Expanding role of percutaneous cholecystostomy and interventional radiology for the management of acute cholecystitis: An analysis of 144 patients.

PURPOSE: To investigate the rates of interval cholecystectomy and recurrent cholecystitis after initial percutaneous cholecystostomy (PC) and identify predictors of patient outcome after PC. MATERIALS AND METHODS: A total of 144 patients with acute cholecystitis who were treated with PC were included. There were 96 men and 48 women, with a mean age of 71±13 (SD) years (range: 25-100 years). Patient characteristics, diagnostic imaging studies and results of laboratory tests at initial presentation, clinical outcomes after the initial PC treatment were reviewed. RESULTS: Among the 144 patients, 56 patients were referred for acute acalculous and 88 patients for calculus cholecystitis. Five procedure-related major complications (3.6%) were observed including bile peritonitis (n=3), hematoma (n=1) and abscess formation (n=1). Recurrent acute cholecystitis after initial clinical resolution and PC tube removal was observed in 8 patients (6.0%). The rate of interval cholecystectomy was 33.6% (47/140) with an average interval period of 100±482 (SD) days (range: 3-1017 days). PC was a definitive treatment in 85 patients (60.7%) whereas 39 patients (27.9%) had elective interval cholecystectomy without having recurrent cholecystitis. The clinical outcomes after PC did not significantly differ between patients with calculous cholecystitis and those with acalculous cholecystitis. Multiple prior abdominal operations were associated with higher rates of recurrent cholecystitis. CONCLUSION: For both acute acalculous and calculous cholecystitis, PC is an effective and definitive treatment modality for more than two thirds of our study patients over 3.5-year study period with low rates of recurrent disease and interval cholecystectomy.

Analysing the response in R2* relaxation rate of intracranial tumours to hyperoxic and hypercapnic respiratory challenges: initial results.

OBJECTIVE: To investigate the response in R2* relaxation rate of human intracranial tumours during hyperoxic and hypercapnic respiratory challenges. METHODS: In seven patients with different intracranial tumours, cerebral R2* changes during carbogen and CO(2)/air inhalation were monitored at 3 T using a dynamic multigradient-echo sequence of high temporal and spatial resolution. The R2* time series of each voxel was tested for significant change. Regions of interest were analysed with respect to response amplitude and velocity. RESULTS: The tumours showed heterogeneous R2* responses with large interindividual variability. In the 'contrast-enhancing' area of five patients and in the 'non-tumoral' tissue most voxels showed a decrease in R2* for carbogen. For the 'contrast-enhancing' area of two patients hardly any responses were found. In areas of 'necrosis' and perifocal 'oedema' typically voxels with R2* increase and no response were found for both gases. For tissue responding to CO(2)/air, the R2* changes were of the same order of magnitude as those for carbogen. The response kinetic was generally attenuated in tumoral tissue. CONCLUSION: The spatially resolved determination of R2* changes reveals the individual heterogeneous response characteristic of intracranial human tumours during hyperoxic and hypercapnic respiratory challenges.

Gated multidetector computed tomography. A technique to reduce intracranial aneurysm clip and coil artifacts.

BACKGROUND AND PURPOSE: Streak artifacts caused by aneurysm clips and coils impede image quality in multidetector computed tomography (MDCT). The authors propose a technique to minimize these artifacts by gated data reconstruction and shifting the reconstruction window. PATIENTS AND METHODS: Intracranial CT angiograms were acquired in the follow-up of six patients with clipped and coiled intracranial aneurysms, respectively. Images were reconstructed from four consecutive 45 degrees rotated segments with an acquisition time of 52.5 ms/segment. Data acquisition was gated via an external pacemaker cable-connected to the scanner. RESULTS: Artifact orientation could be rotated by shifting the reconstruction window and interesting vessel segments visualized without disturbing streak artifacts. This allowed to assess the posterior communicating artery origin in two cases and a middle cerebral artery aneurysm remnant in another case, respectively. However, due to a higher noise interesting vessel segments were not adjustable in another three patients. CONCLUSION: Gated MDCT is a promising technique to reduce the amount and to change the position of artifacts induced by clips or coils.

Short-term effects of transjugular intrahepatic shunt on cardiac function assessed by cardiac MRI: preliminary results.

The purpose of this study was to assess shortterm effects of transjugular intrahepatic shunt (TIPS) on cardiac function with cardiac magnetic resonance imaging (MRI) in patients with liver cirrhosis. Eleven patients (six males and five females) with intractable esophageal varices or refractory ascites were imaged with MRI at 1.5 T prior to, within 24 h after, and 4-6 months after TIPS creation (n = 5). Invasive pressures were registered during TIPS creation. MRI consisted of a stack of contiguous slices as well as phase contrast images at all four valve planes and perpendicular to the portal vein. Imaging data were analyzed through time-volume curves and first derivatives. The portoatrial pressure gradient decreased from 19.8 + or = 2.3 to 6.6 + or = 2.3, accompanied by a nearly two fold increase in central pressures and pulmonary capillary wedge pressure immediately after TIPS creation. Left and right end diastolic volumes and stroke volumes increased by 11, 13, and 24%, respectively (p\0.001), but dropped back to baseline at follow-up. End systolic volumes remained unchanged. E/A ratios remained within normal range. During follow-up the left ventricular mass was larger than baseline values in all patients, with an average increase of 7.9 g (p\0.001). In conclusion, the increased volume load shunted to the heart after TIPS creation transiently exceeded the preload reserve of the right and left ventricle, leading to significantly increased pulmonary wedge pressures and persistent enlargement of the left and right atria. Normalization of cardiac dimensions was observed after months together with mild left ventricular hypertrophy.

Metastasis to pituitary adenoma: case report and review of the literature.

We present a rare case of a metastasis to a pituitary adenoma and review 14 cases published in the literature to date. Metastases to pituitary adenomas most commonly present with rapidly progressing chiasm compression syndromes, headaches and oculomotor nerve palsies. The prognosis for this condition is poor. Metastases to pituitary adenomas have to be considered in the differential diagnosis of sellar tumors.

Visualization of the Adamkiewicz artery in patients with acute stanford a dissections: a prospective 64-row multi-detector CT study.

PURPOSE: To evaluate the detectability of the Adamkiewicz artery (AA) in patients with acute Stanford type A aortic dissections with multi-detector computed tomography (MDCT). MATERIALS AND METHODS: 51 patients with Stanford type A dissection underwent contrast-enhanced 64-row MDCT of the entire aorta (collimation 64 x 0.625 mm; rotation time 0.4sec; 120 kV; 300 mAs). The visualization of the AA, its origin, and whether it originated from the true or false lumen were analyzed using source and multiplanar reformation images. RESULTS: A single anterior radicular artery that formed a hairpin turn constituting the anterior spinal artery was visualized in 36 (70 %) patients. Thirty (83 %) of these arteries originated from the left side, and 35 (97 %) originated between the level T 7 and L 2. Twenty-three (64 %) arteries originated from the true and 13 (36 %) from the false lumen. Two AAs in the same patient were not observed. CONCLUSION: MDCT depicts the AA in a high percentage of patients with acute Stanford type A aortic dissection.

[The role of superselective transcatheter arterial embolisation in management of complications after kidney surgery]. / Radiologisch-interventionelle superselektive Embolisation - universeller Einsatz bei verschiedensten Blutungskomplikationen nach renaler Chirurgie.

PURPOSE: Transcatheter arterial embolisation (TAE) is replacing open procedures in terms of vascular malformations or traumatic haemorrhage. Furthermore, the role of TAE is established in post-surgery bleeding complications. We report on a number of patients with severe haemorrhage after kidney surgery and successful management by TAE. MATERIALS AND METHODS: Gross renal haemorrhage was observed after pyelocalicolithotomy and open kidney-sparing surgery. One patient developed a large arteriovenous fistula after kidney transplantation preceded by open biopsy. Technique of TAE: In all cases the bleeding vessel was located by transfemoral arteriography. Embolisation was performed by dropping platinum coils or gelfoam pellets. RESULTS: TAE stopped the haemorrhage in all patients and occluded the arteriovenous fistula in the renal allograft. No complications were observed. CONCLUSION: TAE can be considered as the treatment of choice for a widespread range of complications after kidney surgery. It should always be taken into consideration before open surgical revision.

Three-dimensional time-of-flight MR angiography at 3 T compared to digital subtraction angiography in the follow-up of ruptured and coiled intracranial aneurysms: a prospective study.

INTRODUCTION: Since digital subtraction angiography (DSA) carries a low risk of morbidity, and is associated with patient discomfort and higher cost, our objective was to determine whether high-resolution 3-D time-of-flight MR angiography (TOF-MRA) at 3 T may replace DSA in the follow-up of patients after coiling of an intracranial aneurysm. METHODS: This prospective study included 50 consecutive patients with a ruptured and subsequently coiled intracranial aneurysm. All patients were followed up at a mean of 14 months after coiling with DSA and high-resolution 3-D TOF-MRA at 3 T generating 0.02 mm3 isotropic voxels. One examiner used DSA and TOF-MR angiograms to assess the need for and risk of retreatment; these data were used to calculate intermodality agreement. Another two examiners independently assessed aneurysm occlusion by DSA and TOF-MRA according to the Raymond scale; these data were used to calculate interobserver agreement. RESULTS: Discrepancies between DSA and TOF-MRA were found in three patients (intermodality agreement kappa=0.86). While DSA indicated complete aneurysm occlusion, TOF-MRA showed small neck remnants in the three patients. Coils on all DSA projections obscured these three neck remnants. Interobserver agreement was higher for DSA (kappa=0.82) than for TOF-MRA (kappa=0.68), which was in part due to the complexity of the information provided by TOF source images and reconstructions. CONCLUSION: 3-D TOF-MRA at 3 T is not only an adjunctive tool but is ready to replace DSA in the follow-up of patients with previously coiled intracranial aneurysms. Additional DSA may only be performed in complex and not clearly laid out aneurysms.

Diffusion tensor pyramidal tractography in patients with anterior choroidal artery infarcts.

BACKGROUND AND PURPOSE: Anterior choroidal artery (AchoA) stroke often evolves into undulating hemipareses, which sometimes progress to high-grade hemiparesis or hemiplegia but may also completely regress. Spatial relationships of AchoA infarcts to corticospinal tracts (CSTs) and CST integrity were investigated with diffusion tensor imaging (DTI) to identify prognostic parameters related to diffusion anisotropy changes in AchoA stroke. MATERIALS AND METHODS: Twenty-five AchoA stroke patients were prospectively examined with 3T DTI and diffusion tensor tractography (DTT) within a 3-day mean interval after onset. Analysis included the following: 1) stroke size on diffusion-weighted imaging; 2) fractional anisotropy (FA) and apparent diffusion coefficients at the largest stroke extents versus contralateral homologous structures; 3) lesion location related to CST ("involvement"); 4) amount of fiber trajectories of affected versus nonaffected CST ("fiber ratio"); and 5) presence of ipsilateral fiber disruption. Imaging findings were related to clinical status 3 months after symptom onset with respect to favorable, moderate, or unfavorable motor outcome. RESULTS: FA differences (due to FA reduction in the affected versus nonaffected hemisphere) were significantly higher for patients with unfavorable outcome (P=.03). Patients with favorable outcome had nearly symmetrical FA. CSTs were involved in ischemic lesions in all but 2 patients (complete involvement, n=3; partial, n=20). Two CSTs were completely disrupted, and both patients were hemiplegic (no disruption, n=14; partial disruption, n=9). Fiber disruption and CST involvement correlated negatively with motor score after AchoA stroke (P < .01), whereas infarct size did not. CONCLUSION: DTT may explain resulting motor dysfunction in patients with AchoA infarcts with more notably decreased FA being an indicator for unfavorable outcome.

Somatostatin receptor scintigraphy in the follow-up of myasthenia gravis.

To evaluate the potential value of somatostatin receptor scintigraphy (SRS) using 111In-DTPA (diethylenetriaminepenta acetic acid)-D-Phe1-octreotide (111In-pentetreotide) in patients with recurring or persisting symptoms of myasthenia gravis (MG), 14 consecutive cases with such supplemental receptor imaging during neurological routine follow-up were retrospectively evaluated in this study. All 14 patients underwent SRS in addition to chest computed tomography (CT). Mean follow-up after imaging was 34 months. Eight patients had previous thymectomy, and three patients were referred to surgery after scintigraphy and chest CT. SRS was positive in one of the 14 patients with local recurrence of thymoma and pleural invasion, and negative in the remaining 13 patients. CT was positive for thymoma in three patients, inconclusive in four patients and negative in seven patients. In conclusion, while SRS may be able to detect thymoma lesions including metastases, it seems of limited value in patients with inconspicuous CT findings. Our initial experience fails to point out a benefit of SRS in the management of persisting or recurring MG (with regard to detection of thymic disorders) compared to CT. Whether SRS is useful for differentiating thymoma from non-neoplastic thymic disease may be investigated by larger series. A predominant proportion of patients with unsatisfactory treatment response, however, continue to suffer an unfavourable clinical course despite absent evidence for thymic pathology.

[CT coronary angiography in patients with atrial fibrillation]. / CT-Koronarangiographie bei Patienten mit Vorhofflimmern.

PURPOSE: Reliable visualization of the coronary arteries with multislice spiral CT angiography (MSCTA) in patients with atrial fibrillation (AF) remains a challenge despite retrospective ECG gating. A recently developed new algorithm automatically compensates dynamic changes in the heart rate during the scan, thus reducing misregistration and motion artifacts. The HeartBeat-RT algorithm combines a fixed-percent delay determined from the first R wave and the fixed offset delay based on the second R wave in the ECG cycle. The purpose of this study was to find out the optimal reconstruction window in MSCTA in patients with AF for each of the three major coronary arteries during the cardiac cycle. MATERIALS AND METHODS: 20 patients with permanent AF were imaged on a 16-slice scanner (slice collimation: 16 x 0.75 mm; rotation time 0.42 s; 140 kV; 380 mAs; 120 ml Ultravist 370 (R) i.v.). The patients had not received any previous drugs for heart frequency regulation. Acquisition was started after bolus tracking of a biphasic bolus of 120 ml Ultravist 370 injected intravenously. Each coronary segment was reconstructed at 0 % - 90 % of the cardiac cycle in increments of 10 %. For image analysis we used coronary segments as defined by the American Heart Association. Two blinded independent readers assessed the image quality in terms of visibility and artifacts (five-point rating scale 1 = very poor, 2 = poor, 3 = fair, 4 = good and 5 = excellent) and the degree of stenosis (five-point rating scale 1 = 0 %, 2 = 1 % - 49 %, 3 = 50 % - 74 %, 4 = 75 % - 99 %, 5 = 100 %) on axial slices, multiplanar reconstructions and three-dimensional volume-rendered images. RESULTS: The heart rate during examination ranged between 42 and 156 beats per minute, the average heart rate was 78 +/- 23. Each of the two readers evaluated 300 segments in 20 patients. Visualization of all coronary artery segments was superior at 40 % (mean score of the image quality 2.79) as compared to the standard diastolic reconstruction window at 80 % (image quality 2.33). The second best image quality (2.57) was acquired at 0 % of the cardiac cycle. CONCLUSION: The use of a frequency adapted delay algorithm with the choice of an end-systolic reconstruction window provided diagnostically valuable images in patients with AF.

[Radiologic features of inflammatory pseudotumors]. / Radiologische Befunde bei inflammatorischen Pseudotumoren.

Inflammatory pseudotumor is a rare benign tumor entity. Because inflammatory pseudotumors mimic malignant tumors both clinically and radiologically, the radiologist should be familiar with this entity. Inflammatory pseudotumor most commonly involves the lung and the orbit, but it has been reported to occur in nearly every site in the body. For making a definite diagnosis a biopsy is often essential. The treatment options are varied and consist of surgery, high-dose steroids, irradiation, and chemotherapeutics.

[Budd-Chiari syndrome in a patient with paroxysmal nocturnal haemoglobinuria]. / Budd-Chiari-Syndrom bei einem Patienten mit paroxysmaler nächtlicher Hämoglobinurie.

HISTORY AND CLINICAL FINDINGS: A 61-year-old man with dyspnea and diffuse abdominal pain due to increasing ascites caused by liver cirrhosis of unknown etiology was admitted for consideration of transjugular intrahepatic portosystemic stent-shunting (TIPSS). The patient's medical history included paroxysmal nocturnal hemoglobinuria (PNH), presenting as slight hemolysis diagnosed 24 years previously. One year before the patient underwent radical retropubic prostatectomy for a localized prostate cancer. Shortly after this intervention he developed ascites. INVESTIGATIONS: Color Doppler ultrasonography revealed an abnormal flow in the major hepatic veins. Transjugular liver biopsy indicated hepatic a circulatory disorder. Hepatic venography revealed the so-called "spider web" pattern characteristic for the Budd-Chiari syndrome. The hypercoagulable state due to paroxysmal nocturnal hemoglobinuria was accentuated by manipulation on the prostate during prostatectomy and presumably resulted in a thrombotic obstruction of the hepatic veins. TREATMENT AND CLINICAL COURSE: After exclusion of contraindications a transjugular intrahepatic portosystemic stent shunt (TIPSS) was performed, which led to a decrease of portal pressure. Signs of portal hypertension such as esophageal varices and ascites resolved completely. The patient has been free of complaints for one year. CONCLUSION: We assume that a hypercoagulopathy due to asymptomatic paroxysmal nocturnal hemoglobinuria resulted in Budd-Chiari syndrome when boosted by postoperative release of procoagulation factors in the thrombokinase-rich prostate. TIPSS is a therapeutic option in these patients.

[Combined FDG PET/CT imaging for restaging of colorectal cancer patients: impact of image fusion on staging accuracy]. / PET-CT in der Nachsorge des kolorektalen Karzinoms: Einfluss der Bildfusion auf die Staginggenauigkeit.

PURPOSE: To evaluate the diagnostic impact of positron emission tomography (PET) with fluorine-18-labeled deoxy-D-glucose (FDG) combined with non-contrast computed tomography (CT) as PET-CT modality in restaging colorectal cancer patients. MATERIAL AND METHODS: In this retrospective study, 29 consecutive patients with histologically proven colorectal cancer (17 female, 12 male, aged 51-76 years) underwent whole body scans in one session on a dual modality PET-CT system (Siemens Biograph) 90 min. after i.v. administration of 370 MBq 18F-FDG. The CT imaging was performed with 40 mAs, 130 kV, slice-thickness 5 mm and without i.v. contrast administration. PET and CT images were reconstructed with a slice-thickness of 5 mm in coronal, sagittal and transverse planes. During a first step of analysis, PET and CT images were scored blinded and independently by a group of two nuclear medicine physicians and a group of two radiologists, respectively. For this purpose, a five-point-scale was used. The second step of data-analysis consisted of a consensus reading by both groups. During the consensus reading, first a virtual (meaning mental) fusion of PET and CT images and afterwards the "real" fusion (meaning coregistered) PET-CT images were also scored with the same scale. The imaging results were compared with histopathology findings and the course of disease during further follow-up. RESULTS: The total number of malignant lesions detected with the combined PET/CT were 86. For FDG-PET alone it was n = 68, and for CT alone n = 65. Comparing PET-CT and PET, concordance was found in 81 of 104 lesions. Discrepancies predominantly occurred in the lung, where PET alone often showed true positive results in lymph nodes and soft tissue masses, where CT often was false negative. Comparing mental fusion and "real" co-registered images, concordance was found in 94 of 104 lesions. In 13 lesions or, respectively, in 7 of 29 patients, a relevant information was gathered using fused images. CONCLUSION: Combined PET/CT leads to greater accuracy in the interpretation of data and is a valuable tool for diagnosis and anatomic localization of metastases in colorectal cancer patients.

[The value of applying nitroglycerin in 3D coronary MR angiographie with real-time navigation technique]. / Wert der Applikation von Nitroglycerin bei der 3D-MR-Koronarangiographie mit Echtzeit-Navigatortechnik.

PURPOSE: Nitroglycerin administration results in dilation of epicardial coronary vessels and in an increase in coronary blood flow, and has been suggested to improve MR coronary angiography. This study evaluates systematically whether administration of nitroglycerin improves the visualization of coronary arteries and, as a result, the detection of coronary artery stenosis during free breathing 3D coronary MR angiography. MATERIALS AND METHODS: Coronary MR angiography was performed in 44 patients with suspected coronary artery disease at a 1.5 Tesla System (Intera, Philips Medical Systems) (a) with and (b) without continuous administration of intravenous nitroglycerin at a dose rate of 2.5 mg/h, using an ECG gated gradient echo sequence with real-time navigator correction (turbo field echo, in-plane resolution 0.70 x 0.79 mm(2), acquisition window 80 ms). Equivalent segments of the coronary arteries in the sequences with and without nitroglycerin were evaluated for visualized vessel length and diameter, qualitative assessment of visualization using a four point grading scale and detection of stenoses > 50 %. Catheter coronary angiography was used as a gold-standard. RESULTS: No significant differences were found between scans with and without nitroglycerin as to average length of the contiguously visualized vessel length (p > 0.05) and diameter (p > 0.05). There was also no significant difference in the coronary MR angiography with and without nitroglycerin in the average qualitative assessment score of the visualization of LM, proximal LAD, proximal CX, and proximal and distal RCA (2.1 +/- 0.8 and 2.2 +/- 0.7; p > 0.05). Sensitivity (77 % [17/22] vs. 82 % [18/22] p > 0.05) and specificity (72 % [13/18] vs. 72 % [13/18] p > 0.05) for the detection of coronary artery stenosis also did not differ significantly between scans with and without intravenous administration of nitroglycerin. CONCLUSION: Administration of nitroglycerin does not improve visualization of the coronary arteries and detection of coronary artery stenosis in free breathing 3D coronary MR angiography.

[Diagnostic imaging of vascular leiomyosarcomas]. / Bildgebende Diagnostik von vaskulären Leiomyosarkomen.

Primary vascular leiomyosarcomas are very rare tumors, with the venous variety most often arising from the inferior caval vein and the arterial variety from the pulmonary artery. The tumors show either an exclusive intra- or extravascular pattern or a mixed growth pattern. The clinical symptoms depend on tumor location, with intraluminal tumors of the inferior caval vein causing edema or a Budd-Chiari syndrome. Leiomyosarcomas of the pulmonary artery can mimic chronic central or recurrent peripheral pulmonary embolism. Contrast enhanced spiral CT with multiplanar reconstruction is the diagnostic method of choice when a vascular leiomyosarcoma is suspected. MRI with MR-angiography can be added. If a tumor of undetermined origin shows a broad contact with a vessel and/or an intraluminal component, possible primary vascular leiomyosarcoma should be included in the differential diagnosis.

Three-dimensional magnetic resonance cholangiopancreatography with respiratory triggering in the diagnosis of primary sclerosing cholangitis: comparison with endoscopic retrograde cholangiography.

BACKGROUND AND STUDY AIMS: The purpose of this study was to evaluate the accuracy of respiratory-triggered three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP) for the detection of primary sclerosing cholangitis (PSC) and to compare the specific findings of magnetic resonance cholangiography and endoscopic retrograde cholangiography in patients with PSC. PATIENTS AND METHODS: The MRCP findings were evaluated in 150 patients with clinical symptoms (progressive fatigue, pruritus followed by icterus) and/or elevated values for alkaline phosphatase and serum aspartate transaminase, and occasionally an elevated serum concentration of bilirubin as a sign of cholestasis, who were consecutively referred for magnetic resonance imaging. Two observers independently classified bile duct abnormalities and established the MRCP diagnosis in a consensus reading. The results of MRCP were compared with the definitive diagnosis, which was based on the clinical history and laboratory and histological data, as well as on endoscopic retrograde cholangio-pancreatography (ERCP) findings. In a second step, the observers compared the delineation of the biliary system and morphological findings using MRCP and ERCP in patients with confirmed PSC. RESULTS: Diagnostic examinations were obtained in 146 of the 150 MRCPs (97 %). The diagnosis of PSC was confirmed by clinical data and ERCP in 34 of these 150 patients (23 %). The sensitivity and specificity of MRCP for diagnosing PSC were 88 % (29 of 33) and 99 % (108 of 109), respectively. MRCP and ERCP yielded similar scores for the delineation of the biliary system (P = 0.2) in patients with PSC. However, different bile duct abnormalities leading to the diagnosis of PSC were depicted by MRCP and ERCP; more bile duct stenoses and pruning were seen with ERCP and more skip dilatation with MRCP (P < 10(-4)). CONCLUSION: In patients with PSC, MRCP is a highly sensitive method and its diagnostic accuracy is comparable to that of ERCP.