[Appropriate uptake period for myocardial PET imaging with 18F-FDG after oral glucose loading]. / Optimaler Akquisitionszeitpunkt für die Herz-PET mit 18F-FDG nach oraler Glukosebelastung.

AIM: Identification of a rationale for the appropriate uptake period for myocardial (18)F-FDG-PET imaging of patients with and without diabetes mellitus. METHODS: In a subset of 27 patients, static 2D-PET examination was performed of patients with chronic coronary artery disease and known myocardial infarction. The patients fasted (at least 4 h) before examination. (18)F-FDG (330 +/- 20 MBq) was injected intravenously. The image quality was semiquantitativly determined by ROI-analysis and the myocardium-to-blood pool activity ratio (M/B) was calculated. I.) Scans 30, 60, and 90 min p. i. of 10 non-diabetic patients (60 g oral glucose loading one hour before FDG-injection, low-dose intravenous insulin bolus if necessary). II.) Scans 30, 60, and 90 min p. i. of 10 patients with known non-insulin dependent diabetes (20 g glucose, insulin bolus). III.) Scans 90 min p. i. of 7 patients with known non-insulin dependent diabetes and elevated fasting serum glucose level (140-200 mg/dl; insulin bolus, no glucose). RESULTS: I.) The M/B ratio significantly increases in nondiabetic patients with the uptake time (30 min 1.95 +/- 0.20; 60 min 2.96 +/- 0.36; 90 min 3.78 +/- 0.43). II.) In patients with non-insulin dependent diabetes the M/B ratio also significantly increases with uptake time. Compared to non-diabetic patients group II reached smaller M/B values (30 min 1.56 +/- 0.10; 60 min 2.15 +/- 0.14; 90 min 2.71 +/- 0.19). III.) In the group of patients with elevated fasting serum glucose level (who only got insulin but no glucose loading) the M/B activity ratio 90 min p. i. was clearly inferior compared with diabetic patients after oral glucose loading and insulin administration (M/B 2.71 +/- 0.19 versus 2.16 +/- 0.07). CONCLUSIONS: In static myocardial viability PET studies with (18)F-FDG an uptake time of 90 min yields image quality superior to that obtained after shorter uptake time.

Comparative detectability of bone metastases and impact on therapy of magnetic resonance imaging and bone scintigraphy in patients with breast cancer.

OBJECTIVE: to evaluate the comparative impact of magnetic resonance imaging and bone scintigraphy in bone metastases of breast cancer. METHODS AND PATIENTS: in 81 patients with histologically proven breast cancer magnetic resonance imaging of the axial skeleton and whole-body bone scintigraphy had been performed. Images were retrospectively reviewed and compared for detection of metastases, extent of metastatic disease and therapeutic implications according to the patients' records. RESULTS: about 54/81 (67%) patients revealed bone metastases. In 7/54 (13%) patients with bone metastases, scintigraphy was false negative. In one patient a solitary sternal metastases was seen. In 26/53 [49%] patients with spinal metastases, magnetic resonance imaging showed more extensive disease. Local radiotherapy or surgery was indicated in ten patients with metastases not evident in bone scintigraphy, in 20 patients with positive results by both imaging modalities and in six patients with metastases of pelvis imaged by bone scintigraphy only. CONCLUSION: magnetic resonance imaging of the axial skeleton and pelvis appears superior for staging as only one patient had metastases merely outside the axial skeleton and local therapy was indicated even in spinal regions negative in bone scintigraphy.

Paraneoplastic polyneuropathy preceding the diagnosis of Hodgkin's disease and non-small cell lung cancer in a patient with concomitant Borrelia burgdorferi infection.

A patient with painful peripheral neuropathy is presented, whose symptoms were thought to result from an infection with Borrelia burgdorferi sensu lato. Investigations of the cerebrospinal fluid for signs of inflammation and borrelial antibodies were negative, and the patient did not benefit from repeated antibiotic treatment. Electrophysiologic studies and sural nerve biopsy showed axonal neuropathy consistent with a paraneoplastic syndrome. Further workup revealed mediastinal Hodgkin's disease (HD; nodular sclerosing subtype) Ann Arbor stage II and non-small cell cancer of the lung (stage T1N0M0). Surgical resection of the lung cancer and combined chemo- and radiotherapy for HD resulted in complete remission of both malignancies. While the preexisting neurologic symptoms persisted during treatment, neurography showed some improvement of the distal nerves. During radiation therapy the patient developed transient left-sided brachial plexopathy. This case illustrates that the diagnosis of borreliosis in patients with isolated painful peripheral neuritis cannot be based solely upon positive IgG titers and supports the requirement for a thorough workup for an underlying--potentially curable--disease. In addition, singular pulmonary lesions in the setting of HD should be suspected to have a separate cause.

Metastatic lymph nodes in patients with cervical cancer: detection with MR imaging and FDG PET.

PURPOSE: To compare the diagnostic accuracy of magnetic resonance (MR) imaging with that of positron emission tomography (PET) with 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) for detecting metastatic lymph nodes in patients with cervical cancer. MATERIALS AND METHODS: Before radical hysterectomy and pelvic lymphadenectomy in 35 patients with International Federation of Gynecology and Obstetrics stage IB or II cervical cancer, abdominal FDG-PET and MR imaging were performed. Malignancy criteria were a lymph node diameter of 1 cm or more at MR imaging and a focally increased FDG uptake at PET. The findings of FDG-PET and MR imaging were compared with histologic findings. RESULTS: Histologic examination revealed pN0-stage cancer in 24 patients and pN1-stage cancer in 11 patients. On a patient basis, node staging resulted in sensitivities of 0.91 with FDG-PET and 0.73 with MR imaging and specificities of 1.00 with FDG-PET and 0.83 with MR imaging. The positive predictive value (PPV) of FDG-PET was 1.00 and that of MR imaging, 0.67 (not significant). The metastatic involvement of lymph node sites was identified at FDG-PET with a PPV of 0.90; at MR imaging, 0.64 (P <.05, Fisher exact test). CONCLUSION: Metabolic imaging with FDG-PET is an alternative to morphologic MR imaging for detecting metastatic lymph nodes in patients with cervical cancer.

Evaluation of positron emission tomography with 2-[18F]fluoro-2-deoxy-D-glucose for the differentiation of chronic pancreatitis and pancreatic cancer.

BACKGROUND: The clinical presentation of patients with pancreatic cancer may resemble the clinical picture of chronic pancreatitis. A definitive preoperative diagnosis is not always obtained in patients with a history of chronic pancreatitis despite the use of modern imaging techniques. Operative strategy therefore remains unclear before operation in these patients. METHODS: Positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) was introduced recently into clinical oncology because of its ability to demonstrate metabolic changes associated with various disease processes. The impact of FDG-PET on the differentiation of chronic pancreatitis and pancreatic cancer was investigated. FDG-PET was performed in 48 patients with chronic pancreatitis (n = 12), acute pancreatitis (n = 3) and pancreatic cancer (n = 27), and in controls (n = 6). Histological examination was undertaken in all cases except controls. The FDG-PET results were obtained without knowledge of results of other imaging procedures. The results were then compared with those of computed tomography, ultrasonography, endoscopic retrograde cholangiopancreaticography, operative findings and histology. PET images were analysed semiquantitatively by calculating a standard uptake value (SUV) 90-120 min after application of the tracer. RESULTS: Cut-off values were validated as follows: SUV greater than 4.0 for pancreatic cancer, SUV of 3.0-4.0 for chronic pancreatitis, and SUV of less than 3.0 for controls. Sensitivity and specificity of PET imaging were 0.96 and 1.0 for pancreatic cancer, and 1.0 and 0.97 for chronic pancreatitis. In five cases only FDG-PET led to the correct preoperative diagnosis. CONCLUSION: The results give further evidence that FDG-PET is an important non-invasive method for the differentiation of chronic pancreatitis and pancreatic cancer. Delayed image acquisition in the glycolysis plateau phase permits improved diagnostic performance. This imaging technique is extremely helpful before operation in patients with an otherwise unclear pancreatic mass, despite its costs.

Influence of urinary iodine excretion on thyroid technetium-99m pertechnetate uptake with and without TSH suppression: what happens when iodine supply increases?

This study examines how thyroid pertechnetate uptake with and without thyroid-stimulating hormone (TSH) suppression changes as a function of increasing iodine supply. This is of special interest in countries at the threshold of sufficient iodine supply, where thyroid scintigraphy plays a key role in thyroid examination, especially for the diagnosis of Plummer's disease. From 1995 to 1997, a total of 1069 patients with euthyroid goitre, Plummer's disease or Graves' disease were included in the study. All patients underwent thyroid examination including sonography, scintigraphy with technetium-99m pertechnetate, and determination of free triiodothyronine, free thyroxine, TSH and urinary iodine excretion. Iodine excretion in the range from 0 to 500 microg iodine/g creatinine showed an inverse correlation with thyroid pertechnetate uptake, but no correlation with TSH was observed. There was no correlation between thyroid pertechnetate uptake and iodine excretion when TSH stimulation was eliminated, with two exceptions: thyroid pertechnetate uptake was significantly increased for iodine excretion values below 50 and 100 microg iodine/g creatinine in patients with Graves' and Plummer's disease, respectively. When iodine excretion exceeded 500 microg iodine/g creatinine, pertechnetate uptake was reduced to a basal level independent of the TSH. In conclusion, the influence of TSH on the thyroid pertechnetate uptake seems to be secondary compared with the influence of the iodine supply. It can be concluded further that the reference range of thyroid pertechnetate uptake under TSH suppression will not change significantly when the iodine supply increases from conditions of mild iodine deficiency to iodine sufficiency. Thyroid pertechnetate uptake with and without TSH suppression cannot be reliably interpreted beyond an iodine excretion of 500 microg iodine/g creatinine.

ACL reconstruction by patellar tendon. A comparison of length by magnetic resonance imaging.

In 50 knees the length of the anterior cruciate ligament (ACL), the patellar tendon, and the distance between the tibial tuberosity and the femoral origin of the ACL were evaluated by means of three-dimensional magnetic resonance imaging (MRI), which permits subsequent reconstruction of any sectional view. The measurements showed that the patellar tendon was always markedly longer than the ACL (mean 14.4 mm), but always shorter than the distance between the tibial tuberosity and the femoral insertion of the ACL (mean 19.2 mm). The mean lengths of the ACL and the patellar tendon were 38.2 mm and 52.6 mm, respectively. The mean distance between the femoral ACL origin and the tibial insertion of the patellar tendon was 71.8 mm. These results demonstrate that a distally based patellar tendon autograft alone (with the patellar bone block but without extension into the periosteum of the patella or the quadriceps tendon) cannot be placed anatomically correctly to the isometric femoral insertion of the ACL. When the patellar tendon is used for ACL reconstruction, it must be implanted as a free autograft. Nevertheless, considerable variations of length must be taken into account.

[Double isotope albumin flux measurement: diagnosis and therapeutic monitoring of acute lung injury]. / Doppelisotopen-Albuminfluxmessung: Diagnose und Therapiemonitoring des Acute Lung Injury.

PURPOSE: Acute Lung Injury (ALI) is a clinical condition which is associated with a high lethality. It is characterized by an increased pulmonary capillary permeability and non-cardiogenic pulmonary edema. This study was designed to answer the question whether double isotope albumin-flux measurement is a useful tool both for diagnosis of increased pulmonary capillary permeability and for monitoring therapeutic interventions (nitric oxide (NO) inhalation). METHOD: In 12 patients with clinical signs of ALI, transvascular albumin-flux was measured by a double radioisotope technique before, during and after NO inhalation. 99mTc labeled albumin and 51Cr labeled autologous erythrocytes were used as tracer. The radioactivity of both radiopharmaceuticals was measured externally over the right lung by a radiation probe and simultaneously in arterial blood. For quantification of transvascular albumin-flux Normalized Index (NI) and Normalized Slope Index (NSI) were calculated. Furthermore, pulmonal vascular pressures and other physiological parameters were recorded. RESULTS: All 12 patients showed markedly increased NSI before inhalation of NO. NSI decreased from 0.0074 +/- 0.0046 min-1 without nitric oxide to -0.0051 +/- 0.0041 min-1 during nitric oxide and increased to 0.0046 +/- 0.0111 min-1 after nitric oxide. The decrease of the NSI correlated well with decrease of venous pulmonary resistance during inhalation of NO. CONCLUSION: Inhalation of NO reduces transvascular albumin-flux in patients with ALI. Double isotope albumin-flux measurement enables diagnosis of increased capillary permeability as well as monitoring therapeutic interventions.

Immunoscintigraphy with anti-225.28S for ocular melanoma--a comparison with histology and immunohistochemistry.

AIM: The purpose of this prospective study was to evaluate the value of immunoscintigraphy (ISG) with anti-225.28S in clinically suspected ocular melanoma. METHODS: For this purpose standardized ISG was performed in 36 patients using both planar acquisition and emission computed tomography (ECT). Ocular melanoma was present in 31 patients. In 21 patients therapy was enucleation of the eye. These specimens were evaluated by histology and immunohistochemistry in 11 of 21 patients. RESULTS: Regarding the clinical diagnosis, ISG was positive only in 15 of 31 patients with ocular melanoma, regarding histology in 11 of 21 and regarding immunohistochemistry in 5 of 6 patients with a positive immunoreaction 5 patients showed no immunoreactivity, their ISG was negative. CONCLUSION: Thus a good correlation between ISG and immunohistochemistry was observed. However ISG using the cutaneous melanoma antibody 225.28S cannot be recommended for the diagnostic work-up of an ocular melanoma considering the poor immunoreactivity.

[Indications for nuclear medicine diagnosis in trauma surgery]. / Indikationen zur nuklearmedizinischen Diagnostik in der Unfallchirurgie.

Skeletal scintigraphy is the most frequently utilized nuclear medicine imaging procedure in traumatology. Concerning any skeletal abnormality associated with changes in local perfusion, exudation and metabolism, it is a sensitive functional imaging procedure to detect bony disease. However, because of the varying causes of bony disease, it is characterized by a low specificity. Further, specificity may be enhanced, when patient history, clinical and lab results as well as results obtained from other diagnostic imaging procedures are combined with the result of skeletal scintigraphy. On the other hand, it is known that metabolic abnormalities of the skeleton depicted by radionuclide imaging occur much earlier than structural changes visible on X-ray imaging. Beside skeletal scintigraphy, antigranulocyte antibody or labelled leucocyte imaging may greatly assist in the detection of inflammation or infection following joint replacement surgery, respectively. Ultimatively, a combination of clinical, lab and imaging results including radionuclide imaging may represent the best approach to answer some questions asked by surgical traumatologists.

[Cerebral findings following cervical spine distortion caused by acceleration mechanism (whiplash injury). Assessment of current diagnostic methods in nuclear medicine]. / Zerebrale Befunde nach Halswirbelsäulendistorsion durch Beschleunigungsmechanismus (HWS-Schleudertrauma). Standortbestimmung zu neuen diagnostischen Methoden der Nuklearmedizin.

In any grade of distortion of the cervical spine as a result of acceleration forces in addition to cervical symptoms cerebral symptoms like headache, vertigo, auditory disturbances, tinnitus, disturbances in concentration and memory, difficulties in swallowing, impaired vision and temporo-mandibular dysfunctions may appear. These symptoms can persist and become invalidating. Cerebral single-photon emission tomography (SPECT) and positron emission tomography (PET) enable new diagnostic horizons for neurotraumatology. In this article we summarize the actual findings of these nuclear medical methods in neuropsychologically deficient patients with distortion of the cervical spine as a result of acceleration forces. Especially the latest results of the group of Basle (University Hospital Basle, Clinic of Rehabilitation Rheinfelden, Switzerland) are illustrated. This group found parieto-occipital hypoperfusion by relative quantitation using SPECT and bicisate (Neurolite, ECD). A first pilot study using PET and F-18-fluoro-deoxyglucose (FDG) could verify the above observation. The group's working hypothesis is that parieto-occipital hypoperfusion may be caused by activation of nociceptive afferences from the upper cervical spine. A critical approach to interpreting new functional methods and, on the other hand, openness in new scientific findings may contribute to answering the lasting controversial medico-legal discussion with more objectivity.

[Magnetic resonance tomography evaluation of the lower limb after compartment syndrome]. / Magnetresonanztomographische Beurteilung des Unterschenkels bei Zustand nach Kompartmentsyndrom.

For the purpose of follow-up of the disease as well as the availability of magnetic resonance imaging (MRI) as a method for diagnosing soft tissue changes 20 patients with imminent and manifest compartment syndrome were examined for their fluid content of the lower limb. Considering the normal side as well as 10 healthy volunteers a significant reduction of fluid content was diagnosed in the manifest compartment syndrome after fasciotomy in the late phase of disease (r = 0.49, p > 0.005, n = 29). This was interpreted as a sign of fibrosis. The patients with imminent compartment syndrome and fasciotomy (r = 0.83, p > 0.001, n = 19) demonstrated no significant changes compared to the normal volunteers (r = 0.91, p > 0.001, n = 40) as well as the normal compartments of the diseased lower extremities (r = 0.85, p > 0.001, n = 32). MRI is a useful method in the examination of soft tissue changes and underlines the importance of an early fasciotomy in case of imminent compartment syndrome.

[High-resolution 3-D imaging in MR tomographic knee joint diagnosis. Correlation with arthroscopy]. / Hochauflösende 3-D-Bildgebung in der kernspintomographischen Kniegelenksdiagnostik: Korrelation zur Arthroskopie.

84 knee joints were examined by a 3-dimensional MR method and the results correlated with subsequent arthroscopy. The findings showed good demonstration of the normal anatomical structures and excellent reliability for the diagnosis of meniscus tears (sensitivity 91%, specificity 95%), cruciate ligament lesions (sensitivity 90%, specificity 99%) and serious cartilage damage (sensitivity 100%, specificity 100%). Demonstration of mild cartilage damage (sensitivity 60%, specificity 99%) was better than with a spin echo technique but is not yet optimal. It is concluded that, by using a 3-dimensional technique, time-consuming spin echo sequences can be abandoned. Significant advantages of the 3-D method are the speed of the examination, narrow section thickness, marked flexibility in contrast rendering and the ability for multiplanar reconstruction.