A case of progressive multifocal leukoencephalopathy in AIDS: neuroimaging with clinical and pathologic correlation

We present the neuroimaging features with clinical and pathologic correlation in a case of Progressive Multifocal Leukoencephalopathy (PML) in AIDS. CT and MRI showed typical lesions of PML. At pathology examination, characteristic lesions of PML were found in association with HIV encephalitis due to CNS infection by the virus.     

Progressive multifocal leukoencephalopathy in patients with AIDS: appearance on MR images

Progressive multifocal leukoencephalopathy (PML) is an uncommon demyelinating disease that occurs in immunocompromised patients. The authors evaluated magnetic resonance (MR) images of 10 patients with pathologically proved PML and clinically diagnosed acquired immunodeficiency syndrome (AIDS) to determine the MR characteristics of this disorder. All patients had asymmetric cerebral involvement. Lesions were distributed throughout the brain, including the brain stem and basal ganglia. White matter was affected in all 10 patients; gray matter was also involved in five. In one patient the lesion enlarged and crossed the corpus callosum and contained focal hemorrhage. The authors conclude that, contrary to reported findings on computed tomographic scans, PML in patients with AIDS has a variable appearance on MR images and has many characteristics that differ from those previously thought to be typical on imaging studies.     

Progressive multifocal leukoencephalopathy: clinical and MR response to treatment.

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease that occurs in immunocompromised hosts. We describe two patients with biopsy-proved PML who showed improvement clinically and radiologically after medical therapy. These cases reveal that interval improvement can in rare instances be consistent with a diagnosis of PML.     

Progressive multifocal leukoencephalopathy in an HIV-infected child

A child with perinatally acquired HIV infection presented with acute neurologic deterioration. A cerebellar white matter lesion seen on CT and MRI later proved to be progressive multifocal leukoencephalopathy (PML) by histology. Although a recognized disease of HIV-infected adults, PML is certain to be seen with more frequency in HIV-infected children who are surviving longer as a result of improved medical care. Recognition of the clinical and radiographic manifestations is important because of the dismal prognosis. Received: 30 April 1996 Accepted: 17 May 1996     

Progressive multifocal leukoencephalopathy: diffusion-weighted imaging and pathological correlations

We examined MRI of two patients with progressive multifocal leukoencephalopathy (PML), including diffusion-weighted imaging (DWI), with calculation of apparent diffusion coefficients (ADC). The pathology findings of one patient were compared with those of MRI. The lesions had different ADC and DWI appearances, depending on the stage of the disease. Newer lesions and the advancing edge of large lesions had normal-to-low ADC and gave high signal on DWI. Older lesions and the centre of large lesions had increased ADC and gave low signal. High signal on DWI and low ADC mark the regions of active infection and cell swelling, distinguishing them from areas of reparative gliosis.Presented in part at the XVII Symposium Neuroradiologicum, Paris, August 2002     

Progressive multifocal leukoencephalopathy: analysis of lesion development with diffusion-weighted MRI

Progressive multifocal leukoencephalopathy (PML), caused by replication of JC virus in oligodendrocytes of immunocompromised patients, is diagnosed by polymerase chain reaction-based demonstration of JC virus DNA. We investigated whether MRI might be used to assess disease activity. Diffusion-weighted imaging (DWI) was obtained in two patients with PML, in whom it was the only MRI sequence on which we could identify areas of progressive disease. The extent of abnormal diffusion appeared to correlate with the speed of clinical progression. DWI would thus seem to be of value in patients with PML.     

Progressive multifocal leukoencephalopathy in AIDS: initial and follow-up CT and MRI

We sought to determine the value of follow-up CT and MRI in patients with acquired immunodeficiency syndrome (AIDS) and progressive multifocal leukoencephalopathy (PML). We reviewed 50 CT and 19 MRI examinations performed in 21 biopsy- or autopsy-proven cases of PML; 17 patients had follow-up examinations (mean time 5.9 weeks). The radiological examinations were correlated with pathological findings at autopsy. On initial imaging studies, 73 lesions were found. On follow-up, the most striking feature was rapid progression in both size and number of the lesions (from a mean of 3.2 to 6.9 per patient). One third of the patients showed increasing mass effect. A central area suggesting necrosis, of variable size, was found in 12/16 patients. Autopsy revealed macroscopic necrotic changes in the lesions in 11/16 patients. Received: 30 May 1996 Accepted: 14 October 1996     

Diffusion-weighted imaging in patients with progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system due to JC polyoma virus infection of oligodendrocytes. PML develops in patients with impaired T-cell function as occurs in HIV, malignancy or immunosuppressive drugs users. Until now no imaging methods have been reported to correlate with clinical status. Diffusion-weighted imaging (DWI) is a robust MRI tool in investigating white matter architecture and diseases. The aim of our work was to assess diffusion abnormalities in focal white matter lesions in patients with PML and to correlate the lesion load measured with conventional MRI and DWI to clinical variables. We evaluated eight patients with a biopsy or laboratory-supported diagnosis of PML. All patients underwent MRI including conventional sequences (fluid attenuated inversion recovery-FLAIR) and DWI. Mean diffusivity (MD) maps were used to quantify diffusion on white matter lesions. Global lesion load was calculated by manually tracing lesions on FLAIR images, while total, central core and peripheral lesion loads were calculated by manually tracing lesions on DWI images. Lesion load obtained with the conventional or DWI-based methods were correlated with clinical variables such as disease duration, disease severity and survival. White matter focal lesions are characterized by a central core with low signal on DWI images and high MD (1.853 × 10⁻³ mm2/s), surrounded by a rim of high signal intensity on DWI and lower MD (1.1 × 10⁻³ mm2/s). The MD value of normal-appearing white matter is higher although not statistically significant (0.783 × 10⁻³ mm2/s) with respect to control subjects (0.750 × 10⁻³ mm2/s). Inter-rater correlations of global lesion load between FLAIR (3.96%) and DWI (3.43%) was excellent (ICC =0.87). Global lesion load on FLAIR and DWI correlates with disease duration and severity (respectively, p = 0.037, p = 0.0272 with Karnofsky scale and p = 0.0338 with EDSS on FLAIR images; p = 0.043, p = 0.0296 with Karnofsky scale and p = 0.0365 with EDSS on DW images). Central core lesion load on DWI correlates with disease duration and severity (respectively p = 0.043, p = 0.0103 with Karnofsky scale and p = 0.0112 with EDSS), while peripheral lesion load does not correlate with any clinical variable. The global lesion load in PML correlates with disease duration and severity. DWI images, which can distinguish within lesions a central core from a peripheral rim, reveal that a larger central core component correlates to a worsened clinical status and longer disease duration. On the other hand the peripheral rim lesion load visualized on DWI images does not correlate with clinical variables and does not achieve obtaining further prognostic information with respect to conventional imaging.     

Neurobrucellosis: clinical and neuroimaging correlation

BACKGROUND AND PURPOSE: Manifestation of nervous system involvement by neurobrucellosis, a treatable infection, is not well documented. We investigated patterns of nervous system involvement and determined if neuroimaging abnormalities correlated with clinical manifestations of neurobrucellosis. METHODS: We reviewed 23 MR imaging studies (17 of brain, six of spine) and seven CT scans of brain in 23 patients (14 male and nine female patients; age range 17-71 years) with positive Brucella titers in their serum and CSF. RESULTS: Twelve patients had central nervous system (CNS) involvement, four had peripheral nervous system (PNS) involvement, two had combined PNS and CNS involvement, and five had isolated hearing loss. Imaging findings were variable: five of seven brain CT studies were normal, and 10 of 23 MR studies were normal (eight brain, one thoracic, one lumbar). One brain CT study showed subthalamic hemorrhage, mild perivascular enhancement, left caudate lacunae, and diffuse white matter changes. One other brain CT study showed enhancement of the tentorium in addition to white matter changes. Abnormal MR findings were basal meningeal enhancement (n = 3), lumbar nerve root enhancement (n = 3), granuloma of the suprasellar region (n = 1), diffuse white matter changes (n = 7), and spinal cord atrophy (n = 1). All patients improved after treatment with three antimicrobial drugs for 3-12 months. Seven patients had follow-up imaging; the enhancement disappeared but the white matter and ischemic changes persisted despite almost complete clinical recovery. CONCLUSION: Clinical-radiologic correlation in neurobrucellosis varies from a normal imaging study despite positive clinical findings, to a variety of imaging abnormalities that reflect either an inflammatory process, an immune-mediated process, or a vascular insult.     

Primary adrenocortical carcinoma: sonographic evaluation with clinical and pathologic correlation in 26 patients

The sonograms of 26 patients (19 adults and seven children) with pathologically proven diagnoses of primary adrenocortical carcinoma were evaluated. Clinical corroboration was obtained in all cases. The size of the lesions ranged from 3 to 22 cm. The five smaller lesions (3-6 cm) showed a homogeneous echo pattern, similar to renal cortical echogenicity. The 21 larger lesions varied in echo texture, having a heterogeneous appearance with focal or scattered echopenic or echogenic zones representing areas of tumor necrosis, hemorrhage, and/or, rarely (19%), calcification. Even the largest lesions were fairly well delineated, often with a lobulated border. Few (7/26 or 27%) showed a surrounding echogenic thin capsulelike rim. All five small lesions showed clinical evidence of endocrine activity. Larger lesions were hormonally active less often (9/21 or 43%). Twelve patients (46%) showed no sign of endocrine activity and presented with symptoms such as fever, weight loss, abdominal discomfort, abdominal mass, hematuria, and hypertension. In the pediatric and adolescent age group (0-16 years), all tumors were hormonally active, while only seven (37%) of tumors in the adult population (17-69 years) were hormonally active. Unfortunately no echo pattern was characteristic enough to allow differentiation of adrenal adenoma from carcinoma. Smaller lesions are more likely to be benign, and larger lesions with areas of necrosis, hemorrhage, and calcification are more likely to be malignant.     

Pancreatic transplants: CT with clinical and pathologic correlation

A retrospective evaluation of 68 CT scans in 17 patients with pancreatic allografts was performed with clinical and pathologic correlation to better define the nature of abnormalities detected with CT and the role of CT in patient treatment. Patients with clinical complications demonstrated variable degrees of pancreatic inhomogeneity and peripancreatic inflammation on CT scans. These findings were similar in appearance to pancreatitis in the native gland. Most patients proved to be undergoing acute rejection. However, these findings were not specific and were also seen with peripancreatic infection, hemorrhage, and exocrine anastomotic leaks. No CT changes were detected in two of three patients with late rejection. Thus, CT was not helpful in the diagnosis of pancreatic rejection. The most beneficial role of CT was in the detection of intraabdominal fluid collections, including abscesses, hematomas, and pseudocysts. Percutaneous aspiration was invaluable in the distinction between infected and sterile fluid collections; however, percutaneous drainage was of limited use in treatment.     

Progressive multifocal leukoencephalopathy and human immunodeficiency virus-associated white matter lesions in AIDS: magnetization transfer MR imaging

PURPOSE: To determine the magnetization transfer features of progressive multifocal leukoencephalopathy (PML) and human immunodeficiency virus (HIV)-associated white matter lesions (WML) (hereafter, HIV-WML) on magnetic resonance (MR) images obtained in patients with acquired immunodeficiency syndrome (AIDS). MATERIALS AND METHODS: Conventional MR imaging and magnetization transfer MR imaging were performed in 21 AIDS patients with 42 areas of white matter hyperintensity on MR images (13 patients had 25 PML lesions, eight patients had 17 WML). The magnetization transfer ratio was calculated for each lesion. RESULTS: Compared with normal-appearing white matter (magnetization transfer ratio = 47.9%), both PML and HIV-WML showed reduced magnetization transfer ratio. The magnetization transfer ratio was significantly lower in PML lesions (magnetization transfer ratio = 26.1%) than in HIV-WML (magnetization transfer ratio = 38.0%, P < .0001), and there was no overlap in the magnetization transfer ratio between PML lesions and HIV-WML. The separation in magnetization transfer ratio between the two lesion types was valid for lesion as small as 0.5 cm2. CONCLUSION: The larger reduction in magnetization transfer ratio for PML lesions is most likely due to demyelination, whereas the reduction in HIV-WML may be associated primarily with gliosis. PML lesions appear to cause strong reductions in magnetization transfer ratio early in the course of disease. Magnetization transfer MR imaging is a noninvasive tool that improves the differentiation between PML and HIV-WML in patients with AIDS.     

Cytomegalic inclusion virus encephalitis in patients with AIDS: CT, clinical, and pathologic correlation

The computed tomographic (CT) scans of 10 patients with acquired immunodeficiency syndrome who had central nervous system (CNS) involvement by cytomegalovirus (CMV) were retrospectively reviewed and correlated with clinical data and pathologic findings. Diagnosis was established in all 10 patients by autopsy, which showed the pathognomonic "owl's eye" intracellular inclusions of CMV. In six patients CMV caused an initial CNS infection that was directly responsible for the patient's progressive encephalopathy and death. In four patients CMV caused a superimposed nondominant CNS infection that had no clinical expression in two. Cortical atrophy and mild hydrocephalus ex vacuo were seen on CT in all 10 patients. Positive findings on CT that could be attributed to infection with CMV were present in only three of the 10 patients, and in these three symptomatic cases autopsy correlation revealed that CT underestimated the degree of CNS involvement. In the other three symptomatic patients, CT showed no parenchymal abnormalities, while autopsy demonstrated diffuse cerebral involvement. In the four patients whose CNS was secondarily involved by CMV, CT showed changes proven at autopsy to be related only to the dominant infection with Toxoplasma gondii and to postoperative hematomas. CT did not demonstrate any abnormalities at the sites of CMV involvement, which were found at autopsy in this latter group. It was concluded that CT is not very sensitive for the detection of CMV encephalitis.     

Progressive multifocal leukoencephalopathy demonstrating contrast enhancement on MRI and uptake of thallium-201: a case report

We describe a patient with AIDS who presented with focal neurological symptoms, and who had contrast-enhancing brain lesions on MRI which demonstrated increased thallium-201 uptake on SPECT. These findings were consistent with lymphoma; however, brain biopsy established a diagnosis of progressive multifocal leukoencephalopathy (PML). To our knowledge, this is the first reported case of PML with increased thallium-201 uptake on brain SPECT. Received: 9 September 1998 Accepted: 25 March 1999     

腹膜后副神经节瘤的临床及CT表现与病理对照研究

目的:探讨腹膜后副神经节瘤的临床表现及CT诊断价值。方法:回顾性分析有完整病历及CT资料、经手术病理证实的腹膜后副神经节瘤27例,将临床及CT表现与病理学结果进行对照分析。结果:临床表现:有高血压症状10例,无高血压症状但术中出现血压波动6例,无高血压及术中血压波动11例。CT表现:肿瘤多位于腹中线大血管周围(19个病灶),并多大于5cm(21个病灶),增强CT表现为实性、明显强化,常伴有囊变或坏死。临床表现与病理对照:嗜铬性副神经节瘤16例,有高血压症状10例,另外6例术中有血压波动;非嗜铬性副神经节瘤11例,无任何症状6例,腹部包块4例,血尿1例。CT表现与病理对照:良性肿瘤边缘光整,病灶内囊变区内壁光整,边界清楚;恶性肿瘤形态不规则,"囊变区"不规则,边界不清楚。CT诊断正确率为88.9%,误诊11.1%。结论:临床症状结合增强CT表现在术前对大多数腹膜后副神经节瘤能做出正确诊断。     

High b-value diffusion-weighted imaging in progressive multifocal leukoencephalopathy in HIV patients

Objectives

An ill-defined hyperintense edge and hypointense core on diffusion-weighted imaging (DWI) is typical of progressive multifocal leukoencephalopathy (PML). We aimed to investigate whether a b-value of 3,000 s/mm² (b3000) can improve visualisation of PML, or provide different structural information compared to 1,000 s/mm² (b1000).

Methods

We retrospectively identified HIV-positive patients with confirmed PML studied under a clinical protocol including both b1000 and b3000 DWI. The rim and core of each PML lesion and normal-appearing white matter (NAWM) were outlined on trace-weighted DWI. Signal intensities, apparent diffusion coefficient (ADC) values and volumes were measured and compared between b1000 and b3000.

Results

Nine lesions from seven patients were analysed. The rim and core were better visualised on b3000, with higher signal of the rim and lower signal of the core compared to NAWM. The hyperintense rim had non-restricted average ADCs, but included foci of low ADC on both b3000 and b1000. Despite similar total lesion volumes, b3000 displayed significantly larger core and smaller rim volumes than b1000.

Conclusion

b3000 improves visualisation of this important PML hallmark. Moreover, b3000 partly reclassifies tissue from rim into core, and might provide potentially more accurate biomarkers of PML activity and prognosis.

Key Points

? B3000 improves contrast resolution between lesion rim, core and normal-appearing white matter.? B3000 improves identification of the typical rim-and-core pattern of PML lesions.? B3000 and b1000 similarly identify lesions, but b3000 results in smaller rims and larger cores.? B3000 excludes some high diffusion components from rim, reclassifying them into core.? B3000 DWI may provide more precise PML biomarkers of disease activity and tissue damage.

     

MR imaging of uterine carcinoma: correlation with clinical and pathologic findings

Thirteen patients with clinical stages I and II endometrial carcinoma were examined with magnetic resonance (MR) imaging before surgery. Depth of invasion and stage of disease were assessed, and the results were compared with those from MR images of the surgical specimens and pathologic findings. Staging with MR imaging was accurate in 11 of 13 patients (85%). Our results agree with previous reports that MR imaging is an accurate, noninvasive method of assessing depth of myometrial invasion and cervical involvement. We anticipate that MR imaging will have an increasing role in treatment of patients with endometrial carcinoma.     

MR imaging in fibromatosis: results in 26 patients with pathologic correlation

Fibromatoses are a diverse group of soft-tissue lesions that have been inconsistently categorized and treated. The purpose of our study was to establish the range of appearances of fibromatoses on MR images and perform a pathologic correlation to explain the variable signal-intensity patterns. During a 3-year period, 26 patients with deep fibromatoses were examined with MR. The MR images were evaluated for signal-intensity characteristics, and findings were correlated retrospectively with the pathologic diagnoses. The results showed that the MR appearance of fibromatoses is similar to that of other soft-tissue lesions, and the signal intensities vary greatly from lesion to lesion and within lesions themselves. The fibromatoses were either hyperintense, isointense, hypointense, or of mixed signal intensity relative to adjacent skeletal muscle. The hypointense areas appear to be zones of hypocellularity and dense collagen deposition. Microscopically all of the lesions invaded adjacent structures, but the MR appearances of the margins varied and were judged to be well demarcated (n = 14), intermediate (n = 5), or poorly demarcated (n = 6). Our experience shows that fibromatoses have a variable MR appearance no different from that of other soft-tissue lesions, and this variability reflects the composition and cellularity of the lesions.