Intravenous Administration Of Contrast Material Research Articles

Differentiation of the various lesions causing an abnormality of the endometrial cavity using MR imaging: emphasis on enhancement patterns on dynamic studies and late contrast-enhanced T1-weighted images

The objectives of this study were to determine the usefulness of magnetic resonance (MR) imaging in the differentiation of various lesions causing an abnormality of the endometrial cavity by evaluating the imaging features on dynamic contrast-enhanced study and late contrast-enhanced T1-weighted images (T1WI). Contrast-enhanced MR imaging of 59 pathologically proven lesions that showed an abnormality of the endometrial cavity, including 32 endometrial cancers, five sarcomas, nine hyperplastic polyps, nine submucosal myomas, three hyperplasia, and one adenomyoma, were retrospectively reviewed. The enhancement degree and patterns on dynamic contrast-enhanced study and late contrast-enhanced T1WI were compared among different pathologies. On dynamic contrast-enhanced study, 72% (23/32) of endometrial cancers showed early peak enhancement to be reached within 1 min following intravenous administration of contrast material. On late-contrast-enhanced T1WI, lesions showed weak enhancement with gradual washout. Ninety-five percent (21/22) of benign lesions and 100% (5/5) of sarcomas showed late peak enhancement to be reached in 2-3 min following intravenous administration of contrast material. On late contrast-enhanced T1WI, both of these lesions showed persistent strong enhancement. Different enhancement patterns on dynamic contrast-enhanced MR imaging and late contrast-enhanced T1WI can provide a useful clue in the differentiation of various lesions causing an abnormality of the endometrial cavity.

Facial paraesthesia: answer

Schwannomas arising from the nerve sheath account for 0.07% to 0.36% of all intracranial tumours, and from 0.8% to 8% of intracranial schwannomas. They usually arise from the vestibular and trigeminal nerves, rarely from the vagus or glossopharyngeal. CT scans are not the preferred imaging modality, but are useful in delineating bony architecture and skull base anatomy. Generally, trigeminal schwannomas appear isodense or slightly hyperdense on CT imaging, enhancing uniformly after administration of intravenous contrast material. On MR imaging, trigeminal schwannomas are isoor slightly hyperintense in T1and T2-weighted images with enhancement after gadolinium injection. Cystic degeneration, seen in our patient, is known to occur in up to 37% of intracranial schwannomas. Trigeminal schwannomas can be removed by microsurgery, but the procedure carries with it the risk of

Clinically unsuspected pulmonary embolism—an important secondary finding in oncology CT

To determine the rate of finding incidental pulmonary embolisms (PE) at staging or follow-up chest computed tomography (CT) in oncology patients. Three hundred and eighty-five consecutive chest CT examinations, performed in patients with cancer, were prospectively assessed during a 9-month period between October 2003 and June 2004. These were spiral acquisitions between 5 and 8mm collimation acquired 25s after intravenous contrast medium administration. PE was diagnosed if a filling defect was seen in the central pulmonary arteries on two or more consecutive slices. Ten of 385 (2.6%) of these patients had incidentally detected PE. This was not attributable to any specific malignancy or chemotherapeutic regimen. These emboli were all central, between the main pulmonary artery and the lobar level. Although the significance of these findings in patients not clinically suspected of having PE could be contentious, all the patients were started on therapeutic anticoagulation as a result of this observation. Over one in 40 oncology patients have incidental central PE visible on the CT images performed to assess their malignancy. Formal review of the pulmonary arteries, using a work station, is advised in patients with malignancy.

CT of the small intestine

CT of the small intestine continues to be a diagnostic challenge. Three protocols have turned out to be useful. The frequently used general protocol is highly suitable for most indications that require an overview of the small intestine and in cases where no specific queries regarding the small intestine have to be answered. A dedicated protocol with opacification of the small intestine by means of a probe appears to be useful in patients with a suspected tumour or to exclude a tumour as well as in cases of inflammatory bowel disease. Filling of the bowel ensures optimal distention and, in combination with intravenous contrast medium administration, allows differentiation of tumours from inflammatory lesions. In cases of suspected intestinal ischaemia, angiographic techniques should be used. State-of-the-art techniques such as bolus tracking and acquisition of a dynamic scan for determination of individual circulation time facilitate optimal arterial opacification of the intestinal wall. The results obtained in our patients suggest that the use of multislice CT in combination with optimal opacification improves sensitivity. Further studies have to show whether the improved diagnostic options also translate into an improved clinical outcome or survival rate.

INVERTED CONTRAST MEDIUM‐URINE LAYERING IN THE CANINE URINARY BLADDER ON COMPUTED TOMOGRAPHY

Contrast medium-urine layering is routinely identified on transverse computed tomography (CT) images in the urinary bladder following intravesicular or intravenous administration of iodinated contrast medium. The contrast opacified urine typically occupies the dependent portion of the urinary bladder whereas the nonopacified urine layers above it. In this retrospective study, three patients with inverted contrast medium layering following intravenous contrast medium administration are described. A review of this phenomenon in humans is presented and an explanation for similar imaging findings in the dog proposed.

ASGE Technology Status Evaluation Report: radiographic contrast media used in ERCP

ASGE Technology Status Evaluation Report: radiographic contrast media used in ERCP

Intravenous Contrast Material Administration at Helical 16–Detector Row CT Coronary Angiography: Effect of Iodine Concentration on Vascular Attenuation

The institutional review board approved this study, and all patients gave written informed consent. One hundred twenty-five patients scheduled to undergo retrospectively electrocardiographically gated 16-detector row computed tomographic coronary angiography were prospectively randomized into the following five groups with respect to the intravenous administration of a 140-mL bolus of contrast material at 4 mL/sec: group 1 (iohexol [300 mg of iodine per milliliter]), group 2 (iodixanol [320 mg I/mL]), group 3 (iohexol [350 mg I/mL]), group 4 (iomeprol [350 mg I/mL]), and group 5 (iomeprol [400 mg I/mL]). Attenuation was measured in the descending aorta and coronary arteries. One-way analysis of variance was used to compare groups. Mean attenuation values in the descending aorta were significantly (P < .05) lower in group 1 and higher in group 5 compared with the mean values in the other three groups. The same pattern was observed in the coronary arteries. Contrast materials with higher iodine concentrations yield significantly higher attenuation in the descending aorta and coronary arteries.

Digital Mammography Using Iodine-Based Contrast Media

We sought to evaluate the potential of dynamic contrast enhancement after the intravenous administration of an iodine-based contrast medium in full-field digital mammography. A protocol for image acquisition was established for contrast-enhanced mammography and the mammography unit (Senographe 2000D, GE Healthcare, Buc, France) changed as required. The effect of the protocol parameters on imaging was investigated. Subsequently, 21 patients with 25 suspicious lesions of the breast (10 benign, 1 borderline, and 14 malignant) underwent mammography with administration of an iodine-based contrast medium (Ultravist 370, Schering AG, Berlin, Germany), after approval of ethical committee as well as permission of German federal office for Radiation protection, and informed consent from each patient was obtained. Three sequential digital mammographic images of the respective breast were acquired after administration of the contrast medium at a dose of 1 mL/kg body weight and a flow of 4 mL/s. The postcontrast images were acquired 60, 120, and 180 seconds after administration. Subsequently, the precontrast image was logarithmically subtracted from the postcontrast images. Enhancement of the lesions was measured in absolute terms as well as relative to the enhancement of the glandular tissue. The subtracted images were evaluated for lesion depiction and dynamic contrast enhancement. Lesion-enhancement kinetics were compared with the histologic findings. All malignant lesions were identified on the contrast-enhanced images of digital mammography. Three of the tumors (2 malignant, 1 benign) were detected only by contrast-enhanced mammography and not by standard mammography. Dynamic enhancement curves of benign and malignant tumors in contrast-enhanced mammography look similar to the curves known from gadolinium-enhanced magnetic resonance imaging. Nevertheless differentiation between malignant and benign tumors based on the enhancement patterns cannot be directly taken over from magnetic resonance imaging, as suggested by our initial results. The results are somewhat better when tumor enhancement relative to surrounding glandular tissue is used instead of absolute enhancement. The results of this preliminary study suggest that contrast-enhanced digital mammography is a potentially useful tool for the detection and the differentiation of benign and malignant breast lesions.

Giant Mixed Retroperitoneal Sarcoma with Metaplastic Bone and Cartilage Formation: Radiological-Pathological Correlation

Soft tissue sarcomas account for less than 1% of all malignancies and 10% of them arise in the retroperitoneal tissues 1,2 . The prognosis for patients with retroperitoneal sarcoma varies widely but is usually poor, with reported five-year survival rates ranging between 12% and 70% 1-6 . Complete surgical resection is the treatment of choice 7 . An accurate preoperative diagnosis is necessary to enable the most radical surgical excision of the mass. A 53-year-old woman was admitted to our hospital because of a six-month history of a painless but growing palpable mass of hard consistency located in the right upper quadrant of the abdomen. The patient’s medical history was unremarkable except for iron deficiency anemia. Physical examination revealed a solid, palpable mass occupying the right upper abdomen. There was no palpable lymphadenopathy. Plain X-ray of the abdomen showed a vast, ill-marginated calcified radiopacity projecting over the right upper quadrant (Figure 1). Ultrasound examination detected a large multilobated, mixed echogenic mass extending from the right iliac wing to the lower surface of the liver, inseparable from the medial aspect of the ipsilateral kidney, which appeared invaded and displaced medially. Spiral CT of the abdomen revealed a single, large mass characterized by heterogeneous soft-tissue density with some areas of fatty density on non-contrast images. The upper part of the mass was completely calcified and the mass appeared to originate from the retroperitoneal space. After administration of intravenous contrast medium the mass showed heterogeneous enhancement (Figure 2). The patient underwent radical surgical excision of the lesion with resection of the right kidney. Histological examination showed predominant features of myxoid and round cell liposarcoma. These areas were juxtaposed to high-grade leiomyosarcoma cells, with some areas of lipoma-like type; malignant fibrous histiocytoma-like areas with malignant cells arranged in whorls were also detected. Metaplastic bone and cartilage formation was also observed, especially in the upper portion of the mass. The final pathological diagnosis was mixed retroperitoneal sarcoma with metaplastic bone and cartilage formation. The patient is free of disease at one year from diagnosis. Retroperitoneal sarcomas are often very large at diagnosis because they become symptomatic only when they reach the size of a huge mass or when there is as

Angioleiomyoma of the Cavernous Sinus: Case Report

Angioleiomyomas (ALMs) are relatively rare, benign, vascular soft tissue tumors that occur most frequently in the extremities of middle-aged individuals. To date, only two cases of intracranial ALMs have been described, both with little emphasis on the clinical, surgical, and radiological aspects. Neither of these reported cases of ALM involved the cavernous sinus. Furthermore, there is no previous intracranial ALM magnetic resonance imaging scan described in the literature. This report presents the first case of cavernous sinus ALM, emphasizing the clinical, radiological, and surgical aspects. A 52-year-old man had a 2-year history of horizontal diplopia and frontal headache. Facial numbness and impaired visual acuity in the previous 6 months were also reported. Physical examination revealed paralysis of right Cranial Nerves III, IV, and VI. A decrease in optical acuity was also noted. Computed tomographic and magnetic resonance imaging scans demonstrated a mass lesion located in the right cavernous sinus, which enhanced homogeneously with administration of intravenous contrast medium. A total resection was performed via a right frontotemporal craniotomy and a pretemporal approach with peeling of the middle fossa. The postoperative course was uneventful. Histological examination identified the ALM, with no recurrence noted during follow-up. It is unknown why intracranial ALMs have not been reported more frequently in the literature. Although ALMs are a rare occurrence, misinterpretation of this lesion may also have contributed to the lack of reported cases. Before surgery, ALMs can be distinguished from meningiomas and schwannomas but not from hemangiomas. The prognosis of intracranial ALM is good, as suggested in this case as well as the two previously reported cases.

CT features of abdominal plasma cell neoplasms

The aim of this study was to describe the CT features of abdominal plasma cell neoplasms. We reviewed CT imaging findings in 11 patients (seven men, four women; mean age 62 years) with plasma cell neoplasms and abdominal involvement. Helical CT of the entire abdomen and pelvis was performed following intravenous administration of contrast material. Images were analyzed in consensus by two radiologists. Diagnoses were made from biopsy, surgery and/or clinical follow-up findings. Multiple myeloma was found in seven patients and extramedullary plasmacytoma in four patients. All patients with multiple myeloma had multifocal disease with involvement of perirenal space (4/7), retroperitoneal and pelvic lymph nodes (3/7), peritoneum (3/7), liver (2/7), subcutaneous tissues (2/7) and kidney (1/7). In three of the four patients with extramedullary plasmacytoma, a single site was involved, namely stomach, vagina and retroperitoneum. In the fourth patient, a double site of abdominal involvement was observed with rectal and jejunal masses. Plasma cell neoplasm should be considered in the differential diagnosis of single or multiple enhancing masses in the abdomen or pelvis. Abdominal plasma cell neoplasms were most frequently seen as well-defined enhancing masses (10/11).

Bladder transitional cell carcinoma: correlation of contrast enhancement on computed tomography with histological grade and tumour angiogenesis

AIM: To investigate the correlation between the degree of contrast enhancement of bladder cancer in the early enhanced phase of helical computed tomography (CT) and microvessel density (MVD), vascular endothelial growth factor (VEGF) and histological grade. MATERIALS AND METHODS: Sixty-five patients with transitional cell carcinoma of the bladder were examined by incremental unenhanced CT and helical CT at 40–45 s after initiation of intravenous administration of contrast medium before surgery. The CT density in Hounsfield units of bladder carcinomas were measured in the middle of the maximum diameter section of the cancer lesions on unenhanced and enhanced CT. The degree of contrast enhancement of the tumour was determined as the absolute increase in Hounsfield units. Histological grade, VEGF and MVD were analysed for each cancer. The Pearson and Spearman correlation tests were used to determine the strength of the relationships between CT enhancement and histological grade, VEGF expression and MVD. RESULTS: Different degrees of enhancement were observed in 91 cancers during the early enhanced phase of helical CT. Mean MVDs and mean CT enhancing values of different histological grade groups were statistically different ( p<0.001). A positive correlation was found in the CT-enhancing value of bladder cancer and MVD (Pearson correlation test; r=0.938, p<0.001) and histological grade (Spearman rank correlation; r=0.734, p<0.001). VEGF of bladder cancer did not correlate with the change in CT attenuation (Spearman rank correlation; r=0.087, p=0.410) and MVD (Spearman rank correlation, r=0.103, p=0.330). CONCLUSION: In bladder cancer, the degree of contrast enhancement during the early enhanced helical CT is correlated with the MVD and histological grade of tumour. It is possible that MVD is the histopathological basis of early contrast enhancement of bladder cancer.

Approaches to CT perfusion imaging in pulmonary embolism

Computed tomography (CT) has become an increasingly accepted technique and is the method of choice for direct visualization of pulmonary emboli (PE). The quantitative assessment of tissue perfusion may yield more important information for patient management than the direct visualization of emboli by CT alone. Several attempts have been made to measure pulmonary blood flow by administration of intravenous contrast material. In this article, various experimental CT approaches for visualization and quantification of pulmonary perfusion are discussed. Ideally, CT will be able to provide both structural and functional information. Simple measurement of lung density before and after intravenous contrast delivery has been performed with single-slice CT technology using region-of-interest methodology. For electron-beam CT, a repeated data acquisition on a 7.6-cm lung volume has proven to be technically feasible. Using such dynamic scanning, reduced blood flow was observed in occluded lung segments. Color-encoded parenchymal density distribution in the axial, coronal, and sagittal planes was derived from thin collimation data sets using four-row multi-slice spiral CT (MSCT). Initial animal data from 16-slice MSCT offer a real CT-subtraction technique of the entire chest for the first time.

MR Imaging of Apparent Small-Bowel Perfusion for Diagnosing Mesenteric Ischemia: Feasibility Study

The purpose of this study, which was approved by the institutional review board, was to assess the differentiation of individuals with from those without mesenteric ischemia. All subjects provided written informed consent. Six healthy volunteers and six patients with documented chronic mesenteric ischemia underwent magnetic resonance (MR) imaging with and without oral caloric stimulation. After intravenous administration of paramagnetic contrast material, signal intensity values of the small-bowel wall were measured up to 130 seconds after contrast material injection. Volunteers and patients, respectively, had maximum enhancement of the bowel wall between 70 and 85 seconds after contrast material administration that amounted to 269% and 267% without and 425% and 333% with caloric stimulation. MR imaging assessment of small-bowel perfusion is possible and seems feasible for differentiating individuals with from those without mesenteric ischemia.

Intraparenchymal epidermoid tumor of the brain

The patient was a 40-year-old woman who presented with headaches mainly felt in the occipital region. A lobulated mass was evident in the isthmus of the right hippocampal gyrus on MRI. It was hypointense on spin-echo T1-weighted images and hyperintense on T2-weighted, and fluid attenuated inversion recovery (FLAIR) images (Fig. 1a). A thin enhancing rim was noted after administration of intravenous paramagnetic contrast medium. An echo-planar diffusion MRI sequence (TR=4,700 ms and TE=118 ms) revealed high signal in the tumor on b=1,000 s/mm2 images (Fig. 1b). The apparent diffusion coefficient (ADC) value in the epidermoid tumor was 0.53×10−3 mm2/s. Normal parenchymal ADC values ranged between 0.67 and 0.98×10−3 mm2/s. The lesion was excised and the histopathological diagnosis was epidermoid tumor. Most (90%) of the epidermoid tumors occur intradurally in the subarachnoid cisterns. Approximately 10% are extradural, mostly intradiploic. Rarely, they can occur in the fourth ventricle and within the cerebral hemispheres [1–3]. Iaconetta et al. [1] reported a case of intracerebral epidermoid tumor and reviewed 34 previous cases. The distribution of the epidermoids in the brain parenchyma were as follows: 11 cases in the frontal lobe (39.2%), 12 in the temporal lobe (42.8%), 3 in the parietal lobe (10.7%) and 1 thalamic and 1 occipital (3.5%) [1]. In addition, Calderelli et al. [2] reported two cases of epidermoid tumors involving the brainstem with a review of 12 similar cases, and Gupta et al. [3] reported a thalamic epidermoid. The cases reported in these three papers Eur Radiol (2005) 15:838–839 DOI 10.1007/s00330-004-2396-z L E T T E R T O T H E E D I T O R

Mimics of renal colic: alternative diagnoses at unenhanced helical CT.

During the past decade, unenhanced computed tomography (CT) has become the standard of reference in the detection of urinary calculi owing to its high sensitivity (>95%) and specificity (>98%) in this setting. Numerous diseases may manifest as acute flank pain and mimic urolithiasis. Up to one-third of unenhanced CT examinations performed because of flank pain may reveal unsuspected findings unrelated to stone disease, many of which can help explain the patient's condition. Alternative diagnoses are most commonly related to gynecologic conditions (especially adnexal masses) and nonstone genitourinary disease (eg, pyelonephritis, renal neoplasm), closely followed by gastrointestinal disease (especially appendicitis and diverticulitis). Hepatobiliary, vascular, and musculoskeletal conditions may also be encountered. Vascular causes of acute flank pain must always be considered, since these constitute life-threatening emergencies that may require the intravenous administration of contrast material for diagnosis. Radiologists must be familiar with the typical findings of urinary stone disease at unenhanced CT, as well as the spectrum of alternative diagnoses that may be detected with this modality, to accurately diagnose the source of flank pain.

MR imaging of maternal diseases of the abdomen and pelvis during pregnancy and the immediate postpartum period.

Magnetic resonance (MR) imaging provides multiplanar large field-of-view images of the body with excellent soft-tissue contrast and without ionizing radiation. As a result, MR imaging is increasingly being used to image the maternal abdomen and pelvis during and immediately after pregnancy. Results of rapid T1- and T2-weighted imaging are often diagnostic, and blood vessels, ductal structures, and the urinary tract can frequently be visualized without intravenous administration of contrast material. Until more conclusive safety data become available, MR imaging should be reserved for cases in which results of ultrasonography are inconclusive and patient care depends on further imaging. In the setting of acute abdomen during pregnancy, MR imaging allows identification of areas of inflammation, abscess formation, hemorrhage, and bowel obstruction. MR imaging also helps determine the organ of origin, extent, and composition of maternal neoplasms and is useful in evaluation of müllerian duct anomalies and abnormalities of placental formation, position, and implantation. Many postpartum complications such as retained products of conception and uterine dehiscence may be diagnosed with MR imaging when results of other modalities are indeterminate.

Volumetry of the Pituitary Gland: An Initial in vitro and in vivo MR Study

Purpose: We have attempted to evaluate the reliability of a new volumetric technique for MR imaging applied on measurements of phantoms with defined volumes and the normal pituitary gland (PG) of healthy individuals. Methods: In nine males without a clinical history of pituitary abnormalities and in a phantom study we performed triplicate MRI measurements before and after repositioning for volumetry of the PG or the phantoms, respectively. Using a standard head coil on a 1.5 T scanner, a tilted sagittal T1w 3D magnetization-prepared rapid gradient-echo sequence was applied with TR/TE/alpha=15/5ms/30, 256×256 matrix, 192 slices, 1mm thickness and an isovoxel size of 1×1×1mm3. For interactive segmentation, a semi-automated 3D-watershed transform was applied to the gradient image. Each segmentation took approx. 4 minutes. Volume was assessed by voxel counting. Results: Mean volume of the nine pituitary glands was 0.62ml (SD:0.02ml) with variation coefficients (VC) between 2.68% and 6.32%, respectively. Furthermore, the intraobserver variability with four repeated volume analyses of an identical MRI measurement ranged from 1.44% to 3.67%. After intravenous administration of contrast medium, the volume calculation showed an overestimation because of reduced demarcation of PG. Reliable and precise results could be ensured up to a slice thickness of 1.8mm, preferably by coronal scanning. The VC from the phantom volume measurements (0.3, 0.5, 0.9, 1.0 and 1.6ml) only ranged from 0.49% (SD:0.006ml) to 1.98% (0.005ml). Conclusion: Our initial results demonstrate a high reliability without a significant difference of volumetric measurement for our in vitro and in vivo studies. This method provides a precise volume estimation of PG up to a slice thickness of 1.8mm and can improve the monitoring of PG volume in follow-up-studies after surgical or conservative treatment.

Metformin monitoring and change in serum creatinine levels in patients undergoing radiologic procedures involving administration of intravenous contrast media.

To evaluate the prevalence and magnitude of serum creatinine level elevations in patients receiving metformin who underwent radiologic procedures involving administration of intravenous contrast media, and to evaluate the efficacy of an electronic consultation in promoting timely evaluation of renal function after the procedure. Retrospective evaluation. Veterans Affairs Medical Center. Ninety-seven patients receiving metformin who underwent a radiologic procedure involving administration of intravenous contrast media over a 27-month period. Ninety-seven patients underwent a total of 111 radiologic procedures with documented administration of intravenous contrast dye. Average time from procedure to laboratory follow-up, excluding one patient, was 2.62+/-1.56 days. Average serum creatinine levels before and after the procedure were 1.10+/-0.19 and 1.13+/-0.23 mg/dl, respectively (p>0.05). Four patients developed contrast material-associated nephropathy. An additional four patients with borderline serum creatinine levels at baseline (1.4 mg/dl) had a serum creatinine level of 1.5 mg/dl or greater after the procedure. Our results indicated that electronic consultations result in timely evaluation of serum creatinine levels in patients receiving metformin who undergo a radiologic procedure involving intravenous contrast material. Also, the study suggests that nearly 4% of patients with diabetes mellitus and normal renal function may develop contrast material-associated nephropathy [corrected] with nonionic contrast material. In addition, about 8% of patients with diabetes treated with metformin (with baseline serum creatinine levels < 1.5 mg/dl) who undergo a procedure with nonionic intravenous contrast material acquire an increased risk (serum creatinine > or = 1.5 mg/dl) of lactic acidosis. These findings support the recommendations of the Food and Drug Administration regarding metformin monitoring in patients undergoing radiologic procedures involving administration of intravenous contrast media.

Imaging features of multicentric Castleman's disease in HIV infection

AIM: To describe the computed tomography (CT) features of human immunodeficiency virus (HIV)-associated Castleman's disease. MATERIALS AND METHODS: Nine HIV-positive patients with biopsy-proven Castleman's disease were studied. Clinical and demographic data, CD4 count, histological diagnosis and human herpes type 8 (HHV8) serology or immunostaining results were recorded. CT images were reviewed independently by two radiologists. RESULTS: CT findings included splenomegaly ( n=7) and peripheral lymph node enlargement (axillary n=8, inguinal n=4). All nodes displayed mild to avid enhancement after intravenous administration of contrast material. Hepatomegaly was evident in seven patients. Other features included abdominal ( n=6) and mediastinal ( n=5) lymph node enlargement and pulmonary abnormalities ( n=4). Patterns of parenchymal abnormality included bronchovascular nodularity ( n=2), consolidation ( n=1) and pleural effusion ( n=2). On histological examination eight patients (spleen n=3, lymph node n=9, lung n=1 bone marrow n=1) had the plasma cell variant and one had mixed hyaline-vascular/plasma cell variant. The majority had either positive immunostaining for HHV8 or positive serology ( n=8). CONCLUSION: Common imaging features of multicentric Castleman's disease in HIV infection are hepatosplenomegaly and peripheral lymph node enlargement. Although these imaging features may suggest the diagnosis in the appropriate clinical context, they lack specificity and so biopsy is needed for diagnosis. In distinction from multicentric Castleman's disease in other populations the plasma cell variant is most commonly encountered, splenomegaly is a universal feature and there is a strong association with Kaposi's sarcoma.