and peak systolic velocity ratio (PSVR). A PSVR >2.0 was used to indicate >50% lumen diameter reduction. RESULTS: Thirty stenoses were available for measurement and analysis. Mean reduction in plaque thickness after angioplasty was greater in echolucent plaques (2.33 +/- 0.9 mm) than echogenic plaques (0.83 +/- 0.6 mm; P < 0.0001). Successful angioplasty (PSVR <2.0) and increase in MLD in echolucent plaques was the result of plaque compression; in echogenic plaques, of wall dilatation. The incidence of restenosis (PSVR >2.0) at 6 months was 12 of 30 (40%) remaining unchanged at 1 year; of the lesions that restenosed, 33% recurred before week 8 and the remainder between weeks 8 and 24, suggesting different mechanisms. During follow-up, all plaques showed "growth"; <2 mm in 17 (57%; group A) and >2 mm in the remaining 13 (43%; group B). The incidence of restenosis (PSVR >2.0) was 4 of 17 (23%) in group A and 8 of 13 (61%) in group B (P <0.05). CONCLUSION: Duplex scanning provides valuable information on both luminal diameter and plaque thickness; it may be used to study the natural history of plaques following angioplasty and also the effects of therapeutic agents aimed at reducing restenosis.

Angioplasty, Balloon↗
PubMed1998

How "gold" is the standard? Interobservers' variation on venograms.

BACKGROUND: The aim of this study was to determine the degree of agreement between radiologists having different levels of experience, in reporting 151 venograms independently. It was also aimed to assess whether the degree of disagreement would have influenced the final outcome of a thromboprophylactic study and the decision to anticoagulate the patients. METHODS: Seventy-eight patients undergoing total hip replacement had bilateral venography on postoperative days 8-12. Patients were allocated to receive either a low molecular weight heparin (enoxaparin) with or without TED stockings or a placebo Each of the 151 venograms obtained has been reported on four times. RESULTS: The overall incidence of deep venous thrombosis was 42% (33 of 78 patients). The range of the Kappa value of each radiologist versus the others was 0.568 to 0.669. There was a significant decrease in the incidence of deep venous thrombosis in the treatment versus the placebo groups. On an intention to treat all diagnosed thrombi, a difference of up to 16% was demonstrated between the report of individual radiologists and the panel. This difference was reduced to 8% when only thrombi proximal to the calf were considered clinically significant. CONCLUSIONS: These differences reflect the radiologist's experience and frequency of reporting on venograms and should be taken into account when studies for thromboprophylaxis are planned.

Aged↗
PubMed1997

Transbrachial coil occlusion of the first intercostal branch of an internal mammary artery bypass graft for angina.

Percutaneous transbrachial insertion of a metallic coil into the first intercostal branch of the left internal mammary artery resulted in resolution of severe angina in a 60-year-old man who had coronary artery bypass surgery 14 years previously. The diagnosis of coronary artery steal was made clinically. This case illustrates the importance of recognising coronary steal in patients who redevelop angina after coronary artery surgery with the use of an incompletely prepared left internal mammary artery as a conduit. The diagnosis can be made clinically and the condition treated without the need for further surgery.

Angina Pectoris↗
PubMed1996

Weight loss.

Explore the source record for details and available documents.

Adult↗
PubMed1996

Intracranial imaging.

This article concentrates on the imaging of intracranial structures and outlines some basic imaging strategies for common clinical presentations.

Acute Disease↗
PubMed1989

Clinical diagnosis from digital displays: preliminary findings of the St Mary's Evaluation Project.

Image quality is a fundamental issue in the introduction of picture archiving and communications systems (PACS), and one that has hitherto been eclipsed by other aspects of the considerable technological challenge facing scientists and manufacturers involved in its development. We conducted a formal evaluation of clinical radiological diagnosis from a commercially available PACS viewing station, using subperiosteal resorbtion in renal osteodystrophy as the test pathological diagnosis, with receiver operating characteristic (ROC) analysis of the results. We conclude that the displayed, digitised images were inferior to film using the apparatus tested and believe that careful, objective clinical evaluation of such systems is of paramount important.

Chronic Kidney Disease-Mineral and Bone Disorder↗
PubMed1988

The significance of cerebral infarction and atrophy in patients with amaurosis fugax and transient ischemic attacks in relation to internal carotid artery stenosis: a preliminary report.

There is a growing appreciation for the high incidence of silent cerebral infarction and cerebral atrophy on CT scans in patients with amaurosis fugax (AF) and hemispheric transient ischemic attacks (TIAs). Seventy patients with AF only (no TIAs), 104 patients with hemispheric TIAs (no AF), 185 patients without focal carotid territory symptoms (i.e., vertebrobasilar TIAs or asymptomatic carotid bruit only), and 129 patients with stroke and good recovery were studied with CT scan and duplex scanning to grade the degree of stenosis of the internal carotid artery (grades: A = normal, B = 0% to 15% stenosis, C = 16% to 49%, D = 50% to 99%, and E = occlusion). In patients with AF, the incidence of infarction increased from 20% in grades A, B, and C to 40% in grade D and 58% in grade E. The incidence of atrophy increased in parallel from 10% in grade A to 30% in grade E. The increased incidence of atrophy with increasing degrees of stenosis was not the result of increasing degrees of stenosis per se, but the associated increase in the incidence of infarction (patients without CT infarcts in grades D and E had 5% and 0% incidence of atrophy). In patients with hemispheric TIAs, the incidence of CT infarction increased from 25% in grades A and B to 48% in grades D and E. The incidence of atrophy did not show a parallel increase. Our findings support the hypothesis that atrophy is associated not only with cerebral infarction but may be causally related.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrophy↗
PubMed1984

The correlation between carotid plaque ulceration and cerebral infarction seen on CT scan.

The purpose of the study was to determine the association between cerebral infarction seen on CT scan and macroscopic ulceration of atheromatous carotid plaques in patients undergoing carotid endarterectomy. Following carotid endarterectomy in 65 patients, specimens were examined for the presence of ulceration without knowing the result of the preoperative CT brain scan. The 65 patients thus investigated underwent 68 carotid endarterectomies: 36 for a history of transient ischemic attacks (TIAs), 13 for amaurosis fugax, and six for prior strokes; 13 asymptomatic patients had prophylactic carotid endarterectomy prior to coronary bypass. A macroscopic ulcer was present in 42 specimens. Twenty-six (62%) of the patients with ulceration had one or more ipsilateral cerebral infarcts on CT scan. Only two (8%) of the 26 patients without an ulcer had cerebral infarcts. Of the 36 patients who presented with TIAs, 26 (72%) had carotid plaque ulcers and 23 (88%) of these had cerebral infarcts on CT scan also. In contrast, only three of 13 asymptomatic patients had plaque ulcers and only one of these had a cerebral infarct. There is a high incidence of cerebral infarction seen on CT scan in patients presenting with TIAs. These infarcts occur predominantly in patients with ulcerated atheromatous carotid lesions.

Aged↗