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PURPOSE: To determine the most efficacious dose of gadodiamide for three-dimensional (3D) contrast-enhanced (CE) magnetic resonance angiography (MRA) of the renal arteries on a patient level based on the sensitivity in detecting the main hemodynamically relevant (> or =50% or occlusion) renal artery stenosis (RAS) using intra-arterial digital subtraction angiography (IA DSA) as the gold standard. MATERIALS AND METHODS: This prospective, randomized, double-blind, parallel-group, multicenter study included 273 patients referred to IA DSA for suspected RAS. Patients underwent 3D CE MRA after injection of 0.01, 0.05, 0.1, or 0.2mmol/kg of body weight gadodiamide (0.5mmol/ml). The images were assessed for location and degree of RAS by independent blinded readers (MRA: three readers, IA DSA: one reader). Hypothesis testing for a significant trend in sensitivity across dose groups was based on the one-sided Cochran-Armitage style trend test for each independent MRA reader. RESULTS: The lowest dose group (0.01mmol/kg) proved non-efficacious in detecting hemodynamically relevant (i.e., > or =50% or occlusion) RAS. A statistically significant dose trend (p<0.001) was shown for each of the three independent readers. Depending on reader, the sensitivity obtained with 0.05, 0.1, and 0.2mmol/kg was 63.9-86.1%, 75.8-91.4% and 80.6-90.6%, the specificity was 66.7-73.9%, 59.3-75.0%, and 59.3-75.0% and accuracy was 67.8-78.9%, 75.4-77.4%, and 76.3-81.0%, for the three dose groups, respectively. There were eight non-severe adverse events (AEs). Three serious AEs occurring in one patient were judged not related to gadodiamide by the on-site investigator. CONCLUSION: A significant dose trend between the four doses examined was observed. The lowest dose (0.01mmol/kg) differed significantly from those of the other three doses. Based on the analysis of the primary and secondary endpoints, 0.1mmol/kg gadodiamide appears to be the most suitable dose in diagnosing hemodynamically relevant RAS. The present study also demonstrated gadodiamide to be safe and well tolerated.

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BACKGROUND: Atherosclerotic renal artery stenosis (RAS) is frequently treated by angioplasty and stent placement. Duplex sonography is an established noninvasive technique for patient follow-up. There is lack of evidence that routine monitoring of asymptomatic patients with stable blood pressure is needed. METHODS: Renal duplex sonography was performed in 64 patients who had received percutaneous angioplasty and stenting of an atherosclerotic RAS. Duplex sonographic diagnosis was made by a combination of direct flow measurement in the renal artery and evaluation of intrarenal resistive indices. Renal function was determined by serum creatinine and calculated glomerular filtration rate (GFR). RESULTS: With a mean follow-up of 28 months after angioplasty, a flow velocity of >2.0 m/s was detected within the stented arteries in 11/64 patients. While the initial blood pressure and GFR as well as the influence of angioplasty on these parameters were not different, the decrease in renal function over time was significantly higher in patients with flow enhancement (annual GFR decrease, 8.0 ml/min vs. 0.8 ml/min; p < 0.05). CONCLUSION: Follow-up duplex sonography in patients after renal artery stenting detected an unexpectedly high rate of in-stent restenosis associated with enhanced loss of renal function. Routine duplex sonographic follow-up may detect patients at risk of more rapidly declining renal function.

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INTRODUCTION: To correlate cross sections of the intercondylar notch to cross sections of the anterior cruciate ligament (ACL) and to analyze gender-related differences in notch and ACL morphometry with an attempt to explain the observation that a small intercondylar notch and the female gender predispose to a rupture of the ACL. MATERIAL AND METHODS: High resolution MR imaging was performed on a 1.5 T magnet using a dedicated extremity-coil in ten left and ten right knee joints of 20 volunteers (10 male, 10 female, mean age 25 years) with no history of knee abnormalities. Continuous axial T2-weighted MR images perpendicular to the longitudinal axis of the ACL were acquired. Cross-sectional areas of the ACL midsubstance at the contact area to the posterior cruciate ligament were measured. For imaging and evaluation of the osseous limits of the intercondylar notch a 3D-dataset of the knee was acquired. Anterior, middle and posterior planes of the intercondylar notch were calculated and analyzed for measurement of the notch area AN and notch width index NWI. The ratio of the ACL cross-sectional area of the ACL and the cross-sectional area of the notch was defined as the ACL notch index (ANI) and used as a standardized tool for evaluation. For statistical evaluation, linear regression analysis was performed. Mean values between male and female were compared using a t test. In addition, five matched pairs of male and female volunteers of same height were analyzed. RESULTS: Mean cross-sectional size of the ACL at the crossing with the PCL was 54.4 +/- 20.4 mm2. Regression analysis showed a significant correlation (P < 0.05) of the ACL cross-sectional area to the notch areas on all three planes and NWI, respectively. Comparison between the sexes revealed that female participants had significantly smaller cross-sectional areas of the ACL, the notch areas, the NWI and ANI. This difference was found for both the complete study group and the matched pairs of same height. CONCLUSIONS: The smaller the intercondylar notch the smaller the cross-sectional area of the ACL midsubstance. In addition to the impingement of the ACL at the anterior and posterior roof of the notch, a biomechanically weaker ACL may be the reason for disposition to an ACL rupture in patients with a small intercondylar notch. Women have a thinner ACL midsubstance than men of the same height which may be one of the critical etiologic factors that predispose women to an ACL rupture.

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Bronchiectasis is defined as localized irreversible dilatation of the bronchial tree. Brochiectasis has been associated with a wide variety of causes, but it is mostly caused by acute, chronic or recurrent infections. This paper should give a review about the manifestation of bronchiectasis and bronchioloectasis in HR-CT and discuss the causing entities. However, integration of bronchiectasis and other HR-CT findings may enable a narrower differential diagnosis, in some cases it is possible to give the correct diagnose directly.

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Nevoid Basal Cell Carcinoma Syndrome (NBCCS) is an autosomal-dominant disorder characterized by multiple basal cell carcinomas, jaw cysts, palmar/plantar pits, calcification of the falx cerebri, and spine and rib anomalies. The combination of clinical, imaging, and histological findings is helpful in identifying NBCCS patients. Imaging plays a crucial role in evaluation of these patients. We present a wide variety of clinical and radiological findings characteristic of this disease.

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Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to be a rare complication of pulmonary embolism. However, it was recently demonstrated that CTEPH is more common than previously thought after pulmonary embolism. Without treatment, CTEPH is associated with a very high mortality rate. Making the correct diagnosis early is essential, because there is a potential curative treatment in the form of pulmonary thromboendarterectomy (PTE). Because of the unspecific clinical symptoms of CTEPH, the different imaging modalities play a crucial role in diagnosis making. Since the introduction of the multidetector CT technology, CT has become an important part in the diagnostic work up of pulmonary embolism and CTEPH and is often used as a first-line diagnostic tool. CT is not only a reliable tool for the diagnosis of CTEPH, but also is helpful in estimating the operability of these patients. PTE is still associated with a mortality rate of about 10%. Particularly an insufficient decrease of the pulmonary vascular resistance after PTE leads to a very high mortality rate. Therefore, it is crucial to correlate the degree of the surgical accessible obstruction of the pulmonary vasculature with the degree of pulmonary hypertension in deciding for or against PTE. The aim of this review is to describe the CT findings in patients with CTEPH and their use in differentiating CTEPH from other diseases like acute pulmonary embolism and primary pulmonary hypertension. Moreover, the correlation of different CT imaging features with surgical success after PTE will be discussed.

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STUDY OBJECTIVES: The aim was to correlate CT scan findings with hemodynamic measurements in patients who had undergone pulmonary thromboendarterectomy (PTE) and to evaluate whether CT scan findings can help to predict surgical outcome. PATIENTS AND METHOD: Sixty patients who underwent PTE and preoperative helical CT scanning were included. Preoperative and postoperative hemodynamics were correlated with preoperative CT imaging features. RESULTS: The diameter of the main pulmonary artery (PA) and the ratio of the PA and the diameter of the ascending aorta correlated with preoperative mean pulmonary artery pressure (PAP) [r = 0.42; p < 0.001; and r = 0.48; p < 0.0001, respectively]. There was a significant correlation of subpleural densities with preoperative pulmonary vascular resistance (PVR) [r = 0.44; p < 0.001] and of the number of abnormal perfused lobes with preoperative PAP (r = 0.66; p < 0.0001) and PVR (r = 0.76; p < 0.0001). Postoperative PVR correlated negatively with the presence and extent of central thrombi (r = -0.36; p = 0.007) and dilated bronchial arteries (p = 0.03) seen on preoperative CT scans. Sixty percent of patients (3 of 5 patients) without visible central thromboembolic material on CT scans had an inadequate hemodynamic improvement in contrast to 4% of patients (2 of 51 patients) with central thrombi (p = 0.003). Preoperative PVR (r = 0.31; p = 0.018) and the extent of abnormal lung perfusion (r = 0.37; p = 0.007) and of subpleural densities (r = 0.32; p = 0.017) were positively correlated with postoperative PVR. CONCLUSIONS: In patients with thromboembolic pulmonary hypertension, CT scan findings can help to predict hemodynamic improvement after PTE. The absence of central thrombi is a significant risk factor for inadequate hemodynamic improvement.

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PURPOSE: To compare the cytotoxic effects of dimeric and monomeric iodinated contrast media on renal tubular cells in vitro with regard to osmolality. MATERIALS AND METHODS: LLC-PK1 cells were incubated with ioxithalamate, ioversol, iomeprol-300, iomeprol-150, iodixanol, iotrolan, and hyperosmolar mannitol solutions for 1-24 hours at concentrations from 18.75 to 150 mg of iodine per milliliter. Cytotoxic effects were assessed with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Data were analyzed with one-way analysis of variance; post hoc tests were performed. RESULTS: At equal iodine concentrations, ioxithalamate showed stronger cytotoxic effects than did other contrast media (MTT conversion for ioxithalamate was 4% vs that for ioversol of 32%, that for iomeprol-300 of 34%, that for iodixanol of 40%, and that for iotrolan of 41% of undamaged control cells at 75 mg of iodine per milliliter, n = 61-90, P < .001); there was no significant difference between low-osmolar monomeric and iso-osmolar dimeric contrast media (P > .05). At equal molarity, dimeric contrast media induced significantly stronger cytotoxic effects than did low-osmolar monomeric contrast media (40% for iodixanol and 41% for iotrolan vs 64% for ioversol and 59% for iomeprol-300 at 98.5 mmol/L, n = 61-75, P < .001). At equimolar concentrations, both dimeric contrast media showed stronger cytotoxic effects than did iso-osmolar formulation of iomeprol-150 (51% for iodixanol and 50% for iotrolan vs 77% for iomeprol-150 at 98.5 mmol/L, n = 35-40, P < .001). Mannitol solutions induced weaker cytotoxic effects than did corresponding contrast media compounds (74% for mannitol-520 vs 34% for iomeprol-300 and 41% for mannitol-1860 vs 4% for ioxithalamate, P < .001). CONCLUSION: Besides hyperosmolality, direct cytotoxic effects of contrast media molecules contribute to their cytotoxic effects. Results of this study indicate that dimeric contrast media molecules have a greater potential for cytotoxic effects on proximal renal tubular cells in vitro than do monomeric contrast media molecules.

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Consolidations are usually result of the replacement of the alveolar air by fluid, cells or tissue but these can also be seen with extensive interstitial processes. These diseases cannot be clearly categorized into the classic classification scheme of airspace and interstitial disease since there are features of both categories seen in the imaging and histologic findings. Because this definition includes wide variety of diseases with overlapping HRCT-findings it is difficult to distinguish among these entities with imaging criteria alone. However, integration of HRCT-findings and clinical findings may enable a narrower differential diagnosis. This review describes the most common types of lung diseases associated with acute appearance of consolidation and discuss the differential diagnosis.

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A cystic lesion in the lung is defined as a well-demarcated epithel-lined cavity, that can be mostly filled with air, water, as well as solid material content. This definition includes a wide variety of diseases such as bronchogenic cyst, abscess formation, lymphangioleiomyomatosis, Langerhans cell histiocytosis, emphysema, bronchiectasis, and pneumatoceles. Despite the difficulties in differential diagnosis, there are some diagnostic criteria for CT-scanning helping the radiologist to differentiate between these cystic entities. Moreover, clinical informations are extremely important. The most important clinical parameters include age, sex, clinical history and symptoms. Thus, a better understanding of classic CT appearance of cystic lung disease will allow more definitive diagnosis and could, in some cases, avoid biopsy.

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RATIONALE AND OBJECTIVES: To investigate whether the lower incidence of vasodilatation upon vascular injection of iotrolan, as compared with monomeric contrast media, is solely the result of its isotonicity. MATERIALS AND METHODS: In an organ bath, isolated segments of swine renal arteries, uncontracted or precontracted by 10 microm phenylephrine, were incubated with increasing concentrations of iotrolan-300, iohexol-300, iomeprol-300, iomeprol-150, and mannitol solutions with the same molarity as the contrast media. RESULTS: At equal iodine and equimolar concentrations, iotrolan-300 relaxed precontracted arteries less than iohexol-300, iomeprol-300, and iomeprol-150, which was, like iotrolan-300, iso-osmolar to blood (P < 0.05). There was no significant difference between iohexol-300 and iomeprol-300 (P > 0.05). Iotrolan had no significant effect on the basal tonus of the vessels whereas iohexol and iomeprol induced a slight relaxation. CONCLUSIONS: Iotrolan, even at equimolar concentrations, resulted in less vasorelaxation than iohexol and iomeprol. Both osmolarity and chemotoxicity contribute to the greater vasorelaxant effect on swine renal artery of monomeric contrast media when compared to that of the nonionic dimeric contrast medium, iotrolan.

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Consolidations are characterized on CT by the presence of one or more airspace opacities with little or no volume loss. Because HRCT findings overlap among various entities, it may be sometimes to be impossible to make a definite diagnosis with imaging criteria alone. If the symptoms are chronic (weeks to months) the differential diagnosis may include alveolar proteinosis, bronchioloalveolar carcinoma, lymphoma as well as inflammatory diseases. This review describes the most common types of lung diseases associated with chronic appearance of consolidation and discuss the differential diagnosis.

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Since its introduction in the early 1990s, contrast-enhanced (CE) cardiac magnetic resonance imaging (MRI) has evolved rapidly for the assessment of cardiac pathologies, including in particular ischemic heart disease and inflammatory conditions. Likewise, CE-magnetic resonance angiography (MRA) is now used routinely to evaluate the thoracic vasculature. This article reviews the current use of extracellular gadolinium-based agents in CE cardiovascular imaging, focusing on ischemic heart disease, inflammatory myocardial conditions, and the use of CE-MRA in imaging of the pulmonary and aortic vasculature. Recent advances in fast and ultrafast MRI combined with the use of extracellular contrast media allow noninvasive measurements of multiple parameters of the cardiovascular system in less than 40 minutes. Beyond the assessment of left ventricular wall motion and morphology, CE cardiac MRI allows depiction of myocardial perfusion and thereby provides information regarding microvascular integrity and myocardial viability. The excellent spatial resolution of MRI, especially for the distinction of nontransmural versus transmural extent of pathology, has been shown to be superior to other modalities that are often nonlocalizing, nonspecific, or more invasive. Additional advantages of CE-MRA, particularly for the thoracic vasculature, include safety, its noninvasive character, large field of view, and the ability to demonstrate complicated three-dimensional relationships without the need for iodinated, nephrotoxic contrast media.

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PURPOSE: To find out if digital subtraction angiography (DSA) has a different diagnostic power than conventional cut-film angiography in investigating acute lower gastrointestinal (GI) hemorrhage. MATERIALS AND METHODS: Retrospective analysis of two cohorts of patients investigated by angiography for acute lower GI hemorrhage was performed. One group of patients treated at one center ("hospital H") underwent conventional angiography. The other patients, treated at another center ("hospital G"), were investigated exclusively by DSA. The groups were compared for demographic characteristics, etiology, and bleeding parameters. The diagnostic power of both angiographic modalities was compared and statistically analyzed. RESULTS: Fifty-five lower GI hemorrhages investigated by conventional cut-film angiography and 53 cases studied by DSA were included. Both study groups had statistically similar demographic and bleeding characteristics. Overall sensitivity, specificity, and positive and negative predictive values of cut-film angiography for localizing the lower GI bleeding were 62%, 73%, 86%, and 42%, whereas, for DSA, the respective values were 60%, 100%, 100%, and 24% (Z-test P values were.78,.02,.03, and.16). CONCLUSIONS: DSA is as sensitive as conventional cut-film angiography for localizing acute lower GI bleeding. If a lesion is found, the chance that it will be the bleeding source is higher with DSA than with conventional angiography.

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OBJECTIVE: The aim of our study was to describe the role of interventional radiology, especially in the use of vascular stents, in early renal perfusion failure after transplantation. CONCLUSION: Angiography revealed intimal dissection of the graft artery and graft venous thrombosis, which were successfully treated with stent angioplasty and thromboaspiration. For early vascular complication after transplantation, timely use of angiography and subsequent intervention should be recognized as potentially effective and safe treatment techniques.

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OBJECTIVES: Athlete's heart represents a structural and functional adaptation to regular endurance exercise. BACKGROUND: While left ventricular (LV) hypertrophy of the athlete's heart has been examined in many studies, the extent of right ventricular (RV) hypertrophy is still uncertain because of its complex shape and trabecular structure. To examine RV hypertrophy, we used magnetic resonance imaging (MRI) and hypothesized that athlete's heart is characterized by similar LV and RV hypertrophy. METHODS: The LV and RV mass, volume, and function in 21 male endurance athletes (A) (27 +/- 4 years; 70 +/- 8 kg; 178 +/- 7 cm; maximal oxygen uptake [VO(2)max]: 68 +/- 5 ml/min per kg) and 21 pair-matched untrained control subjects (C) (26 +/- 3 years; 71 +/- 9 kg; 178 +/- 6 cm; VO(2)max: 42 +/- 6 ml/min per kg) were analyzed by MRI (Magnetom Vision 1.5T, Siemens, Erlangen, Germany). RESULTS: Left ventricular masses: (A: 200 +/- 20 g; C: 148 +/- 17 g) and RV masses (A: 77 +/- 10 g; C: 56 +/- 8 g) differed significantly between the groups (p < 0.001). The LV and RV end-diastolic volumes (EDV) (LV-EDV 167 +/- 28 ml [A]; 125 +/- 16 ml [C]; RV-EDV 160 +/- 26 ml [A]; 128 +/- 10 ml [C]), and stroke volumes (SV) (LV-SV: 99 +/- 18 ml [A], 74 +/- 11 ml [C]; RV-SV: 102 +/- 18 ml [A], 79 +/- 8 ml [C]) were significantly different between the athletes and control subjects (p < 0.001), whereas ejection fractions (EF) (LV-EF: 59 +/- 3% [A]; 59 +/- 6% [C]; RV-EF: 63 +/- 3% [A], 62 +/- 3% [C]) and LV-to-RV ratios were similar for both groups (LV-to-RV mass: 2.6 +/- 0.2 [A], 2.6 +/- 0.3 [C]; LV-to-RV EDV: 1.05 +/- 0.14 [A], 0.99 +/- 0.14 [C]; LV-to-RV SV: 0.98 +/- 0.17 [A], 0.95 +/- 0.17 [C]; LV-to-RV EF: 0.93 +/- 0.07 [A], 0.96 +/- 0.10 [C]). CONCLUSIONS: Regular and extensive endurance training results in similar changes in LV and RV mass, volume, and function in endurance athletes. This leads to the conclusion that the athlete's heart is a balanced enlarged heart.

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RATIONALE AND OBJECTIVES: The vasoconstriction of the renal arteries is frequently considered as a crucial factor for radiocontrast-induced nephropathy. A direct effect of iodinated radiographic contrast medium (RCM) on vascular smooth muscle is supposed to be one component of the vascular response. We studied the effect of the nonionic RCM iomeprol and iohexol on the tonus of isolated human and porcine renal arteries in vitro. METHODS: In an organ bath renal arterial rings, uncontracted or precontracted by 10 micromol/L phenylephrine were incubated with increasing concentrations (15-103 mg iodine/mL) of iohexol, iomeprol, and mannitol solution isoosmolar to the contrast media. In a part of the preparations the endothelium was destroyed. Human vessels were obtained from tumor nephrectomy specimens of 10 patients. RESULTS: In human experiments iomeprol and iohexol (P < 0.05) relaxed renal arterial rings whereas mannitol produced concentration-dependent contractions. The relaxation by both contrast media was slightly attenuated upon increasing their concentration. The differences between mannitol solutions and RCM were statistically significant (P < 0.001) at concentrations of 57 mg iodine/mL and higher. Precontracted rings were significantly stronger relaxed by the RCM compared with mannitol (P < 0.001). The contrast medium induced relaxation did not depend on the presence of an intact endothelium (P > 0.05). Experiments with renal arterial segments prepared from swine showed similar results, with stronger relaxations than the human preparations. CONCLUSION: Iomeprol and iohexol relaxed isolated renal arterial segments. These observations are in contradiction with the hypothesis that contrast media induce nephropathy by a direct vasoconstrictive effect on vascular smooth muscle. They do not exclude, however, a reduction of renal blood flow by other factors like liberation of hormones.

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We report on a 15-year-old girl with a secondary aneurysmatic bone cyst of the thoracic spine with extension into the spinal canal on the basis of an osteoblastoma. Surgical treatment was facilitated by preoperative embolization of the highly-vascular tumor. Excision of the tumor was performed without extensive intraoperative blood loss. Following excision, transpedicular-stabilization of the spinal column was achieved using a fixateur intern. We conclude that superselective embolization of benign lesions of the spinal column constitutes a feasible means of reducing intraoperative bleeding complications, thus enhancing resectability.

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A rupture of corpus cavernosum (CC) is a rare injury of the erect penis. The present study describes the role of MRI for diagnosis and follow-up of this injury. Four patients with clinically suspected acute penile fractures underwent MRI. Imaging findings were confirmed at surgery. In three patients, follow-up MRI was also available at 1, 6 and 16 weeks after surgical repair. In all patients pre-contrast T1-weighted images (T1WI) clearly disclosed ruptures of CC, which depicted as discontinuity of low signal intensity of the tunica albuginea (TA). Concomitant subcutaneous haematoma were well visualised both on T1-weighted (T1WI) and T2-weighted images, whereas haematoma in CC were optimally demonstrated on contrast-enhanced T1WI. On follow-up MRI all fractures presented similar healing process. Shortly after the repair, the tunical suture showed an increase in signal intensity on pre-contrast T1WI and was strongly enhanced with the administration of contrast material. Then the tear site gradually recovered low signal intensity on all spin-echo sequences by 4 months after surgery. These serial findings may suggest the formation of vascularised granulation tissue during cicatrisation. Magnetic resonance imaging is of great value for the diagnosis and follow-up in patients with penile fracture.

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