Magnetic resonance imaging of the lumbar spine and blood volume in professional cyclists.

Stimulated hematopoiesis is observed in the bone marrow of endurance-trained athletes by magnetic resonance imaging (MRI) independent of the hemoglobin concentration (hematocrit or erythrocyte count) or circulating reticulocytes, but may be related to blood volume (BV). This study determined whether hyperplasia of hematopoietic bone marrow of professional cyclists correlates with their red cell volume (RCV). Twelve male professional cyclists (mean +/- SD; 20.2 +/- 1.4 years, 69.0 +/- 4.5 kg, VO2max 64.4 +/- 4.6 ml/min/kg, BV 7257 +/- 884 ml, RCV 2990 +/- 299 g) completed an MRI of the lumbar spine, a total BV determination using a CO-rebreathing method and a graded exercise testing within two consecutive days. Significant correlations were found between performance and BV data. A significant correlation existed also between the signal intensity of the Turbo inversion-recovery sequence with short inversion time (Turbo-STIR) and BV (r (2) = 0.47, P < 0.05), RCV (r (2) = 0.56, P < 0.05) and plasma volume (r (2) = 0.39, P < 0.05) per kilogram body mass. The present study provides evidence of stimulated erythropoiesis with hyperplasia of the hematopoietic bone marrow of endurance athletes explaining their large RCV.

Quantitative and semiquantitative evaluation of erythropoietin-induced bone marrow signal changes in lumbar spine MRI in patients with tumor anemia.

BACKGROUND: The topic of this article is the quantitative and semiquantitative assessment of bone marrow signal alteration in magnetic resonance imaging (MRI) of the lumbar spine in patients with tumor anemia during therapy with epoietin beta or placebo. PATIENTS AND METHODS: We examined 32 patients with head or neck cancer (16 epoietin beta, 16 placebo) during radiotherapy in a double-blind multicenter trial. During radiotherapy, the patients underwent epoietin beta therapy for 7-9 weeks. Lumbar spine measurements using T1-w SE, OPP and Turbo- STIR were taken prior to the first epoietin beta or placebo therapy, after the acquired hemoglobin level had been reached, and after the final radiotherapy. The semiquantitative assessment was made blinded by 2 independent radiologists. RESULTS: We found significant differences between both groups. The first MRI showed normal marrow signals. The second MRI revealed a quantified decrease in bone marrow signal in T1-w SE (p < 0.018) and an increase in OPP (p < 0.01) and Turbo-TIR (p < 0.048) sequences. At the third MR imaging, quantified relative marrow signals returned to baseline level in all sequences. Semiquantitative assessment confirmed these results. CONCLUSION: In both analyses, lumbar spine MRI demonstrates significant bone marrow changes in T1-w SE, OPP and Turbo-STIR sequences during epoietin beta therapy.

Detectability of liver metastases in malignant melanoma: prospective comparison of magnetic resonance imaging and positron emission tomography.

PURPOSE: We evaluated the diagnostic accuracy of magnetic resonance imaging (MRI) and positron emission tomography (PET) for detection of liver metastases in malignant melanoma. MATERIAL AND METHODS: Thirty-five patients with 39 combined unenhanced MRI and fluorine-18 deoxyglucose (F-18 FDG) PET scans were prospectively studied. In discordant imaging findings final diagnosis was proven by clinical follow-up >6 months and demonstration of progressive liver metastases by at least one imaging method. Sensitivities and specificities were compared and the influence of lesion size and melanin content on diagnostic accuracy was determined. RESULTS: MRI and PET were concordantly negative for presence and number of liver metastases in 28 patients and positive in four patients. PET and MRI were false positive in one patient each. In one patient MRI showed a single metastases not seen by PET and in one patient MRI demonstrated more metastases at the first examination. In follow-up investigations MRI revealed more metastases than PET in both patients. The sensitivities for lesion detection were 47% (16/34) for PET and 100% for MRI. Lesion detectability by PET was related to lesion size (P < 0.0001) but not to melanin content. CONCLUSION: MRI is more sensitive in the detection of liver metastases in patients with malignant melanoma. Small lesions are easily missed by PET, while melanin content does not influence detectability by PET.

[CT and MRI in the differential diagnosis of lesions of the adrenal gland]. / Computertomographie und Magnetresonanztomographie in der Differentialdiagnose von Nebennierenraumforderungen.

Adrenal gland tumors are often incidental findings during imaging of the upper abdomen. In the majority of cases, benign adrenal gland tumors, especially nonfunctioning adenomas, are diagnosed, although the evaluation of dignity is essential in order to avoid unnecessary biopsy and tumor extirpation. Lipid-containing adrenocortical adenomas and nonadenomas can be differentiated with high diagnostic accuracy and specificity by computed tomography (CT) and magnetic resonance imaging (MRI). The fat content of these lesions can be correlated with CT attenuation values or with signal decrease in chemical shift imaging in MRI. Furthermore, low-fat adenomas can be distinguished from nonadenomas with delayed contrast enhancement and washout characterization. For the differentiation of non-fat-containing nonadenomas (metastases, lymphoma, pheochromocytoma, and inflammatory processes), morphological imaging criteria in CT and MRI (signal alterations, contrast media enhancement), clinical signs and laboratory test are essential in order to establish the diagnosis. The localization of functioning adenomas can be easily performed with CT and MRI. Both imaging techniques reveal typical findings of lesions-like cysts and myelolipomas.

Lymphangiography causes false-positive findings on 18F-FDG PET imaging.

BACKGROUND: 18F-FDG positron emission tomography (PET) may alter therapeutic management of patients with cervical cancer because 18F-FDG-positive pelvic and para-aortic lymph nodes are associated with lower progression-free survival and vice versa. However, the accuracy of 18F-FDG PET might be impaired by a preceding lymphangiography (LAG). MATERIALS AND METHODS: LAG, magnetic resonance (MR)-imaging and 18F-FDG PET were performed in 6 patients with cervical cancer stage FIGO IB and II. All patients were scheduled for radical hysterectomy and pelvic and para-aortic lymphadenectomy. The results of LAG, MR-imaging and 18F-FDG PET were compared with histological findings. RESULTS: 18F-FDG PET showed false-positive foci in both patients who had LAG before PET-study but not in 4 patients who had LAG thereafter. Histology confirmed false-positive 18F-FDG accumulation in lymphnodes to be consistent with granulomateous changes as induced by foregoing LAG. CONCLUSION: Whenever 18F-FDG PET and LAG are performed in the same patient to assess the extent of lymph-node metastases, LAG should always be done after the 18F-FDG PET study to obviate false-positive results.

Computed tomography in gastrointestinal stromal tumors.

The aim of this study was to define the imaging characteristics of primary and recurrent gastrointestinal stromal tumors (GIST) in computed tomography with respect to the tumor size. Computed tomography was performed in 35 patients with histologically confirmed gastrointestinal stromal tumors and analyzed retrospectively by two experienced and independent radiologist. The following morphologic tumor characteristics of primary ( n=20) and ( n=16) recurrent tumors were evaluated according to tumor size, shape, homogeneity, density compared with liver, contrast enhancement, presence of calcifications, ulcerations, fistula or distant metastases and the anatomical relationship to the intestinal wall, and the infiltration of adjacent visceral organs. Small GIST (<5 cm) showed a sharp tumor margin with homogeneous density and structure on unenhanced and contrast-enhanced images, and were characterized by an intraluminal tumor growth. Intermediate sized GIST (>5-10 cm) demonstrated an irregular shape, inhomogeneous density on unenhanced and contrast-enhanced images, a combined intra- and extraluminal tumor growth with aggressive findings, and infiltration of adjacent organs in 9 primary diagnosed and 2 recurrent tumors. Large GIST (>10 cm), which were observed in 8 primary tumors and 11 recurrent tumors, showed an irregular margin with inhomogeneous density and aggressive findings, and were characterized by signs of malignancy such as distant and peritoneal metastases. Small recurrent tumors had a similar appearance as compared with large primary tumors. Computed tomography gives additional information with respect to the relationship of gastrointestinal stromal tumor to the gastrointestinal wall and surrounding organs, and it detects distant metastasis. Primary and recurrent GIST demonstrate characteristic CT imaging features which are related to tumor size. Aggressive findings and signs of malignancy are found in larger tumors and in recurrent disease. Computed tomography is useful in detection and characterization of primary and recurrent tumors with regard to tumor growth pattern, tumor size, and varied appearances of gastrointestinal stromal tumors, and indirectly gives hints regarding dignity and therefore prognostic outcome.

Ectopic thyroid gland in the porta hepatis and lingua.

A rare case of an ectopic thyroid gland in the porta hepatis and in the tongue in an asymptomatic euthyroid 24-year-old woman is reported. A solitary inhomogeneous, hypoechogenic and hyperechogenic mass in the porta hepatis was accidentally discovered by ultrasonography. Subsequent computed tomography demonstrated a heterogeneous, well-defined tumor with small calcifications without signs of environmental invasion. A hemangioma and focal nodular hyperplasia were excluded by blood pool and hepatobiliary scintigraphy. Surprisingly, fine-needle aspiration cytology revealed normal thyroid tissue. (123)I-scintigraphy confirmed the presence of ectopic dual thyroid tissue in the hepatic porta and lingua. At clinical inspection the lingual thyroid gland was palpable and visible, and appeared solid and spheroidal. The subhepatic, ectopic thyroid mass was resected. Postoperatively, thyroid hormone replacement was started to prevent an enlargement of the lingual thyroid. Today, 4 years after surgery, the patient remains euthyroid.

18F-DOPA positron emission tomography for the detection of glomus tumours.

The purpose of this study was to evaluate (18)F-DOPA whole-body positron emission tomography ((18)F-DOPA PET) as a biochemical imaging approach for the detection of glomus tumours. (18)F-DOPA PET and magnetic resonance imaging (MRI) were performed in ten consecutive patients with proven mutations of the succinate dehydrogenase subunit D ( SDHD) gene predisposing to the development of glomus tumours and other paragangliomas. (18)F-DOPA PET and MRI were performed according to standard protocols. Both methods were assessed under blinded conditions by two experienced specialists in nuclear medicine (PET) and diagnostic radiology (MRI). Afterwards the results were compared. A total of 15 lesions (four solitary and four multifocal tumours, the latter including 11 lesions) were detected by (18)F-DOPA PET. Under blinded conditions, (18)F-DOPA PET and MRI revealed full agreement in seven patients, partial agreement in two and complete disagreement in one. Eleven of the 15 presumed tumours diagnosed by (18)F-DOPA PET were confirmed by MRI. The correlation of (18)F-DOPA PET and MRI confirmed three further lesions previously only detected by PET. All of them were smaller than 1 cm and had the signal characteristics of lymph nodes. For one small lesion diagnosed by PET, no morphological MRI correlate could be found even retrospectively. No tumour was detected by MRI that was negative on (18)F-DOPA PET. All tumours diagnosed by MRI showed a hyperintense signal on T2-weighted images and a distinct enhancement of contrast medium on T1-weighted images. The mean tumour size was 1.5+/-0.5 cm. (18)F-DOPA PET seems to be a highly sensitive metabolic imaging procedure for the detection of glomus tumours and may have potential as a screening method for glomus tumours in patients with SDHD gene mutations.

Radiological findings in Boerhaave's syndrome.

The aim was to define the diagnostic value of chest radiography, esophagography, and computed tomography (CT) in patients with Boerhaave's syndrome. CT findings in 14 patients (11 male, 3 female; mean age: 60 years; median age: 66 years; age range: 36-78 years) with spontaneous esophageal perforation were retrospectively reviewed and compared to those of esophagography ( n=11) and chest radiography ( n=14). In six patients unenhanced CT scans were available; in ten patients (2/10 patients had an unenhanced CT before) a contrast-enhanced CT was performed as an emergency investigation. In 5/14 patients additional oral contrast medium was given. Chest radiography revealed pleural effusions in 9/14 and infiltrates in 9/14 patients. Pneumothorax and pneumopericardium were observed in two patients each. Pneumomediastinum was seen in three patients. Two chest radiographs were normal. Esophagography performed in 11 patients demonstrated contrast medium extravasation at a supradiaphragmatic level in seven patients, indicating esophageal perforation with esophagopleural fistula, and a submucosal contrast medium collection in four cases. Unenhanced CT scans revealed four intramural hematomas with typical localization. Unenhanced and contrast-enhanced CT demonstrated periesophageal air collections indicating esophageal perforation in all patients. Pleural effusions were seen in 11/14 and infiltrates in 8/14 patients. Contrast medium extravasation was observed in 5/14 patients, whereas a thickening of the esophageal wall was depicted in 11/14 patients. Periaortic air tracks ( n=7), pneumothorax ( n=3), pneumomediastinum ( n=6), and mediastinal fluid collections ( n=7) were depicted in CT. By demonstrating periesophageal air tracks suggestive of esophageal perforation, CT reveals the decisive criteria for diagnosing Boerhaave's syndrome and should therefore be performed in the diagnostic work-up of patients in whom this syndrome is part of the differential diagnosis.

Pancreatico-mediastinal fistula with a mediastinal mass lesion demonstrated by MR imaging.

Internal pancreatic fistulas are uncommon but well-recognized complications of inflammatory pancreatic disease. A case of a pancreatico-mediastinal fistula with a mediastinal mass lesion in a patient with a documented history of chronic alcohol consumption and previous episodes of acute pancreatitis is described. Since the clinical symptomatology was dominated by pulmonary complaints, magnetic resonance (MR) imaging using a breathhold coronal T2-weighted sequence with spectral fat saturation was essential in clarifying this difficult and rare pathology. Furthermore, the depiction of a fistulous tract between a mediastinal mass lesion and the retroperitoneum posterior to the pancreas, i.e., a pancreatico-mediastinal fistula by MR imaging has not been previously reported, to the best of our knowledge.

Characterization of hematopoietic bone marrow in male professional cyclists by magnetic resonance imaging of the lumbar spine.

PURPOSE: To prospectively evaluate hematopoietic bone marrow of male professional cyclists in relation to performance data and laboratory data, and in comparison to age-matched healthy volunteers. MATERIALS AND METHODS: Twenty male cyclists and 44 volunteers (27 males and 17 females) were prospectively studied by magnetic resonance imaging (MRI) at high-field strength. A sagittal T1-weighted (T1-w) spin-echo (SE) sequence, a gradient-echo (GE) sequence with an echo time (TE) for out-of-phase (OOP) imaging, and a turbo inversion-recovery sequence with short inversion time (TIRM) for fat suppression was used. The averaged bone marrow signal intensity (SI) of three adjacent vertebrae was related to the signal of an adjacent nondegenerative disk. RESULTS: The cyclists revealed a significantly different SI as compared to male volunteers in the OOP (0.34 +/- 0.14 vs. 0.28 +/- 0.09, P < 0.05) and T1-w sequences (1.62 +/- 0.19 vs. 1.77 +/- 0.30, P < 0.05). Only in TIRM was there a significant difference compared to female volunteers (0.36 +/- 0.08 vs. 0.44 +/- 0.04, P < 0.01). MRI data of cyclists did not correlate to hemoglobin, erythrocyte, or reticulocyte counts; ferritin, relative heart volume, relative maximal power (rPmax; W/kg bw), or relative maximal oxygen consumption (VO(2)max). A borderline linear correlation was found for hematocrit (OOP: r = 0.42, P = 0.06; TIRM: r = 0.44, P = 0.06). CONCLUSION: Bone marrow hyperplasia is observed in male professional cyclists in the axial skeleton. The MR findings are probably independent of mechanically induced marrow edema. A multifactorial cause must be considered, as single laboratory and performance data did not appear to contribute significantly to these results.

Comparative diagnostic value and therapeutic relevance of magnetic resonance imaging and bone marrow scintigraphy in patients with metastatic solid tumors of the axial skeleton.

PURPOSE: To evaluate the comparative impact of magnetic resonance imaging (MRI) and bone marrow scintigraphy (BMS) in bone marrow metastases of solid tumors. METHODS: In 20 patients with solid tumors MRI of the axial skeleton and whole-body BMS were retrospectively reviewed. Detectability of metastases, extent of disease and therapeutic implications were assessed. RESULTS: In 15/20 (75%) patients MRI and BMS concordantly revealed bone marrow metastases of the axial skeleton. In nine of these 15 patients (60%) MRI showed more metastases. Local radiotherapy or surgery was performed in seven of these cases (78%). BMS detected additional metastases of the appendicular skeleton in 8/15 (53%) patients. In 4/20 cases (20%) the imaging findings were discordant. In three patients with degenerative changes (n=2) or lipoma (n=1) BMS was false positive. In another patient BMS failed to detect metastases proven by MRI and clinical follow-up resulting in subsequent radiation therapy. One patient had normal bone marrow. CONCLUSION: MRI appears to be more sensitive and specific in the detection of bone marrow metastases in the axial skeleton and is of clinical importance for subsequent local therapy.

Germ-line mutations in nonsyndromic pheochromocytoma.

BACKGROUND: The group of susceptibility genes for pheochromocytoma that included the proto-oncogene RET (associated with multiple endocrine neoplasia type 2 [MEN-2]) and the tumor-suppressor gene VHL (associated with von Hippel-Lindau disease) now also encompasses the newly identified genes for succinate dehydrogenase subunit D (SDHD) and succinate dehydrogenase subunit B (SDHB), which predispose carriers to pheochromocytomas and glomus tumors. We used molecular tools to classify a large cohort of patients with pheochromocytoma with respect to the presence or absence of mutations of one of these four genes and to investigate the relevance of genetic analyses to clinical practice. METHODS: Peripheral blood from unrelated, consenting registry patients with pheochromocytoma was tested for mutations of RET, VHL, SDHD, and SDHB. Clinical data at first presentation and follow-up were evaluated. RESULTS: Among 271 patients who presented with nonsyndromic pheochromocytoma and without a family history of the disease, 66 (24 percent) were found to have mutations (mean age, 25 years; 32 men and 34 women). Of these 66, 30 had mutations of VHL, 13 of RET, 11 of SDHD, and 12 of SDHB. Younger age, multifocal tumors, and extraadrenal tumors were significantly associated with the presence of a mutation. However, among the 66 patients who were positive for mutations, only 21 had multifocal pheochromocytoma. Twenty-three (35 percent) presented after the age of 30 years, and 17 (8 percent) after the age of 40. Sixty-one (92 percent) of the patients with mutations were identified solely by molecular testing of VHL, RET, SDHD, and SDHB; these patients had no associated signs and symptoms at presentation. CONCLUSIONS: Almost one fourth of patients with apparently sporadic pheochromocytoma may be carriers of mutations; routine analysis for mutations of RET, VHL, SDHD, and SDHB is indicated to identify pheochromocytoma-associated syndromes that would otherwise be missed.

Imaging findings in the rare catastrophic variant of the primary antiphospholipid syndrome.

We report imaging findings in a case of the rare catastrophic variant of antiphospholipid syndrome (CAPS) characterized by widespread microvascular occlusions, which may lead to multiple organ failure. We present a case of a 66-year-old woman with bone marrow necrosis, acute acalculous cholecystitis (AAC), focal liver necrosis, subtle patchy splenic infarctions, and bilateral adrenal infarction. The demonstration of multiple microvascular organ involvement (three or more) is crucial for the diagnosis of the catastrophic variant of APS. This can be performed radiologically intra-vitam. Imaging can even reveal subclinical microinfarctions, which are often only diagnosed at autopsy.

Pheochromocytomas: detection with 18F DOPA whole body PET--initial results..

PURPOSE: To evaluate fluorine 18 ((18)F) dihydroxyphenylalanine (DOPA) whole-body positron emission tomography (PET) as a biochemical imaging approach for detection of pheochromocytomas. MATERIALS AND METHODS: (18)F DOPA PET and magnetic resonance (MR) imaging were performed in 14 consecutive patients suspected of having pheochromocytomas (five sporadic, nine with von Hippel-Lindau disease); metaiodobenzylguanidine (MIBG) scintigraphy was performed in 12 of these patients. The individual imaging findings were assessed in consensus by specialists in nuclear medicine and radiologists blinded to the results of the other methods. The findings of the functional imaging methods were compared with those of MR imaging, the reference standard. Histologic verification could be obtained in eight patients with nine tumors. RESULTS: Seventeen pheochromocytomas (11 solitary, three bifocal; 14 adrenal, three extraadrenal) were detected with MR imaging. (18)F DOPA PET and MR imaging had concordant results in all 17 tumors. In contrast, MIBG scintigraphy had false-negative results in four patients with three adrenal tumors smaller than 2 cm and one extraadrenal tumor with a diameter of 3.6 cm. On the basis of these data, sensitivities of 100% for (18)F DOPA PET and of 71% for MIBG scintigraphy were calculated. Specificity was 100% for both procedures. CONCLUSION: (18)F DOPA PET is highly sensitive and specific for detection of pheochromocytomas and has potential as the functional imaging method of the future.