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Biomedical subjects

G G Hartnell

Publications and source records attributed to G G Hartnell.

At least 73 records · Page 4Linked to original sources
PubMed1993

Embolization in the treatment of acquired and congenital abnormalities of the heart and thorax.

Embolization is well suited to the treatment of a range of vascular abnormalities found only in the thorax. This includes congenital arteriovenous fistulas or malformations affecting the chest wall and the pulmonary and coronary arteries. Acquired bronchial artery anomalies and some types of congenital heart disease are also suitable for embolization. Embolization in the thorax presents problems related to the need to work through or in the heart or to the risk to important branches of the intrathoracic aorta, such as the carotid arteries. The choice and use of different catheters and embolic materials for thoracic embolization depend on the nature and configuration of the lesion and the experience of the operator. Selection must also be based on consideration of the risk of inadvertent embolization of adjacent structures such as the spinal arteries. With embolization experience elsewhere in the body and an understanding of the particular problems presented by thoracic embolization, various important, even if uncommon, conditions can be effectively treated.

Arteriovenous Malformations↗
PubMed1993

Central venous occlusion: MR angiography.

The authors evaluated time-of-flight magnetic resonance (MR) angiography in 30 patients with suspected thoracic venous occlusion. The results of the MR studies were compared with results at contrast venography in 22 patients and at central venous cannulation in seven of the remaining eight patients. Twenty-eight patients had abnormalities on MR venograms; 21 of these abnormalities involved multiple veins. Eight patients had superior vena cava (SVC) occlusion with retrograde azygos blood flow, and two patients had nonocclusive SVC thrombus. Fifteen patients had thrombosis involving the brachiocephalic veins; 14, involving the subclavian veins; and eight, involving the internal jugular veins. Correlation was excellent between findings of venous obstruction and occlusion at contrast venography and MR angiography. MR imaging provided more comprehensive information than catheter venography on central venous anatomy and blood flow. For evaluation of central veins, MR angiography is an accurate and graphic technique that may succeed in cases in which other methods may give inadequate findings or may be impossible to perform.

Adult↗
PubMed1993

Magnetic resonance angiography of systemic thoracic and abdominal veins.

The development of MR angiography has greatly expanded the use of MR imaging for investigating the systemic veins both in the thorax and in the abdomen. With its multiplanar imaging capabilities and three-dimensional image acquisition, MR angiography is the definitive method for imaging the systemic veins in the vast majority of patients.

Abdomen↗
PubMed1993

Magnetic resonance angiography of the thoracic aorta.

The development of MR angiography techniques has improved the quality of information available from MR of the thoracic aorta. With current cine techniques and three-dimensional MR angiography, the thoracic aorta can be examined noninvasively with a high degree of accuracy.

Aorta, Thoracic↗
PubMed1993

Radiologic investigation of abdominal aortic aneurysm disease: comparison of three modalities in staging and the detection of inflammatory change.

PURPOSE: The purpose of this study was to compare the ability of ultrasonography (US), contrast-enhanced computed tomography (CT), and magnetic resonance imaging (MRI) to display the anatomy of abdominal aortic aneurysms and to detect the presence of inflammatory change. METHODS: We prospectively studied 79 patients with abdominal aortic aneurysms (64 noninflammatory aneurysms [NIAAs] and 15 inflammatory aneurysms [IAAs]) with US, CT, and MRI. RESULTS: Ultrasonography failed to diagnose the level of the aneurysm neck in three IAAs and 18 NIAAs. It failed to differentiate NIAAs from IAAs and to visualize the origins of the renal arteries in all cases. With CT the level of the aneurysm neck was incorrectly stated as lying above the level of the renal arteries in two cases of IAA and four cases of NIAA, and the renal artery origins were seen in only 10 of 77 patients. Inflammatory change was diagnosed correctly in seven of 15 patients, whereas six NIAAs were falsely diagnosed as inflammatory. MRI successfully diagnosed neck level and inflammatory change in all cases. Of two failures to visualize the renal artery origins, only one was caused by radiologic factors. In addition, characteristic radiologic features were seen in MRI images of IAAs, and these will be described both in vivo and in vitro. CONCLUSIONS: Our results suggest that MRI is superior to other methods in identifying the anatomy of aneurysms and the presence of inflammatory change.

Aorta, Abdominal↗
PubMed1992

Diagnosis of acute thoracic aortic dissection using combined echocardiography and computed tomography.

Acute dissection of the thoracic aorta is a life-threatening emergency requiring a diagnosis which is rapid, accurate and safe, and which will distinguish between dissections involving the ascending and descending aorta. In the absence of any general agreement on the best method of making this diagnosis we studied the use of combined echocardiography and contrast-enhanced computed tomography (CT) to diagnose acute aortic dissection. Over a 3 year period 23 patients were investigated in this way. Aortic dissection was demonstrated in 18 cases, involving the ascending aorta in 15, and the descending aorta alone in three. The diagnosis of aortic dissection was confirmed in 13 patients at surgery, in one at aortography and in one at autopsy. Three patients died without surgery or autopsy being performed to confirm the diagnosis and the subsequently which accounted for their symptoms. This combined approach has proved a valuable and safe means of investigating aortic dissection.

Acute Disease↗
PubMed1992

Inflammatory aortic aneurysms: characteristic appearance on magnetic resonance imaging.

Ten to 15% of all aortic aneurysms show inflammatory change. They are characteristically covered on their anterior and lateral sides with thick white fibrous tissue. Peri-aortic fibrosis may spread into the retroperitoneum to encase and obstruct adjacent organs making operative treatment more difficult and increasing the operative morbidity and mortality. Fifteen patients with inflammatory aneurysms and 46 patients with simple non-inflammatory aneurysms were studied prospectively. Each patient underwent magnetic resonance imaging (MRI) using a Picker Vista MR2055 scanner operating at 0.5 tesla. Each scan was reviewed by a radiologist (G.G.H.) preoperatively and a diagnosis of inflammatory or non-inflammatory aneurysm made. At operation, the diagnosis of aneurysm type was made on macroscopic features of inflammatory change, and confirmed histologically using previously published criteria. The radiological diagnosis was found to correspond to the surgical and pathological diagnosis in all cases. In cases of inflammatory aortic aneurysm the aneurysm wall appeared laminated on MRI scan, showing three or more bright, high-signal layers. These appearances of inflammatory change are characteristic, and were present in all 15 patients with such aneurysms. There were no false positives among those patients with simple aneurysms, and no false negatives. Operative specimens of aortic wall were taken from four patients with inflammatory aortic aneurysms and four patients with simple non-inflammatory aortic aneurysms, and subjected to MRI scanning. The characteristic banding appeared only in the inflammatory aneurysm wall samples. Magnetic resonance imaging is a highly sensitive investigative technique for the detection of inflammatory aneurysms, showing characteristic changes. These changes are also seen in in vitro scans of wall samples from inflammatory aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Assessment of the thoracic aorta by spiral CT.

A recently developed technique, spiral CT, allows rapid data acquisition through an entire anatomic region during a single breath-hold. High-quality spiral CT scans of the thoracic region have been obtained with volumes of contrast material that are small relative to those used with conventional CT. This essay illustrates the diseases of the aorta as seen on spiral CT performed with low volumes of contrast material.

Aged↗
PubMed1991

Limitations in the use of five French coronary catheters.

Five french (5F) catheters are being widely promoted for use in patients undergoing day case angiography including coronary angiography. Although there are theoretical advantages to this practice there are also potential disadvantages. We reviewed various performance parameters of four different brands of 5F coronary catheter and compared them with performance of the six (6F) and eight french (8F) coronary catheters used in routine coronary angiography. All the 5F catheters performed significantly less satisfactorily than the 6F and 8F catheters. 5F coronary catheters cannot be recommended for routine transfemoral coronary angiography.

Cardiac Catheterization↗
PubMed1991

The right aortic arch revisited.

The association between congenital cardiac defects and a right-sided aortic arch was assessed in 900 children undergoing cardiac angiography. Some of the associations observed differ from those reported in the established radiological literature. A right arch occurred in 15% of children with truncus arteriosus (up to 50% quoted in the literature), and in only 3% of those with tricuspid atresia (15% quoted in the literature). Anatomically corrected transposition of the great arteries was more strongly associated (18.2%) than has previously been suggested. These differences from previous series may, in part, be due to the improved survival of sick neonates allied with earlier diagnosis and better surgical management.

Abnormalities, Multiple↗
PubMed1991

Complications of direct brachial artery puncture for arteriography: a comparison of techniques.

Direct brachial artery puncture is used increasingly for day-case arteriography and patients with severe aorto-iliac disease. In expert hands low complication rates are reported, but the risks of brachial artery puncture may be higher when it is performed by less experienced operators. Over a 2 year period 49 direct brachial artery punctures were performed for arteriography. In 27 cases catheters were inserted directly over a guide-wire via a variable puncture site. In 22 cases catheters were inserted through an introducer sheath via a high brachial puncture. Significant complications requiring active treatment or surgical intervention occurred in three (11%) cases where direct catheter insertion was used. There were no complications when an introducer sheath was used. Percutaneous high brachial aortography using an introducer sheath is a safer technique when brachial artery puncture is performed infrequently.

Angiography↗