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Biomedical subjects

Panos Prassopoulos

Publications and source records attributed to Panos Prassopoulos.

At least 19 recordsLinked to original sources
PubMed2006

Imaging of small intestinal Crohn's disease: comparison between MR enteroclysis and conventional enteroclysis.

The purpose of this study was to compare MR enteroclysis (MRE) with conventional enteroclysis (CE) in patients with small intestinal Crohn's disease. Fifty-two consecutive patients with known or suspected Crohn's disease underwent MR and conventional enteroclysis, which was considered the gold standard. Eleven imaging features, classified in three groups, mucosal, transmural and extraintestinal, were subjectively evaluated by two experienced radiologists. MRE and CE were in full agreement in revealing, localizing and estimating the length of all involved segments of the small bowel. The sensitivity of MRE for the detection of superficial ulcers, fold distortion and fold thickening was 40, 30 and 62.5%, respectively. The sensitivity of MRE for the detection of deep ulcers, cobble-stoning pattern, stenosis and prestenostic dilatation was 89.5, 92.3, 100 and 100%, respectively. Additional findings demonstrated on MRE images included fibrofatty proliferation in 15 cases and mesenteric lymphadenopathy in 19 cases. MRE strongly correlates with CE in the detection of individual lesions expressing small intestinal Crohn's disease. It provides additional information from the mesenteries; however, its capability to detect subtle lesions is still inferior to conventional enteroclysis.

Adolescent↗
PubMed2006

Computed-tomography-guided direct percutaneous transhepatic embolization of a bleeding hepatic artery branch aneurysm.

A case of successful direct percutaneous transhepatic coil embolization of a ruptured intrahepatic aneurysm under computed tomography (CT) guidance is presented. The patient had a history of multiple operations for liver echinococcosis and was transferred to the emergency department in a deteriorating clinical condition due to active hemorrhage. The aneurysm was treated with percutaneous transhepatic embolization under CT guidance. The procedure is not time-consuming and keeps the time interval between diagnosis and treatment to a minimum, thereby limiting subsequent blood loss.

Aged↗
PubMed2006

Primary hydatid disease in a retroplaced gallbladder.

A 60-year-old man with abdominal distension, fever, vomiting and pain on the right upper quadrant of the abdomen was admitted to our hospital. US revealed a well circumscribed lesion of mixed echogenicity. CT revealed hypoplasia of the right liver lobe, and a cystic mass with solid components replacing a retroplaced gallbladder. On T1-weighted MR images the lesion had low signal intensity and presented mild peripheral post-contrast enhancement, while on T2-weighted images the periphery was of moderately high signal intensity and the centre of fluid-like, high signal intensity. Adjacent liver parenchyma had relatively high signal intensity on T2-weighted images. The patient underwent exploratory laparotomy, and a hydatid cyst of the gallbladder that was inflamed was evidenced.

Cholangiography↗
PubMed2005

U-stitching splenorraphy technique: experimental and clinical study.

BACKGROUND: The aim of the present study was to describe the laboratory development and the subsequent clinical utility of the U-stitching technique for splenorraphy over the recent years in a general non-trauma hospital. Patients with splenectomies and patients treated conservatively during the same time period, are also presented. METHODS: In the 15-year period from September 1988 until September 2003, 65 patients were diagnosed with splenic injury following admission to 2nd Department of Surgery, Democritus University Hospital, after blunt abdominal trauma. During the first 3 years, 14 patients were admitted; one of them was treated conservatively and 13 had splenectomies. Because computed tomography (CT) was not available at that time, these 14 patients form a control group. During the remaining 12-year period, 51 patients (39 male and 12 female; age, 4-82 years; mean, 31.1 years; SD, 19.7 years) were treated conservatively or surgically, either with splenectomy or with splenorraphy. Splenorraphy was performed using the U-stitching technique. This alternative splenorraphy technique was first tested on experimental models at 2nd Department of Surgery, Democritus University Hospital, then followed by successful clinical application. The medical records for these patients were reviewed to extract the data for the present study. RESULTS: Thirty-six patients (70.6% of 51 patients) were treated surgically; of these, 21 (41.2% of 51 patients) had splenectomy and 15 (29.4% of 51 patients) had splenorraphy. Non-operative treatment was initially given to 15 patients (29.4% of 51 patients). Two of them had delayed rupture of the spleen and underwent splenectomy (at 8 and 40 days). The total number of preserved spleens was 28 of 51 (54.9%). None of the patients with conservative treatment or splenorraphy died. One patient with splenectomy died later from overwhelming sepsis. CONCLUSIONS: Splenic salvage is now a treatment goal. If the patient is haemodynamically unstable and splenorraphy is possible, the U-stitching technique is a promising approach.

Adult↗
PubMed2004

Assessment of Crohn's disease activity in the small bowel with MR and conventional enteroclysis: preliminary results.

Every single imaging finding that can be disclosed on conventional and MR enteroclysis was correlated with the Crohn's disease activity index (CDAI). Nineteen consecutive patients with Crohn's disease underwent colon endoscopy and both conventional and MR enteroclysis examinations. Seventeen MR imaging findings and seven conventional enteroclysis findings were ranked on a four-point grading scale and correlated with CDAI, with a value of 150 considered as the threshold for disease activity. Six patients had active disease in the colon according to colon endoscopy. In the remaining 13 patients, the presence of deep ulcers ( P=0.002), small bowel wall thickening ( P=0.022) and gadolinium enhancement of mesenteric lymph nodes ( P=0.014) identified on MR enteroclysis images were strongly correlated to disease activity. The product of deep ulcers and enhancement of lymph node ranks identified on MR enteroclysis were the optimum combination for discriminating active from non-active disease ( F-test: 55.95, P<0.001). Additionally, the ranking of deep ulcers on conventional enteroclysis provided statistically significant differences between active and non-active patients ( F-test: 14.12, P=0.004). Abnormalities strongly suggestive of active Crohn's disease can be disclosed on MR enteroclysis examinations and may provide pictorial information for local inflammatory activity.

Adult↗
PubMed2004

Stereology versus planimetry to estimate the volume of malignant liver lesions on MR imaging.

Liver tumor volume measurements are clinically useful in patients undergoing cancer treatment. The techniques of planimetry and stereology were applied for this purpose on magnetic resonance (MR) imaging. Fifty-eight malignant liver lesions were depicted on MR images in 20 consecutive patients. The volume of all lesions was estimated using stereology technique, based on point counting. Stereological tumor volume estimations were compared with those determined by manual planimetry. The repeatability of both techniques was assessed. Tumor volumes estimated by the two techniques were highly correlated (r = 0.98, p < 0.0001). The 95% limits of agreement showed that the stereological volume estimations may differ from the planimetric assessments by less than 23%. Both techniques presented comparable intra- and interobserver variability. The planimetry was 1.5 times faster than the stereology. Both volumetric techniques may provide reliable and reproducible liver tumor volume estimations. The planimetry may be the method of choice because of its superior speed.

Adult↗
PubMed2003

T2 relaxation time analysis in patients with multiple sclerosis: correlation with magnetization transfer ratio.

The aim of the current study was to perform T2 relaxation time measurements in multiple sclerosis (MS) patients and correlate them with magnetization transfer ratio (MTR) measurements, in order to investigate in more detail the various histopathological changes that occur in lesions and normal-appearing white matter (NAWM). A total number of 291 measurements of MTR and T2 relaxation times were performed in 13 MS patients and 10 age-matched healthy volunteers. Measurements concerned MS plaques (105), NAWM (80), and "dirty" white matter (DWM; 30), evenly divided between the MS patients, and normal white matter (NWM; 76) in the healthy volunteers. Biexponential T2 relaxation-time analysis was performed, and also possible linearity between MTR and mean T2 relaxation times was evaluated using linear regression analysis in all subgroups. Biexponential relaxation was more pronounced in "black-hole" lesions (16.6%) and homogeneous enhancing plaques (10%), whereas DWM, NAWM, and mildly hypointense lesions presented biexponential behavior with a lower frequency(6.6, 5, and 3.1%, respectively). Non-enhancing isointense lesions and normal white matter did not reveal any biexponential behavior. Linear regression analysis between monoexponential T2 relaxation time and MTR measurements demonstrated excellent correlation for DWM( r=-0.78, p<0.0001), very good correlation for black-hole lesions( r=-0.71, p=0.002), good correlation for isointense lesions( r=-0.60, p=0.005), moderate correlation for mildly hypointense lesions( r=-0.34, p=0.007), and non-significant correlation for homogeneous enhancing plaques, NAWM, and NWM. Biexponential T2 relaxation-time behavior is seen in only very few lesions (mainly on plaques with high degree of demyelination and axonal loss). A strong correlation between MTR and monoexponential T2 values was found in regions where either inflammation or demyelination predominates; however, when both pathological conditions coexist, this linear relationship is lost.

Adolescent↗
PubMed2003

Cystadenocarcinoma of the appendix: an incidental imaging finding in a patient with adenocarcinomas of the ascending and the sigmoid colon.

BACKGROUND: Primary adenocarcinomas of the appendix are uncommon. Mucoceles that result from mucinous adenocarcinomas of the appendix may be incidentally detected on imaging. CASE PRESENTATION: A case of a mucocele of the appendix, due to cystadenocarcinoma, is presented as an incidental imaging finding in a female, 86-year-old patient. The patient was admitted due to rectal hemorrhage and underwent colonoscopy, x-ray, US and CT. Adenocarcinoma of the ascending colon, adenomatous polyp of the sigmoid colon and a cystic lesion in the right iliac fossa were diagnosed. The cystic lesion was characterized as mucocele. The patient underwent right hemicolectomy, excision of the mucocele and sigmoidectomy. She recovered well and in two-year follow-up is free from cancer. CONCLUSIONS: Preoperative diagnosis of an underlying malignancy in a mucocele is important for patient management, but it is difficult on imaging studies. Small lymph nodes or soft tissue stranding in the surrounding fat on computed tomography examination may suggest the possibility of malignancy.

Adenocarcinoma↗
PubMed2003

The course of traumatic pancreatitis in a patient with pancreas divisum: a case report.

BACKGROUND: The peculiar anatomy of pancreatic ducts in pancreas divisum (PD) may interfere with the development of acute chronic pancreatitis. In the presented case, PD influenced the evolution of lesions after pancreatic trauma. CASE PRESENTATION: A 38 years old patient refferred to our hospital with recurrent episodes of mild pancreatitis during the last two years. The first episode occurred four months after blunt abdominal trauma. Endoscopic Retrograde Cholangiopancreatography, Magnetic Resonance Imaging of upper abdomen and Magnetic Resonance Cholangiopancreatography disclosed pancreas divisum, changes consistent with chronic pancreatitis in the dorsal pancreatic duct, atrophy in the body and tail of the pancreas and a pseudocyst in the pancreatic head, that was drained endoscopically. CONCLUSION: Pancreas Divisum may interfere with the evolution of posttraumatic changes in the pancreas after blunt abdominal trauma.

Abdominal Injuries↗
PubMed2003

MR colonography with fecal tagging: comparison between 2D turbo FLASH and 3D FLASH sequences.

The objective of this study was to compare inversion recovery turbo 2D fast low-angle shot (FLASH) and 3D FLASH sequences for fecal-tagged MR colonography studies. Fifteen consecutive patients with indications for colonoscopy underwent MR colonography with fecal tagging. An inversion recovery turbo-FLASH sequence was applied and compared in terms of artifacts presence, efficiency for masking residual stool, and colonic wall conspicuity with a fat-saturated 3D FLASH sequence. Both sequences were acquired following administration of paramagnetic contrast agent. Contrast-to-noise ratio and relative contrast between colonic wall and lumen were calculated and compared for both sequences. Turbo 2D FLASH provided fewer artifacts, higher efficiency for masking the residual stool, and colonic wall conspicuity equivalent to 3D FLASH. An inversion time of 10 ms provided homogeneously low signal intensity of the colonic lumen. Contrast to noise between colonic wall and lumen was significantly higher in the 3D FLASH images, whereas differences in relative contrast were not statistically significant. An optimized inversion-recovery 2D turbo-FLASH sequence provides better fecal tagging results and should be added to the 3D FLASH sequence when designing dark-lumen MR colonography examination protocols.

Barium Sulfate↗
PubMed2003

Transtympanic iontophoresis of gadopentetate dimeglumine: Preliminary results.

OBJECTIVE: We sought to demonstrate the feasibility of using iontophoresis to deliver pharmaceutical agents into the middle and inner ear for the treatment of middle and inner ear diseases, which is proved in this study by the successful iontophoresis of the ferromagnetic contrast agent gadopentetate dimeglumine. Study design and setting Eight rabbits were iontophoresed using gadopentetate dimeglumine solution 469 mg/mL. Then, all rabbits underwent magnetic resonance imaging for the detection of gadopentetate dimeglumine in the middle and inner ear structures. The study was conducted in the tertiary referral center the University Hospital of Crete. RESULTS: The high signal intensity of the gadopentetate dimeglumine solution was demonstrated within the middle ear cavity and inner ear structures of all iontophoresed ears and in none of the noniontophoresed ones. CONCLUSIONS: Transtympanic iontophoresis could be an effective method for the passage of pharmaceutical agents into the middle and inner ear for the treatment of middle and inner ear diseases.

Administration, Topical↗
PubMed2003

Relevance of the restoration of humeral length and retroversion in hemiarthroplasty for humeral head fractures.

Sixteen patients, with a fracture of the upper humerus treated with hemiarthroplasty, were followed-up for 45.7 +/- 15.1 (20-72) months after surgery. The results were assessed using the Constant-Murley scale. The mean score was 75.8 +/- 15.7 (54-96) points out of a possible maximum of 100. At the time of their last follow-up they underwent CT of the fractured and contralateral humerus. Humeral length and retroversion were measured and evaluated. A very good final outcome (Constant score more than 71) was achieved in patients with a difference in retroversion less than 10 degrees and a difference in length less than 14 mm, between fractured and sound humerus. The mean difference in retroversion was 8.7 degrees and the mean difference in length was 0.65 cm, between fractured and sound humerus. We attribute the very good clinical outcome in our series to the quality of the anatomical reconstruction that was performed.

Adult↗
PubMed2002

MR enteroclysis: technical considerations and clinical applications.

Magnetic resonance enteroclysis (MRE) is an emerging technique for the evaluation of small bowel abnormalities. Adequate luminal distention, achieved by the administration of iso-osmotic water solution through a nasojejunal catheter, in combination with ultrafast sequences, such as single-shot turbo spin echo, true fast imaging with steady precession, half-Fourier acquired single-shot turbo spin echo, and 3D fast low-angle shot, results in excellent anatomic demonstration of the small bowel. Magnetic resonance fluoroscopy can be performed during MRE examination and might be useful in studying low-grade stenosis or motility-related disorders. Magnetic resonance enteroclysis is very promising in detecting the number and extent of involved small bowel segments in patients with Crohn's disease, and in disclosing lumen narrowing and extramural manifestations and complications of the disease. Initial experience shows that MRE is very efficient in the diagnosis of small bowel tumors and can be used in the evaluation of small bowel obstruction.

Contrast Media↗
PubMed2002

Conceptus radiation dose and risk from chest screen-film radiography.

The objectives of the present study were to (a) estimate the conceptus radiation dose and risks for pregnant women undergoing posteroanterior and anteroposterior (AP) chest radiographs, (b) study the conceptus dose as a function of chest thickness of the patient undergoing chest radiograph, and (c) investigate the possibility of a conceptus to receive a dose of more than 10 mGy, the level above which specific measurements of conceptus doses may be necessary. Thermoluminescent dosimeters were used for dose measurements in anthropomorphic phantoms simulating pregnancy at the three trimesters of gestation. The effect of chest thickness on conceptus dose and risk was studied by adding slabs of lucite on the anterior and posterior surface of the phantom chest. The conceptus risk for radiation-induced childhood fatal cancer and hereditary effects was calculated based on appropriate risk factors. The average AP chest dimension (d(a)) was estimated for 51 women of childbearing age from chest CT examinations. The value of d(a) was estimated to be 22.3 cm (17.4-27.2 cm). The calculated maximum conceptus dose was 107 x 10(-3) mGy for AP chest radiographs performed during the third trimester of pregnancy with maternal chest thickness of 27.2 cm. This calculation was based on dose data obtained from measurements in the phantoms and d(a) estimated from the patient group. The corresponding average excess of childhood cancer was 10.7 per million patients. The risk for hereditary effects was 1.1 per million births. Radiation dose for a conceptus increases exponentially as chest thickness increases. The conceptus dose at the third trimester is higher than that of the second and first trimesters. The results of the current study suggest that chest radiographs carried out in women at any time during gestation will result in a negligible increase in risk of radiation-induced harmful effects to the unborn child. After a properly performed maternal chest X-ray, there is no need for individual conceptus dose estimations.

Abnormalities, Radiation-Induced↗
PubMed2002

Acute cholecystitis in high-risk patients: percutaneous cholecystostomy vs conservative treatment.

Our objective was to compare the effectiveness of percutaneous cholecystostomy (PC) vs conservative treatment (CO) in high-risk patients with acute cholecystitis. The study was randomized and comprised 123 high-risk patients with acute cholecystitis. All patients fulfilled the ultrasonographic criteria of acute inflammation and had an APACHE II score > or =12. Percutaneous cholecystostomy guided by US or CT was successful in 60 of 63 patients (95.2%) who comprised the PC group. Sixty patients were conservatively treated (CO group). One patient died after unsuccessful PC (1.6%). Resolution of symptoms occurred in 54 of 63 patients (86%). Eleven patients (17.5%) died either of ongoing sepsis (n=6) or severe underlying disease (n=5) within 30 days. Seven patients (11%) were operated on because of persisting symptoms (n=3), catheter dislodgment (n=3), or unsuccessful PC (n=1). Cholecystolithotripsy was performed in 5 patients (8%). Elective surgery was performed in 9 cases (14%). No further treatment was needed in 32 patients (51%). In the CO group, 52 patients (87%) fully recovered and 8 patients (13%) died of ongoing sepsis within 30 days. All successfully treated patients showed clinical improvement during the first 3 days of treatment. Percutaneous cholecystostomy in high-risk patients with acute cholecystitis did not decrease mortality in relation to conservative treatment. Percutaneous cholecystostomy might be suggested to patients not presenting clinical improvement following 3 days of conservative treatment, to critically ill intensive care unit patients, or to candidates for percutaneous cholecystolithotripsy.

APACHE↗