Darstellung von Metastasen eines Schilddrüsenkarzinoms mittels 111In-Pentetreotide-Szintigraphie

Zur Darstellung von Schilddrüsenkarzinomgewebe mittels Somatostatin-Rezep-torszintigraphie liegen bisher wenig Erfahrungen vor. Wir stellen die Kasuistik einer akromegalen Patientin vor, bei der die 111 In-Pentetreotide-Szintigraphie -außer einem Somatostatinrezeptor-positiven Hypophysentumor - auch Metastasen eines papillären Schilddrüsenkarzinoms darstellte, die im unter Hypothyreose angefertigten Radiojodszintigramm kein Korrelat fanden. Der mögliche Stellenwert dieses Radiopharmazeutikums bei entdifferenzierenden Schilddrüsenkarzinomen wird in bezug auf den lokalisationsdiagnostischen Nutzen sowie auf die prädiktive Aussagekraft hinsichtlich des Erfolges einer Octreotide-Langzeit-behandlung diskutiert.

[Acute right-sided upper abdominal pain in a 46-year-old woman]

A 46-year-old woman presented with acute abdominal pain in the right upper quadrant. Esophagogastroduodenoscopy revealed a duodenal stenosis within the horizontal part of the duodenum. Based on the findings of abdominal computed tomography (CT), endosonography, Doppler duplex sonography and angiography, the diagnosis of an aneurysm of a branch of the inferior pancreaticoduodenal artery was established. This arterial branch was part of a collateral circulation between the superior mesenteric artery and the proper hepatic artery caused by obturation of the celiac artery. The symptomatic duodenal stenosis was the result of a local hematoma due to prior rupture of an aneurysm. After successful coiling of the afferent vessels to the aneurysm follow-up examinations showed progredient resorption of the hematoma and the patient was free of complaints.

[Unusual postoperative fistula of the abdominal wall, caused by an ingested wooden spit perforating the intestine and lodging itself in the abdominal wall]

Abdominal fistula caused by an ingested wooden spit, which penetrated the intestinal wall and remained in the abdominal wall: a laparascopy was performed in a 41-year-old man suffering from acute appendicitis and an inflamed Meckel's diverticulum. After removal of the appendix and the diverticulum, a fistula developed in the excision channel of the left quadrant of the abdominal wall post-operatively. Despite repeated incision of the abscess in the course of 2 months, the fistula did not heal. Ultrasound examination of the abdominal wall was therefore performed. The postoperative status was without conspicuous findings. We could, however, detect a foreign body, a few centimetres long and 2-3 mm thick, displaying a smooth surface, deep down in the abdominal wall. A fistulography confirmed the diagnosis. After removal of the wooden spit, complete healing of the fistula in the abdominal wall was observed. Subsequently, the patient reported to have eaten a beef roulade, fixed with a wooden spit, 7 weeks before the abdominal operation.

Biliary infarction mimicking liver metastasis

A 38-year-old man with a history of chronic alcohol abuse had suffered from numerous acute episodes of chronic pancreatitis in the last 7 years. Those episodes were complicated by the formation of a pseudocyst in the pancreatic head. He presented himself with vomiting and abdominal pain as well as diarrhoea for 10 days. In the ultrasound examination of the liver numerous circumscribed hypoechoic formations in both lobes of the liver were found. A subsequent computerised tomography scan confirmed multiple hypodense liver lesions. Because of suspected metastasis or abscesses in the liver, sonographically guided fine needle biopsies of these liver structures were carried out. The histological examination of the liver specimens showed bile infarcts and proliferated bile ducts; there were no signs of a malignant or infectious process. The bacteriological cultures of the biopsy specimens were negative.

[Sensitivity of magnetic resonance tomography in detecting meniscus tears]

In order to assure diagnostic accuracy, 172 knee joints were examined prospectively by MRI. After MRI, all knee joints were examined by arthroscopy. Tears of the medial meniscus were found in 102 patients, the lateral meniscus showed a tear in 29 cases. Assuming that arthroscopy represents the golden standard of diagnostic measure concerning the knee joint, it can be stated that false-positive MRI findings on the medial and lateral meniscus were diagnosed in three cases and false-negative MRI findings were diagnosed for two knee joints regarding the medial meniscus and four times regarding the lateral meniscus. For the medial meniscus a sensitivity of 98%, a specificity of 96%, an accuracy of 94%, and the positive and negative value of prediction were calculated at 97% each. Regarding the lateral meniscus, a sensitivity of 85%, a specificity of 98%, an accuracy of 92%, a positive predictive value of 88%, and a negative predictive value of 85% were found. Under the prerequisite that the MRI is carried out correctly and assessed by an experienced radiologist, the accuracy of the MRI for meniscus diagnosis is almost equivalent to the one by arthroscopy. Under these conditions, MRI can be recommended when no safe and sufficient clinical diagnosis can be made. The rate of unnecessary arthroscopies with a pure diagnostic purpose can be lowered significantly by means of MRI.

A new type of artificial urinary calculi: in vitro study by spiral CT

RATIONALE AND OBJECTIVES

Artificial urinary calculi similar to natural stones have long been sought in urologic research. In an experimental study, the authors assessed the CT characteristics of a new type of artificially produced urinary calculus [BON(N)-STONE].

METHODS

Six different types of urinary calculi (uric acid, struvite, cystine, calcium oxalate, brushite, and apatite) were produced by a coating technique in which several layers of a suspension of pure substance were applied around a core and dried. A total of 60 stones (10 per group) were studied by spiral CT at two energy levels (100 and 120 kV, 250 mA) with 1-mm slice thickness.

RESULTS

All calculi showed a small hyperdense core surrounded by a homogeneous matrix and a slightly hyperdense outer rim. From the least to the most dense, the stone types were uric acid, struvite, cystine, calcium oxalate, brushite, and apatite. Absolute CT values at 100 and 120 kV could differentiate between all groups of stones at a significance level of P < 0.001 or better. Attenuation values were in a comparable range to reported values for natural stones, with the exception of uric acid and struvite, which were notably lower.

CONCLUSION

These artificially produced urinary calculi showed properties similar to those of natural stones. Thus, this seems to be a promising stone model for further investigations.

A new technique for oral endotracheal airway access in rabbits under fluoroscopic control: An easy way for drug administration in chronic experiments

Endotracheal drug administration plays an important role in rabbit models of pulmonary injury and lung disease. However, anatomical features of the oral fissure and pharynx of rabbits make orotracheal intubation a difficult task with a high failure rate. We developed a new technique for airway access in rabbits under fluoroscopic control using a balloon catheter. The procedure consists of four major steps: (1) a shortened 5-french vertebralis catheter is placed into the mesopharynx just above the epiglottic valve, (2) through the catheter lumen a guidewire is carefully moved across the epiglottis and inserted into the trachea, (3) the vertebralis catheter is replaced by a balloon catheter that subsequently is introduced into the tracheal tree over the guidewire, and (4) with the balloon catheter in the right position the guidewire is removed and the balloon is inflated so that finally the drug can be delivered. This procedure was performed in 55 New Zealand White rabbits under general anesthesia with ketamine/xylazine. In all 55 cases the procedure was performed successfully without any major complications and within a reasonably short time period. Removal of the catheter and awakening of the animals were uneventful. The described technique is a simple and safe method for airway access in rabbits and can be useful in chronic experiments for endotracheal drug administration.

Intraarterial HCC therapy with I-131-Lipiodol

We report on our 2-year experience with intraarterial liver therapy with I-131-Lipiodol in patients with hepatocellular carcinoma in Germany. 30 therapies with intraarterial delivery of I-131-labeled Lipiodol were performed in 14 patients with hepatocellular carcinoma (HCC) with or without portal vein thrombosis during hepatic angiography. The patients were monitored for 1) distribution of Lipiodol by CT, 2) distribution of applied activity by planar scintigraphy and SPECT, and 3) tumor response by CT, MRT and 18-FDG-PET. In 5 patients the tumor size was reduced after the first treatment (responder). Eight patients, primarily with big tumors (> 7 cm), had stable (4) or progressive disease (4), and 1 patient died because of renal failure. CT and SPECT showed pronounced I-131-lipiodol accumulation in the tumor tissue in all patients with variable distribution patterns. One patient had an acute pancreatitis like syndrome together with elevation of liver enzymes, probably due to arterial spasm. 9 patients had transient and mild symptoms in the upper abdomen, fever to 40 degrees C, and a leukocytosis. Two patients had a transient mild elevation of pancreatic enzymes. All patients had a transient rise in liver enzymes. In conclusion, therapeutic efficacy was dependent on the tumor mass. Side effects due to the radiopharmaceutical were tolerable, and other side effects may result from the angiography procedure related manipulations. These results are encouraging for tumors up to a moderate mass.

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.

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.

Differentiation of alveolitis and pulmonary fibrosis in rabbits with magnetic resonance imaging after intrabronchial administration of bleomycin

RATIONALE AND OBJECTIVES

The authors investigate the ability of magnetic resonance imaging to differentiate alveolitis and pulmonary fibrosis by correlating magnetic resonance and pathologic findings.

METHODS

Lung damage was induced in 52 rabbits by instillation of 5 mL bleomycin sulfate (10 mg/kg) into a lower-lobe bronchus using a balloon catheter. Magnetic resonance examinations were performed in a group of 7 animals 3 hours after the initial damage, and in groups of 8 animals 24 hours and 8, 14, 30, and 80 days after the initial damage. Control animals were examined 3 hours (n = 5), 24 hours, and 8 days (n = 3 for each), respectively, after the instillation of 5 mL 0.9% sodium chloride. Magnetic resonance imaging at 1.5 T included conventional T1-weighted sequences before and after injection of gadolinium-DTPA (0.1 mmol/kg), and T2-weighted fast spin echo sequences. The signal intensity and contrast enhancement of injured lung were evaluated and compared with the contralateral healthy lung and with the lungs of control animals. All animals were killed immediately after the magnetic resonance examination, and the lungs were removed and fixed before sectioning and staining.

RESULTS

There was good correlation between signal intensity and contrast enhancement with magnetic resonance imaging and histologic examination. The early phase of acute alveolitis showed lesions with high signal intensity on both T1- and T2-weighted images and marked contrast enhancement after gadolinium-DTPA administration, whereas in the late fibrotic stage the lesions displayed significantly lower signal intensity and contrast enhancement.

CONCLUSION

Magnetic resonance imaging can differentiate between alveolitis and fibrosis by means of signal intensity and contrast enhancement after gadolinium-DTPA administration.

[MRI in typical and atypical aortic dissection]

PURPOSE

To determine the value of MRI in typical and atypical aortic dissections.

METHODS

MRI investigations on 16 patients with aortic dissections were analysed retrospectively; for 8 patients CT investigations carried out at almost the same time were available for comparison.

RESULTS

In all cases the diagnosis of aortic dissection was possible from MRI and CT. If a dissection membrane and a double lumen were present these were detected in all patients by both methods. In three patients with atypical dissections, only an asymmetrical abnormal wall thickening as sole sign for the presence of an aortic dissection was seen. A differentiation between true and false lumen was possible in 16 of 17 MRI investigations and in 5 of 8 CT investigations on the basis of differing blood flow velocities or, respectively, the detection of a thrombus in the false lumen. The relationship of the dissection membrane to the large aortic branches as well as the determination of the branch vessel origin with regard to true or false lumen could be evaluated better with MRI than with CT.

CONCLUSIONS

Thus MRI has a significant role in the diagnosis and follow-up of aortic dissections. The advantage in comparison to the alternative spiral CT technique is, in addition to the absence of radiation exposure, the better analysis of the extent of the dissection as a result of the multi-planar slice orientation (especially in the region of the aortic arch and the arch vessel origins) without the necessity to administer iodine-containing contrast media.

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.

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.

Diagnosis of pulmonary metastases with turbo-SE MR imaging

The sensitivity of MR imaging for detection of pulmonary metastases was evaluated in 23 patients. The MR imaging was performed with T2-weighted turbo-spin-echo (TSE) sequences at 1.5 T. The MR images were compared with spiral volumetric CT which served as the radiological standard. All MR images were interpreted by two radiologists without knowledge of CT findings. The MR imaging technique initially enabled correct identification of altogether 286 of 340 metastases (84 %) resulting in sensitivities of 36 % (size of nodules < 5 mm), 83 % (size of nodules 5-10 mm), 92 % (size of nodules 10-15 mm), and 100 % (size of nodules > 15 mm). Retrospectively with knowledge of CT findings an additional 39 metastases were visible; 15 remained undetected even retrospectively. The results of this paper suggest that MRI still does not have a role for screening for pulmonary metastases. It proves, however, that the incidental diagnosis of a pulmonary lesion on T2-weighted TSE images is highly reliable in representing a pulmonary nodule also visible on CT. However, thus far the malignant nature especially of small nodules detected by MRI (as by CT) remains uncertain even in patients with known malignant neoplasm.

[Dynamic 31-phosphorus magnetic resonance spectroscopy of the m. quadriceps: therapy-induced changes in arterial occlusive disease]

PURPOSE

The present investigation aimed at examining changes in muscle metabolism caused by treatment of arterial occlusive disease, using dynamic 31-phosphorus methods.

METHOD

32 patients with arterial occlusive disease were examined in a 1.5 T apparatus with a 6 cm surface coil before and after treatment. The metabolic changes in the quadriceps muscles were visualised during a 36 s phosphorus spectrum during rest, exercise (isometric and isotonic) and during a period of recovery.

RESULTS

Vascular therapy resulted in a significant increase in the duration of both types of exercise during dynamic phosphorus spectroscopy (isometric exercise: 282 s against 199 s: p = 0.002, isotonic exercise: 575 s against 222 s; p = 5 x 10(-6). After treatment, exercise-induced changes in pH (7.00 against 6.94; p = 0.004 and 7.00 against 6.93; p = 0.02) and the ratio Pi/PCr (0.34 against 0.44; p = 0.002 and 0.36 against 0.50; p = 0.009) were significantly smaller than before therapy, using a similar amount of exercise. Recovery time of Pi/PCr (45 s against 82 s; P = 10(-5) and 42 s against 57 s; p = 0.01) and pH value (154 s against 181 s; p = 0.14 and 173 s against 214 s; p = 0.22) showed significant reduction after treatment.

CONCLUSIONS

Dynamic 31-phosphorus magnetic resonance spectroscopy indicates increased mitochondrial oxidative capacity in the quadriceps muscles as evidence for increased oxygen supply to muscle tissue following vascular therapy.

[Follow-up of Crohn's disease: can hydro-MRI replace fractionated gastrointestinal passage examination?]

PURPOSE

To compare the value of hydro-MRI with follow-through examinations in the follow-up of Crohn's disease.

METHOD

22 patients known to be suffering from Crohn's disease were examined via 1.5 T-MR system; an oral contrast examination using 1000 ml of a 2.5% mannitol solution was performed in all patients. T2-weighted TSE sequences and T1-weighted SE sequences were performed before and after the intravenous injection of Gd-DTPA. To reduce movement artifacts caused by peristalsis of the gut, intravenous injection of 40 mg Buscopan was given. The findings of hydro-MRI were compared with the follow-through examinations.

RESULTS

In the upper gastrointestinal tract, the follow-through examination showed clear advantages compared with hydro-MRI for the demonstration of inflammatory changes in the gut; Hydro-MRI was, however, somewhat more reliable in the ileum and colon. It was also more sensitive than the follow-through for the demonstration of enteric fistulae (four as compared with two cases), and in demonstration extraluminal changes (free fluid in six against zero, and inflammatory adherent loops (four against zero)). Amongst the 22 patients, hydro-MRI was equal (in 10) or better (in 8) than the follow-through examination for demonstrating the intestinal manifestations of Crohn's disease, and follow-through was better in only four.

CONCLUSION

For follow-up of Crohn's disease, hydro-MRI is at least as good as follow-through examination, and is even preferable, because of the absence of radiation exposure of the usually young patients.

[Dynamic 31phosphorus magnetic resonance spectroscopy of the quadriceps muscle: metabolic changes under 2 different forms of loading]

PURPOSE

The aim of the present investigation was to examine the metabolism of the quadriceps muscles of normal young individuals using dynamic 31phosphorus magnetic resonance spectroscopy.

METHODS

22 normal individuals were examined in a 1.5T-MRT using a 6 cm surface coil. The metabolic changes in the quadriceps muscle as shown by the phosphorus spectrum were evaluated during rest, exercise (isometric and isotonic exercise) and during a 36-second period of recovery.

RESULTS

The Pi/PCr quotient rose from its resting value of 0.11 +/- 0.02 following exercise to a maximum of 0.83 +/- 0.47 (isometric) or 1.40 +/- 0.59 (isotonic) (difference p = 0.0001). Half-time recovery of Pi/PCr was 35 +/- 11 s or 31 +/- 10 s, respectively (p = 0.13). During the recovery phase Pi/PCr fell briefly but significantly below its rest value. Following an initial rise in pH, there was a continual fall. Minimum pH (6.68 +/- 0.21 and 6.53 +/- 0.27 respectively; p = 0.01) occurred in the early recovery phase. The recovery process of pH values lasted longer following isotonic than after isometric exercise (half-value recovery time 229 +/- 72 s and 146 +/- 55 s, respectively; p = 0.001).

CONCLUSION

Compared with isometric exercise, isotonic stress is more expensive in terms of metabolism. Dynamic 31phosphorus MRT spectroscopy can differentiate changes in muscle metabolism during different forms of exercise.

[Adenocarcinoma of the lobus v. azygos, characteristics of lymphogenous and hematogenous metastasis]

A tumor originating in a lobus v. azygos is very seldom. We report here on a patient with a poorly differentiated adenocarcinoma of the lobus v. azygos which exhibits a very aggressive growth. Depending on the tumor localization, the metastasis is typical and can be recognized by computertomography (CT). In spite of the large number of treatment strategies, the prognosis is poor.

[Rupture of lateral ligaments of the ankle joint: MR imaging before and after functional therapy]

PURPOSE

Documentation via MRI of the healing of ruptured lateral collateral ankle ligaments after functional therapy.

PATIENTS AND METHODS

35 patients with ankle sprain were examined by MRI and stress radiographs, 13 were operated afterwards, 22 patients underwent a functional conservative therapy and were examined by MRI and stress radiographs and second time after three months.

RESULTS

MRI reports were correct in 12 of 13 operated cases. After conservative therapy we did not find any disrupted ankle ligament. MRI showed intact ligaments thickened by scar.

CONCLUSION

MRI is able to show injuries of the lateral collateral ankle ligaments and demonstrates the healing by scar after conservative therapy.

[CT and MRI in malignant peripheral neuroectodermal tumors]

To evaluate the diagnostic accuracy of CT and MRI in the diagnosis of malignant peripheral neuroectodermal tumors (MPNT), the imaging data of nine patients with immunehistochemically proven MPNT were retrospectively analyzed. The average age was 24 years (ranging from 5 to 63 years). MRI and CT of all patients showed large tumors with direct infiltration of the surrounding structures. Intratumoral calcifications were not identified. All tumors showed equal to less high signal intensity in T1- and high signal intensity in T2-weighted images. Because of its high soft-tissue contrast, MRI is the most capable imaging modality in the diagnosis and therapy-monitoring in these tumors.

[MRI studies on the distensibility of cruciate ligaments of healthy knee joint]

AIM

Examination of the distensibility of the cruciate ligaments to evaluate the tense plasty of the cruciate ligaments.

MATERIAL AND METHOD

A functional MR study was performed using a Magnetom Open (0.2 Tesla, Fa. Siemens). We measured the length and width of the anterior and posterior cruciate ligament in volunteers (n = 12), age 20-40. We examined in 4 knee positions between maximal extension and maximal flexion.

RESULTS

Using the Wilcoxon test, the statistics do not show any significant difference between the length and width of the cruciate ligaments in the monoxial movement.

CONCLUSION

Our results may support the operative tense plasty of the cruciate ligaments although the entire complex mechanical system has not been examined.

[Imaging of metastases from thyroid carcinomas using 111In-pentetreotide scintigraphy]

There is little experience with imaging of thyroid carcinoma tissue by somatostatin receptor scintigraphy. Our case report describes an acromegalic patient, in whom 111In pentetreotide scintigraphy did not only demonstrate a receptor-positive pituitary tumor but also visualized metastases from a papillary thyroid carcinoma which had no correlate in radioiodine scintigraphy carried out under hypothyroid conditions. The possible role of this radiopharmaceutical in dedifferentiating thyroid carcinoma is discussed for its usefulness in tumor localisation and its predictive value for the outcome of an octreotide therapy.

Malignant peripheral neuroectodermal tumors in urology

During the past few years, a new tumor type has emerged in the pediatric and adolescent group of cancer patients, which has been designated malignant peripheral neuroectodermal tumor (MPNT). This tumor has some clinical and pathological signs in common with either soft-tissue sarcomas or classic Ewing's sarcoma, but is defined as a distinct entity because of its immunohistological characteristics. The tumor expresses neuronal markers, but the pattern varies: chromogranin, neuron-specific enolase, synaptophysin, protein S-100 and others. MPNT can occur in the urogenital region. The differential diagnosis on clinical grounds must include Ewing's and soft tissue sarcomas, and also Wilms' tumor and its variants. MPNT are often wide spread in the urogenital region when first diagnosed. Response to radiotherapy and combination chemotherapy is limited. Radical surgery is not always possible. The prognosis therefore remains rather poor at this time. A selection of MPNT patients is presented to demonstrate the various problems associated with this diagnosis. MRI and CT of all patients showed large tumors with direct infiltration of the surrounding structures. MRI is the best imaging modality for diagnosis and therapy monitoring in these tumors, because of its high soft-tissue contrast.

[Optimizing pelvic MR diagnosis with a new gastrointestinal contrast medium]

AIM

Optimization of pelvic MRI by a new concept of water-equivalent bowel contrast agent.

METHODS

We performed contrast enhancement of the bowel by oral application of 1000 ml of an aqueous mannitol solution one hour before pelvic MRI. In addition we performed an enema by 250 ml of water in one patient.

RESULTS

Oral and rectal contrast enhancement of the bowel was tolerated without complications by our patients. Pelvic MRI was improved by a better delineation of the bowel.

CONCLUSION

The concept of water-equivalent bowel enhancement is promising. It must be assessed by further studies; in particular, it must be compared with the available concepts of positive and negative bowel contrast enhancement.

[A mannitol solution as an oral contrast medium in pelvic MRT]

PURPOSE

Improvement of pelvic MRI using peroral administration of an aqueous mannitol solution.

METHODS

We retrospectively evaluated magnetic resonance examinations of 72 patients with suspected or proven pelvic abnormalities: In 36 patients, no bowel marking was carried out. In further 36 patients, we performed a contrast enhancement of the bowel by oral application of 1000 ml of an aqueous mannitol solution.

RESULTS

8/36 (22%) patients suffered from diarrhoea, nausea or meteorism as a result of mannitol application. In group 2, an excellent bowel marking of the small intestine could be obtained in 36/36 (100%) patients. Contrast enhancement of the bowel significantly improved delineation between intestinal structures and pelvic organs or pathologic lesions, respectively. In summary, bowel marking was desirable in 25/36 (69%) of group 1 and helpful in 26/36 (72%) of group 2.

CONCLUSION

Aqueous mannitol solution is a safe bowel contrast agent and improves the diagnostic value of pelvic MRI, but in some cases delineation between marked bowel and cystic pelvic lesions may be uncertain.

Parosteal osteosarcoma of the talus

A case of parosteal osteosarcoma in the very rare location of the talus is presented. The radiological, pathological, and clinical characteristics of parosteal osteosarcoma are described and the differential diagnosis discussed.

[Solitary epithelioid hemangioendothelioma, a rare vascular tumor of the lung]

The following case report describes a solitary epithelioid haemangioendothelioma of the lung as an uncommon radiomorphologic differential diagnosis of an aspergilloma. Epithelioid haemangioendotheliomas are rare low-grade malignant mesenchymal tumours that typically appear multifocally in the body.

Pulmonary artery sarcoma mimicking chronic thromboembolic disease: computed tomography and magnetic resonance imaging findings

PURPOSE

The diagnosis of the rare primary malignant tumors of the pulmonary arteries is often delayed as symptoms are nonspecific.

METHODS

Computed tomography (CT) and magnetic resonance imaging (MRI) of three patients with occlusion of the right pulmonary artery, two with sarcoma and one with chronic thromboembolic disease were analyzed for discriminating diagnostic criteria.

RESULTS

Criteria suggesting pulmonary artery sarcoma are inhomogeneous high or low attenuation (hemorrhage, necrosis), soft-tissue density in pulmonary arteries, vascular distension, enhancement after administration of gadopentetate dimeglumine. Criteria for chronic thromboembolic disease are homogeneous soft-tissue lesions, abrupt vascular narrowings and cut-offs, as well as regional parenchymal hyperdensities.

CONCLUSION

CT and MRI provide complementary findings suggesting advanced pulmonary artery sarcoma instead of chronic thromboembolism.

[1H-MR spectroscopic imaging: an approach to evaluating alcohol breakdown in the brain]

The local alcohol concentration in the human brain was determined in 10 cases using MR spectroscopic imaging. Therefore 7 subjects with an average blood alcohol concentration of 0.8/000 were examined after oral intake of alcoholic beverages. Varying alcohol concentration was found intracranially which was recorded spectroscopically w.r.t. time. Relatively high ethanol concentrations were determined in the cerebellum as well as in the ventricular system. Contrary to this, lower concentrations were found in the regions of grey and white matter.

Effectiveness of platinum wire microcoils for venous occlusion: a study on patients treated for venogenic impotence

The purpose of this study was to determine the effectiveness of venous occlusions achieved by embolization with platinum microwire coils. Follow-up venographies in 19 patients, 1-20 months (average 8 months) after coil embolizations, were evaluated. Twenty-eight of 126 (22.2%) coil embolizations were found to be patent. Coils which had not formed or partially formed upon embolization had a patency/recanalization rate of 37.5% (12/32). Among coils which had formed nearly completely or completely only 16 of 95 (17%) showed venous patency. As coil embolization had been augmented by sclerotherapy in all patients, the effectiveness of long-term venous occlusion by platinum wire coils alone is probably lower than our figures indicate. We conclude that attention to complete or near-complete coil formation upon embolization appears to be critical to maximize long-term occlusive effects of platinum microcoils. Their effectiveness in general, however, is lower than anticipated.

[Computed tomography of the kidneys following tumor enucleation]

Two weeks to 120 months after enucleation of renal tumours the postoperative defects were correctly localized by renal computed tomography in 34 patients. Typical defect morphology was either wedge-shaped or concave. No dependence on tumour localization, tumour size, operative technique or a certain surgeon was observed. The cortical defects were smaller (mean 2.0 cm) than the original, prominent tumours (mean 3.4 cm). In small defects without tension suture of the capsule is sufficient, leading to minor defects. Larger defects were closed with a retroperitoneal or free peritoneal fat flap resulting in larger residual defects. In case of intra- or postoperative bleeding, CT could demonstrate parenchymatous or perirenal haematomas or delayed perfusion of adjacent parenchyma. In one patient a recurrent tumour was correctly diagnosed, different postoperative complications (such as abscesses) were not observed.

[Application possibilities of MR arthrography in diseases of the shoulder joint]

In a prospective study possible indications for MR arthrography of the shoulder were evaluated. 37 patients were examined before and after intraarticular administration of a 2-mmolar solution of Gd-DTPA. MR arthrography was performed if there was no joint effusion and/or an uncertain finding concerning the rotator cuff or the capsulolabral complex on plain MR images. MR arthrography leads to a better demonstration of labrum pathology in 11/22 patients and to a superior delineation of the capsuloligamentous apparatus in 20/22 cases. In 9/15 patients with impingement lesions MR arthrography allowed a differentiation of severe tendinitis from partial and small full-thickness tears of the rotator cuff. MR arthrography of the shoulder joint enhances the accuracy of MR in case of an uncertain finding on plain MR images.

[Computed tomography in malignant primary soft tissue tumors]

The results of CT examinations in 36 patients suffering from histologically confirmed malignant primary tumours of the soft tissues are presented (6 rhabdomyosarcomas, 4 leiomyosarcomas, 6 liposarcomas, 4 malignant schwannomas, 5 malignant fibrous histiocytomas, 4 malignant haemangiopericytomas, 3 angiosarcomas, 1 fibrosarcoma, 1 renal sarcoma, 2 malignant mesenchymal tumours without histologically clear classification). The CT image alone will not yield information on the type of tumour or on the tumour status. However, CT continues to rank in the diagnosis of tumours of the soft tissues and is even superior to MR especially in the identification of gas accumulations due to infection in a tumour of the soft tissues that is otherwise unclear. Comparing the literature conclude that MR is now the imaging method of choice in the diagnosis of soft tissue tumours.

[MRT for surgical planning in anal atresia]

We evaluated in this study the value of preoperative examinations of anal atresia with an optimised MRI strategy. 13 patients with anorectal anomalies, most of them younger than one year, underwent an MRI examination of the pelvis. 10 of these patients were operated afterwards. Compared with the situs shown by the operation the results of the MRI examination were very exact in all cases in respect of the level of atresia and the development of the striated muscle complex. Fistulas could be completely described in most cases. MRI demonstrated additional lesions in some patients which were of great importance for planning the further treatment of the patients. As a consequence MRI can give valid information on anal atresia for planning the operative treatment.

Percutaneous penile venoablation for treatment of impotence

Percutaneous penile venoablation with sclerosing agents and coils was performed in 58 patients. Of 104 ablations attempted, 44 of 51 (86%) transpenile, and 46 of 53 (86.7%) retrograde interventions were technically successful. In 40 patients (69%) erectile function improved (intercourse was possible in 21 without additional measures). Initially improved erectile function deteriorated in 24 patients during follow-up (in an average of 6 months); in 15 of these, intercourse was still possible with injection of vasoactive drugs. In 7 patients, repeat venoablation improved erectile function again. Hot contrast medium was slightly superior to sodium morrhuate as a sclerosing agent. In successfully treated patients, the average decrease in venous leakage was 30 ml/min vs 13 ml/min in treatment failures, with considerable overlap between both groups. Only minor complications were observed. We conclude that percutaneous penile venoablation is technically feasible, and safe. Whether the procedure will have a definite role in the treatment of venogenic impotence, however, still has to be determined.

[The importance of imaging techniques in gallstone disease]

The available surgical and non-surgical therapy options for treatment of gallstone disease are presented. Conventional cholecystectomy is regarded as standard therapy of symptomatic cholecystolithiasis. Other modes of therapy may be indicated under certain circumstances, depending on the results of imaging procedures. In this context conventional X-ray examination, oral and intravenous cholecystography, sonography, computed tomography, endoscopic retrograde cholangiography/cholecystography, and magnetic resonance imaging are discussed and their influence on therapeutic decisions is explained.

[A comparison of the value of magnetic resonance tomography and computed tomography in Nelson syndrome patients]

The hypophyses of 13 patients with Nelson syndrome following bilateral adrenalectomy were examined by MRI and CT. Diffuse enlargement of the hypophysis was demonstrated in 8 patients by CT and in 9 by MRI. Compared with CT, MRI provides better demonstration of tumour development, such as abnormal convexity of the cranial margin of the hypophysis (MRI 4/13, CT 1/13), displacement of the infundibulum (MRI 4/13, CT 0/13) or optic chiasm (MRI 2/13, CT 0/13). MRI also provides diagnostically important differentiation between scar tissue and recurrence of tumour following hypophysectomy (MRI 1/3, CT 0/3) and more accurate demonstration of infiltration of the cavernous sinus (MRI 4/13, CT 2/13). CT is superior only in showing the floor of the sella. MRI is the method of choice for imaging in cases of Nelson syndrome.

Technetium-99m-HMPAO brain SPECT in medically intractable temporal lobe epilepsy: a postoperative evaluation

The aim of the present study was to evaluate the predictive value of interictal single-photon emission computed tomography (SPECT) using technetium-99m-labeled hexamethyl propyleneamine oxime (HMPAO) for the outcome after temporal lobectomy in patients with complex partial seizures. Out of 40 patients, 21 underwent right-sided and 19 left-sided temporal lobectomy. EEG and CT/MRI were primarily used to select the side of surgery. SPECT results correlated with temporal lobectomy in 68% of the patients. After surgical intervention, memory function was tested for both sides. Following left-sided temporal lobectomy, verbal memory was impaired in 8% of the patients, if SPECT agreed with the side selected for surgery, but in 83%, if it diverged from it. In the present study, there was no relationship between SPECT concordance with the side of temporal lobectomy and outcome as to seizure frequency and non-verbal memory. We conclude that preoperative interictal HMPAO/SPECT can contribute to the prediction of postoperative verbal memory function and that this method should be considered for use prior to temporal lobectomy.

[A comparison of imaging procedures in the diagnosis of gallbladder and bile duct carcinomas]

Fourteen patients with carcinomas of the gallbladder and eight patients with biliary duct carcinomas were examined by CT, sonography, percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiography (ERC) and angiography. The results were compared retrospectively. Sonography proved suitable as a screening method. For accurate demonstration, this should be supplemented by CT. PTC and ERC demonstrate intraductal extension of biliary carcinomas and of gallbladder carcinomas infiltrating the bile ducts. The value of angiography consists merely in the preoperative demonstration of the vascular anatomy.

[Computed tomography in malignant primary bone tumors]

The importance of computed tomography is examined in malignant primary bone tumours using a strongly defined examination group of 13 Patients (six Ewing's-sarcomas, five osteosarcomas, one chondrosarcoma and one spindle-shaped cell sarcoma). Computed tomography is judged superior compared to plain radiographs in recognition of bone marrow infiltration and presentation of parosteal tumour parts as well as in analysis of tissue components of tumours, CT is especially suitable for therapy planning and evaluating response to therapy. CT does not provide sufficient diagnostic information to determine dignity and exact diagnosis of bone tumours.

Multiple nodular foci in the liver associated with chronic hepatic porphyria after previous treatment of breast cancer

More than 7 years after the diagnosis and treatment of breast cancer (T1N1aM0), multiple nodular foci were observed in the liver of a 40-year-old woman at ultrasonographic examination. The lesions were confirmed by CT scan, but CT-guided liver biopsy revealed only non-specific alterations. At subsequent peritoneoscopic examination, bluish-brown foci were indeed visible on the liver surface, but guided liver biopsies again failed to corroborate the suspected metastases. Instead, histology showed mild portal fibrosis, moderate steatosis and siderosis of hepatocytes, as before. Only the intense red fluorescence of part of the biopsy material under Wood's light suggested the diagnosis of chronic hepatic porphyria or porphyria cutanea tarda, here presumably as a consequence of prolonged alcohol consumption. Subsequent porphyrin studies in urine, faeces and plasma yielded the typical constellation of latent porphyria cutanea tarda (chronic hepatic porphyria type C). The activity of erythrocyte uroporphyrinogen decarboxylase was normal, which argued against a genetic predisposition. After 1 year of strict alcohol abstinence and low-dose chloroquine treatment the "nodular foci" in the liver were no longer visible on ultrasonogram and CT scan; only proton-weighted NMR imaging (SE 1500/30) still showed ill-defined areas of higher signal intensity. The renal excretion of porphyrins had decreased considerably. The levels are now consistent with the diagnosis of subclinical chronic hepatic porphyria type A. Modern non-invasive imaging techniques are tremendously useful, but they have their pitfalls. Focal liver lesions may present serious diagnostic problems, especially when they are found in a patient with a history of carcinoma at an extrahepatic primary site. A rare example is described.(ABSTRACT TRUNCATED AT 250 WORDS)

[The value of x-ray signs in the follow-up of Crohn's disease]

The value of various radiological signs in the follow-up of Crohn's disease has been studied in 175 radiological examinations of the gastro-intestinal tract in 39 patients. Changes in the significant radiological signs in Crohn's disease, such as spicula, cobblestone pattern, stenoses and fistulas, provide information on the development of the disease and on the effect of treatment. The signs have a prognostic significance only insofar as their persistence excludes any improvement. Radiological follow-up is particularly useful for spotting complications and for the early recognition of recurrences.

[Radiological diagnosis and therapy of postoperative abdominal lymphoceles]

Eighty-one patients with postoperative abdominal lymphoceles were examined by CT and ultrasound. Both methods provide accurate information regarding localisation and extent of the lymphocele. In 51 patients conservative treatment under sonographic or CT observation was carried out. In seven patients, irradiation lead to complete regression. In 21 patients, interventional radiological therapy was carried out with simultaneous irradiation in seven cases. In five patients surgery was necessary. Asymptomatic lymphoceles should be treated conservatively and only after the appearance of clinical symptoms should interventional radiological or surgical measures be carried out.

[Acute renal failure in a prominent aneurysm of the iliac artery]

This is a report on a patient of 64 years of age who was admitted to hospital as an inpatient thirteen years after obliteration of the iliac artery with an extension plasty. He complained of irregular stools and occasional abdominal pain. Imaging methods were employed on account of a drop in the haemoglobin count, progressive renal insufficiency and a palpable tumor in the lower abdomen. These methods supplied evidence of a false aneurysm originating from the iliac endarterectomy, combined with compression of the ureter and small intestine. Based on the present case report, the general complex of problems in diagnosing aneurysms of the iliac artery is discussed.

[MR tomography of hepatic hemangioma]

MR tomography of the liver using 1.5 T has been carried out in 63 patients with focal lesions in order to demonstrate haemangiomas and to differentiate these from primary and secondary malignant liver tumours. This differentiation was possible in all patients, using conventional spin echo and inversion recovery sequences in combination with sonography. Accuracy was much less good when using gradient echo sequences. With sufficiently large tumours, measurement of relaxation time made possible diagnosis of all the 22 haemangiomas.

[Arterial DSA using a trans-brachial 4-French catheter]

Arterial DSA by the trans-brachial route, using a 4-French-catheter has been performed in 33 patients. In these patients, trans-femoral DSA is contra-indicated because of previous surgery or markedly reduced femoral pulsation. Intravenous DSA was not expected to provide diagnostically adequate information in these patients, in view of the well known method limitations of this method. In 20 patients, the abdominal aorta, pelvis and lower limb arteries were examined, in 14 only the leg arteries, in ten patients the arteries in the neck and in three patients the thoracic and abdominal aorta. Trans-brachial DSA provided good demonstration of the vessels in all cases.