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F P McGrath

Publications and source records attributed to F P McGrath.

At least 19 recordsLinked to original sources
PubMed2003

Ultrasound-guided endocavitary drainage of pelvic abscesses: technique, results and complications.

AIM: To evaluate the experience in our institution with ultrasound-guided transrectal and transvaginal (endocavitary) drainage of pelvic abscesses. MATERIALS AND METHODS: Eighteen patients (four male, 14 female; mean age 55 years, range 30-78 years) presenting with pelvic abscesses were referred to our institution for therapeutic drainage over a 4 year period. Patients received broad-spectrum antibiotics prior to drainage, which was performed by either the transvaginal or transrectal route under ultrasound guidance. Patients were given sedo-analgesia in the form of midazolam and fentanyl and local anaesthesia was also employed. Eight French catheters were inserted into the abscess cavities, and patients were subsequently monitored on a daily basis by a member of the interventional radiology team until such time as it was deemed appropriate to remove the catheter. RESULTS: Eighteen catheters were placed in 17 patients, and transvaginal aspiration alone was performed in one patient. Drainage was successful in 16 of 17 patients, but a transgluteal approach was ultimately required in the remaining patient to enable passage of a larger catheter into an infected haematoma. The mean duration of drainage was 5 days, mean time to defervesce 2 days. Spontaneous catheter dislodgement occurred in four patients associated with straining, but this did not have any adverse effect in three of the four patients. CONCLUSION: Endocavitary drainage is an effective method of treatment for pelvic abscesses. Spontaneous catheter dislodgement does not affect patient outcome.

Abscess↗
PubMed1999

Evaluation of the role of magnetic resonance myelography in lumbar spine imaging.

The purpose of our study was to evaluate the accuracy of MR myelography in depicting disc herniation in the lumbar spine when compared with conventional MRI in patients presenting with clinical evidence of disc herniation. One hundred patients referred for conventional MR imaging of the lumbar spine also had coronal MR (TR 9000 ms, TE 272 ms eff, NEX 3, echo train length 32) myelography performed. Three experienced observers compared magnetic resonance myelography (MRM) with conventional lumbar spine MR using the following variables: visibility of thecal sac and nerve roots, and the presence, location and severity of disc herniation. Disc protrusions were seen at 110 disc space levels on conventional MR images as opposed to 93 on MRM. However, only 72 % of lesions seen on conventional MR were diagnosed by MRM. Similarly, only 63.8 % of nerve root compression abnormalities seen at conventional MR were visualized when compared with conventional MRM. The sensitivity, specificity and accuracy of MRM when compared with conventional MR was 72, 93 and 85 %, respectively. The MRM technique yields images that resemble conventional myelography and may be used to help confirm abnormalities seen on conventional MR in selected cases; however, the large number of false-positive and false-negative examinations indicates that caution should be used in interpreting MRM images.

Humans↗
PubMed1997

A comparison of compression ultrasound with color Doppler ultrasound for the diagnosis of symptomless postoperative deep vein thrombosis.

BACKGROUND: Despite advances in primary prophylaxis, venous thromboembolism still occurs in a considerable number of high-risk surgical patients. Screening with conventional ultrasound imaging to detect asymptomatic deep vein thrombosis (DVT) has been suggested as a strategy to improve management of such patients, but it is insufficiently sensitive. We evaluated the ability of color Doppler ultrasound to improve the sensitivity of compression ultrasound in the detection of asymptomatic DVT in high-risk orthopedic patients. METHODS: We prospectively evaluated bilateral compression and color Doppler ultrasound measurements of the entire leg in 204 consecutive patients who underwent elective hip or knee replacement surgery, using contrast venography as the reference test. The sensitivity, specificity, and positive predictive value of the ultrasonography tests were determined. RESULTS: The sensitivity, specificity, and positive predictive value (with 95% confidence intervals [CIs]) of compression ultrasound for the detection of proximal DVT were 60% (39%-81%), 96% (92%-99%), and 71% (48%-89%) respectively. The sensitivity, specificity, and positive predictive value (with 95% CIs) of compression ultrasound for the detection of calf vein thrombosis were 33% (18%-52%), 91% (83%-96%), and 58% (34%-80%), respectively. Color Doppler ultrasonography did not identify any additional proximal or calf vein thrombi to those detected by compression ultrasound alone. The sensitivity for all thrombi was 47% (95% CI, 34%-61%) with a positive predictive value of 65% (95% CI, 48%-79%). CONCLUSIONS: Color Doppler ultrasonography has a moderate to low accuracy for the detection of DVT in patients who have had hip and knee replacement surgery. Color Doppler ultrasonography does not increase the detection rate for asymptomatic DVT over compression ultrasound and thus cannot be recommended as a screening test in this setting.

Hip Prosthesis↗
PubMed1995

Fibrin sealant in interventional radiology: a preliminary evaluation.

Tisseel, a fibrin sealant not approved for use in the United States, was tested in abdominal fistulas and sinuses (13 patients) and interventional biliary procedures (11 patients). The two components of Tisseel were introduced via a double-lumen catheter and formed a fibrin gel at the point of contact. Tracts were sealed permanently in seven fistulas and sinuses and in all 11 biliary cases.

Adult↗
PubMed1994

Pneumatic reduction of intussusception using carbon dioxide.

Pneumatic reduction using air has recently become popular for the initial non-surgical management of intussusception. Since carbon dioxide (CO2) is rapidly absorbed from body surfaces, it should theoretically result in less cramping and distension following reduction. We reviewed our recent experience with the pneumatic reduction of intussusception using CO2 in 26 children. In 22 of these the intussusception was reduced (85%). There was one performation with CO2; the patient did not suffer any postoperative complications. Five additional children who had been treated unsuccessfully with barium had intussusception subsequently reduced with CO2. Following CO2 reduction, most children were fed within hours, and there were no instances of significant abdominal distension or cramping. We conclude that pneumatic reduction of intussusception using CO2 is safe and effective, and has the theoretical advantage of more rapid absorption from the gastrointestinal tract than air.

Carbon Dioxide↗
PubMed1994

Hepatic interstitial laser photocoagulation. An investigation of the relationship between acute thermal lesions and their sonographic images.

OBJECTIVES: The relationship between hepatic interstitial laser photocoagulation (ILP) lesions and their acute ultrasound images was evaluated. In addition, the natural history of ILP lesions in normal pig liver was documented. METHODS: Eighteen pigs underwent laparotomy and ultrasound-monitored ILP. In part 1 of the study, 12 pigs each had four separate exposures (1.50 W for 60, 100, 300, and 500 seconds) and were divided into four groups according to when they were killed (0, 3, 7, and 21 days). In part 2 of the study, six pigs each had two sequential exposures (1.60 W for 1,000 and then 500 seconds) at separate hepatic sites. Survival time was 3 days. Necropsy and histologic examination were performed in all animals. In 0- and 3-day survivors, actual thermal lesions were compared with "early" (immediately after ILP) and "late" (1 hour after ILP) ultrasound images. RESULTS: In the 300-, 500-, and 1,000-second exposures of parts 1 and 2, thermal lesions were overestimated or approximated by early ultrasound and were underestimated or approximated by late ultrasound. Analysis of variance showed statistically significant differences between thermal lesions and their early and late ultrasound images (F = 18.6, P < .001, no interactions). Time-growth characteristics of ILP lesions were reasonably consistent on ultrasound; exceptions were identifiable 200 seconds into the exposure. In part 2, ultrasound changes were minimal in five of six 500-second (second sequential) technically satisfactory exposures. Thermal lesions were seen at necropsy. All lesions healed by formation of granulation tissue and collagen. CONCLUSIONS: During ILP, early ultrasound images frequently overestimate actual thermal lesions. Ultrasound-monitored ILP of tumors may be most effective if, on early ultrasound, echogenic changes extend beyond the tumor margins. Late ultrasound images underestimate or approximate thermal lesions. Their value in clinical ILP should be investigated. It is unclear why ultrasound images of proven thermal lesions were not seen during 5 of 6 otherwise satisfactory 500-second ILP exposures performed immediately after 1,000-second exposures.

Animals↗
PubMed1994

High-resolution ultrasound in assessment of the gastrointestinal tract.

Ultrasound (US) is frequently the first investigation performed in patients presenting with a variety of abdominal symptoms, and there is a growing appreciation of its value in a wide range of gastrointestinal (GI) disorders. The advantages of US are that it is quick, safe, readily available, noninvasive, and avoids ionizing radiation. It is now the primary imaging investigation when conditions such as appendicitis and hypertrophic pyloric stenosis (HPS) are suspected. For the diligent examiner careful assessment of the bowel can be rewarding either by diagnosing bowel pathology or identifying possible pathology and determining the most appropriate sequence of diagnostic investigations. Its real time capabilities are of particular usefulness in abdominal conditions; clinical correlation is instant and features such as peristalsis and bowel compressibility can be readily assessed. This review describes and illustrates the current role of high-resolution transabdominal US in the detection of GI pathology with discussion on some of the applications of endoscopic ultrasound (EUS) as they relate to this topic.

Digestive System Diseases↗
PubMed1994

Focal nodular hyperplasia of the liver--an imaging conundrum.

Focal nodular hyperplasia is a common benign tumour of the liver that usually does not require treatment. This tumour can be difficult to distinguish noninvasively from other lesions in young patients that may require intervention, such as hepatic adenoma and fibrolamellar carcinoma. The authors report three cases of histologically proven focal nodular hyperplasia and one case in which the imaging features strongly suggested this tumour. These cases illustrate many of the variable imaging features of focal nodular hyperplasia. The authors review the typical imaging findings for focal nodular hyperplasia, hepatic adenoma and fibrolamellar carcinoma, indicate the areas of overlap that make noninvasive diagnosis impossible and discuss the role of percutaneous biopsy in establishing the definitive diagnosis.

Adult↗
PubMed1994

Perforated jejunal diverticulosis: radiologic diagnosis.

Jejunoileal diverticulosis, which is usually asymptomatic, is commonly found at autopsy or during small-bowel barium examination. Perforation of diverticula can cause generalized or localized intra-abdominal inflammatory disease, depending to some extent on the site of the perforation. The authors describe a patient with perforation of a jejunal diverticulum; the condition mimicked colonic inflammatory disease clinically and ultrasonographically. The correct diagnosis was made on the basis of the findings of cross-sectional imaging and barium examination.

Diverticulum↗
PubMed1993

Prenatal compensatory renal growth: documentation with US.

PURPOSE: To determine whether compensatory renal growth (CRG), which occurs in adults, children, and infants after loss of functioning renal tissue, occurs in fetal life. MATERIALS AND METHODS: Prenatal ultrasound scans were used to select 29 patients with a unilateral multicystic dysplastic kidney and four patients with unilateral renal agenesis. Accurate measurements of prenatal renal length were obtained in 21 of these patients; an accurate measurement of postnatal renal length and birth weight was obtained in 27 of these patients. Prenatal and postnatal renal measurements of the contralateral kidney were compared with renal length in 23 matched control patients and previously reported normal renal lengths. RESULTS: The single functioning kidneys in the study patients were significantly longer than those in the control patients before and after birth (P = .001). CONCLUSION: This study provides strong evidence to support the belief that CRG occurs before birth.

Birth Weight↗
PubMed1993

Same-day computed tomography during arterial portography and delayed high-dose iodine computed tomography: an efficient approach to imaging potentially resectable liver tumours.

Preoperative imaging in patients with potentially resectable liver tumours has traditionally been performed in specialized hepatobiliary centres. To assess the feasibility and value of establishing a same-day, pre-resectional hepatic imaging service, computed tomography during arterial portography (CTAP) and delayed high-dose iodine computed tomography (DICT) were used to examine patients considered suitable for curative hepatic resection. The study group comprised 27 patients (14 from hospitals not affiliated with a university and 13 from two university-affiliated hospitals) for whom pre-referral imaging showed tumour distribution amenable to resection. Among the patients from centres not affiliated with a university, seven had undergone ultrasonography (US) and equilibrium-phase CT, four had undergone US and unenhanced CT, two had undergone equilibrium-phase CT only and one had undergone bolus dynamic incremented CT (BDCT) only. For 12 of the patients coming from the university-affiliated centres, the pre-referral imaging had consisted of US and BDCT; the other had undergone US only. After CTAP and DICT, 20 (74%) of the 27 patients were reclassified as having unresectable disease: 7 (54%) of the 13 patients who had undergone BDCT before CTAP and DICT and 12 (92%) of the 13 patients who had undergone unenhanced or equilibrium-phase CT, as well as the patient who had undergone US only. By averting laparotomy in 20 of the patients, CTAP and DICT resulted in short-term health care savings of about $160,000. These findings suggest that BDCT was underused in the hospitals not affiliated with university centres.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1993

Optimizing the detection of colorectal liver metastases within the Canadian health care system.

Colorectal metastases in the liver are common. In appropriately selected patients resection can increase the 5-year survival rate from 0% to 33%. When consulted by their surgery colleagues about patient selection, radiologists now have a wide choice of imaging methods, including nuclear medicine, ultrasonography, unenhanced computed tomography (CT), intravenously enhanced CT (by infusion or by the dynamic and delayed methods), arterially enhanced CT (specifically, CT arterial portography and CT angiography) and magnetic resonance imaging. In Canada this wide range of techniques has appeared in an era of cost constraint. This article discusses the surgical background for imaging colorectal metastases in the liver and reviews the available imaging methods. The authors present an algorithmic approach that attempts to balance the need for accuracy with the logistic and financial constraints under which radiologists work in Canada. They suggest that this algorithm would allow optimal use of available resources in most Canadian hospitals.

Colorectal Neoplasms↗
PubMed1993

Computed tomography during arterial portography in malignant carcinoid syndrome: a report of two patients.

Computed tomography during arterial portography (CTAP) and delayed high-dose iodine computed tomography (CT) have improved the preoperative localization of hepatic metastases from colon cancer. Nearly all patients presenting with malignant carcinoid syndrome have liver metastases, and removal of tumour bulk is considered the most effective means of management. To determine suitability for hepatic resection, CTAP and delayed high-dose iodine CT were used to evaluate the distribution of hepatic disease in two patients with malignant carcinoid syndrome. In both patients CTAP showed lesions not seen during recent dynamic incremented CT; the location of the lesions precluded resection. CTAP also demonstrated metastases less than 1 cm in diameter in one patient. Facial flushing (both patients) and hypotension (one) occurred during infusion of the contrast agent into the superior mesenteric artery. Because CTAP can demonstrate small hepatic metastases (less than 1 cm in diameter), it is recommended for patients with malignant carcinoid syndrome who are being considered for hepatic resection. The infusion of contrast media through the superior mesenteric artery may induce a carcinoid crisis, and prophylaxis with a somatostatin analogue is suggested.

Contrast Media↗
PubMed1992

Color Doppler imaging of the cystic artery.

Color Doppler ultrasonography was used to examine the gallbladder vascular supply in 30 volunteers and in 30 biliary lithotripsy patients pre- and 2 hours posttreatment. A preliminary study of 10 cases of acute cholecystitis was also performed. A cystic artery waveform was obtained in 24 of the volunteers, 18 pre- and postlithotripsy patients, and in 1 of 10 patients with acute cholecystitis. The mean pulsatility indices obtained were 1.04 in the volunteers, 0.98 pre- and 1.02 postlithotripsy (p greater than 0.1). This study shows that the normal gallbladder blood supply can be consistently identified using color Doppler flow imaging and that there is no appreciable difference in the cystic artery pulsatility index following medium-energy shock-wave extracorporeal lithotripsy. Preliminary results in acute cholecystitis suggest that flow is decreased below the sensitivity of the color Doppler imaging system used in this investigation.

Adult↗
PubMed1992

The value of sonography in determining cystic duct patency.

A prospective blinded comparison of ultrasonography (US) and oral cholecystography (OCG) was performed in 100 patients with symptomatic gall-stones to determine whether US would enable an accurate assessment of cystic duct patency to be made. Patency of the cystic duct was defined as gall-bladder opacification on OCG or a greater than 20% decrease in gall-bladder volume by US post-fatty meal. The ellipsoid method of volume measurement was used. Any patient who had a non-opacified gall-bladder on OCG but a greater than 20% volume decrease on US had cholescintigraphy performed (DISIDA). Oral cholecystography demonstrated cystic duct patency in 88 patients (88%), and fatty-meal gall-bladder US met the specified study criteria for patency in 86 patients (86%). False negative results were identified in four of the OCG and in six of the US examinations. The results of this study indicate that gall-bladder sonography with a post-fatty meal contraction of greater than 20% is a very accurate predictor of cystic duct patency. A contraction of less than 20%, however, cannot be considered a reliable predictor of cystic duct occlusion.

Adult↗