Whole-body FSE STIR MR imaging of lymphoma

Purpose

To evaluate the role of FSE STIR whole body MRI in diagnosis and initial staging of malignant lymphoma, and can FSE STIR whole body MRI replace conventional staging procedures including computed tomography and bone marrow biopsy in initial staging of lymphoma.

Materials and methods

Twenty one newly diagnosed histologically proven lymphoma patients underwent whole body MR imaging and conventional staging procedures including computed tomography and bone marrow biopsy for initial staging of lymphoma using Modified Ann Arbor staging system. Both methods evaluated positive involvement by lymphoma to the nodal and extra-nodal sites including parenchymal organs, serosal cavities and bone marrow. The numbers of involved nodal and extra-nodal sites detected by both methods were compared, then agreement and disagreement between whole-body MRI and conventional procedures regarding lesions detection and staging according to the Ann Arbor staging system were calculated, along with binomial exact 95% confidence intervals (CIs).

Results

Twenty one patients had a total of 145 abnormalities. One hundred and twenty four were correctly diagnosed by conventional staging procedures, however, FSE STIR whole body MRI correctly diagnosed all the 144 abnormalities with 1 false negative and 3 false positive abnormalities with a total of detected abnormalities of 147 lesions. FSE STIR whole body MRI was significantly more accurate than conventional staging procedures in the diagnosis of positive lymphoma lesions [(99.3%; 95% CI: 95.6-100.0%) versus (85.5%; 95% CI: 78.5-90.6%)]. FSE STIR whole body MRI correctly staged 20 out of 21 patients, Kappa test 0.93 (P < 0.001) while conventional staging procedures correctly staged 17 and incorrectly staged 4 cases, Kappa test 0.74 (P < 0.001).

Conclusion

Whole body MR imaging can replace conventional staging procedures in the diagnosis and initial staging of malignant lymphoma as it offers a whole body overview of the lymphoma infiltration through the lymph node stations, parenchymal organs, serosal cavities and bone marrow.     

Comparison of whole-body STIR-MRI and <Superscript>99m</Superscript>Tc-methylene-diphosphonate scintigraphy in children with suspected multifocal bone lesions

The study was performed to compare whole-body short time inversion recovery (STIR) MR imaging and ^99mTc-methylene diphosphonate planar scintigraphy in the examination of children with suspected multifocal skeletal malignant lesions. Sixteen patients with known or suspected malignant skeletal disease underwent both whole-body STIR MR imaging and bone scintigraphy. The lesions were described and numbered according to scintigraphic evaluation criteria. Thus, 16 regions were analyzed in each patient for the comparison between the two modalities. Histology was proven in the primary malignant regions. Follow-up MRIs were registered. Scintigraphy and MRI follow-up were evaluated as gold standard. A total of 139 different lesions was observed by both modalities. Baseline whole-body MRI revealed 119 bone lesions in 256 possible sites (46.5%); scintigraphy revealed only 58 lesions (22.6%). Congruence was observed in only four patients (25%). According to the location of the lesion, correlation was observed in 39/139 lesions (28%). In all, 57.5% of the lesions were detected only by MRI and 14.5% of the lesions were detected only by scintigraphy. Whole-body MRI was more sensitive (P<0.001). Of all lesions numbered which could be separated in the initial MRI, whole-body MRI detected 178 lesions in the patients. The results suggest that whole-body MRI using a STIR sequence is an effective radiation free method for examination of children with suspected multifocal bone lesions. MRI showed more lesions than conventional ^99mTc-methylene diphosphonate scintigraphy. Therefore, whole-body MRI may be feasible as a screening modality for metastatic and skip lesions in osteosarcoma, PNET, Ewing sarcoma and Langerhans cell histiocytosis in children.     

Bone involvement in patients with lymphoma: the role of FDG-PET/CT

Purpose To evaluate the diagnostic impact and clinical significance of FDG-avid bone lesions detected by FDG-PET/CT in patients with lymphoma. Methods The study population comprised 50 consecutive patients (mean age 41.7±15.5 years; 27 female, 23 male; 41 staging, 9 restaging) with Hodgkin’s disease (n=22) or aggressive non-Hodgkin’s lymphoma (n=28) in whom FDG-avid bone lesions were detected by FDG-PET/CT. All patients had either direct biopsy of the FDG-avid bone lesion (n=18), standard bone marrow biopsy at the iliac crest (BMB; n=43) or both procedures (n=11). In 15 patients, additional MRI of the bone lesions was performed. All patients underwent FDG-PET/CT after the end of treatment. All CT images of FDG-PET/CT scans were analysed independently regarding morphological osseous changes and compared with FDG-PET results. Results In the 50 patients, 193 FDG-avid lesions were found by PET/CT. The mean standardised uptake value was 6.26 (±3.22). All direct bone biopsies (n=18) of the FDG-avid lesions proved the presence of lymphomatous infiltration. BMB (n=43) was positive in 12 patients (27.9%). In CT, 32 of 193 (16.6%) lesions were detected without the PET information. No additional morphological bone infiltration was detected on CT compared with FDG-PET. All morphological bone alterations on CT scans persisted after the end of therapy. Additional PET/CT information regarding uni- or multifocal bone involvement resulted in lymphoma upstaging in 21 (42%) patients compared with the combined information provided by CT and BMB. Conclusion In patients with FDG-avid bone lesions, FDG-PET is superior to CT alone or in combination with unilateral BMB in detecting bone marrow involvement, leading to upstaging in a relevant proportion of patients.     

MR detection of iliac bone marrow involvement by malignant lymphoma with various MR sequences including diffusion-weighted echo-planar imaging

OBJECTIVE: To assess the diagnostic accuracy of MR imaging for detecting bone marrow infiltration by malignant lymphoma. PATIENTS AND DESIGN: Fifty-three patients with malignant lymphoma underwent MR imaging and bone marrow biopsy. In 80 iliac crests of the 53 patients (13 positive specimens in 9 patients and 67 negative specimens in 44 patients), biopsy results and the signal intensity characteristics were compared. MR sequences included T1-weighted SE, T2-weighted FSE with fat suppression, FSE STIR, and diffusion-weighted EPI with fat suppression at 1.5 T. RESULTS AND CONCLUSIONS: To detect lymphoma infiltration, T1-weighted SE had the highest sensitivity (92%) and diffusion-weighted EPI with fat suppression and FSE STIR had the highest specificity (92.5% and 92%, respectively). A combination of T1-weighted SE and FSE STIR yielded the highest sensitivity and specificity (85% and 97%, respectively). A combination of T1-weighted SE and FSE STIR sequences seems to be the current choice of imaging protocol for detecting bone marrow infiltration by malignant lymphoma.     

Whole-body MR imaging for detection of bone metastases in children and young adults: comparison with skeletal scintigraphy and FDG PET.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy of whole-body MR imaging, skeletal scintigraphy, and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for the detection of bone metastases in children. SUBJECTS AND METHODS: Thirty-nine children and young adults who were 2--19 years old and who had Ewing's sarcoma, osteosarcoma, lymphoma, rhabdomyosarcoma, melanoma, and Langerhans' cell histiocytosis underwent whole-body spin-echo MR imaging, skeletal scintigraphy, and FDG PET for the initial staging of bone marrow metastases. The number and location of bone and bone marrow lesions diagnosed with each imaging modality were correlated with biopsy and clinical follow-up as the standard of reference. RESULTS: Twenty-one patients exhibited 51 bone metastases. Sensitivities for the detection of bone metastases were 90% for FDG PET, 82% for whole-body MR imaging, and 71% for skeletal scintigraphy; these data were significantly different (p < 0.05). False-negative lesions were different for the three imaging modalities, mainly depending on lesion location. Most false-positive lesions were diagnosed using FDG PET. CONCLUSION: Whole-body MR imaging has a higher sensitivity than skeletal scintigraphy for the detection of bone marrow metastases but a lower sensitivity than FDG PET.     

Magnetic resonance imaging of disseminated bone marrow disease in patients treated for malignancy

Magnetic resonance imaging (MRI) is a sensitive method for the diagnosis of bone marrow abnormalities, but its usefulness in detecting active disseminated cancer in this tissue in treated patients has not been determined. We therefore examined 14 children who had been treated for disseminated bone marrow involvement by neuroblastoma (n=6), lymphoma (n=3), Ewing's sarcoma (n=3), osteosarcoma (n=1), and leukemia (n= 1). MRI studies were performed at 21 marrow sites to evaluate residual or recurrent tumor and were correlated with histologic material from the same site. T₁- and T₂-weighted sequences were employed in 21 and 14 studies, respectively; short tau inversion recovery (STIR) in 18; and static gadolinium diethylene triamine pentaacetic acid (Gd-DPTA)-enhanced, T₁-weighted sequences in 13. All MRI studies showed an altered bone marrow signal. Technetium 99m methylene diphosphonate (^99mTc-MDP) bone scintigraphy was also performed (19 studies). On histologic examination, 7 marrow specimens contained tumor, and 14 did not. Of the 7 tumor-positive lesions, all T₁-weighted, 4 of 6 T₂-weighted, and all 6 STIR sequences showed abnormal signal; all 5 GdDTPA-enhanced, T₁-weighted sequences showed enhancement of the lesion. However, abnormal signals were also observed on all T₁-weighted, 6 of 8 T₂-weighted, 11 of 12 STIR, and 5 of 8 Gd-DTPA-enhanced, T₁-weighted images of the tumor-negative sites. In this clinical setting, MRI did not consistently differentiate changes associated with treatment from malignant disease.     

Parenchymal lymphoma of the brain on initial MR imaging: A comparative study between primary and secondary brain lymphoma

Background and purpose

Parenchymal lymphomatous brain masses have not been investigated considering if they are primary or as a part of systemic lymphoma (secondary) on imaging studies previously. We aimed to determine characteristics of the secondary parenchymal lymphomatous involvement of the brain and to find if there is any radiologic feature to help discrimination of untreated primary and secondary central nervous system lymphoma on patients’ initial magnetic resonance imaging.

Materials and methods

We evaluated MR images of 18 patients with the diagnosis of primary (n = 12) and secondary central nervous system lymphoma (n = 6). We considered the number, localization, enhancement pattern, signal characteristics, diffusion properties, presence of hemorrhage and presence of butterfly pattern on MR imaging at initial presentation.

Results

Secondary central nervous system lymphomas predominantly presented as multiple (n = 4, 66.7%) lesions. Homogenous nodular enhancement and supratentorial white matter involvement were present in all patients with butterfly pattern and infiltrative/perivenular enhancement in half (n = 3) of the patients. Deep gray matter (n = 1, 16.7%) and infratentorial involvement (n = 1, 16.7%) were scarce and no ring enhancement was observed. There was no statistically significant difference in any of the investigated MR features between the two groups.

Conclusion

Statistical analyses revealed no significant distinctive radiologic characteristics between primary and secondary lymphoma of the brain parenchyma.     

Whole-body MRI in the detection of bone marrow infiltration in patients with plasma cell neoplasms in comparison to the radiological skeletal survey

To compare the diagnostic value of whole-body MRI versus radiological skeletal survey (RSS) in staging patients with plasma cell neoplasms (PCN) and to evaluate the possible therapeutic impact of the replacement of RSS by whole-body MRI. Fifty-four patients with PCN [multiple myeloma (MM), n=47; monoclonal gammopathy of unknown significance (MGUS), n=7] were studied by whole-body MRI and RSS in a monocenter prospective analysis from August 2002 to May 2004. The MRIs were performed using a rolling table platform “AngioSURF” for unlimited field of view with a 1.5-T system (Magnetom Sonata/Maestro Class, Siemens Medical Solutions, Erlangen, Germany). A coronal STIR sequence (TR5500-4230/TE102-94/TI160) was used for imaging of the different body regions, including the head, neck, thorax, abdomen, pelvis and upper and lower extremities. The RSS consisted of eight different projections of the axial and appendicular skeleton. In 41/54 (74%) patients, the results of the whole-body MRI and RSS were concordant. In 11/54 (20%) patients, both imaging techniques were negative. Bone involvement was observed in 30/54 (55%) patients; however, whole-body MRI revealed this more extensively than the RSS in 27/30 (90%) patients with concordant positive imaging findings. In 3/30 (10%) patients, both imaging techniques demonstrated a similar extent of bone marrow infiltration. In 10/54 (19%) patients, the whole-body MRI was superior to RSS in detecting bone marrow infiltration, whereas the RSS was negative. In 3/54 (6%) patients, the RSS was proven to be false positive by the clinical course, whereas the whole-body MRI was truly negative. Whole-body MRI is a fast and highly effective method for staging PCN patients by the use of a rolling table platform. Moreover, it is more sensitive and specific than RSS and reveals bone marrow infiltration and extensive disease more reliably. Therefore, whole-body MRI should be performed as an additional method of exactly staging PCN patients and - with more data in the field - may even prove to be an alternate and more sensitive staging procedure than RSS in PCN patients.     

Prostate carcinoma: diffusion-weighted imaging as potential alternative to conventional MR and 11C-choline PET/CT for detection of bone metastases

In a technical development study approved by the institutional ethics committee, the feasibility of fast diffusion-weighted imaging as a replacement for conventional magnetic resonance (MR) imaging sequences (short inversion time inversion recovery [STIR] and T1-weighted spin echo [SE]) and positron emission tomography (PET)/computed tomography (CT) in the detection of skeletal metastases from prostate cancer was evaluated. MR imaging and carbon 11 ((11)C) choline PET/CT data from 11 consecutive prostate cancer patients with bone metastases were analyzed. Diffusion-weighted imaging appears to be equal, if not superior, to STIR and T1-weighted SE sequences and equally as effective as (11)C-choline PET/CT in detection of bone metastases in these patients. Diffusion-weighted imaging should be considered for further evaluation and comparisons with PET/CT for comprehensive whole-body staging and restaging in prostate and other cancers.     

Staging of malignant lymphoma with three-station black-blood fast short-inversion time inversion recovery (STIR).

PURPOSE: The purpose of this study was to assess the usefulness of three-station black-blood fast short-inversion time inversion recovery (STIR) imaging in detecting and staging malignant lymphoma. METHODS: Seventeen patients with malignant lymphoma were examined with a 1.5T imager. The findings and stagings determined with three-station black-blood fast STIR imaging were compared with reference standards (e.g., computed tomography [CT] findings and clinical stagings). RESULTS: Three-station black-blood fast STIR imaging provided a fat-suppressed T2-weighted imaging contrast with fewer flow artifacts and revealed nodal involvement as well as bone marrow and spleen involvement to an extent comparable with CT. Especially notable was the excellent specificity (94%) of this imaging technique. Regarding disease staging, significant agreement was observed between clinical staging (k=0.60) and staging as evaluated by three-station black-blood fast STIR, although the detection of lymphadenopathy in the thorax was relatively poor. The average time required for this imaging was approximately 30 min. CONCLUSION: Three-station black-blood fast STIR MR imaging may be useful as a staging tool for malignant lymphoma because this imaging technique reveals lymphoma lesions, which determine the staging, without radiation exposure or the use of contrast agents.     

Clinical relevance of gallium-67 scintigraphy in lymphoma before and after therapy

The clinical impact of gallium-67 scintigraphy before and after therapy for lymphoma remains controversial. The aims of this study were: (1) to compare the staging of lymphoma by ⁶⁷Ga scintigraphy only with staging by clinical examination and conventional imaging (CI), and (2) to analyse the clinical relevance of both ⁶⁷Ga imaging and CI after treatment. From March 1995 to November 1998, 86 ⁶⁷Ga scintigraphy studies were performed in 62 patients with Hodgkin’s disease (n=52) or non-Hodgkin’s lymphoma (n=10). ⁶⁷Ga scintigraphy was performed at diagnosis (n=44) or after therapy (n=42) using 185–220 MBq ⁶⁷Ga citrate and planar and single-photon emission tomography (SPET) studies. Treatment comprised radiotherapy, chemotherapy or combined modalities. CI included plain chest radiography, computed tomography (CT) of the chest and abdomen/pelvis, ultrasound of the abdomen, lymphography, bone marrow biopsy and, when necessary, magnetic resonance imaging (MRI) and bone scintigraphy. For individual suspected sites of disease before treatment, complete agreement between clinical examination and CI on the one hand and ⁶⁷Ga scintigraphy on the other hand was observed in 25/44 patients (57%; 95% confidence interval 41%–72%). Clinical examination and CI showed more sites than did ⁶⁷Ga scintigraphy in 12/44 patients (27%) and ⁶⁷Ga imaging demonstrated more sites than CI in 6/44 patients (11%). The clinical stage of the disease as assessed using ⁶⁷Ga scintigraphy only was in agreement with that using all diagnostic procedures in 34/44 patients (77%; 95% confidence interval 62%–89%). Compared with CI staging, ⁶⁷Ga scintigraphy downstaged seven patients (16%) and upstaged three (7%). ⁶⁷Ga scintigraphy downstaged mainly because of the limited value of the technique below the diaphragm and upstaged owing to the good sensitivity in the lung. After therapy, both CI and ⁶⁷Ga scintigraphy were normal in 11 patients. All but one of these patients were in complete remission after a median follow-up of 31 months. In contrast, radiological residual mass was observed in 31/42 patients. ⁶⁷Ga imaging was normal in 22/31 (71%); 17 of these 22 patients, including nine with a large residual mass (≥2 cm), were in complete remission after a median follow-up of 32 months, while four suffered relapses 8–45 months later. The cause of death remained unknown in one patient. ⁶⁷Ga scintigraphy showed abnormal uptake in 9 of the 31 patients with a large residual mass. Active disease was demonstrated in eight patients and one patient was in complete remission 30 months thereafter. Our data show that ⁶⁷Ga imaging cannot replace CI in initial staging but can demonstrate additional individual sites of disease in more than 10% of patients and can lead to clinical upstaging with potential prognostic and therapeutic consequences. After therapy, ⁶⁷Ga scintigraphy has a clinical impact when radiological abnormalities persist because it can either avoid unnecessary complementary treatment or confirm the need to change treatment modalities. Received 5 July and in revised form 9 September 1999     

Detection of bone marrow and extramedullary involvement in patients with non-Hodgkin’s lymphoma by whole-body MRI: comparison with bone and <Superscript>67</Superscript>Ga scintigraphies

The aim of this study was to evaluate the diagnostic potential of whole-body MRI (WB-MRI) for the detection of bone marrow and extramedullary involvement in patients with non-Hodgkins lymphoma. WB-MRI, which was performed on 34 patients, consisted of the recording of T1-weighted spin-echo images and a fast STIR sequence covering the entire skeleton. The WB-MRI findings for bone marrow and extramedullary involvement were compared with those from ⁶⁷Ga and bone scintigraphies and bone marrow biopsy results. Two MRI specialists reviewed the WB-MRI results and two expert radiologists in the field of nuclear medicine reviewed the bone and ⁶⁷Ga scintigraphy findings. Bone marrow and extramedullary involvement of non-Hodgkins lymphoma were confirmed by follow-up radiographs and CT and/or a histological biopsy. The detection rate of WB-MRI was high. More bone marrow involvement was detected by biopsy, and more lesions were detected by scintigraphies. In total, 89 lesions were detected by WB-MRI, whereas 15 were found by biopsy, 5 by ⁶⁷Ga scintigraphy, and 14 by bone scintigraphy. WB-MRI could also detect more extramedullary lesions than ⁶⁷Ga scintigraphy; i.e., 72 lesions were detected by WB-MRI, whereas 54 were discovered by ⁶⁷Ga scintigraphy. WB-MRI is useful for evaluating the involvement of bone marrow and extramedullary lesions throughout the skeleton in patients with non-Hodgkins lymphoma.     

Malignant lymphoma: bone marrow imaging versus biopsy

In 107 patients with malignant Hodgkin and non-Hodgkin lymphoma, bone marrow was evaluated with scintigraphy, magnetic resonance (MR) imaging, and biopsy to detect bone marrow infiltration. Imaging and biopsy results were classified as normal (class 0), suggestive of reactive changes (class 1), or suspicious for infiltration (class 2). About one-half of biopsy and imaging results agreed completely. In patients with chronic lymphocytic leukemia, false-negative findings were frequent with both imaging techniques. Although a positive biopsy result is usually accepted as proof of bone marrow infiltration, results indicate that negative biopsy findings do not exclude tumor involvement. When suspected infiltration was found with MR imaging or scintigraphy but results were normal or suggestive of reactive changes in the first blind biopsy, repeat blind or guided biopsy helped confirm the imaging results. Autopsy findings in two patients completely confirmed previous results with MR imaging and scintigraphy, although findings at antemortem biopsy were different. Scintigraphy and MR imaging should be included routinely in the staging of malignant lymphoma as an adjunct to blind biopsy in the complete evaluation of bone marrow status.     

Small cell lung cancer: staging with MR imaging

Small cell lung cancer is an aggressive neoplasm; metastases are detected in two-thirds of patients at diagnosis with use of conventional staging, which includes bilateral bone marrow biopsy, bone scintigraphy, and computed tomography (CT) of the head and abdomen. In 25 patients, small cell lung cancer was staged prospectively with both conventional staging and a magnetic resonance (MR) imaging protocol that included 1.5-T MR imaging of the pelvis, abdomen, spine, and brain. According to conventional staging, 14 patients had extensive disease and 11 patients had limited disease; according to staging with MR, 19 patients had extensive disease and six had limited disease. All metastatic disease sites seen with conventional staging were identified on MR images. MR images showed additional metastatic involvement in bone (four patients) and liver (three patients) not detected at conventional staging. A low-attenuation hepatic lesion on a CT scan was identified as a hemangioma on MR images. These preliminary data suggest that small cell lung cancer may be accurately staged with use of a single MR imaging study.     

Comparison of fat-saturation fast spin echo versus conventional spin-echo MRI in the detection of rotator cuff pathology

The purpose of this study was to compare the diagnostic performance of fat-saturation fast-spin-echo (FSE) T2-weighted (T2W) sequences with conventional spin-echo (CSE) T2W sequences in the detection of rotator cuff pathology using surgery as the reference standard. Oblique coronal dual-echo CSE and FSE T2W images with fat saturation from 50 surgically confirmed MR shoulder examinations were acquired on a 1.5-T MR scanner. Blinded MR readers retrospectively analyzed each imaging sequence separately and ultimately correlated both sequences together with findings at surgery. FSE was 100% sensitive and 94% specific in detection of full-thickness tears (n = 19) and 73% sensitive and 97% specific in the detection of partial-thickness rotator cuff tears (n = 13). There was no statistically significant difference in the performance of FSE with fat saturation compared with CSE. The two discrepancies between imaging sequences related to the extent of partial-thickness tears. Our findings suggest that fat-saturation FSE imaging can effectively replace CSE imaging in the evaluation of rotator cuff pathology.     

Staging non-small cell lung cancer with whole-body PET.

PURPOSE: To compare the accuracies of whole-body 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) and conventional imaging (thoracic computed tomography [CT], bone scintigraphy, and brain CT or magnetic resonance [MR] imaging) in staging bronchogenic carcinoma. MATERIALS AND METHODS: Within 20 months, 100 patients with newly diagnosed bronchogenic carcinoma underwent whole-body FDG PET and chest CT. Ninety of these patients underwent radionuclide bone scintigraphy, and 70 patients underwent brain CT or MR imaging. For each patient, all examinations were completed within 1 month. A radiologic stage was assigned by using PET and conventional imaging independently and was compared with the pathologic stage. The accuracy, sensitivity, specificity, and negative and positive predictive values were calculated. RESULTS: PET staging was accurate in 83 (83%) patients; conventional imaging staging was accurate in 65 (65%) patients (P < .005). Staging with mediastinal lymph nodes was correct by using PET in 67 (85%) patients and by using CT in 46 (58%) patients (P < .001). Nine (9%) patients had metastases demonstrated by using PET that were not found with conventional imaging, whereas 10 (10%) patients suspected of having metastases because of conventional imaging findings were correctly shown with PET to not have metastases. CONCLUSION: Whole-body PET was more accurate than thoracic CT, bone scintigraphy, and brain CT or MR imaging in staging bronchogenic carcinoma.     

Malignant lymphoma of the gingiva: MR evaluation.

PURPOSEOur purpose was to document the MR imaging findings of malignant lymphoma of the gingiva.METHODSFive patients with histologically proved malignant lymphoma of the gingiva were studied by MR imaging. The MR images were analyzed for tumor size, extent, and signal characteristics, bone involvement, and associated cervical lymph node enlargement.RESULTSClinical examination tended to underestimate the size of lymphomatous lesions. The signal intensity of the lesions was isointense to hyperintense relative to muscle on noncontrast T1-weighted images and showed variable contrast enhancement patterns. On T2-weighted images, signal intensity was isointense to hypointense relative to the oral mucosa. In one case, the mass extended to the submandibular space; in the remaining cases, the masses were limited to the gingiva and the adjacent bone. MR imaging revealed that gingival lymphomatous masses were broad-based along the mandible or maxilla and eroded through the cortex into the marrow space, but the cortex was still recognizable. No nodal involvement was noted in any of the patients with malignant lymphoma.CONCLUSIONThe signal characteristics of gingival lymphoma overlap those of other tumors. The cortex separating marrow involvement from the broad-based gingival mass generally appears to be permeated with small erosions but is still recognizable.     

Whole-body fast inversion recovery MR imaging of small cell neoplasms in pediatric patients: a pilot study

OBJECTIVE. The purpose of this study was to assess the ability of whole-body turbo short tau inversion recovery (STIR) MR imaging to detect metastases in children with small cell tumors and to compare its performance with that of conventional imaging. CONCLUSION. Early data suggest that whole-body turbo STIR MR imaging is as reliable as other conventional imaging studies for staging newly diagnosed small cell tumors in pediatric patients.     

Whole-body MRI for the detection of bone marrow involvement in lymphoma: prospective study in 116 patients and comparison with FDG-PET

Objective

To assess and compare the value of whole-body MRI with FDG-PET for detecting bone marrow involvement in lymphoma.

Methods

A total of 116 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and blind bone marrow biopsy (BMB) of the posterior iliac crest. Of 116 patients, 80 also underwent FDG-PET. Patient-based sensitivities of whole-body MRI for detecting bone marrow involvement were calculated using BMB as reference standard and compared with FDG-PET in aggressive and indolent lymphomas separately.

Results

Sensitivity of whole-body MRI in all lymphomas was 45.5 % [95 % confidence interval (CI): 29.8–62.0 %]. Sensitivity of whole-body MRI in aggressive lymphoma [88.9 % (95 % CI: 54.3–100 %)] was significantly higher (P?=?0.0029) than that in indolent lymphoma [23.5 % (95 % CI: 9.1–47.8 %)]. Sensitivity of FDG-PET in aggressive lymphoma [83.3 % (95 % CI: 41.8–98.9 %)] was also significantly higher (P?=?0.026) than that in indolent lymphoma [12.5 % (95 % CI: 0–49.2 %)]. There were no significant differences in sensitivity between whole-body MRI and FDG-PET (P?=?1.00)

Conclusion

Sensitivity of whole-body MRI for detecting lymphomatous bone marrow involvement is too low to (partially) replace BMB. Sensitivity of whole-body MRI is significantly higher in aggressive lymphoma than in indolent lymphoma and is equal to FDG-PET in both entities.

Key Points

? Bone marrow involvement in lymphoma has prognostic and therapeutic implications. ? Blind bone marrow biopsy (BMB) is standard for bone marrow assessment. ? Neither whole-body MRI nor FDG-PET can yet replace BMB. ? Both techniques have higher sensitivity in aggressive than in indolent lymphoma. ? Both imaging techniques are complementary to BMB.     

Advanced imaging of melorheostosis with emphasis on MRI

Objective: To describe the CT and MR imaging appearance of both osseous and extraosseous manifestations of melorheostosis. Design and patients: We retrospectively reviewed the CT (n=7) and/or MR imaging findings (n=12) of 17 patients with characteristic radiographic findings of melorheostosis (undulating cortical hyperostosis with marked uptake on radionuclide bone scintigraphy). Results: CT and MR imaging revealed cortical hyperostosis as high attenuation and low signal intensity on all MR pulse sequences, respectively. Encroachment on the marrow space was seen in all cases resulting from endosteal involvement. Thirteen patients demonstrated 14 soft tissue masses with infiltrative margins in 80% of cases and seven showed extensive mineralization on CT or MR imaging (low intensity on all pulse sequences). Seven soft tissue masses were predominantly nonmineralized with intermediate signal intensity on T1-weighted and intermediate to high signal on T2-weighted MR images corresponding to vascularized fibrous tissue with variable collagen content pathologically. Enhancement after intravenous gadolinium was seen in all patients imaged with soft tissue masses (n=2). Two patients demonstrated muscle atrophy resulting from nerve involvement. Conclusions: The osseous abnormalities in melorheostosis are identical on advanced imaging and radiographs. Mineralized or nonmineralized soft tissue masses should be recognized as another manifestation of this disease as opposed to a more ominous finding, making biopsy unwarrranted. Received: 16 January 2001 Accepted: 21 February 2001