Hepatobiliary scintigraphy in the assessment of biliary obstruction after hepatic resection with biliary-enteric anastomosis

We investigated the usefulness of hepatobiliary scintigraphy (HBS) for diagnosing biliary obstruction after curative hepatic resection with biliary-enteric anastomosis. The study population consisted of 54 patients who underwent surgery for benign (n=18) or malignant (n=36) biliary disease. We analysed 68 technetium-99m DISIDA scintigrams which were performed at least 1 month after the surgery (median: 9 months). Final diagnosis was made by operative exploration, other invasive radiological studies or clinical and radiological follow-up for at least 6 months after the surgery. Diagnostic accuracy was analysed according to the pretest likelihood of biliary obstruction. There were two total and 15 segmental biliary obstructions. In patients with symptoms of biliary obstruction and abnormal liver function, HBS always allowed correct diagnosis (two instances of total obstruction, seven of segmental obstruction and seven of non-obstruction). Among the patients with non-specific symptoms or isolated elevation of serum alkaline phosphatase, HBS diagnosed segmental biliary obstruction in seven of the eight instances, and non-obstruction in 22 of 23 instances. There were no cases of biliary obstruction and no false-positive results of HBS in 21 instances with no clinical signs or symptoms of biliary obstruction. The diagnostic sensitivity and specificity of HBS for biliary obstruction were 94% (16/17) and 97% (50/51), respectively. In conclusion, HBS is a highly accurate modality for the diagnosis of segmental biliary obstruction during long-term follow-up after hepatic resection with biliary-enteric anastomosis. Received 1 August and in revised form 14 October 1999     

Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT

Despite advances in patient and graft management, biliary complications (BC) still represent a challenge both in the early and delayed period after orthotopic liver transplantation (OLT). Because of unspecific clinical presentation, imaging is often mandatory in order to diagnose BC. Among imaging modalities, magnetic resonance cholangiography (MRC) has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively, using both the conventional technique (based on heavily T2-weighted sequences) and contrast-enhanced MRC (based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents). On this basis, MRC is generally indicated to: (1) avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications; and (2) provide a road map for interventional procedures or surgery. As illustrated in the review, MRC is accurate in the diagnosis of different types of biliary complications, including anastomotic strictures, non-anastomotic strictures, leakage and stones.     

Postoperative findings following the Whipple procedure: determination of prevalence and morphologic abdominal CT features

This study was conducted to determine characteristic CT findings following the Whipple procedure and to evaluate the usefulness of CT in predicting tumor recurrence. Eighty-four postoperative abdominal CT scans and medical records of 43 patients were retrospectively reviewed. Perioperative histopathologic examinations revealed malignancy in 32 patients (74.4 %). Time interval between surgery and CT varied from 13 days to 6 years and 7 months. Common postoperative findings were unopacified anastomotic bowel loops in the porta hepatis (n = 69 scans), perivascular cuffing (n = 42 scans), pneumobilia (n = 40 scans), dilated intrahepatic bile ducts (n = 22 scans), reactive lymphadenopathy (n = 21 scans), and transient fluid collections (n = 20 scans). Postoperative complications were detected on 17 CT scans (20.2 %): generalized ascites (n = 8 patients), deep abscesses (n = 3 patients), wound abscess (n = 1 patient), pancreatitis (n = 1 patient), and pseudomembranous colitis (n = 1 patient). Tumor recurrence appeared in 15 patients (46.8 %) after a mean postoperative period of 11 months (1 month to 3 years): local (9 of 15), regional lymph nodes (9 of 15), and liver metastasis (8 of 15). Detection of generalized ascites more than 30 days after surgery was associated with tumor recurrence in 6 of 6 patients (100 %). Diffuse ascites (> 30 days after surgery) behaved as an early predictive sign of tumor recurrence. In our series CT accuracy for detecting recurrent tumor with CT was 93.5 %. No predilection site for disease recurrence could be determined. Received: 1 February 1999; Revised: 15 April 1999; Accepted: 19 April 1999     

MRI in the diagnosis of small bowel disease: use of positive and negative oral contrast media in combination with enteroclysis

The aim of the study was to evaluate the additional findings of MRI following small bowel enteroclysis and to compare the efficacy of negative and positive intraluminal contrast agents. Fifty patients with inflammatory or tumorous small bowel disease were investigated by small bowel enteroclysis and consecutive MRI using breathhold protocol (T1-weighted fast low-angle shot, T2-weighted turbo spin echo). Patients were randomly assigned to either receiving a positive oral (Magnevist, Schering, Berlin, Germany) or a negative oral MR contrast media (Abdoscan, Nycomed, Oslo, Norway). The pattern of contrast distribution, the contrast effect, presence of artifacts, as well as bowel wall and extraluminal changes, were determined and compared between the contrast type using Fischer's exact test. Sensitivity, specificity, and diagnostic accuracy for MRI and enteroclysis were calculated. Twenty-seven patients had clinically proven Crohn's disease and two patients surgically proven small bowel tumours. Magnetic resonance imaging had important additional findings as abscesses and fistulae in 20 patients. Surgically compared sensitivities were 100 and 0 % for MRI and enteroclysis, for the detection of abscesses, and 83.3 and 17 % for the diagnosis of fistulae, respectively. Bowel wall thickening was more reliably detected with use of positive oral contrast media without intravenous enhancement (p < 0.001), whereas postcontrast negative oral contrast media allow for a superior detection (p < 0.001). T2-weighted sequences were necessary with use of negative oral contrast media, because loop abscesses may be masked. Magnetic resonance imaging should be performed in all patients with suspicion of extraintestinal complications, because the complications are more reliably detected by MRI. Negative oral contrast media show advantages with the use of intravenous contrast but can mask loop abscesses using only T1-weighted imaging. Received: 5 March 1999; Revised: 21 September 1999; Accepted: 3 February 2000     

Helical CT: a useful technique in the evaluation of aortic intramural hematoma

Purpose: To investigate the diagnostic role of helical CT in aortic intramural hematoma. Material and methods: We retrospectively evaluated CT images obtained during a 6-year period, between 1994 and 2000, in 427 patients who underwent helical CT. Only 21 patients had typical findings of aortic intramural hematoma. All studies were performed with helical technique before and after a power injection of nonionic contrast material. Results: Twenty-one patients had aortic wall thickening (9 type A and 12 type B in Stanford's classification). Wall thickening was more than 4 mm in all cases, it was irregular in shape in 16/21 patients (76 %) and had a regular concentric shape in the remaining 5/21 patients (24 %). One patient with type A hematoma died soon after CT diagnosis because of arrhythmia caused by hemopericardium. Five patients (4 type B and one type A) underwent pharmacological therapy and radiological follow-up. Fifteen patients (7 type A and 8 type B) underwent prosthetic surgery and six of these died of postoperative complications. Conclusion: Helical CT represents the first step in the early diagnosis of aortic intramural hematoma before complications develop. In our experience, which agrees with the reports of other authors, helical CT is an accurate and valuable investigation for identifying the location and extent of an aortic intramural hematoma.     

Tracheal rupture caused by blunt chest trauma: radiological and clinical features

The aim of this study was to assess radiomorphologic and clinical features of tracheal rupture due to blunt chest trauma. From 1992 until 1998 the radiomorphologic and clinical key findings of all consecutive tracheal ruptures were retrospectively analyzed. The study included ten patients (7 men and 3 women; mean age 35 years); all had pneumothoraces which were persistent despite suction drainage. Seven patients developed a pneumomediastinum as well as a subcutaneous emphysema on conventional chest X-rays. In five patients, one major hint leading to the diagnosis was a cervical emphysema, discovered on the lateral cervical spine view. Contrast-media-enhanced thoracic CT was obtained in all ten cases and showed additional injuries (atelectasis n = 5; lung contusion n = 4; lung laceration n = 2; hematothorax n = 2 and hematomediastinum n = 4). The definite diagnosis of tracheal rupture was made by bronchoscopy, which was obtained in all patients. Tracheal rupture due to blunt chest trauma occurs rarely. Key findings were all provided by conventional chest X-ray. Tracheal rupture is suspected in front of a pneumothorax, a pneumomediastinum, or a subcutaneous emphysema on lateral cervical spine and chest films. Routine thoracic CT could also demonstrate these findings but could not confirm the definite diagnosis of an tracheal rupture except in one case; in the other 9 cases this was done by bronchoscopy. Thus, bronchoscopy should be mandatory in all suspicious cases of tracheal rupture and remains the gold standard. Received: 22 February 1999; Revision received: 29 June 1999; Accepted: 1 July 1999     

Sonography in acute appendicitis: diagnostic utility and influence upon management and outcome

A study is made of the diagnostic utility of echography in clinically suspected appendicitis, and its influence upon patient management and outcome. A total of 374 consecutive patients with possible appendicitis were prospectively evaluated by ultrasound. Two groups were established: group A (high clinical probability, ≥ 0.70) and group B (moderate clinical probability, 0.20–0.60). In group-A patients (n = 105, 28 %), prevalence of appendicitis = 0.90) underwent surgery regardless of the echographic findings. In group B (n = 269, 72 %), prevalence of appendicitis = 0.28) surgery was performed in the event of positive echography, whereas negative echographic findings did not definitively discard appendicitis. The diagnostic utility of echography was evaluated by applying the Pauker-Kasirer threshold approach to clinical decision making. The influence of ultrasound upon outcome was in turn evaluated by contrasting the total appendectomized patients (190 of 374) with a series of 181 individuals subjected to appendectomy prior to the introduction of echography. The probability of appendicitis in the presence of positive echography was 0.95 in group A (sensitivity = 0.92) and 0.89 in group B (sensitivity = 0.91). The probability of appendicitis in the event of negative ultrasound was 0.58 in group A (specificity = 0.55) and 0.03 in group B (specificity = 0.95) . In 46 % of cases the echographic findings led to a change in therapeutic regimen. In addition, the incidence of negative appendectomies was significantly reduced (19.3 vs 11.6 % with echography; p = 0.03), as was the delay in establishing a diagnosis (under 6 h in 68.5 vs 84.2 % with echography; p = 0.002) and the number of medical acts required (three in 71.3 vs 84.1 % with echography; p = 0.001). There was no significant reduction in the incidence of perforated appendicitis (17.1 vs 17.9 % with echography), in the number of postoperative complications (13.8 vs 7.6 % with echography), or in the days of hospital stay (4.44 vs 4.80 with echography). Echography proved useful in group B, and was generally of little utility in group A. The technique had a positive influence on treatment, with management reorientation in a considerable number of patients, and on outcome, since ultrasound contributed to establishing an earlier diagnosis, with a reduction of unnecessary appendectomies. Received: 4 October 1999, Revised: 11 February 2000, Accepted: 17 May 2000     

Multifocal nodular fatty infiltration of the liver mimicking metastatic disease on CT: imaging findings and diagnosis using MR imaging

The aim of this study was to describe the MR appearance of multifocal nodular fatty infiltration of the liver (MNFIL) using T1-weighted in-phase (IP) and opposed-phase (OP) gradient-echo as well as T2-weighted turbo-spin-echo sequences with fat suppression (FSTSE) and without (HASTE). Magnetic resonance imaging examinations at 1.5 T using T1-weighted IP and OP-GRE with fast low angle shot (FLASH) technique, and T2-weighted FSTSE, T2-weighted HASTE of 137 patients undergoing evaluation for focal liver lesions were reviewed. Five patients were identified in whom CT indicated metastatic disease; however, no liver malignancy was finally proven. Diagnosis was confirmed by biopsy (n = 3), additional wedge resection (n = 1) or follow-up MRI 6–12 months later (n = 5). Regarding the identified five patients, the number of focal liver lesions was 2 (n = 2) and more than 20 (n = 3). The MR imaging characteristics were as follows: OP-image: markedly hypointense (n = 5); IP image: isointense (n = 2) or slightly hyperintense (n = 3); T2-weighted FSTSE-image: isointense (n = 5); T2-weighted HASTE image isointense (n = 1); slightly hyperintense (n = 4). On OP images all lesions were sharply demarcated and of almost spherical configuration (n = 5). Further evaluation by histology or follow-up MR imaging did not give evidence of malignancy in any case. Histology revealed fatty infiltration of the liver parenchyma in three patients. Magnetic resonance follow-up showed complete resolution in two patients and no change in three patients. Multifocal nodular fatty infiltration can simulate metastatic disease on both CT and MR imaging. The combination of in-phase (IP) and opposed-phase (OP) gradient-echo imaging can reliably differentiate MNFIL from metastatic disease. Received: 15 September 1999 Revised: 3 February 2000; Accepted: 7 February 2000     

Value of magnetic resonance cholangiography in benign and malignant biliary stenosis: comparative study with direct cholangiography

PURPOSE: Magnetic resonance cholangiography (MRC) is currently under investigation for imaging of biliary stenosis. The purpose of this study was to evaluate the diagnostic value of MRC compared with direct cholangiography in biliary duct diseases, with the exception of biliary-enteric anastomosis. METHOD: Forty-nine patients (26 men, 23 women; median age 60 years) with clinically suspected bile duct stenosis were prospectively included. Magnetic resonance cholangiography was performed within 7 days before direct cholangiography, considered to be the gold standard. Stenosis location, extension, and type according to Bismuth classification as well as diagnostic presumed causes were determined by 2 radiologists and 1 endoscopist. RESULTS: Magnetic resonance cholangiography correctly identified the level of biliary ductal obstruction compared with direct cholangiography findings in 96% patients. Excellent agreement between MRC and direct cholangiography was found for the stenosis location (kappa value, 0.89). Sensitivity and specificity of MRC to detect common bile duct stenosis were 88% and 100%, respectively. Sensitivity and specificity of MRC to detect biliary confluence stenosis were 96% and 93%, respectively. Precise location of the lesion according to Bismuth classification was correctly evaluated on MRC in 74% of patients (kappa value, 0.64). The overall interobserver concordance between radiologists for the level of stenosis was good (kappa value, 0.625). In 35 patients with intrahepatic bile ducts dilation identified on direct cholangiography, 97% of patients were identified on MRC. Moderate concordance between MRC and direct cholangiography was confirmed in the evaluation of the surgical management (kappa value, 0.55). CONCLUSION: Magnetic resonance cholangiography is able to replace diagnostic direct cholangiography to restrict the use of invasive procedures to cases in which therapeutic procedures are anticipated or MRC findings are equivocal, especially in biliary tract diseases.     

Rationale diagnostic approach to biliary tract imaging

Summary Since the introduction of MR cholangiography (MRC) diagnostic imaging of the biliary tract has been significantly improved. While percutaneous ultrasonography is still the primary examination, computed tomography (CT), conventional magnetic resonance imaging (MRI), as well as the direct imaging modalities of the biliary tract – iv cholangiography, endoscopic-retrograde-cholangiography (ERC), and percutaneous-transhepatic-cholangiography (PTC) are in use. This article discusses the clinical value of the different diagnostic techniques for the various biliary pathologies with special attention to recent developments in MRC techniques. An algorithm is presented offering a rational approach to biliary disorders. With further technical improvement shifts from ERC(P) to MRC(P) for biliary imaging could be envisioned, ERCP further concentrating on its role as a minimal invasive treatment option.      

Pulmonary MALT lymphoma: imaging findings in 24 cases

The aim of this study was to describe the imaging features of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma. The chest radiographs (n = 18) and CT scans (n = 17) of 24 patients (18 men and 6 women) aged 27–78 years (mean = 56 years), with a known diagnosis of pulmonary MALT lymphoma, were retrospectively reviewed by two radiologists and the imaging findings are described. Six of the 24 patients had a history of an autoimmune disorder and 1 patient had acquired immune deficiency syndrome. Multiple pulmonary lesions were identified in 19 of 24 patients (79 %) and solitary lesions in 4 of 24 patients (17 %). Diffuse pulmonary infiltration was present in 1 patient. Lesions included masses or mass-like areas of consolidation (n = 21) and pulmonary nodules (n = 18). Associated findings were air bronchograms, airway dilatation, a positive angiogram sign and a halo of ground-glass shadowing at lesion margins. Peribronchovascular thickening was also observed, as were hilar or mediastinal lymph node enlargement and pleural effusions or thickening. Although rare, the diagnosis of pulmonary MALT lymphoma should be considered in patients with the imaging features described, particularly when in association with an indolent clinical course or a history of autoimmune disease. Received: 4 October 1999; Revised: 24 February 2000; Accepted: 18 April 2000     

Rectal tumour staging: MR imaging using pelvic phased-array and endorectal coils vs endoscopic ultrasonography

The aim of this study was to compare MR imaging and endoscopic ultrasonography (EUS) for the local staging of rectal tumours. Forty-nine patients were examined on a 1.5-T MR unit using either a pelvic phased-array coil (n = 37) alone or combined with an endorectal coil (n = 12). Sagittal and axial sequences with T2-weighted fast spin-echo and axial T1-weighted spin-echo techniques were employed. The EUS technique was performed using a flexible endosonoscope. The results were compared with findings at histopathological sectioning of the specimen. The T-stage on MR correlated with histopathology in 32 of 49 patients and on EUS in 29 of 49 patients. The N-stage on MR correlated with histopathology in 22 of 49 patients and on EUS in 26 of 49 patients. Tumour penetration of the rectal wall was predicted by MR with 86 % sensitivity and 65 % specificity, and by EUS with 89 % sensitivity and 33 % specificity. Preoperative radiotherapy was administered to 40 of the patients after the examinations which may explain some of the overstaging by MR and EUS. Three patients with surgically and histopathologically confirmed invasion of neighbouring organs in the pelvis were detected preoperatively on MR but none on EUS. Tumour penetration of the rectal wall and local lymph node metastases cannot accurately be predicted with MR or EUS. Magnetic resonance, however, seems to be more useful for preoperative identification of clinically occult advanced disease. Received: 18 February 1999; Revised: 17 September 1999; Accepted: 20 September 1999     

Malignant biliary hilar stenosis: MR cholangiography compared with direct cholangiography]

AIM: To assess the diagnostic value of three-dimensional (3D) magnetic resonance cholangiography (MRC) versus direct cholangiography such as endoscopic retrograde cholangiography (ERC) and percutaneous transhepatic cholangiography (PTC) in malignant biliary stenosis. MATERIAL AND METHODS: Twenty-nine patients (15 female and 14 male) (mean age 62 years) with malignant biliary strictures underwent MRC and ERC. Breath-hold 3D steady state free precession MR cholangiography was performed on a 1.5-T imager in the patients before ERC. In 25 patients findings at ERC/PTC were considered the standard of reference: 19 patients underwent ERC, 5 PCT and 1 both ERC and PTC due to unsuccessful papilla cannulation during the endoscopic examination. In the 4 remaining patients the surgical specimen was considered the standard of reference. In the 29 patients studied, histology performed during direct cholangiography and the examination of the surgical specimens demonstrated that the malignant hilar stenoses were caused by hilar cholangiocarcinoma (n=7), cholangiocarcinoma of the distal VBP (n=1), gallbladder cancers (n=6), endometrial metastasis (n=2), ovary metastasis (n=1), colon metastasis (n=1), breast metastasis (n=1). The correct identification of biliary stenosis and extension of the tumor (according to the Bismuth classification) by MR cholangiography and ERC were independently assessed by two readers blinded to each other's report. The results were compared. RESULTS: Identification of biliary stenosis and neoplastic extension were accurate in respectively 29/29 (100%) and 26/29 (89%) cases with MR cholangiography. The comparison of ERC/PTC and MRC images yielded the following results: Bismuth Type I (6 vs 6), Type II (5 vs 8), Type III (13 vs 10), Type IV (5 vs 5). Our results indicate that MR is less capable of identifying the extension of small lesions at the primary confluence of bile ducts than are ERC/PCT. DISCUSSION AND CONCLUSIONS: MR cholangiography is a non-invasive technique for biliary tract imaging. It does not require administration of contrast medium and allows complete visualisation of the biliary ducts. MR cholangiography allowed accurate diagnosis of malignant hilar stenosis providing equal information as direct cholangiography and may therefore obviate the need for ERC/PTC.     

Esophageal lipomatosis: another consequence of the use of steroids

After we incidentally found on CT extensive esophageal fat accumulations in a patient with long-term use of steroids, we prospectively evaluated during a 6-month period all CT studies of the chest for esophageal lipomatosis and related the findings to the possible use of steroids. The diagnosis of esophageal fat on CT was made by density measurements or if too small for reliable density measurements by comparison with mediastinal fat. In 21 of 1320 exclusively older male patients the diagnosis of esophageal lipomatosis was definite in 7 and likely in 14 patients. All fat accumulations were located in the upper third of the esophagus (mean length 22 ± 6 mm) and presented ring-like (n = 10), irregular (n = 3), or as a horseshoe sparing the posterior border (n = 8). In 20 patients there was an unequivocal history of steroid treatment. Associated centripetal fat infiltration was found in 11 patients. None of the patients had swallowing problems. Prolonged use of steroids, either orally or inhalationally administered, is associated with esophageal lipomatosis. The predisposition for the upper esophagus might be related to the presence of striated muscle cells in this part of the esophagus; moreover, inhalational steroid therapy may adversely affect the upper esophagus. Received: 3 April 2000; Accepted: 2 May 2000     

Role of magnetic resonance cholangiography in biliary complications of orthotopic liver transplantation

Purpose

The aim of this study was to evaluate the role of magnetic resonance cholangiography (MRC) in the detection of biliary complications following orthotopic liver transplantation (OLT).

Materials and methods

Seventy-eight transplant patients with clinically suspected biliary complications were evaluated with 1.5-T magnetic resonance imaging (MRI) using a surface coil. All patients were imaged with the following sequences: axial T1-weighted and axial and coronal T2-weighted, 2D spin echo (SE) breath-hold radial cholangiography, and coronal 3D single-shot turbo spin echo (SS-TSE) with respiratory triggering. Patients with negative MRI underwent clinical and sonographic followup. When biliary complications were present, diagnostic confirmation was obtained by endoscopic retrograde cholangiopancreatography (ERCP) (n=13), percutaneous transhepatic cholangiography (PTC) (n=20), ultrasonography (n=10) or computed tomography (CT) (n=2). In 11 cases, surgical confirmation was also obtained.

Results

MRC detected biliary complications in 44/78 patients, in particular, 42 biliary strictures (37 anastomotic and five intrahepatic), 40 of which were confirmed by other imaging modalities. In 25/37 cases of anastomotic stricture, preanastomotic dilatation of the biliary tract was also demonstrated. Other MRC-detected biliary complications were biliary sludge (n=4), biloma (n=5), and biliary stones (n=3). In four cases, PTC revealed biliary complications that had not been detected with MRC (false negative results). In two cases, MRC showed unconfirmed strictures of the intrahepatic ducts and biliodigestive anastomosis (false positive results). The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and diagnostic accuracy of MRC were 93.5%, 94.4%, 96.7%, 89.5% and 93.9%, respectively.

Conclusions

Our results confirm that MRC is a reliable technique for depicting biliary anastomoses and detecting biliary complications after OLT. The high diagnostic accuracy of MRC indicates that this examination should be routinely employed in all OLT patients with clinically suspected biliary complications.     

Functional imaging of the thoracic outlet syndrome in an open MR scanner

Symptoms due to thoracic outlet syndrome may present only in abduction, a position that cannot be investigated in conventional MR scanners. Therefore, this study was initiated to test MRI in an open magnet as a method for diagnosis of thoracic outlet syndrome. Ten volunteers and 7 patients with a clinical suspicion of thoracic outlet syndrome were investigated at 0.5 T in an open MR scanner. Sagittal 3D SPGR acquisitions were made in 0 and 90 ° abduction. In the patients, a similar data set was also obtained in maximal abduction. To assess compression, the minimum distance between the first rib and the clavicle, measured in a sagittal plane, was determined. In the neutral position, no significant difference was found between patients and controls. In 90 ° abduction, the patients had significantly smaller distance between rib and clavicle than the controls (14 vs 29 mm; p < 0.01). On coronal reformatted images, the compression of the brachial plexus could often be visualised in abduction. Functional MR examination seems to be a useful diagnostic tool in thoracic outlet syndrome. Examination in abduction, which is feasible in an open scanner, is essential for the diagnosis. Received: 22 February 1999; Revised: 15 June 1999; Accepted: 30 June 1999     

US in blunt abdominal trauma: need to be there 24 hours a day!

Purpose: To evaluate the utility of routine abdominal ultrasound (US) as first diagnostic imaging method 24 h a day in a series of patients admitted with blunt abdominal trauma to our level II trauma center. Methods: Two thousand four hundred and eleven consecutive patients admitted after blunt abdominal trauma over 12 months were prospectively evaluated using abdominal US. The examinations were performed within 25 min after admission. An experienced senior radiologist was available on site 24 h a day (including holidays) to perform all the US examinations. The US examination included a full abdominal exploration. The US results were compared to findings at computed tomography (n = 115), clinical follow-up (n = 2244), or surgery (n = 47). Results: Overall, 2411 US abdominal studies were performed. In 5/2411 (0.2 %) patients, the US examinations were incomplete or indeterminate because of patient obesity and were therefore excluded from the study. Of the remaining 2406 US studies, 265 (11 %) were performed between 0 and 6 a.m., 770 (32 %) were performed between 6 a.m. and 12 midday, 673 (28 %) were performed between 12 midday. and 6 p.m., and the remaining 698 (29 %) were performed between 6 and 12 p.m. At US, the following post-traumatic injuries were correctly detected: 67 splenic lesions, 62 liver injuries, 13 renal contusions, 2 bowel lacerations, and 1 pancreatic injury. Nineteen patients had a sonogram with negative findings followed by CT with positive findings, while 18 patients had a sonogram with positive findings followed by CT with negative findings. The following rates were calculated for the US studies: true negative = 2224; true positive = 145; false positive = 18; false negative = 19; sensitivity = 88.4 %; specificity = 99.2 %; diagnostic accuracy = 98.2 %; positive predictive index = 88.9 %; negative predictive index = 99.1 %. Conclusion: Abdominal US provides a highly accurate, noninvasive imaging evaluation in patients who have sustained blunt abdominal trauma. This can be obtained particularly if a team of senior radiologists can perform the examination to provide high quality sonograms and be on site 24 h a day.     

Image-guided percutaneous drainage of thoracic empyema: Can sonography predict the outcome?

The aim of this study was to assess the safety and efficacy of image-guided percutaneous catheter drainage (IGPCD) of thoracic empyemas, and to correlate the outcome of IGPCD with the pre-procedural sonographic appearance. One hundred three patients (74 males and 29 females) with thoracic empyema (age range 1 month to 70 years, median age 28 years) underwent IGPCD. In 63 (61.17 %) patients, IGPCD was the primary treatment modality; in 40 (38.84 %) patients it was used after unsuccessful intercostal chest tube drainage (ICTD). Ultrasound was the main modality used for guidance; CT guidance was used in only 7 patients (6.8 %). Eight- to 12-F pigtail catheters or 10- to 14-F Malecot catheters were used. The outcome was correlated with the pre-procedural US appearance (anechoic, complex non-septated or complex septated) of the empyema. The IGPCD technique was successful in 80 of 102 patients. Based on the US appearance, IGPCD was successful in 12 of 13 (92.3 %) patients with anechoic empyemas; 53 of 65 (81.54 %) patients with complex non-septated empyemas, and in 15 of 24 (62.5 %) patients with complex septated empyemas. A statistically significant difference (p < 0.01) was seen in the outcome of IGPCD in the three categories. Twenty-two patients required further treatment: ICTD (n = 9; 2 of them later also underwent surgery); and surgery (n = 15). The duration of catheter drainage ranged from 2–60 days. No major complications were encountered. Percutaneous catheter drainage of thoracic empyemas with imaging guidance ensures accurate catheter placement with a high success and a low complication rate. Pre-procedural US can predict the likelihood of success of IGPCD. Received: 16 September 1998; Revision received: 6 January 1999; Accepted: 9 June 1999     

Diagnosing biliary complications of orthotopic liver transplantation with mangafodipir trisodium-enhanced MR cholangiography: comparison with conventional MR cholangiography

OBJECTIVE: This study was designed to determine whether the addition of mangafodipir trisodium-enhanced MRI could improve the image quality, visualization of ductal structures, and diagnostic confidence provided by conventional T2-based MR cholangiography (MRC) in patients with suspected biliary complications after orthotopic liver transplantation. SUBJECTS AND METHODS. Our study group consisted of 25 consecutive patients who were referred for MR evaluation of clinically suspected biliary complications after orthotopic liver transplantation. Conventional MRC in the axial and coronal planes was performed in each patient, followed by fat-suppressed volumetric gradient-echo imaging in the same planes both before and after the IV administration of mangafodipir trisodium. Imaging was performed in all patients until the contrast agent was seen in the bowel. Images were then graded for quality, visualization of bile ducts and anastomoses, presence of significant stricture or leak, and level of diagnostic confidence. RESULTS: Mangafodipir trisodium-enhanced MRC tended to outperform conventional MRC in overall image quality and extrahepatic duct visualization; it was also more effective in delineating biliary anastomoses, and the difference was statistically significant (p < 0.001). All 25 enhanced examinations were considered diagnostic. Diagnostic confidence was scored as poor or lacking in 14 of the conventional MRC examinations for biliary stenosis and in 12 examinations for biliary leak. CONCLUSION: Enhancement with mangafodipir trisodium improves the performance of MRC for the detection and exclusion of biliary abnormalities after orthotopic liver transplantation. Future investigations should compare the performance of mangafodipir trisodium-enhanced MRC with the performance of more invasive techniques.     

Imaging in ureteral complications of renal transplantation: value of static fluid MR urography

Ureteral obstruction is an infrequent complication after renal transplantation that may cause rapid loss of transplant function. We tested static fluid MR urography for determining the cause of graft hydronephrosis. Magnetic resonance urography was performed in nine transplants with dilated collecting systems on ultrasound. A heavily T2-weighted 3D turbo spin-echo sequence on a 1.5-T scanner was used and maximum intensity projections were obtained. The patients also underwent excretory urography (n = 1), renal scintigraphy (n = 1), antegrade pyelography (n = 3), voiding cystourethrography (n = 4), and non-enhanced CT (n = 2). Six patients had pathologic conditions including ureteral stricture, compression by lymphoceles, implantation stenosis, vesicoureteral reflux, and late-occurring transitional cell carcinoma at the implantation site. Static MRU was able to diagnose or exclude a dilation of the graft collecting system. It visualized the course of the ureters and localized the obstruction site in four of five obstructed transplants. In one case the ureter was obscured by lymphoceles, which were demonstrated by hydrographic MRU as well. The definite cause for obstruction was provided in only 2 of 5 cases. Dilation due to vesicoureteral reflux could not be differentiated. The current multimodality approach to renal transplant imaging already provides comprehensive assessment of graft hydronephrosis. Static MRU may be useful in some cases since complications associated with intravenous iodinated contrast or antegrade pyelography can be avoided. Its main drawback, the lack of functional information, may be overcome by combining it with contrast-enhanced MRU. Received: 18 February 1999; Revised: 23 July 1999; Accepted: 18 November 1999