Pathways in the diagnosis of prevertebral tendinitis.

INTRODUCTION: The prevertebral tendinitis is an inflammatory process, which affects the cervicothoracic prevertebral muscles. This extremely rare entity was first described by Hartley and Fahlgren in 1964 and until now there are just some case reports dealing with this process. Unfortunately it is quite easy to misdiagnose or mistake the prevertebral tendinitis as an abscess, because of the imaging features. The aim of this case series is to offer guidelines in the diagnosis of this rare disease to prevent unnecessary surgery. MATERIAL AND METHODS: Six patients with already by imaging or retrospectively after surgery by pathologic report diagnosed prevertebral tendinitis were included in this study. None of these patients suffered from a chronically inflammatory disease. Three patients just received contrast enhanced computed tomography (CT) and another group of three patients received magnetic resonance imaging (MRI). In two out of three MRI examinations, we additionally performed diffusion weighted images and calculated the apparent diffusion coefficient (ADC) map. The laboratory reports obtained on the day of the computed tomography (CT) or magnetic resonance imaging (MRI) examinations were reviewed for C-reactive protein (CRP) and white blood cell count (WBCC). RESULTS: All patients revealed a prevertebral cervical effusion. Five out of six patients showed amorphous calcifications in the tendon of the prevertebral muscles. In one case calcifications could not be identified at all because of very strong beam hardening artefacts caused by dental prothesis. The CRP values were increased in all patients (mean value 44.9 mg/l; SD ± 28.3). However, WBCC remained normal (mean value 8.4G/l; SD ± 2.7). Only for the two patients who received DWI it was possible to assess the quality of the prevertebral fluid accumulation and to detect the benign prevertebral effusion, which is typical for the retropharyngeal tendinitis. CONCLUSION: According to the experience with our patients the best imaging feature is MRI with DWI and ADC map to reveal the benign prevertebral effusion and confirm the diagnosis of prevertebral tendinitis. In some cases MRI might not be available. Here we recommend CT scans to detect typical prevertebral calcifications. Especially a slight elevation of CRP and normal WBCC make the prevertebral tendinitis more likely.

Diagnostic accuracy of 3D time-of-flight MR angiography compared with digital subtraction angiography for follow-up of coiled intracranial aneurysms: influence of aneurysm size.

BACKGROUND AND PURPOSE: 3D time-of-flight MR angiography (3D TOF MRA) may be used as noninvasive alternative to digital subtraction angiography (DSA) for the follow-up of patients with intracranial aneurysms treated with Guglielmi detachable coils (GDCs). We aimed to determine the influence of aneurysm size and location on diagnostic accuracy of 3D TOF MRA for follow-up of intracranial aneurysms treated with GDCs. MATERIALS AND METHODS: Two hundred and one 3D TOF MRAs in 127 consecutive patients with 136 aneurysms were compared with DSA as standard of reference. Sensitivity and specificity of 3D TOF MRA for detection of residual or reperfusion of the aneurysms was calculated with regard to aneurysm size and location. RESULTS: Overall sensitivity and specificity of MRA was 88.5% and 92.9%, respectively. Sensitivity was lower for aneurysms

Minimizing macrovessel signal in cerebral perfusion imaging using independent component analysis.

The pronounced susceptibility effect of macrovessels in MR bolus-tracking studies induces spots of artificially high blood flow and volume in perfusion parameter images. These high-intensity regions impede the detection of perfusion changes and lead to elevated perfusion parameters in adjacent tissues. The purpose of this work was to explore postprocessing methods to reduce the influence of macrovessel signal in dynamic MRI. After data reduction was performed with the use of a principal component analysis (PCA), an independent component analysis (ICA) was applied to separate signal components of different compartments. Based on this decomposition, the dynamic time series were reconstructed with minimized contributions of macrovessel signal and noise. The influence of the temporal resolution and signal-to-noise ratio (SNR) of the source data were investigated by means of a simulation study. A region-of-interest (ROI)-based analysis of corrected and uncorrected in vivo data demonstrated that the influence of arteries and veins was reduced at least by 50%, while gray matter (GM) and white matter (WM) tissues were nearly unaffected by the correction process. Hemodynamic parameter images of the cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) were calculated from corrected and uncorrected scans. The corrected parameter images showed a clearly reduced macrovessel signal and an improved perceptibility of microvascular perfusion changes compared to the uncorrected ones.

Imaging of the neonatal CNS.

Imaging of the central nervous system is one of the major tasks of Paediatric Radiology, particularly in newborns, who present with a variety of conditions that need more or less urgent imaging. Imaging is usually performed primarily by bedside US, in rare cases supplemented by a skull or spine radiograph. For more detailed information and preoperatively, MRI has become the neuroimaging tool. Thus, CT today is only used for acute trauma assessment, for assessment of potential cerebral calcifications or when MRI is not available. In cases with vascular anomalies or unsuccessful punctures, image guided interventions (embolisation) or image guidance for access (lumbar puncture, puncture of skull collections ...) may become necessary. This article tries to give a brief overview on the common disease entities, their typical imaging features in the major modalities applied and the implications of imaging potential for indication and choice of imaging method. In general, acute assessment may become everywhere and major features of important diseases should be recognised not to miss conditions which need urgent treatment or referral to a dedicated paediatric unit. Many other conditions will only be seen at centres with a dedicated neonatal care unit and dedicated paediatric radiologist who then also will be able to provide proper imaging with adapted protocols and methods for these partially severely sick babies. As these specific features and adapted capabilities as well as dedicated training and clinical experience are necessary for providing best results and proper handling in neonates, many neonatal conditions will not be imaged at a peripheral site, but primarily should be referred to a paediatric (radiology) centre.

Degree of hypomyelination and magnetic resonance spectroscopy findings in patients with Pelizaeus Merzbacher phenotype.

As only 10 - 30 % of patients with a Pelizaeus Merzbacher disease (PMD) phenotype carry mutations of the proteolipid protein (PLP) gene, we were interested if the degree and time-dependent progression of abnormal MRI and MRS findings would discriminate patients with mutations of the PLP gene (Pelizaeus Merzbacher disease, PMD) from patients without a defect of the PLP gene (Pelizaeus Merzbacher-like disease, PMLD). For a standardised intraindividual follow-up and for comparison of the degree of hypomyelination, we have applied a newly developed semiquantitative myelination score on a total of 18 MRI series of 4 PMD and 4 PMLD patients. We found severe hypomyelination (< 50 % of normal) in 2 PMD and in 2 PMLD patients, moderate hypomyelination (< 75 % of normal) in 2 PMD and mild hypomyelination (> 75 % of normal) in 2 PMLD patients. Our score revealed a clear correlation between the degree of hypomyelination and the severity of clinical handicap in PMD but not in PMLD patients. MRS showed heterogeneous cerebral metabolite patterns in both patient groups and seems to reflect a mixture of unspecific changes due to primary hypomyelination and secondary gliosis and demyelination. Neither by MRI nor by MRS were patterns found that would allow differentiation between PMD and PMLD patients.

Feasibility of MR urography in neonates and infants with anomalies of the upper urinary tract.

The aim of this study was to evaluate the feasibility and diagnostic potential of dynamic MR urography (MRU) in neonates and infants with sonographically detected abnormalities of the upper urinary tract. Thirty infants (age range 5 days to 3 years, mean age 7.9 months; male:female: 22:8) underwent MRU using T2 and contrast-enhanced dynamic T1-weighted sequences. The results were compared with the findings of ultrasound ( n=30), intravenous urography (IVU, n=19) and/or scintigraphy ( n=25) based on the criteria suggestive of obstructive uropathy. Oral sedation was sufficient to perform MRU with diagnostic quality in 20 of 21 patients younger than 1 year; 9 older patients needed intravenous sedation. Diagnosis of the 66 renal units (58 kidneys, 29 successful examinations) included normal systems (contralateral units), duplex systems, vesico-ureteral reflux, obstructive megaureter, ureteropelvic junction obstruction and accompanying renal parenchymal disease, with complex pathology in 10 patients. Magnetic resonance urography demonstrated anatomy better than IVU, particularly the renal parenchyma, (ectopic) ureters, and poorly functioning dilated systems. Magnetic resonance urography was superior to US in showing ureteral pathology. Tiny cysts in dysplastic kidneys were better seen by US. Gadolinium-enhanced dynamic MRU allowed accurate assessment of obstruction applying IVU criteria. Here MRU matched IVU results, and most of the scintigraphic findings. Magnetic resonance urography can be performed in young infants with diagnostic quality using oral sedation. Magnetic resonance urography correctly depicts anatomy and allows assessment of the urinary tract better than US and IVU, with additional functional information. Magnetic resonance urography thus has the potential to replace IVU for many indications.

[Congenital hypopituitarism and giant cell hepatitis in a three month old girl]. / Konnataler Panhypopituitarismus und Riesenzellhepatitis bei einem 3 Monate alten Säugling.

CASE REPORT: A three month old girl, with recurrent hypoglycemia and neonatal cholestasis, is reported. A metabolic disease could be excluded. The liver biopsy revealed giant cell hepatitis and intrahepatic bile duct hypoplasia. ACTH, Cortisol and hGH measured during hypoglycemia were low. Magnetic tomography (MR) of the brain showed an "empty sella". After beginning a replacement therapy with hydrocortisone, growth hormone and thyroxine there was no further episode of hypoglycemia. Transaminases and bilirubin levels normalized. The girl is in good condition, growth and development are normal. DISCUSSION: Hypoglycemia is often the first sign in childrens with neonatal hypopituitarism. The association of liver disease and hypopituitarism has been documented in a few reports. The pathophysiological mechanism leading to the liver dysfunction is not well understood. The prognosis of neonatal hypopituitarism as well as the concomitant liver disease is good under sufficient replacement therapy.

Diffusion-weighted imaging of patients with subacute cerebral ischemia: comparison with conventional and contrast-enhanced MR imaging.

BACKGROUND AND PURPOSE: The importance of diffusion-weighted imaging (DWI) for delineating acute ischemic lesions has been investigated extensively; however, few studies have investigated the role of DWI in the subacute stage of stroke. Because these lesions tend to appear bright throughout the first days of ischemia, owing to restricted diffusion, we speculated that DWI could also improve the detection of subacute infarcts as compared with conventional and contrast-enhanced MR imaging. METHODS: Interleaved echo-planar DWI with phase navigation was performed on a 1.5-T MR unit in a consecutive series of 53 patients (mean age, 66 +/- 14 years) with suspected recent cerebral ischemia. The interval between onset of clinical symptoms and MR imaging ranged from 1 to 14 days (mean, 6 +/- 4 days). Contrast material was given to 28 patients in a dose of 0.1 mmol/kg. RESULTS: DWI clearly delineated recent ischemic damage in 39 patients (74%) as compared with 33 (62%) in whom lesions were identified or suspected on conventional T2-weighted images. DWI provided information not accessible with T2-weighted imaging in 17 patients when evidence of lesion multiplicity or detection of clinically unrelated recent lesions was included for comparison. Subacute ischemic lesions were also seen more frequently on DWI sequences than on contrast-enhanced images (20 versus 13 patients). DWI was more likely to make a diagnostic contribution in the first week of stroke and in patients with small lesions or preexisting ischemic cerebral damage than was conventional MR imaging. CONCLUSION: Recent ischemic damage is better shown on DWI sequences than on conventional and contrast-enhanced MR images throughout the first days after stroke and may provide further information about the origin of clinical symptoms. Adding DWI to imaging protocols for patients with subacute cerebral ischemia is recommended.

Diffusion-weighted MR imaging of the spinal cord.

Diffusion-weighted MR imaging may increase the sensitivity and specificity of MR imaging for certain pathologic conditions of the spinal cord but is rarely performed because of several technical issues. We therefore tested a novel phase-navigated spin-echo diffusion-weighted interleaved echo-planar imaging sequence in seven healthy volunteers and six patients with intramedullary lesions. We performed diffusion-weighted MR imaging of the spinal cord with high spatial resolution. Different patterns of diffusion abnormalities observed in patient studies support the possible diagnostic impact of diffusion-weighted MR imaging for diseases of the spinal cord.

Idiopathic sclerotic inflammation of the orbit with left optic nerve compression in a patient with multifocal fibrosclerosis.

We present the MR imaging findings in a 43-year-old male patient with bilateral idiopathic sclerosing inflammation of the orbit. Bilateral enhancing retrobulbar masses, with concentric compression of the retrobulbar segment of the left optic nerve, were seen. MR imaging proved to be the only means to distinguish between the different intraorbital structures and to determine the exact site of optic nerve compression. To our knowledge, this is the first documented case of MR imaging findings of this entity.

Diffusion-weighted imaging with navigated interleaved echo-planar imaging and a conventional gradient system.

PURPOSE: To demonstrate the technical feasibility and precision of a navigated diffusion-weighted (DW) MR imaging method with interleaved echo-planar imaging and test its diagnostic sensitivity for detection of ischemic stroke. MATERIALS AND METHODS: Apparent diffusion coefficient (ADC) measurements were performed in phantoms, and six healthy adult volunteers were examined to determine intrasubject (precision) and intersubject (reference range) variations in absolute ADC and relative ADC (rADC) measurements. DW imaging maps and lesion rADC values were also obtained in 34 consecutive stroke patients to evaluate the sensitivity and reliability of DW-interleaved echo-planar imaging for detection of ischemic brain damage. RESULTS: Phantom and volunteer ADC values were in excellent agreement with published data. The intrasubject variation of rADC was 6.2%. The ADC precision ranged from 6.5% in the subcortical white matter in the frontal lobe to 12.9% in the head of the caudate nucleus. Interleaved echo-planar imaging enabled rapid acquisition of high-quality images of the entire brain without substantial artifacts. Within the 1st week, the sensitivity of DW-interleaved echo-planar imaging for detection of acute infarction was 90% (18 of 20 true-positive studies) and independent of lesion location. CONCLUSION: DW-interleaved echo-planar imaging with phase navigation and cardiac triggering is robust, reliable, and fast. With high sensitivity for detection of early ischemic infarction, it is useful for examining stroke patients by using MR systems with conventional gradient hardware.

Clinical and magnetic resonance findings in the temporomandibular joints of patients before and after orthognathic surgery.

It is difficult to achieve the correct position of the condyle in the temporal fossa during orthognathic surgery in angle class II patients with disorders of the temporomandibular joint. This led us to examine the TMJ of 25 of our own patients before and shortly after orthognathic operations. We recorded the clinical and magnetic resonance imaging findings of the temporomandibular joint preoperatively and three months postoperatively. The patients had skeletal class II dysgnathia and had been treated with fixed orthodontic appliances for a mean of two years and three months before operation. Operation resulted in a mean reduction of maximal incisor distance of 12 mm. In five of the 25 patients, the pattern of mouth-opening changed. Nine patients had less pain than before surgery, and nine had fewer abnormal joint sounds. The magnetic resonance imaging showed displacement of the articular disc in 38 of the 50 joints preoperatively and in 28 postoperatively. Degenerative joint changes were not improved by operation. Improvement of the disc position was achieved by repositioning of the condylar-disc complex during orthognathic surgery in angle class II patients. Clinical and magnetic resonance imaging findings regarding the temporomandibular joint in class II patients correlated significantly both preoperatively and postoperatively.

Cerebral arteriovenous malformations: diagnostic value of echo-enhanced transcranial Doppler sonography compared with angiography.

BACKGROUND AND PURPOSE: The purpose of our study was to examine the clinical value of echo-enhanced transcranial power Doppler sonography (EE-TCD), including it ability to assess hemodynamic parameters of the intracranial vasculature, in patients with suspected cerebral arteriovenous malformations (AVMs) and to compare this method with angiography. METHODS: Sixteen patients with suspected cerebral AVMs were examined with EE-TCD and angiography. As an echo-enhancing agent, SHU 508A (Levovist) was administered intravenously by bolus injection in nine patients and by continuous infusion in seven. Sonograms were reviewed without knowledge of other imaging results and were correlated with angiographic findings. RESULTS: Angiography showed AVMs in 12 of 16 patients. Eleven lesions were located in the anterior or middle fossa and one was in the posterior fossa. EE-TCD was slightly less sensitive in the detection of AVMs (92%, 11/12 lesions), since in one patient the lacking acoustic window did not allow a transcranial examination. EE-TCD slightly underestimated AVM size compared with angiographic findings but showed feeding arteries with sufficient acoustic properties. In seven patients (58%), angiography revealed a coincidental blood supply from another intracranial or extracranial vessel, which was missed by EE-TCD in all cases. Assessment of peak systolic velocities and resistive indexes resulted in a higher (mean, 191.1 cm/s) and a lower (mean, 45.7%) value, respectively, in the feeding arteries as compared with the contralateral arteries (mean, 101.8 cm/s and 55.6%, respectively). Side-to-side differences were significantly higher in patients with AVMs than in those without a malformation. Signal enhancement was markedly longer with continuous infusion (mean, 520 seconds +/- 28.2) than with bolus injection (mean, 145 seconds +/- 10.5) of the contrast agent. CONCLUSION: In our limited study group, EE-TCD was a sensitive method for the detection of AVMs, and Levovist proved to be a safe and effective echo-enhancing substance.