Cognitive dysfunction and impaired organization of complex motility in degenerative parkinsonian syndromes

PURPOSE: Our purpose was to present imaging findings of six cases proven or supposed to be von Meyenburg complexes (VMCs) with a basis of reviewing the pathologic literature and to describe imaging points for the diagnosis of typical VMC along with its differential diagnosis. METHOD: Six cases were diagnosed as VMC of the liver with imaging modalities (one had histopathologic proof). Both ultrasound (US) and CT were available for all cases, and MRI was used for three cases. Follow-up with US, CT and/or MRI was performed in five cases. RESULTS: US detected varying abnormalities of the livers in four cases. CT and MRI revealed multiple or numerous intrahepatic tiny (usually < 5 mm) cystoid lesions in all of the cases. The lesions were scattered throughout the livers, and some of them were located more frequently adjacent to the medium-sized portal veins than to the hepatic veins of similar size on CT. Moreover, some lesions were apparently located in the subcapsular areas (up to the hepatic capsules). They were usually irregular in shape and showed no enhancement but increased in number by approximately 80-150% after administration of intravenous contrast medium. The T2-weighted MR images and MR cholangiopancreatography showed the lesions to be much more apparent and to be more numerous than T1-weighted images did. Follow-up of five cases with imaging modalities did not show remarkable change of the lesions. CONCLUSION: Despite our limited experience, VMC lesions seem to show some CT and MR features different from those of other multiple small hepatic lesions. They presented as multiple or numerous intrahepatic tiny cystoid lesions usually with irregular contour, scattered throughout the liver up to the subcapsular areas, and were detected in far greater number by enhanced CT or T2-weighted MR images than by unenhanced CT or T1-weighted images. They showed no remarkable change on long term follow-up imaging. We propose that a diagnosis of typical VMC could be made after analyzing CT or MR images carefully with good understanding of its pathologic basis, but imaging follow-up is necessary in oncology patients.     

Neuroimaging in psychiatry

The promise of neuroimaging as an aid to diagnosis is discussed, and findings from the most accessible imaging techniques are reviewed. In addition, some of the earliest findings from functional MR imaging and other technologies are presented with several illustrations. Strategies for interpretation, critique of imaging techniques, and review of major findings for brain injury, mood, anxiety, schizophrenia, and attention deficit disorders are offered. Examples of normal and pathologic images illustrate actual cases and examples of the newer imaging technologies.     

Localization of abnormal parathyroid glands of the mediastinum with MR imaging

PURPOSE: To determine the sensitivity of magnetic resonance (MR) imaging for preoperative localization of abnormal parathyroid glands in the mediastinum and to compare the sensitivity of MR imaging with those of scintigraphy and ultrasonography (US). MATERIALS AND METHODS: The prospective sensitivity of MR imaging was compared with those of thallium-technetium scintigraphy and US in 25 patients in whom the abnormal gland was located in the mediastinum at surgery. RESULTS: MR imaging had a much higher sensitivity (22 of 25 cases [88%]) than did scintigraphy (11 of 19 cases [58%]) or US (three of 24 cases [12%]). The most common locations for the mediastinal gland were intrathymic (eight of 25 cases) and paraesophageal (six of 25 cases) sites. CONCLUSION: MR imaging should be considered the modality of choice for preoperative localization in this group of patients.     

Quantitative analyses for facial nerve MR imaging

It is clear, from our clinical experience, that the facial nerve in patients with facial palsy is enhanced on magnetic resonance (MR) imaging after intravenous administration of gadolinium diethylenetriamine. However, some problems with clinical reliability persist. There have been reports that normal facial nerves often show enhancement on MR imaging. We also question whether there are any differences in the degree of enhancement between Bell's palsy and Ramsay Hunt syndrome. To solve these problems, analyses were conducted using a personal computer by means of digital image-processing to measure the gray scale levels of enhanced facial nerves on MR imaging films. Seventeen cases of Bell's palsy, eight cases of Ramsay Hunt syndrome and fourteen normal subjects whose facial nerves showed enhancement on MR imaging were selected for the analyses. The concept of a facial nerve/whole image ratio (F/W ratio), analyzing the degree of enhancement of the facial nerve quantitatively, is introduced in this paper. The F/W ratio is the ratio of the gray scale level of the facial nerve region to the highest gray scale level in the skull at the MR imaging film. When the F/W ratios of these subjects were analyzed, no significant differences were found between Bell's Palsy and Ramsay Hunt syndrome in the degree of enhancement; facial palsy cases showed quantitatively larger F/W ratios than normal subjects.     

Temporal bone imaging

Ameliorated computed tomography techniques and new magnetic resonance sequences have led to an important improvement in temporal bone imaging. Computed tomography is still the method of choice for imaging of temporal bone fractures, middle ear disease, and conductive hearing loss, although magnetic imaging can add important information. Patients with lesions of the cerebellopontine angle; internal auditory canal; inner ear; and, in general, all patients with sensorineural hearing loss, vertigo, and tinnitus are best examined with magnetic resonance imaging. In some cases, however, such as congenital malformations and petrous apex lesions, magnetic resonance imaging and computed tomography are complementary. The value of both modalities is discussed.     

High resolution, dynamic, magnetic resonance imaging in complicated strabismus

Strabismus cases, especially after previous surgery or trauma to extraocular muscles, often present diagnostic challenges. Conventional clinical tests are helpful in some cases but may be inconclusive. High resolution, dynamic, orbital magnetic resonance imaging (MRI) may yield additional critical information about orbital and extraocular muscle anatomy and function. We report four complicated strabismus cases for which dynamic surface coil MRI helped formulate a precise diagnosis and the most appropriate surgical plan.     

Metabolic imaging of malignant pleural mesothelioma with fluorodeoxyglucose positron emission tomography

BACKGROUND: The diagnosis of malignant mesothelioma is a challenging medical problem. CT often cannot differentiate between benign diffuse pleural thickening and malignant mesothelioma, while thoracentesis and CT-guided biopsies are insensitive. We have assessed the value of positron emission tomography (PET) with 2-fluoro-2-deoxy-D-glucose (FDG) in the evaluation of malignant mesothelioma. METHODS: Twenty-eight consecutive patients referred for the evaluation of suspected malignant mesothelioma were evaluated by FDG-PET imaging. Measured attenuation correction was performed in 26 of 28 cases for quantitation with the standardized uptake value (SUV) method. The results of PET imaging were compared with those of video-assisted thoracoscopy or surgical biopsies. RESULTS: Surgical biopsy specimens confirmed the presence of malignant disease in 24 patients and demonstrated benign processes in the remaining four. The uptake of FDG was significantly higher in malignant than in benign lesions (SUV=4.9+/-2.9 and SUV=1.4+/-0.6, respectively; p<0.0001). With a SUV cutoff of 2.0 to differentiate between malignant and benign disease, a sensitivity of 91% and a specificity of 100% could be achieved, although the activity in some epithelial mesotheliomas tended to be close to this threshold. FDG-PET images provided excellent delineation of the active tumor sites. Hypermetabolic lymph node involvement was noted on FDG-PET images in 12 patients, 9 of which appeared normal on CT scans. Histologic examination in six patients confirmed malignant nodal disease in five cases and indicated granulomatous lymphadenitis in one. CONCLUSION: In this highly selected population, FDG-PET imaging was a sensitive method to identify malignant mesothelioma and determine the extent of the disease process.     

MR of the heart under pharmacologic stress

Magnetic resonance imaging is one method for assessing cardiac function and perfusion at rest and under stress conditions. In this article, the potential of stress magnetic resonance imaging for evaluating ischemic heart disease is reviewed, and technical aspects of some developments that may contribute to comprehensive magnetic resonance imaging assessment of heart disease under rest and stress are discussed.     

Clinical applications of ultrasound contrast agents

Within the last decade safe and practical ultrasound contrast agents have been introduced. Most of these are based on gas-filled microbubbles, which markedly enhance Doppler signals and, in some cases, also gray-scale images. The clinical improvements expected from ultrasound contrast is reviewed. Tissue-specific contrast agents constitute another area of potential clinical significance. One particular agent is taken up by the reticulo-endothelial system and produces so-called acoustic emission signals when imaged. An introduction to the unique clinical applications of acoustic emission is given. Harmonic imaging is a new contrast-specific imaging modality, which utilizes the nonlinear properties of some agents in an attempt to alleviate current limitations of ultrasound contrast studies. Examples of harmonic images are presented.     

Advances in the imaging of renal infection. Helical CT and modern coordinated imaging

Traditionally, imaging of renal infections was largely through a multimodality approach. Excretory urography, ultrasonography, nuclear scintigraphy, and CT all played major roles; however, in recent years, CT has increased in prominence in the imaging and evaluation of renal infection. Part of the reason for this trend includes improvements in the availability of CT scanners and more timely access to them. Helical scanning technology has also greatly increased the quality and usefulness of the information CT provides. Most uncomplicated cases of acute renal infection in adults do not require imaging for diagnosis and treatment. When imaging is indicated, however, contrast-enhanced CT almost always is the study of choice. For cases in which renal calculi may be present, the study should also include noncontrast images through the kidneys.     

MRI of the pediatric shoulder: nontraumatic lesions

Magnetic resonance imaging is an established technique for imaging the shoulder because it demonstrates clearly the articular surfaces, medullary canal and the extra-articular soft tissues which can be affected in shoulder disorders. The value of MR imaging in the evaluation of the traumatized shoulder has been described [1]; however, few cases of MR imaging in nontraumatic disorders in children have been reported. We reviewed the findings in 55 children undergoing MRI of the shoulder for nontraumatic conditions and included selected cases showing a broad range of imaging findings.     

Diabetic fibrous breast disease: a clinical entity that mimics cancer

Three typical cases of fibrous mastopathy associated with diabetes mellitus are described. The histological change is a connective-tissue overgrowth with vasculitis and some proliferation of duct epithelium. The clinical changes are indistinguishable by physical or radiographic findings from malignancy. In young patients with long-standing diabetes the presence of one or more suspicious clinical and imaging findings can suggest the presence of this lesion but a surgical biopsy or, at least, a close follow-up is required.     

MR imaging of small hepatocellular carcinoma (< or = 20 mm)--correlation with vascularity and histological features

We have evaluated the efficacy of magnetic resonance (MR) imaging for detecting hepatocellular carcinoma less than 20 mm in diameter (sHCC). This study involved 72 cases of sHCC tumors which were also investigated by angiography and histology. These cases were retrospectively examined for correlations between tumor stain (vascularity) on angiography, histological features (fat deposition, clear cells and the grade of differentiation) and the findings on T1 and T2 weighted MR imaging. The sHCC detection rate by MR imaging was 73.6% (53 cases) and by angiography was 59.7% (43 cases). Thirty-five cases were detected both the MR imaging and by angiography. The main MR imaging patterns were hypo to isointense on T1 weighted images (T1WI) and hyperintense on T2 weighted images (T2WI) in 22 cases, and hyperintense on both T1WI and T2WI in 7. In 18 cases which were not demonstrated by tumor staining on angiography, the main MR imaging patterns were hyperintense on T1WI and isointense on T2WI in 14. The histological features included fat deposition in 22 cases, 20 cases of which were hyperintense on T1WI, and 10 of these 20 were hyperintense on both T1WI and T2WI. Fat deposition was marked in 9. According to the grade of differentiation, 23 of the 26 cases with well differentiated HCC tumors were hyperintense on T1WI, and 21 of the 27 cases with moderately to poorly differentiated HCC were hypo to isointense on T1WI and hyperintense on T2WI. sHCC was visualized by MR imaging, reflecting vascularity, fat deposition and the grade of differentiation. In particular, MR imaging is useful for a differential diagnosis between the well differentiated HCC and the moderately to poorly differentiated HCC, and useful for the diagnosis of an early HCC.     

Applications of PET in lung cancer

An estimated 180,000 new cases of lung cancer will be diagnosed in the United States this year, and lung cancer accounts for approximately 25% of all cancer deaths. The overall 5-year survival rate is 14%, and this has not changed over the past several decades. Lung cancer diagnosis and treatment is a major health problem globally. Most lung cancers are detected initially on chest radiographs, but many benign lesions have radiologic characteristics similar to malignant lesions. Thus, additional studies are required for further evaluation. Computed tomography (CT) is most frequently used to provide additional anatomic and morphologic information about the lesion, but it is limited in distinguishing benign from malignant abnormalities in the lung, pleura, and mediastinum. Because of the indeterminate results from anatomic imaging, biopsy procedures including thoracoscopy and thoracotomy may be used even through one-half of the lesions removed are benign and do not need to be removed. FDG-PET imaging provides physiologic and metabolic information that characterizes lesions that are indeterminate by CT and that accurately stages the distribution of lung cancer. Exploiting the fundamental biochemical differences between cancer and normal tissues, FDG imaging takes advantage of the increased accumulation of FDG in transformed cells. FDG-PET is very sensitive (approximately 95%) for the detection of cancer in patients who have indeterminate lesions on CT. The specificity (approximately 85%) of PET imaging is slightly less than the sensitivity because some inflammatory processes such as active granulomatous infections accumulate FDG avidly. The high-negative predictive value of PET suggests that lesions considered negative on the study are benign, biopsy is not needed, and radiographic follow-up is recommended. Several studies have documented the increased accuracy of PET compared with CT in the evaluation of the hilar and mediastinal lymph node status in patients with lung cancer. If the mediastinum is normal on PET imaging and there is no other evidence of metastatic disease, the patient has a thoracotomy. If the mediastinum is abnormal on PET imaging, mediastinoscopy is performed with the PET images providing the lymph node stations to target. Whole-body PET studies detect metastatic disease that is unsuspected by conventional imaging and demonstrate some of the anatomic abnormalities detected by CT to be benign lesions. Management changes have been reported to occur in up to 41% of patients based on the results of the whole-body studies.     

Imaging of mediastinal lymph nodes: CT, MR, and FDG PET

The evaluation of mediastinal lymph nodes is an important aspect of staging in patients with non-small cell lung cancer. Anatomic imaging of lymph nodes with computed tomography (CT) and magnetic resonance (MR) imaging has been limited by the relatively low sensitivity and specificity of these techniques. Advances in physiologic imaging of mediastinal lymph nodes with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) have resulted in improved diagnostic accuracy in the determination of nodal status. Despite the limitations of CT, this technique still plays an important role by aiding in the selection of the most appropriate procedure for staging, by guiding biopsy, and by providing anatomic information for visual correlation with FDG PET images. At present, anatomic MR imaging of lymph nodes is primarily a problem-solving tool for cases with inconclusive CT results. Physiologic MR imaging with iron oxide is an exciting area of investigation, and the accuracy of this technique is being assessed in clinical trials. Anatomic and physiologic imaging techniques should be considered complementary rather than competitive imaging strategies.     

Laparoscopic colpopoiesis using sigmoid colon

Superficial siderosis of the central nervous system (CNS) is a rare disease resulting in the accumulation of haemosiderin in the meninges, the brain surface, the spinal cord and the cranial nerves. The pigment is deposited as a result of chronic bleeding in the subarachnoid space. This produces a clinical picture of deafness, ataxia, cranial nerve deficits and in the latest stages dementia. In some cases the source of bleeding can be identified, whilst in others it can not. Despite its rarity the disease should be considered in the differential diagnosis of sensorineural deafness, particularly as it is a progressive and in some cases curable disease which is easily diagnosed by magnetic resonance imaging (MRI). In this case report the haemosiderin was derived from an ependymoma of the fourth ventricle with extension into the cerebello-pontine angle. The first symptom was a worsening sensorineural hearing loss.     

Viral croup: current diagnosis and treatment

Viral croup, a common illness in children, manifests with noisy, labored breathing. Parainfluenza viruses are the most common cause of croup; however, other causes including epiglottitis and bacterial tracheitis should be considered in the differential diagnosis. The diagnosis is primarily based on clinical findings; imaging studies may be useful in selected cases. Although most children recover from this self-limited illness with only minimal medical intervention, some are severely affected by laryngeal swelling and require respiratory support with analgesics, cool mist, corticosteroids, nebulized epinephrine, heliox, and, rarely, intubation. In this article, the current diagnostic and management strategies for viral croup are summarized.     

Septic arthritis of lumbar facet joints. A review of six cases

Hematogenous infection of the facet joints by pyogenic organisms is exceedingly rare. We report six cases of lumbar facet joint septic arthritis due to hematogenous spread of a pyogenic organism. A review of the literature identified ten anecdotal reports of similar cases. An analysis of these 16 cases showed that the diagnosis was based mainly on imaging study findings and that clinical data failed to discriminate between facet joint septic arthritis and infectious discitis. Increased uptake on the radionuclide bone scan was an early finding and the pattern of uptake was different from that seen in discitis. Computed tomography was the investigation that best delineated the facet joint lesions. Magnetic resonance imaging of the lumbar spine was superior over computed tomography in demonstrating spread of the infection to the epidural space and/or soft tissues and in some instances demonstrated enhancement of the infected facet joint on T1 images after gadolinium injection. Aspiration of the facet joint under fluoroscopic guidance was required only when blood cultures were negative or when the diagnosis of the septic nature of the arthritis was in doubt. Blood cultures yielded a Staphylococcus aureus in the six cases in our series. Appropriate antimicrobial therapy was successful in most cases. In our series, four of the six patients had posterior epiduritis, pyomyositis, or an abscess in the paraspinal muscles or psoas muscle, suggesting that some epidural infections or psoas muscle abscesses believed heretofore to be primary may in fact be complications of facet joint septic arthritis. Facet joint septic arthritis is a new aspect of pyogenic spinal infections that deserves to be considered in patients with febrile spinal syndromes not explained by discitis.     

Urethrography and cavernosography imaging in a small series of penile fractures: a comparison with surgical findings

OBJECTIVES: To compare our results of preoperative corporal cavernosography and retrograde urethrography in penile fractures with the clinical and intraoperative findings. METHODS: From January to October 1996, 7 cases of penile fracture were diagnosed at our inner city trauma center. All cases were associated with sexual activity and patients underwent preoperative retrograde urethrography and corpus cavernosography with immediate surgical intervention. RESULTS: We found that 2 patients who presented with blood at the meatus had intact urethras, whereas 2 of the 3 patients who had urethral lacerations did not have a bloody meatus. In 2 cases the urethrogram and cavernosogram revealed lacerations that were not initially detected surgically. However, in another 2 cases, the urethrogram and cavernosogram were falsely negative. Two of the seven corporal fractures were bilateral and five were unilateral. CONCLUSIONS: On the basis of this small sample, it appears that preoperative cavernosography and retrograde urethrography may show additional sites of tears in the corpora and urethra because hematoma formation may mask some ruptures. However, the presence or absence of a bloody meatus may not necessarily correlate with the status of the urethra, and the urologist also should be wary of a false-negative imaging study. We suggest that all cases of penile fracture be explored surgically, but preferably by a subcoronal degloving incision that allows careful examination of the urethra and corpora. Results of a larger series may determine if the routine use of these imaging modalities is justified intraoperatively.     

Role of MR imaging with transrectal coil in the evaluation of complex urethral abnormalities

OBJECTIVE: The purpose of this study was to show the usefulness of MR imaging with a transrectal coil (TRC) in the management of various urethral abnormalities. This report also reveals the appearance of various postsurgical changes relating to the therapy of urethral abnormality. CONCLUSION: The high-resolution images obtained with TRC MR imaging were useful in evaluating urethral abnormalities. The imaging guided therapy in most cases. In two patients, TRC MR imaging more accurately depicted abnormality than did voiding cystourethrography and transvaginal sonography. In one case, TRC MR imaging was the only imaging technique that revealed the abnormality of periurethral scarring.