Scintigraphic diagnosis of acoustic neurofibromas.

Radioisotope brain scanning gave positive results in 57 out of 68 acoustic neurofibromas in three British neurosurgical centres. Acoustic neurofibromas over 2 cm in diameter may be expected to give a positive scintigraphic result, and tumours of this size also erode the petrous bone. Since most are 3-4 cm in diameter, correlation between the results of petrous radiography and cerebral scintigraphy often permits a specific diagnosis of acoustic neurofibroma to be made. No other radiological investigation may be necessary preoperatively.     

Scintigraphic diagnosis of polysplenia in the adult

PURPOSE: The authors describe an adult patient with low index of suspicion for polysplenia. The diagnostic contribution of various investigative modalities is considered, and the key role of scintigraphy is specifically highlighted. RESULTS: CT scan findings revealed multiple abdominal and retroperitoneal masses. Needle biopsy of a flank mass was nonspecific. Tc-99m sulfur colloid liver spleen scintigraphy and Tc-99m heat-denatured RBC scans showed the presence of polysplenia. CONCLUSIONS: Multiple spleens can be mistaken for abdominal neoplasms on CT. Biopsy results may not always be helpful. In patients in whom there is such a diagnostic dilemma, Tc-99m heat-denatured RBC scans can successfully establish the definitive diagnosis of polysplenia.     

Scintigraphic diagnosis of sacral fractures

The H- or butterfly-pattern of uptake in the sacrum on Tc-99m-methylene diphosphonate bone scintigraphy is typical of fractures of the body of the sacrum that involve the sacral alae. This report describes four patients with a focal linear or curvilinear pattern of uptake in sacral fractures without alae involvement. This pattern differs from that associated with metastases in the sacrum, which typically has a random pattern. Recognition of this scintigraphic linear dot pattern of uptake in horizontal fractures in the inferior body of the sacrum is useful for detecting fractures without alae involvement that are not readily apparent on radiographs.     

Scintigraphic diagnosis of tricuspid regurgitation

The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%.     

影像学技术在霍奇金淋巴瘤诊疗中的价值

在我国,霍奇金淋巴瘤（HL）占全部恶性淋巴瘤的10.9％,约90％起源于淋巴结,通常呈对称性淋巴结肿大,很少累及结外组织.HL对放疗、化疗很敏感,是可治愈的肿瘤之一.该文主要就CT成像、MRI、67Ga成像、PET或PET/CT在HL诊断及预后评估等方面的应用作一综述,以进一步提高对HL影像学表现及其临床应用的认识.     

Scintigraphic diagnosis of right ventricular ischemia

We present a patient with exercise induced right ventricular ischemia demonstrated on stress TI-201 myocardial scintiscan. The patient underwent cardiac catheterization, and subtotal occlusion was found at the proximal right coronary artery. Repeat stress TI-201 scan became normal following the successful percutaneous transluminal coronary angioplasty.     

Scintigraphic criteria for the diagnosis of renal arteriovenous fistulas

Visualization of the inferior vena cava (IVC) on renal perfusion imaging occurs in cases of renal arteriovenous (AV) fistulas. A review of consecutive renal scans demonstrated IVC visualization in three of 217 patients without AV fistulas. IVC visualization occurred 3-6 seconds after peak aortic activity in normal patients. With renal AV fistulas, an intrarenal focus of increased activity is seen and IVC visualization occurs coincident with peak aortic activity.     

Scintigraphic diagnosis of bile leakage after laparoscopic cholecystectomy. A prospective study.

To assess the role of Tc-99m IDA cholescintigraphy in diagnosing bile leakage and bile obstruction after laparoscopic cholecystectomy, 51 studies were performed in 51 patients on the first postoperative day. Two different radioactive bile acid analogs were used, Tc-99m HIDA and Tc-99m trimethylbromo IDA. Scintigraphic findings were correlated with the clinical conditions. Results of seven out of 51 cholescintigrams were abnormal, showing accumulations of activity in the right paracolic gutter. Of these seven patients, only three had clinical symptoms consisting of more than normal postoperative abdominal pain and peritoneal irritation. The other four patients had minimal abnormal accumulation in the right paracolic gutter and showed no clinical signs postoperatively. Complete common bile duct obstruction or other bile duct-related complications, except for bile leakage, were not observed. Cholescintigraphy is feasible for the early detection of bile leakage and bile flow obstruction after laparoscopic cholecystectomy in patients with increased postoperative abdominal discomfort.     

Scintigraphic techniques for the diagnosis of infectious disease of the musculoskeletal system

In imaging infectious diseases of the musculoskeletal system, the metabolic information provided by nuclear medicine studies complements the structural information of radiologic modalities. Often the diagnosis can be confirmed by combining the methods in a diagnostic algorithm. The decision about whether a single study is best depends on the clinical setting and the questions that require an answer. Whereas radiography, magnetic resonance imaging (MRI), and computed tomography (CT) usually focus on a single area, nuclear medicine imaging offers the advantage of whole body imaging. However, despite significant improvements it cannot approach the detailed anatomical visualization provided by MRI or CT. In most cases scintigraphy is a very sensitive (e.g., bone scan, positron emission tomography) and often quite specific tool (e.g., white blood cell scintigraphy). The metabolic information of the single scintigraphic procedure depends on the accumulation mechanism. For the work-up of infectious disorders different radiopharmaceuticals can be used, and the decision for the best modality should be tailored to the clinical question and the special pathophysiologic condition of the infection. This article describes the most common nuclear medicine studies and their clinical relevance in some infectious diseases.     

Scintigraphic imaging of the adrenal glands.

This article presents the well established scintigraphic imaging techniques of the adrenal glands. Both adrenocortical scintigraphy with [131]6beta-iodomethylnorcholesterol (NP-59) and adrenomedullary imaging with 131I or 123I-labelled metaiodobenzylguanidine (MIBG) as function-dependant imaging techniques provide functional metabolic information for lesion characterization. They enable the distinction between unilateral and bilateral adrenal lesions. Furthermore, they have the advantage of giving the possibility of a whole body evaluation with a single administration of the tracer without additional radiation dose. On the other hand, radiological imaging modalities provide excellent anatomical details which is essential for planning therapy. Both radiological and scintigraphic imaging methods of the adrenal glands are necessary and should, therefore, be considered complementary.     

Scintigraphic portrayal of beta receptors in the heart.

Myocardial beta adrenergic receptors play important roles in physiology and disease, but the receptors have not before been portrayed. The beta antagonist, iodocyanopindolol (ICYP), was used to develop a scintigraphic method for depicting the receptors in the living heart. Labeled with 125I, ICYP bound firmly to beta receptors in the rat heart; the data conformed to a mathematical model. In vivo saturation kinetics indicated binding sites with two affinities. Inhibition of ICYP binding by beta antagonists of different potency and different selectivity for beta-1 and beta-2 receptors produced the expected pharmacologic effects. Inhibition by lipophilic and hydrophilic antagonists gave no evidence that ICYP was appreciably bound to internalized receptors. Fractional binding by tracer quantities of (-) ICYP and (+/-) ICYP demonstrated stereospecificity. Labeled with 123I, ICYP bound to the hearts of intact dogs so that scintigraphic tomographs depicted ventricular myocardium. Small doses of beta antagonists selectively reduced the binding of ICYP to lung enabling better visualization of the heart. Thus, 123I-ICYP appears to portray the beta receptors in the living heart, and the characteristics of binding permit the development of mathematical models and lay the basis for quantifying this receptor binding.     

Scintigraphic diagnosis of gastrointestinal bleeding with 99mTc-labeled blood-pool agents

Abdominal scintigraphy with 99mTc-labeled albumin or red blood cells was used in 68 patients to localize gastrointestinal bleeding or confirm that it had stopped. Acute, active bleeding was identified in 33 patients; characteristic patterns of bleeding from the stomach, biliary passages, small intestine, and colon are shown. Sensitivity was 0.86 (95% confidence limits, 0.57-0.98) and specificity was 1.0 (95% confidence limits, 0.82-1.0) in 33 patients who had scintigraphy and endoscopy performed in succession. Abdominal scintigraphy appears to be a valuable supplement to conventional diagnostic methods. In upper gastrointestinal bleeding, scintigraphy should be considered when endoscopy fails. In lower intestinal bleeding, scintigraphy should be the method of choice.     

Scintigraphic features of nonosteogenic fibroma.

Three cases of nonosteogenic fibroma or fibrous cortical defect are presented which demonstrated scintigraphic findings of minimal to mild increased uptake of bone-seeking radiopharmaceutical and thus helped to distinguish these lesions from other benign or malignant abnormalities. The authors suggest that the two types of lesion are not fundamentally different from one another.     

Scintigraphic diagnosis of intrathoracic extramedullary hematopoiesis in a patient with β-thalassemia

We report the scintigraphic diagnosis of intrathoracic extramedullary hematopoiesis (EMH) in a patient with β-thalassemia. A patient had a mass in the right thoracic paravertebral region on radiography and CT. Bone marrow imaging of the thorax by means of both Tc-99m nanocolloid and phytate demonstrated uptake of the tracer in the mediastinal mass, establishing the diagnosis of EMH.     

Spontaneous osteonecrosis of the knee. Scintigraphic findings

Three cases of spontaneous osteonecrosis (SON) of the knee, comprised of two cases involving the medial tibial plateau and one involving the medial femoral condyle, are reported. Because of the relatively normal x-rays early in the course of the disease, the differential diagnosis of a painful knee is markedly shortened with the typical scintigraphic findings in SON. The scintigraphic findings represent a focal area of increased activity at the affected site on a three-phase bone scan.