Intramural leiomyoma of the bladder

Mesodermal tumors of the urinary bladder are rare and the majority of them are malignant. We report a case of an intramural leiomyoma of the bladder presenting with symptoms of a mild lower urinary tract infection. The patient was managed with partial cystectomy and the outcome was excellent. Received: 31 May 1999; Revised: 21 September 1999; Accepted: 21 September 1999     

Delayed posttraumatic adrenal hematoma

Posttraumatic adrenal hemorrhage is a frequent finding after severe abdominal trauma and can have important clinical implications if it is bilateral. With the increased use of helical CT in the evaluation of trauma patients, posttraumatic adrenal hematoma is more frequently diagnosed. We present the CT findings of a unilateral posttraumatic adrenal hemorrhage where the diagnostic findings only appeared in the follow-up study. We think that mild enlargement of the adrenal gland in a trauma patient can be an early sign of an impending adrenal hemorrhage. Received: 10 May 1999; Revised: 28 July 1999; Accepted: 18 August 1999     

Calcification of intracranial vessels in neurocysticercosis

We report calcification of intracranial vessels in neurocysticercosis. Calcification was observed in the middle cerebral arteries in two patients, and the circle of Willis in two others. The patients with middle cerebral artery calcification underwent CT with inhaled stable xenon and an area of mild hypoperfusion was observed in the ipsilateral cerebral hemisphere. Received: 2 August 1999 Accepted: 24 October 1999     

Radiological findings in acute adult epiglottitis

Acute epiglottitis is a rare but life-threatening disease that commonly occurs in children, and also rarely in adults. The symptoms may be mild and non-specific before a rapid onset of airway obstruction occurs. Early diagnosis is essential, as delayed treatment is associated with a high rate of complications including death. We present the clinical and radiological findings of this unusual condition in an adult. Received: 9 November 1998; Revision received: 27 January 1999, Accepted: 16 February 1999     

Long-standing painless intussusception in adults

Long-standing painless intussusception in adults is considered to be rare. We report three such cases with an emphasis on color Doppler results. In our three cases the indication for abdominal US was a palpable mass in all these cases, and intussusception was detected by US at a time when the patients had only very mild abdominal discomfort. Persistence of sufficient blood flow, as was suggested by the color Doppler results, was thought to be the most likely pathomechanism of long-standing painless intussusception. The underlying disease was tuberculosis in two of the three cases. Thus, when encountering patients with painless intussusception, tuberculosis must be kept in mind. Received: 8 July 1999; Revised: 25 October 1999; Accepted: 25 October 1999     

Intramuscular vascular malformations of an extremity: findings on MR imaging and pathologic correlation

Objective. To analyze the findings of intramuscular vascular malformations of an extremity on MR imaging and to correlate these findings with histopathologic examination. Design and patients. The findings on MR imaging and the medical records of 14 patients with an intramuscular vascular malformation of the extremity were retrospectively studied. All patients underwent surgical excision. Diagnoses were based on the results of pathologic examination. Findings on MR imaging were noted and correlated with the histopathologic findings. Results. Intramuscular vascular malformations of an extremity showed multi-septate, honeycomb, or mixed appearance on MR imaging. Multi-septate areas correlated with dilated and communicating vascular spaces with flattened endothelium. Honeycomb areas corresponded to vascular spaces with inconspicuous small lumina and thickened vascular walls. Areas of increased signal intensity on T2-weighted images were found in all intramuscular vascular malformations. Infiltrative margins were more commonly seen in intramuscular lymphaticovenous malformations. Adherence to neurovascular structures and orientation of the lesion along the long axis of the affected muscle were more commonly seen in intramuscular venous malformations. Conclusions. Intramuscular vascular malformations showed either a multi-septate, honeycomb, or mixed appearance, reflecting the size of the vascular spaces and the thickness of the smooth muscles of the vessel walls. Prediction of the subtype of an intramuscular vascular malformation of an extremity on MR imaging seems to be difficult, although there are associated findings that may be helpful in the differential diagnosis of each subtype. Received: 19 January 1999 Revision requested: 4 May 1999 Revision received: 23 June 1999 Accepted: 29 June 1999     

Pial involvement in Wegener's granulomatosis shown on MRI

Involvement of the brain and meninges is rare in Wegener's granulomatosis (WG); it has been reported in 1.2–8 % of patients. Meningeal involvement in WG has been reported in imaging as being confined to the duramater, and is thought to represent granulomatous infiltration. We present a case of WG with abnormal pial enhancement and involvement of the perivascular spaces on MRI, pathologically proven to represent granulomatous infiltration due to the primary disease rather than to infection. Received: 27 November 1998 Accepted: 25 March 1999     

Brain MRI findings in patients with mucopolysaccharidosis types I and II and mild clinical presentation

Our objective was to determine the brain magnetic resonance imaging (MRI) abnormalities in a selected group of patients with mucopolysaccharidosis (MPS) types I and II who had only mild clinical manifestations. We retrospectively assessed MRI brain studies in 18 patients with MPS (type I: 6 and type II: 12). We evaluated abnormal signal intensity in the white matter, widening of the cortical sulci, size of the supratentorial ventricles, dilatation of the perivascular spaces (PVS) and enlargement of the subarachnoid spaces. We observed a broad spectrum of findings, and despite severely abnormal MRI studies, no patients had mental retardation. We also observed that dilated PVS, previously believed to be caused by macroscopic deposition of the mucopolysaccharides, had an appearance similar to cerebrospinal fluid (CSF) in all MRI sequences performed, even in FLAIR and trace diffusion weighted images. Based on our results, we believe that with the exception of white matter abnormalities and brain atrophy, all other findings may be related to abnormal resorption of CSF, and there is no relationship between the imaging and clinical manifestations of the disease.     

MRI and 18F-fluorodeoxyglucose positron emission tomography in hemimegalencephaly

We report hemimegalencephaly in a 44-year-old woman with mental retardation, epilepsy and a mild hemiparesis. In addition to typical findings on MRI, 2-deoxy-2[¹⁸F]fluorodeoxyglucose positron-emission tomography (PET) demonstrated glucose hypometabolism of the affected hemisphere. The results of PET have been coregistered with morphological information from the MRI studies by image fusion. Received: 14 December 1999/Accepted: 15 February 2000     

Malignant peritoneal mesothelioma presenting with respiratory symptoms

Malignant peritoneal mesothelioma is a rare disease associated with mild, nonspecific abdominal symptoms and a wide spectrum of imaging findings, with thickened mesentery and peritoneum being the most common ones. A case of a malignant peritoneal mesothelioma presenting with manifestations of pulmonary disease is reported. Imaging evaluation revealed pleural, lung and pericardial involvement together with retroperitoneal lymphadenopathy, little ascites and extensive omental, but only subtle, mesenteric thickening. Received: 1 February 1999; Revised: 14 June 1999; Accepted: 22 September 1999     

Cognitive impairment due to widespread enlarged perivascular spaces

Perivascular spaces, also known as Virchow-Robin spaces, are usually considered as a normal, asymptomatic finding. However, this finding can occasionally demonstrate an atypical appearance and can be symptomatic. We report herein a rare case of cognitive impairment associated with extremely enlarged perivascular spaces. A 68-year-old Japanese woman visited our hospital with a 1-year history of progressive memory impairment. In addition to temporal disorientation and short-term memory impairment, neuropsychological testing showed frontal lobe-related symptoms such as slowed thinking processes, reduced verbal fluency, attention deficit, and reduced working memory. Magnetic resonance imaging of the brain showed widespread enlarged perivascular spaces almost symmetrically in the subcortical white matter of bilateral hemispheres, prominently in bilateral insulas, and frontal opercula. On 99mTc-ethyl cysteinate dimer single photon emission computed tomography, hypoperfusion was apparent in bilateral insulas and frontal opercula where enlarged periventricular spaces were prominent, whereas cerebral perfusion was preserved in areas where enlargement of perivascular spaces was mild or absent. Because symptoms were consistent with the distribution of the enlarged perivascular spaces and hypoperfusion in the brain, cognitive impairment due to enlarged perivascular spaces was diagnosed. Clinicians should note enlarged perivascular spaces as a potential cause of neurological deficits including cognitive impairment.     

A quantitative index of intracranial cerebrospinal fluid distribution in normal pressure hydrocephalus using an MRI-based processing technique

Our purpose was to quantify the intracranial cerebrospinal fluid (CSF) volume components using an original MRI-based segmentation technique and to investigate whether a CSF volume index is useful for diagnosis of normal pressure hydrocephalus (NPH). We studied 59 subjects: 16 patients with NPH, 14 young and 13 elderly normal volunteers, and 16 patients with cerebrovascular disease. Images were acquired on a 1.5-T system, using a 3D-fast asymmetrical spin- echo (FASE) method. A region-growing method (RGM) was used to extract the CSF spaces from the FASE images. Ventricular volume (VV) and intracranial CSF volume (ICV) were measured, and a VV/ICV ratio was calculated. Mean VV and VV/ICV ratio were higher in the NPH group than in the other groups, and the differences were statistically significant, whereas the mean ICV value in the NPH group was not significantly increased. Of the 16 patients in the NPH group, 13 had VV/ICV ratios above 30 %. In contrast, no subject in the other groups had a VV/ICV ratios higher than 30 %. We conclude that these CSF volume parameters, especially the VV/ICV ratio, are useful for the diagnosis of NPH. Received: 17 June 1999/Accepted: 12 October 1999     

A case of sclerosing hemangioma surrounded by emphysematous change

A 44-year-old woman presented with high-grade fever. Chest radiography showed a 30 mm solitary pulmonary mass in the left lower lobe. Chest CT revealed a well-defined solid mass in the left lower lobe. On contrast-enhanced CT, the mass showed homogeneity and mild enhancement. There was an emphysematous portion in the surrounding lung parenchyma. The patient underwent partial lobectomy of the left lower lobe. The final diagnosis of sclerosing hemangioma with abundant vasculature was confirmed pathologically. Pulmonary sclerosing hemangioma is a rare benign neoplasm. Some cases have been reported in which sclerosing hemangioma is surrounded by air spaces. We suggest that the air spaces around the tumor were formed by not only peritumoral bleeding but also a check-valve effect of the compressed bronchus.     

Histologic characteristics of normal perivascular spaces along the optic tract: new pathogenetic mechanism for edema in tumors in the pituitary region

BACKGROUND AND PURPOSE: Perivascular (PV) spaces are known to distend and cause edema along the optic tract (OT) in pituitary-region tumors. Interstitial fluid may be retained in PV spaces when tumors block their drainage outlets to subarachnoid spaces. However, these spaces and their outlets have not been anatomically elucidated. Our purpose was to evaluate how often large PV spaces are present along the OT and demonstrate their superficial communication points to adjacent subarachnoid spaces. METHODS: We examined serial histologic sections of 10 hemispheric blocks obtained from cadavers without cerebral abnormality. RESULTS: Large PV spaces, 0.5-1.5 mm in maximum height, were always present along the middle portion of the OT. Perforation points of the largest spaces were noted at the medial sulcus of the OT in seven hemispheres and through the OT in three. CONCLUSION: Large PV spaces are present along the middle portion of the OT. Their communication point to adjacent subarachnoid spaces was histologically demonstrated. The locations and variations of the outlet of large PV spaces explain the clinical features of edemas; these findings anatomically support the hypothesis that blockage of the outlets to subarachnoid spaces may play a role in distending the PV spaces and in causing edema in pituitary-region tumors. Only MR imaging has revealed this change; further pathologic investigations are awaited.     

Detection of severe acute pancreatitis by contrast-enhanced magnetic resonance imaging

The aim of the study was to assess the ability of MRI to differentiate between the two forms of severity of acute pancreatitis (AP), which is important for the detection of patients who require intensive monitoring and therapy. The second objective was to evaluate whether the distinction would be possible regardless of the MRI equipment. Magnetic resonance imaging was performed before and after intravenous administration of a gadolinium (Gd) chelate at 1.0 T using the breath-hold multislice rapid gradient-echo turbo fast low-angle shot (FLASH) sequence in 14 patients, and at 1.5 T with the 2D FLASH(50) sequence with fat saturation in 18 patients with acute pancreatitis early in the course of the disease. The patients were classified according to the Atlanta classification system as having the mild (MAP) or severe (SAP) form of the disease. At 1.0 T with use of a body coil, contrast-enhanced MRI failed to distinguish mild from severe pancreatitis. At 1.5 T with a phased-array body coil, the signal intensities of the patients with SAP were statistically significantly lower than those of the MAP group. Our initial clinical experience suggests that MRI with a sufficient magnetic field gradient strength may be useful for separating the two forms of acute pancreatitis in their early phases. Received: 19 January 1999; Revised: 28 May 1999; Accepted: 22 July 1999     

Angiosarcoma associated with chronic lymphedema (Stewart-Treves syndrome) of the leg: MR imaging

Magnetic resonance (MR) imaging findings of two patients with Stewart-Treves syndrome are presented. MR imaging showed edematous changes in the subcutaneous fat and skin masses that proved to be angiosarcomas. MR signal intensity of the tumor was low compared with fat on T1-weighted images and intermediate and heterogeneous on T2-weighted images. In one patient, administration of intravenous Gd-DTPA showed marked enhancement in the early phase, which persisted until the delayed phase. These finding on dynamic MR imaging may reflect the abundant vascular spaces seen in these tumors. Received: 20 August 1999 Revision requested: 28 October 2000 Revision received: 31 January 2000 Accepted: 8 February 2000     

Technical innovation: creation of a peripheral vascularized trough to enhance healing in cryopreserved meniscal allograft reconstruction

The important functions of the meniscus have been well described. Lack of a meniscus may lead to instability and early osteoarthrosis of the knee. Meniscal transplantation is an option following complete or subtotal meniscectomy in symptomatic patients with correct alignment, and mild to moderate chondrosis with the goal of preventing further degenerative sequelae to the knee. Since the first meniscus allograft implantation was performed 1984, there have been reported several open and arthroscopic techniques. We present our technique of arthroscopically assisted transplantation of a cryopreserved meniscal allograft with special consideration given to the technical details of this procedure. This technique employs creation of a circumferential osseocancellous trough in combination with transosseous tibial tunnel fixation and arthroscopic suture passage to both secure and enhance healing of the meniscal allograft. Received: 22 June 1999/Accepted: 2 February 2000     

Giant ranula of the neck: differentiation from cystic hygroma

BACKGROUND AND PURPOSE: Occasionally, diving ranulas may attain large dimensions (giant ranula); gross involvement of the submandibular and parapharyngeal spaces makes differentiation from other cystic neck masses, particularly cystic hygroma, difficult. As diving ranula and cystic hygroma are managed with different surgical approaches, avoidance of this pitfall is critical. Our purpose was to review the imaging findings of giant ranula and compare them with those of cystic hygroma to define those features that are helpful in differentiating these different disease entities. METHODS: We conducted a retrospective review of all cases of ranulas that had been surgically treated at our institution in a 15-year period. These were compared with cases of cystic hygroma that involved the same anatomic regions. Images were analyzed for anatomic location and morphology, with specific attention paid to those characteristics that might assist differentiation. Giant ranula was defined as any ranula that significantly involved the paraphyngeal space in addition to the submandibular space. RESULTS: Six patients with giant ranula and fifteen patients with cystic hygroma were reviewed. All giant ranulas retained tapered communication with the sublingual space and were homogeneous, thin-walled, anatomically defined, fluid-containing masses. One infected lesion enhanced, and another previously operated lesion demonstrated mild septation. Cystic hygroma commonly did not communicate with the sublingual space and had features of lobulation, septation and heterogeneity. Additional involvement of spaces not typically involved by ranula further assisted differentiation. CONCLUSION: Although giant ranulas may superficially resemble cystic hygroma, several imaging features allow confident differentiation of these two entities.     

Popliteal vascular malformation simulating a soft tissue sarcoma

Differentiation of vascular abnormalities from soft tissue sarcomas may be difficult on clinical grounds, but is usually possible on imaging criteria. We report the MRI and digital subtraction angiography (DSA) findings in a patient presenting with a mass behind the knee. We discuss differentiating features and review the literature of similar cases. Received: 28 January 1999 Revision requested: 23 February 1999 Revision received: 29 March 1999 Accepted: 30 March 1999     

Chronic ulceration of the leg following extensive scarring due to a snake bite complicated by squamous cell carcinoma

Chronic ulcers of the leg are common in Brazil, perhaps more common than in the developed world. We report a case of a chronic ulcer of the leg following extensive scarring due to a bite by a venomous snake, which eventually led to a squamous cell carcinoma. Received: 16 August 1999 Revision requested: 8 October 1999 Revision received: 10 December 1999 Accepted: 15 December 1999