Gemcitabine plus sorafenib versus gemcitabine alone in advanced biliary tract cancer: a double-blind placebo-controlled multicentre phase II AIO study with biomarker and serum programme.

BACKGROUND: Since sorafenib has shown activity in different tumour types and gemcitabine regimens improved the outcome for biliary tract cancer (BTC) patients, we evaluated first-line gemcitabine plus sorafenib in a double-blind phase II study. PATIENTS AND METHODS: 102 unresectable or metastatic BTC patients with histologically proven adenocarcinoma of gallbladder or intrahepatic bile ducts, Eastern Cooperative Oncology Group (ECOG) 0-2 were randomised to gemcitabine (1000 mg/m2 once weekly, first 7-weeks+1-week rest followed by once 3-weeks+1-week rest) plus sorafenib (400 mg twice daily) or placebo. Treatment continued until progression or unacceptable toxicity. Tumour samples were prospectively stained for sorafenib targets and potential biomarkers. Serum samples (first two cycles) were measured for vascular endothelial growth factors (VEGFs), vascular endothelial growth factor receptor 2 (VEGFR-2) and stromal cell-derived factor 1 (SDF1)α by enzyme-linked immunosorbent assay (ELISA). RESULTS: Gemcitabine plus sorafenib was generally well tolerated. Four and three patients achieved partial responses in the sorafenib and placebo groups, respectively. There was no difference in the primary end-point, median progression-free survival (PFS) for gemcitabine plus sorafenib versus gemcitabine plus placebo (3.0 versus 4.9 months, P=0.859), and no difference for median overall survival (OS) (8.4 versus 11.2 months, P=0.775). Patients with liver metastasis after resection of primary BTC survived longer with sorafenib (P=0.019) compared to placebo. Patients who developed hand-foot syndrome (HFS) showed longer PFS and OS than patients without HFS. Two sorafenib targets, VEGFR-2 and c-kit, were not expressed in BTC samples. VEGFR-3 and Hif1α were associated with lymph node metastases and T stage. Absence of PDGFRß expression correlated with longer PFS. CONCLUSION: The addition of sorafenib to gemcitabine did not demonstrate improved efficacy in advanced BTC patients. Biomarker subgroup analysis suggested that some patients might benefit from combined treatment.

Echinococcosis mimicking autoimmune or malignant bile duct disease.

Indeterminate strictures of the bile ducts are common diagnostic dilemmas in gastroenterology, and differential diagnosis includes inflammatory and neoplastic diseases. Alveolar echinococcosis (AE) is rarely considered as a differential diagnosis, although it is endemic in the Northern hemisphere. In this case report on a 50-year-old male patient, the lack of cystic lesions or calcifications on CT, and suggestive ERCP findings made a hilar cholangiocellular carcinoma the most probable differential diagnosis, and only explorative laparotomy provided the definite diagnosis of AE. AE should therefore be included in the differential diagnosis of indeterminate biliary strictures even in the absence of typical stigmata in imaging studies.

IgG4-related sclerosing cholangitis mimicking cholangiocarcinoma.

IgG4-related disease has gained increased attention worldwide. While the initial focus was on autoimmune pancreatitis which was first described in Asian populations and turned out to be of relevance in Western populations too, the scope has recently broadened towards a notion of a multi-systemic disease with very diverse manifestations such as autoimmune pancreatitis, IgG4-related sclerosing cholangitis (IgG4-SC), retroperitoneal fibrosis and tubulointerstitial nephritis. IgG4-SC (also known as IgG4-associated cholangitis, IAC) represents a rare but clinically challenging differential diagnosis in patients with obstructive jaundice and proximal extra- or intrahepatic biliary strictures which can be mistaken for cholangiocarcinoma (CC). We present the case of a 79-year-old male patient who presented with obstructive jaundice and biliary strictures at the hepatic duct bifurcation without any evidence for autoimmune pancreatitis and without elevation of serum IgG4-concentrations who underwent hemihepatectomy for suspected CC. However, on histological examination of the resection specimen CC could not be confirmed. It was only after several episodes of obstructive jaundice had reoccurred that the diagnosis of IgG4-SC could be established by reexamination of the surgical specimen which showed extensive infiltration with IgG4-positive plasma cells. Appropriate medical treatment with steroids and azathioprine led to complete remission of the disease. Early recognition of IgG4-SC can save patients from potential harmful and unnecessary surgical interventions. Here we describe the clinical features of this rare case of IgG4-SC with extensive liver tissue infiltration with IgG4-positive cells but without elevated serum IgG4 concentration or evidence of autoimmune pancreatitis. We describe diagnostic criteria for IgG4-SC and review recent insights in pathophysiology and treatment options.

6-18F-fluoro-L-dihydroxyphenylalanine positron emission tomography is superior to 123I-metaiodobenzyl-guanidine scintigraphy in the detection of extraadrenal and hereditary pheochromocytomas and paragangliomas: correlation with vesicular monoamine transporter expression.

CONTEXT: Pheochromocytomas (PHEOs) and paragangliomas (PGLs) may be better detected by (18)F-fluorodihydroxyphenylalanine-positron emission tomography (FDOPA-PET) than (123)I-metaiodobenzyl-guanidine (123-I-MIBG) scintigraphy. OBJECTIVE: The objective of the study was to correlate functional imaging results with immunohistochemical, molecular-genetic, and biochemical findings. DESIGN AND SETTING: Thirty consecutive patients with suspected PHEO/PGL presenting at a tertiary referral centre were investigated in a prospective study. PATIENTS: Twenty-five patients had confirmed PHEO/PGL. Thirteen of 25 patients had a hereditary PHEO/PGL syndrome (two multiple endocrine neoplasia II, six succinate dehydrogenase complex, subunit D, two succinate dehydrogenase complex, subunit B, one von Hippel Lindau tumor suppressor protein, two Neurofibromatosis-1), and 12 of 25 were classified as sporadic. Five patients had hormonally inactive adrenal incidentalomas. MAIN OUTCOME MEASURES: In all patients computed tomography scan and/or magnetic resonance imaging as well as both 123-I-MIBG scintigraphy and FDOPA-PET were performed. Resected tumors were examined by immunohistochemistry for expression of the vesicular monoamine transporter (VMAT)-1 and -2 and other markers. RESULTS: A total of 64 lesions were found with both functional imaging modalities. FDOPA-PET detected 62 lesions, whereas only 34 lesions were detected by 123-I-MIBG scintigraphy. This resulted in an overall sensitivity and specificity for FDOPA-PET of 98 and 100% and for MIBG of 53 and 91%, respectively. Comparable sensitivities were found for adrenal and extraadrenal abdominal lesions (94 vs. 97%), whereas in thoracic/cervical lesions, the sensitivity for 123-I-MIBG scintigraphy (15%) was inferior to that of FDOPA-PET imaging (100%). Immunohistochemistry demonstrated a lack of VMAT-1 expression in all MIBG-negative tumors. Clinical predictors for MIBG negativity were a predominant norepinephrine/normetanephrine secretion, an age less than 45 yr, and a hereditary cause. CONCLUSION: FDOPA-PET is superior to 123-I-MIBG scintigraphy in patients with extraadrenal, predominantly noradrenaline-secreting, and hereditary types of PHEO/PGL. The lack of VMAT-1 expression predicts negativity for MIBG-scintigraphy.

[Hemorrhagic pericardial effusion and multiple pulmonary nodules in a 37 year old male who has "never smoked"]. / Hämorrhagischer Perikarderguss mit multiplen pulmonalen Rundherden bei einem 37-jährigen "Nie-Raucher"

Even people which have never smoked can develop lung cancer. In this population a mutation in the exons 19-21 of the Epidermal Growth Factor Receptor (EGFR) can be detected. For this patient group targeted therapies with EGFR tyrosinkinase inhibitors are available. In this case report we describe a 37 year old non-smoker who developed a non-small cell lung cancer. Following therapy with Erlotinib a partial response could be achieved.

[Correlation of degenerative intervertebral disk displacement using MRI with discography findings in patients with back pain]. / Korrelation degenerativer Bandscheibenveränderungen im MRT mit dem Befund der Diskographie bei Rückenschmerzpatienten.

BACKGROUND: MRI can be too sensitive for detecting degenerative changes and commonly displays pathology that is not necessarily responsible for the patient's symptoms. METHODS: Retrospectively, we investigated MRI findings and results of discography in 23 patients with lower back pain. MRI investigations were performed with a 1.0 and 1.5 Tesla device using T1-weighted and T2-weighted sagittal plane imaging and T2-weighted transverse plane imaging. RESULTS: Of the 35 degenerated discs, 16 were detected on MRI as having a high intensity zone (HIZ). Eleven of the 35 segments had previous lumbar disc surgery with a HIZ rate of 81.8%, whereas the HIZ rate for unoperated segments was only 29.2%. CONCLUSIONS: HIZ is known to be a common lesion found using MRI in lower back pain patients. In operated segments, we found an incidence of 81.8% and in unoperated segments of 28.2%. Discography can discriminate between painful and non-painful discs. With the help of additional parameters such as contrast mean volume and pain characteristics during puncture, the number of false positive discograms can be reduced.

The impact of Syme amputation in surgical treatment of patients with diabetic foot syndrome and Charcot-neuro-osteoarthropathy.

INTRODUCTION: Charcot-neuro-osteoarthropathy with its severe destruction of bones remains a challenge for physicians and surgeons. The aim of the study was to characterise a patient population treated in a specialised foot care centre who underwent surgical treatment for their diabetic foot syndrome. Special attention was paid to patients who suffered from Charcot-neuro-osteoarthropathy and the impact of Syme amputation if amputation of the foot was inevitable. MATERIALS AND METHODS: A total of 121 patients with diabetic foot syndrome and ulcerations underwent an interdisciplinary strategy for diagnostic and therapeutic procedures including MRI and surgical interventions. If peripheral arterial vessel disease was present, revascularisation by distal bypass grafting was done before the orthopaedic intervention. Some 24% showed the typical neuro-osteoarthropathy with severe bone destruction. In 8 cases amputation of the foot was performed using the Syme technique. RESULTS: In our population the short-term results (follow-up 12 months, 20% lost to follow-up) are good, only 4% of the patients required further surgery on the same foot. In all patients with Charcot feet, plain radiographs showed the typical radiographic signs of the disease, and MRI was most helpful to detect abscess formations. The typical clinical problems of patients with Charcot disease are pointed out, and conservative and surgical treatment options are discussed. All patients with Syme amputation did well, wound healing and weight-bearing of the limb were accomplished. CONCLUSION: The crucial diagnostic tool for decision-making in diabetic foot syndrome was MRI, which normally shows osteomyelitis with high sensitivity and specificity. In patients with Charcot-neuro-osteoarthropathy, the bone marrow oedema of the involved parts of the skeleton might misleadingly suggest the diagnosis of osteomyelitis. If amputation is inevitable in severe abscess formation combined with instability and perforation of the dislocated and destroyed bones in Charcot-neuro-osteoarthropathy, these patients might benefit from a foot amputation according to the technique Syme described. For this procedure the blood supply of the posterior tibial artery is essential. All these patients were able to walk without support. The material presented helps to generate hypotheses for further prospective studies.

[Interdisciplinary treatment of diabetic foot syndrome]. / Die interdisziplinäre Therapie des diabetischen Fusssyndroms.

The amputation rate in patients with diabetic foot syndrome (DFS) in Germany is still as high as 28,000 per year. Ischemia and osteomyelitis often complicate the DFS. Impaired wound healing frequently requires further surgery with a higher amputation level. The results of treating patients with DFS in our specialized foot care center were evaluated in order to assess our interdisciplinary strategy. Advanced diabetic foot wounds in patients with ischemia and osteomyelitis first require diagnostics concerning polyneuropathy, osteomyelitis, and blood supply. If peripheral arterial vessel disease is present, surgical revascularization by distal bypass grafting is the first and crucially important element of the interdisciplinary approach. Minor amputation or elective resection of the infected bone improves wound healing. Post-interventional care for wounds with secondary healing and prevention of new ulcers are provided in a foot care clinic specialized in diabetes. The clinical and radiological results of 77 patients who underwent this treatment algorithm including bypass surgery and bone resection within 1 year were collected using a standardized questionnaire. Those results were subjected to a historical comparison. Only three patients needed further intervention because of persisting ulcers and osteomyelitis. The frequency of major amputations in all patients with DFS and ischemia combined with osteomyelitis was low (10.3%). This interdisciplinary concept of treatment guarantees a high healing rate in patients even with osteomyelitis and ischemia and allows the reduction of the rate of major amputations. The data obtained allow a fact-based design for future studies.

Perineal excision of a large angiomyxoma in a young woman following magnetic resonance and angiographic imaging.

BACKGROUND: Aggressive angiomyxomas are rare, arise from connective tissue of the perineum or the lower pelvis, and affect predominantly young women. CASE: We describe an unusual case of aggressive angiomyxoma in which the perineal approach was possible owing to MRI scanning and selective angiography indications. CONCLUSION: In cases of large aggressive angiomyxomas these diagnostic procedures should make it possible to decide which operative route might be best for the patient.

[Dynamic 31-phosphorus magnetic resonance spectroscopy of the m. quadriceps: the effect of sex and age on the spectroscopic parameters]. / Die dynamische 31-phosphor-Magnetresonanz-Spektroskopie des M. quadriceps: Einfluss von Geschlecht und Alter auf spektroskopische Parameter.

PURPOSE: 31P-MRS is used to assess the influence of sex und age on quadriceps muscle metabolism before and after exercise. MATERIALS AND METHODS: 32 healthy volunteers (15 women, 17 men, mean age: 38 +/- 17 yrs.) were examined by dynamic phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). In the magnet, the quadriceps muscle was stressed by an isometric und an isotonic form of exercise until exhaustion, respectively. RESULTS: Resting conditions: With increasing subjects' age, the ratio beta-adenosine triphosphate/total phosphate decreased (r = -0.37; p = 0.02). With increasing subjects' age, the ratios inorganic phosphate/phosphocreatine (r = 0.79; p = 5 x 10(-8), phosphomonoester/beta-adenosine triphosphate (r = 0.74; p = 10(-6) and phosphodiester/beta-adenosine triphosphate (r = 0.62; p = 10(-4) increased. The pH was the only one of the evaluated spectroscopic parameters which showed a sex-dependence: Female subjects had a significantly lower pH (7.03 +/- 0.02) than male subjects (7.05 +/- 0.03; p = 0.01). Exercise: With increasing age, the maxima of inorganic phosphate/phosphocreatine were less extreme during both of the exercises (r = -0.42; p = 0.0005). Likewise, the exercise-induced acidosis was less severe with increasing age (r = 0.53; p = 6 x 10(-6). After the end of the exercise, the times of half recovery of inorganic phosphate/phosphocreatine and the pH correlated neither with the subjects' age nor with sex or cross-sectional areas of the quadriceps muscle. CONCLUSION: Sex and age of volunteers affect spectroscopic results. This influence had to be considered in the interpretation of spectroscopic studies.

Contributions of dynamic phosphorus-31 magnetic resonance spectroscopy to the analysis of muscle fiber distribution.

RATIONALE AND OBJECTIVES: In high-performance athletes, conclusions regarding the muscle fiber distribution were to be drawn from dynamic 31phosphorus magnetic resonance spectroscopy (31P MRS). METHODS: Eleven volleyball players (V), eight bodybuilders (B), and 22 nonathletic volunteers (N) were examined by dynamic 31P MRS. During rest, exhaustive exercise, and recovery, respectively, up to 60 consecutive phosphorus spectra of the quadriceps muscle were acquired by "time series" in 36 s each. Two main spectroscopic approaches to the spectroscopic analysis of muscle fiber distribution were applied: evaluation of the ratio Pi/PCr at rest and the computer-assisted analysis of the Pi-peak at its exercise-induced line width maximum. RESULTS: At rest, the bodybuilders showed a significant lower Pi/PCr (0.07 +/- 0.03), in comparison with the volleyball players (0.11 +/- 0.03) and the nonathletic volunteers (0.11 +/- 0.02). The computer-assisted analysis of the Pi-peak at its line width maximum revealed a significantly lower pH of both of the subpeaks in the bodybuilders [6.30 versus 6.37 (V) and 6.38 (N); 6.89 versus 6.92 (V, N)], whereas the volleyball players provided the largest proportion of oxidative muscle fibers (68%), compared to bodybuilders (64%) and nonathletic volunteers (59%). A correlation between the ratio Pi/PCr and the area of the subpeak with the high pH (representing oxidative fibers) could not be demonstrated. CONCLUSIONS: Spectroscopic results during rest and exercise may be influenced by the muscle fiber distribution of the respective volunteer. The applied spectroscopic approaches to the analysis of muscle fiber composition are not compatible with each other; depending on the applied method, the classification of a muscle fiber as type I or type II fiber may change. The influence of physiologic factors like muscle fiber distribution on spectroscopic results has to be considered in the interpretation of pathological conditions.

[Low-field MRI of the knee joint: results of a prospective, arthroscopically controlled study]. / Niederfeld-MR-Tomographie des Kniegelenkes: Ergebnisse einer prospektiven, arthroskopisch kontrollierten Studie.

PURPOSE: To define the diagnostic accuracy of an open low-field MR unit (Magnetom Open, Siemens, Erlangen) in traumatic knee lesions. MATERIALS AND METHODS: The MRIs of 150 patients were prospectively evaluated by two independent readers with different experience levels. The study protocol included a proton-density weighted SE-sequence in the sagittal, a T2.-weighted Flash-2D-sequence in the coronal, and a 3D-acquisition (DESS) in the axial plane. 75 patients were treated either conservatively or operatively. RESULTS: Based on arthroscopy as the gold standard, the sensitivities, specificities, and diagnostic accuracies for lesions of the medial and lateral meniscus, the anterior cruciate ligament (ACL), the hyaline cartilage, and the posterior cruciate ligament (PCL) were 92%, 92% and 92%, 83%, 93% and 92%, 95%, 96% and 96%, 74%, 93% and 85%, and 100%, respectively, for reader 1. The values for reader 2 were 81%, 74% and 77% (medial meniscus), 61%, 86% and 80% (lateral meniscus), 79%, 95% and 91% (ACL), 48%, 91% and 73% (hyaline cartilage), and 100% each (PCL), respectively. There were no statistical differences between the two readers (Fisher's Exact Test, 95%-confidence interval). CONCLUSIONS: Using a time-consuming examination protocol, the diagnostic accuracies of the open low-field MR unit are well comparable to those obtained with mid- or high-field units. Although not statistically significant in this study, the experience level of the examiner seems to be of considerable clinical relevance.

Dynamic phosphorus-31 magnetic resonance spectroscopy of the quadriceps muscle: effects of age and sex on spectroscopic results.

RATIONALE AND OBJECTIVES: Phosphorus-31 (31p) magnetic resonance spectroscopy (MRS) is used to assess the influence of sex and age on quadriceps muscle metabolism before and after exercise. METHODS: Fifty-four healthy volunteers and 56 patients with an arterial occlusive disease were examined by dynamic 31p MRS. In the magnet, the quadriceps muscle was stressed by an isometric and an isotonic form of exercise until exhaustion. RESULTS: Older subjects showed a significantly larger ratio of inorganic phosphate (P(i)) to phosphocreatine (PCr) than younger subjects (r = 0.52, P = 8 x 10(-9)). With subjects' increasing age, the ratio of adenosine triphosphate (beta-ATP) to total phosphate decreased (r = -0.36, P = 5 x 10(-5)). The ratio of phosphomonoester to beta-ATP and phosphodiester (PDE) to beta-ATP showed a strong age dependence (r = 0.71 and 0.69, P = 3 x 10(-17) and 4 x 10(-15), respectively). The pH was the only one of the evaluated spectroscopic parameters that showed a sex dependence. Female subjects had a significantly lower pH (7.03+/-0.02) than male subjects (7.05+/-0.03) (P = 6 x 10(-4)). With increasing age, the maxima of P(i) to PCr were less extreme during both of the exercises (r = -0.51, P = 3 x 10(-16)). Likewise, the exercise-induced acidosis was less severe with increasing age (r = -0.51, P = 7 x 10(-16)). After the exercises ended, the times of half recovery of P(i) to PCr and the pH neither correlated with the subjects' age nor with sex or the cross-sectional area of the quadriceps muscle. CONCLUSIONS: The sex and age of volunteers or patients may affect spectroscopic results in a significant way. This influence has to be considered in the interpretation of spectroscopic studies. According to the recovery rates of P(i) to PCr and the pH, an age-related deterioration of muscular metabolism seems to be avoidable by appropriate physical activity.

[Magnetic resonance imaging (MRI) of liver and brain in hematologic-oncologic patients with fever of unknown origin]. / Magnetresonanztomographie (MRT) der Leber und des Gehirns bei hämatologisch-onkologischen Patienten mit Fieber unbekannter Ursache.

PURPOSE: To examine the advantage of liver and brain MRI in clinically anomalous haematological patients with fever of unknown origin. MATERIAL AND METHODS: Twenty liver MRI (T2-TSE, T2-HASTE, T1-FLASH +/- Gd dynamic) and 16 brain MRI (T2-TSE, FLAIR, T1-TSE +/- Gd) were performed searching for a focus of fever with a suspected organ system. Comparison with clinical follow-up. RESULTS: A focus was detected in 11/20 liver MRI. Candidiasis (n = 3), mycobacteriosis (n = 2), relapse of haematological disease (n = 3), graft versus host disease (n = 1), non-clarified (n02). The remaining 9 cases with normal MRI were not suspicious of infectious hepatic disease during follow-up. In brain MRI, 3/16 showed a focus (toxoplasmosis, aspergillosis, mastoiditis). Clinical indication for an infectious involvement of the brain was found in 4/16 cases 2-5 months after initially normal brain MRI. No suspicion of an infectious involvement of brain was present in the remaining 9/16 cases. CONCLUSION: In case of fever of unknown origin and suspicion of liver involvement, MRI of the liver should be performed due to data given in literature and its sensitivity of 100%. Because of the delayed detectability of cerebral manifestations, in cases of persisting suspicion even a previously normal MRI of the brain should be repeated.

Dynamic phosphorus-31 magnetic resonance spectroscopy in arterial occlusive disease: effects of vascular therapy on spectroscopic results.

RATIONALE AND OBJECTIVES: The aim of the authors' prospective study was to explore therapy-induced changes of muscular metabolism in arterial occlusive disease (AOD). MATERIALS: Before and after vascular therapy, respectively, 31 patients with AOD were examined by dynamic phosphorus-31 (31P) magnetic resonance spectroscopy (MRS) at 1.5 T; in the magnet, the quadriceps muscle was stressed by an isometric and an isotonic form of exercise until exhaustion, respectively. Twenty-three patients were treated by standardized percutaneous transluminal angioplasty; eight patients underwent a vascular operation. RESULTS: Vascular therapy induced a marked improvement of clinical and angiographic results. At the same work load, exercise-induced metabolic changes of the quadriceps muscle were significantly less pronounced after the vascular therapy: maxima of the ratio inorganic phosphate (Pi)/phosphocreatine (PCr) (isometric exercise: 0.34 [after therapy] versus 0.44 [before therapy]; isotonic exercise: 0.36 [after therapy] versus 0.51 [before therapy]) as well as minima of pH (isometric exercise: 7.00 [after therapy] versus 6.93 [before therapy]; isotonic exercise: 7.00 [after therapy] versus 6.93 [before therapy]). In relation to maximal values of Pi/PCr, the extent of acidosis was smaller after vascular therapy, resulting in a flatter slope of the regression line between these parameters (b = -0.24 +/- 0.10 versus b = -0.31 +/- 0.09). After both of the exercises, time of half recovery of Pi/PCr was significantly shorter after vascular therapy (isometric exercise: 43 seconds [after therapy] versus 83 seconds [before therapy]; isotonic exercise: 42 seconds [after therapy] versus 57 seconds [before therapy]). CONCLUSIONS: After effective vascular therapy, minor exercise-induced metabolic changes (increased "work/energy cost-index"), a decreased contribution of anaerobic glycolysis to total adenosine triphosphate production as well as a markedly increased recovery rate of Pi/PCr are unequivocal spectroscopic proofs of an improved oxidative metabolism of muscle cells because of increased tissue perfusion.

[Diagnostic imaging of benign and malignant liver tumors: computerized tomography or magnetic resonance tomography?]. / Bildgebende Diagnostik benigner und maligner Lebertumore: Computertomographie oder Magnetresonanztomographie?

A reliable preoperative detection and characterization of all liver lesions is necessary for the clarification of the operability of a patient. In patients, who are considered as good candidates for a partial liver resection, a double spiral-CT with an oral bowel opacification and an intravenous contrast medium administration is recommended. In those patients, who continue to be candidates for partial liver resection after CT, a CT arterioportography with arterial and portalvenous liver enhancement should be performed as the present gold standard of preoperative liver diagnostics. The aim of CT arterioportography is the further selection of patients for liver surgery. Because of its high specificity, MRI is useful for the characterization of liver lesions of unknown histology. For the differentiation between malignant (metastases) and benign (hemangioma) liver lesions, MRI is the method of choice. Because of the expected technical developments of MRI, a short-term comparison of CT and MRI in prospective studies is necessary.

Dynamic phosphorus-31 magnetic resonance spectroscopy in arterial occlusive disease. Correlation with clinical and angiographic findings and comparison with healthy volunteers.

RATIONALE AND OBJECTIVES: The aim of this prospective study was to explore muscular metabolism in arterial occlusive disease (AOD) by dynamic phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). METHODS: The authors examined 56 patients with AOD. Acquisition of up to 60 consecutive phosphorus spectra of the quadriceps muscle was done by "time series" in 36 seconds each. In this way, the authors achieved uninterrupted monitoring of muscle metabolism during rest, exhaustion, and recovery. During 31P MRS, the volunteers performed an isometric and an isotonic exercise until exhaustion of the quadriceps muscle. Spectroscopic results of 56 patients with AOD were correlated with clinical and angiographic findings and were compared with spectroscopic results of 10 age-matched healthy volunteers. RESULTS: There were no significantly differing spectroscopic results between patients and volunteers at rest, except for an elevated ratio phosphomonoester (PME)/beta-adenosine triphosphate (ATP) in patients with AOD (0.66 +/- 0.19 versus 0.48 +/- 0.09). Despite a sixfold duration of both of the exercises until exhaustion in healthy volunteers, exercise-induced changes of inorganic phosphate (P1)/phosphocreatine (PCr), PME/beta-ATP, and pH were similar in healthy volunteers and patients with AOD. Compared with maximal exercise-induced values of Pi/PCr, acidosis was relatively increased in AOD, resulting in a steeper slope of linear regression line (-0.33 +/- 0.06 versus -0.14 +/- 0.06) between these parameters. Recovery rate of Pi/PCr was markedly prolonged in AOD (time of half recovery: 80 seconds versus 25 seconds [isometric exercise] and 70 seconds versus 37 seconds [isotonic exercise]), whereas recovery rate of pH was not significantly slowed down in our patients (192 seconds versus 166 seconds [isometric exercise] and 234 seconds versus 220 seconds [isotonic exercise]). CONCLUSIONS: Dynamic 31P MRS provides a direct judgment of muscular metabolism, which is not only influenced by macro-, but also by microangiopathia. Results of 31P MRS suggest a reduced mitochondrial oxidative phosphorylation in AOD.