[Pathological changes of the hypopharynx in the focus of imaging]. / Pathologische Veränderungen des Hypopharynx im Brennpunkt der Bildgebung.

The spectrum of pathological changes in anatomical sections of the hypopharynx ranges from benign pathologies to hypopharyngeal carcinoma. Beside the clinical status and the endoscopic evaluation performed by ear, nose and throat specialists, imaging techniques play an important role in pre-therapeutic and post-therapeutic diagnostics and in the follow-up of pharyngeal disease patterns, especially for malignant lesions. A conventional x-ray swallow examination, contrast-enhanced multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI), as well as positron emission tomography (PET) and positron emission tomography computed tomography (PET-CT) are applied depending on the medical question and disease. Especially in radiological oncology, it is extremely important in regions which are clinically difficult to assess to determine the exact localization and extent of hypopharyngeal pathologies to plan the optimal therapy for the patient. This article demonstrates the radiological appearance of pathological changes of the hypopharynx and discusses in particular the hypopharynx carcinoma in the focus of pre-therapeutic and post-therapeutic imaging.

Can quantitative diffusion-weighted MR imaging differentiate benign and malignant cold thyroid nodules? Initial results in 25 patients.

BACKGROUND AND PURPOSE: The characterization of cold nodules of the thyroid gland is mandatory because approximately 20% of these nodules are of malignant origin. The purpose of this study was to evaluate the distinction of cold thyroid nodules by using quantitative diffusion-weighted MR imaging (DWI). MATERIALS AND METHODS: In 25 patients with cold nodules on scintigraphy and suggestive findings at fine-needle aspiration, thyroid carcinoma was suggested. In these patients, cold nodules and the normal parenchyma of the contralateral thyroid lobe were prospectively investigated with quantitative DWI (echo-planar imaging sequence; maximum b-value, 800 s/mm(2)) before surgery. The differences in the mean apparent diffusion coefficient (ADC) values in benign and malignant nodules were tested by using a Mann-Whitney U test. RESULTS: Histologically, there were 20 carcinomas with a minimum size of 8 mm and 5 adenomas. The mean ADC values (in 10(-3) mm(2)/s) differed significantly among carcinoma, adenoma, and normal parenchyma (P < .05). The ranges (95% confidence interval) of the ADC values for carcinoma (2.43-3.037), adenoma (1.626-2.233), and normal parenchyma (1.253-1.602) showed no overlap. When an ADC value of 2.25 or higher was used for predicting malignancy, the highest accuracy of 88%, with 85% sensitivity and 100% specificity, was obtained. CONCLUSIONS: Quantitative DWI seems to be a feasible tool with which to differentiate thyroid carcinomas from adenomas; however, further studies are required including larger numbers of patients to confirm our results.

Modern imaging lymph node staging of the head and neck region.

The aim of this paper is to describe the modern imaging methods, their techniques, ability, and performance in staging head and neck lymph nodes. Also, the imaging morphologies of benign and malignant lymph nodes according to the different imaging techniques will be delineated. The imaging techniques of ultrasound including contrast-enhanced ultrasound, computed tomography and magnetic resonance imaging (MRI) including diffusing weighted imaging and contrast-enhanced iron oxide MRI are explained. Imaging examples of the different modalities of benign and malignant transformed lymph nodes will be demonstrated. Furthermore, the diagnostic sensitivity of each modality will be delineated and further aspects of modern lymph node staging of the head and neck region such as those with special contrast agents will be described. These modern imaging modalities have sensitivity rates of 70-80% depending on the technical equipment and ability and on the experience of the investigator. The technique of near-infrared-imaging will be mentioned in another article in this journal. Also the value of biopsy techniques including recently developed ultrasonography guided needle biopsy with molecular analysis of the cells of about 97-100% accuracy in diagnosing benign from malignant lymph nodes will be mentioned. Overall, the reader will get an overview of the present imaging modalities to potentially stage correctly lymph nodes in the head and neck region to facilitate the therapeutic procedure.

Rotator cuff tears in asymptomatic individuals: a clinical and ultrasonographic screening study.

OBJECTIVE: To determine the prevalence and clinical impact of rotator cuff tears in asymptomatic volunteers. MATERIALS AND METHODS: Sonographic examinations of the shoulder of 212 asymptomatic individuals between 18 and 85 years old were performed by a single experienced operator. The prevalence and location of complete rotator cuff tears were evaluated. The clinical assessment was based on the Constant Score. Magnetic resonance imaging (MRI) of the shoulder was obtained in those patients where US showed rotator cuff pathology. RESULTS: Ultrasound showed a complete rupture of the supraspinatus tendon in 6% of 212 patients from 56 to 83 years of age (mean: 67 years). MRI confirmed a complete rupture of the supraspinatus tendon in 90%. All patients reported no functional deficits, although strength was significantly lower in the patient group with complete supraspinatus tendon tear (P < 0.01). CONCLUSION: There is a higher prevalence in older individuals of rotator cuff tendon tears that cause no pain or decrease in activities of daily living.

[Bone metastases: new trends in diagnostic imaging]. / Skelettmetastasen: Neue Trends in der bildgebenden Diagnostik.

Skeletal metastases are common in patients with cancers of the breast, lung, kidneys, prostate, and thyroid gland. Two main aspects have to be considered in diagnostic imaging. Screening in patients with known primary tumor. Triphasic Sczintigraphy is the imaging modality of choice for this purpose, however, whole-body-magnetic resonance imaging seems to be a potential alternative. Evaluation of suspicious skeletal lesions, which is currently dominated by magnetic resonance imaging. New perspectives for preoperative staging as well as for reconstruction- and implant-surgery are made available by multidetector-row-computed tomography. Non-invasive techniques, such as diffusion weighted imaging, positron emission tomography and positron emission tomography/computed tomography are now available, which seem to have potential for reliable tissue characterization. This feature is critical for monitoring treatment response in oncology.

Skeletal cystic angiomatosis with severe hip joint deformation resembling massive osteolysis.

An aggressive destruction pattern resulting in joint deformation has not been described in skeletal cystic angiomatosis (SCA) so far. We present the case of a 6-year-old boy with such findings strongly resembling Gorham's disease (massive osteolysis). Since the prognosis of the latter entity tends to be less favorable than in SCA, particularly SCA without extraskeletal involvement, careful differentiation of both disorders appears to be important.

Scaphoid fractures: evaluation with high-spatial-resolution US initial results.

PURPOSE: To evaluate the diagnostic accuracy of high-spatial-resolution ultrasonography (US) in the diagnosis of scaphoid fractures. MATERIALS AND METHODS: In 72 hours after acute wrist trauma, 15 consecutive patients were examined for possible scaphoid fractures clinically and with conventional radiographs, including scaphoid views. Thereafter, high-spatial-resolution US was performed by two experienced radiologists blinded to the results of the previously performed investigations. High-spatial-resolution US of the scaphoid bones was performed from the palmar, lateral, and dorsal directions in the longitudinal and transverse planes. US findings indicative of a scaphoid fracture were cortical discontinuity and/or periosteal elevation. Finally, magnetic resonance (MR) images (short inversion time inversion-recovery, T1- and T2*-weighted) (ie, the standard) of the affected wrist were obtained and evaluated for a possible scaphoid fracture by two radiologists in consensus. RESULTS: Nine of 15 patients had scaphoid fractures. Seven (78%) of nine patients had positive findings at high-spatial-resolution US and five (56%) had such findings at conventional radiography (ie, four occult scaphoid fractures), with an accuracy of 87% and 73%, respectively. Two (50%) of four radiographically occult scaphoid fractures were depicted with high-spatial-resolution US. Sonographic findings of scaphoid fractures were either cortical discontinuity (n = 4), periosteal elevation (n = 2), or a combination of these two findings (n = 1). CONCLUSION: High-spatial-resolution US is a reliable diagnostic tool for the evaluation of occult scaphoid fractures and should be considered an adequate alternative diagnostic tool prior to computed tomography or MR imaging.

Role of Doppler sonography in the evaluation of accessory spleens after splenectomy.

OBJECTIVE: Splenectomy influences the Doppler blood flow pattern in the splenic artery. Blood flow in this vessel might return to normal if an accessory spleen increases in size after splenectomy. Our objective was to evaluate the resistive index of the splenic artery depending on the presence or absence of a hypertrophic accessory spleen in splenectomized patients. METHODS: The resistive index of the splenic artery was evaluated by duplex Doppler sonography in 19 splenectomized patients (8 with a hypertrophic accessory spleen) and in 8 healthy volunteers. The resistive index was measured within 3 cm of the origin of the splenic artery, and 3 different measurements were averaged. The presence or absence of a hypertrophic accessory spleen was diagnosed on the basis of sonography, computed tomography, magnetic resonance imaging, or scintigraphy, as well as by the presence or absence of Howell-Jolly bodies on a peripheral blood smear. RESULTS: The resistive index of the splenic artery in the splenectomized patients without a hypertrophic accessory spleen (mean +/- SD, 0.82 +/- 0.06; n = 11) was significantly (P < or = .0001) higher than in splenectomized patients with a hypertrophic accessory spleen (0.63 +/- 0.06; n = 8) and in control subjects (0.63 +/- 0.05; n = 8). CONCLUSIONS: In the splenectomized patient, a hypertrophic accessory spleen is associated with a normal resistive index in the splenic artery.

[The value of diffusion-weighted MRT in assessing the bone marrow changes in vertebral metastases]. / Wertigkeit der diffusionsgewichteten MRT in der Beurteilung von Knochenmarkveränderungen bei Wirbelkörpermetastasen.

AIM OF THE STUDY: The aim of the study was the evaluation of the diffusion coefficient (ADC) of vertebral metastasis and regular vertebral bodies with diffusion weighted MRI (DWI). DWI evaluates the tissue-specific molecular diffusion of protons. In tissues with high cell densities (neoplasm) a decreased ADC can be expected due to restricted diffusion according to an exaggerated amount of intra- and intercellular membranes (i.e. diffusion barriers). METHODS: In 5 breast cancer patients the ADC of both known vertebral metastases and of adjacent regular vertebral bodies were measured with DWI (1.0 T; Phased-Array-Body-Coil; b: 880 and 440 s/mm2). RESULTS: The ADC of regular vertebral bodies (1.3 +/- 0.23 x 10(-3) s/mm2) was significantly (p < or = 0.0002) higher than in vertebral metastases (0.39 +/- 0.11 x 10(-3) s/mm2). CONCLUSIONS: These data demonstrate that the ADC can be reliably measured in vertebral bodies. The quantitative evaluation of the ADC in vertebral bodies seems to be an objective and comparable parameter for differentiating malign from benign vertebral tissue.

Preoperative fast MRI of brain tumors using three-dimensional segmented echo planar imaging compared to three-dimensional gradient echo technique.

The purpose of this study was to compare the diagnostic efficacy of a newly developed T(1)-weighted three-dimensional segmented echo planar imaging (3D EPI) sequence versus a conventional T(1)-weighted three dimensional spoiled gradient echo (3D GRE) sequence in the evaluation of brain tumors. Forty-four patients with cerebral tumors and infections were examined on a 1.0 T MR unit with 23 mT/m gradient strength. The total scan time for the T(1) 3D EPI sequence was 2 min 12 s, and for a conventional 3D GRE sequence it was 4 min 59 s. Both sequences were performed after administration of a contrast agent. The images were analyzed by three radiologists. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, and image artifacts. In addition, signal-to-noise and contrast-to-noise-ratio (C/N) were calculated. The gray-white differentiation and C/N ratio of 3D EPI were found to be inferior to conventional 3D GRE images, but the difference was not statistically significant. In the qualitative comparison, lesion detection and conspicuity of 3D EPI images and conventional 3D GRE images were similar, but a tow-fold reduction of the scanning time was obtained. With the 3D EPI technique, a 50% scan time reduction could be achieved with acceptable image quality compared to conventional 3D GRE. Thus, the 3D EPI technique could replace conventional 3D GRE in the preoperative imaging of brain.

MR imaging of the ischiopubic synchondrosis.

The ischiopubic synchondrosis (IPS) is a temporary joint, occurring in childhood prior to fusion of the ischial and pubic bones. On conventional radiographs this tumor-like appearance is a well known normal anatomic variant, however, there are no reports in the literature of the appearance of IPS on MRI. Therefore the purpose of this study was to evaluate typical magnetic resonance features of the IPS. All pelvic MRIs from 1/1992 to 4/1998 of children ranging in age from 4 to 16 years, who were scanned for reasons other than bone disorders, were retrospectively investigated. Twenty-eight children were included and the morphologic appearance of IPS on MRI was evaluated. Seventeen (61%) of these 28 children had the following findings of IPS on MRI. Listed in order of frequency we found signal alteration of the ischiopubic fusion zone [hyperintense on T(2) with fat-saturation (89%) or STIR (74%), hypointense on T(1) (71%)], fibrous "bridging" (68%) [hypointense band on all sequences in perpendicular orientation to the axis of the inferior pubic ramus], fusiform swelling (68%), signal alteration of the adjacent soft tissue (57%) and irregular margins (56%). In 10 children contrast enhanced scans were available for evaluation, showing contrast enhancement of the bone marrow in 83.3% and of the adjacent soft tissue in 66.7%. Fusiform swelling of the ischiopubic fusion zone, signal alteration and contrast enhancement of both the bone marrow and the adjacent soft-tissue are characteristic features of the IPS on MRI, which may be due to mechanical stress at this temporary joint. These features are nonspecific and may resemble tumor, infection or trauma. Fibrous "bridging" was the only finding on MRI, which has not been described for any other entity and thus, it seems to be a characteristic MRI-feature.

Successful conservative treatment of severe renal candidosis with fungus balls.

Partial fungal obstruction of the renal collecting system is an unusual finding among infants that poses specific management problems. We report a patient with sepsis and fungal infection of the kidneys post surgery who presented with bilateral fungus balls and was successfully managed by conservative measures. Sonography is the imaging technique of choice in the diagnosis and follow-up of such patients. The need for prompt diagnosis in high-risk patients and the role of sonography are discussed.

Role of tryptophan in the elevated serotonin-turnover in hepatic encephalopathy.

The increase of the brain levels of 5-hydroxyindoleacetic acid (5-HIAA) in hepatic encephalopathy (HE) suggests an increased turnover of serotonin (5-HT). To study the role of tryptophan on the increased brain 5-HT metabolism in HE, we attempted to monitor brain levels of tryptophan in rats with thioacetamide-induced acute liver failure by intravenous infusion of branched-chain amino acids (BCAA). The effect of this treatment on 5-HT synthesis and metabolism was investigated in five brain areas. BCAA-infusions (1 and 2 gm/kg/24 h) increased the ratio BCAA/aromatic amino acids in plasma two- and fourfold, respectively, and lowered both plasma and brain levels of tryptophan. At the higher BCAA-dose all parameters suggesting an altered brain 5-HT metabolism (increased brain levels of 5-HT and 5-HIAA, increased 5-HIAA/5-HT ratio) were almost completely normalized. These results provide further evidence for the role of tryptophan in the elevation of brain 5-HT metabolism and for a potential role of BCAA in the treatment of HE.

Hepatic perfusion after liver transplantation: noninvasive measurement with dynamic single-section CT.

PURPOSE: To compare hepatic perfusion values after orthotopic liver transplantation with those in healthy volunteers. MATERIALS AND METHODS: Dynamic single-section computed tomography (CT) of the liver was performed in 50 participants, including 30 study patients who had undergone orthotopic liver transplantation and had no clinical evidence of postoperative complications (mean age, 53.7 years) and 20 healthy volunteers (control subjects) (mean age, 59.0 years). CT scans were obtained at a single level to include the liver, spleen, aorta, and portal vein. Scans were obtained over 88 seconds (one baseline scan followed by 16 scans every 2 seconds and, then, eight scans every 7 seconds) beginning with the injection of 40 mL of contrast agent (flow rate, 10 mL/sec). On each CT scan, the attenuation of these organs was measured in regions of interest to provide time-attenuation curves. From these data, the arterial, portal venous, and total perfusion of the liver were calculated, and the hepatic perfusion index was assessed. RESULTS: In control subjects and study patients, respectively, mean arterial hepatic perfusion was 0.16 and 0.25 mL/min/mL (P = .001 [two-tailed paired Student t test]), mean portal venous perfusion was 1.22 and 1.26 mL/min/mL, mean total liver perfusion was 1.38 and 1.50 mL/min/mL (difference not significant), and the mean hepatic perfusion index was 0.12 and 0.16 (P = .002). CONCLUSION: Arterial hepatic perfusion was significantly increased after orthotopic liver transplantation, but differences in portal venous and total liver perfusion were not significant. Dynamic single-section CT might also help evaluate hepatic vascular complications, chronic transplant rejection, and hepatic perfusion in liver cirrhosis.

Testicular blood flow in boys as assessed at color Doppler and power Doppler sonography.

PURPOSE: To investigate at which age testicular blood flow can be demonstrated consistently by color Doppler sonography and power Doppler sonography. MATERIALS AND METHODS: In this prospective study, 172 normal testes of 86 boys (age range, 4 days to 15 years) were examined with gray-scale ultrasound, color Doppler sonography, and power Doppler sonography. Presence of supratesticular and capsular vessels was determined, testicular volumes were assessed, and intratesticular vessels were quantified by using a semiquantitative score. RESULTS: Supratesticular and capsular vessels were always detectable. Demonstration of intratesticular vessels was inconsistent until 8 years of age at power Doppler sonography and until 12 years of age at color Doppler sonography. Power Doppler sonography depicted more vessels than did color Doppler sonography in 37 (22%) testes (P = .001), and it depicted vessels in 13 (25%) of 51 testes in which color Doppler sonography could not (P = .0002). Correlation between the number of visible intratesticular vessels was slightly closer with age than with testicular volume (r = .59, r = .55 for color Doppler sonography and power Doppler sonography, respectively). CONCLUSION: Intratesticular blood flow can be detected more sensitively and more consistently from a younger age on with power Doppler sonography than with color Doppler sonography.

Modulation of hepatic encephalopathy in rats with thioacetamide-induced acute liver failure by serotonin antagonists.

OBJECTIVE: Accumulated neurochemical data in different animal models of fulminant hepatic failure and in humans with hepatic encephalopathy suggest that serotoninergic tone is increased in the brain in hepatic encephalopathy. Since neurochemical alterations may not have behavioural or electrophysiological consequences the contribution of the serotoninergic system to the pathogenesis of hepatic encephalopathy was explored. METHODS: The effects of drugs modulating serotoninergic neurotransmission, the nonselective serotonin receptor antagonist methysergide and the serotonin2 receptor antagonist seganserin were tested neuropharmacologically in thioacetamide-induced acute liver failure in rats. RESULTS: Methysergide had no effect in control rats, but dose dependently increased motor activity in stage II-III hepatic encephalopathy by 232% (5 mg/kg methysergide), 531% (10 mg/kg) and 507% (20 mg/kg). In contrast, seganserin had no effect in encephalopathic rats. CONCLUSION: It is suggested that the beneficial effects of methysergide are serotonin, receptor mediated. Overall the results suggest that serotoninergic mechanisms contribute to some of the behavioural manifestations of hepatic encephalopathy in this animal model.