W. Roolker

The diagnostic management of suspected scaphoid fracture

The role of radiography and bone scintigraphy in the diagnostic management of patients with clinically suspected scaphoid fracture after carpal injury is reviewed. Evidence is provided that bone scintigraphy is indicated in patients with negative initial scaphoid radiographs. A normal bone scan excludes scaphoid fracture, and a positive bone scan sufficiently confirms the presence of clinically relevant scaphoid fracture. Furthermore, this review assesses the possibility on non-invasive additional radiographs, for the diagnosis or exclusion on scaphoid fracture as a means of avoiding bone scintigraphy in patients with negative first-day X-series.

Magnetic resonance imaging versus bone scintigraphy in suspected scaphoid fracture

Magnetic resonance imaging (MRI) has become increasingly useful in the evaluation of musculoskeletal problems, including those of the wrist. In patients with a wrist injury, MRI is used mainly to assess vascularity of scaphoid non-union. However, the use of MRI in patients in the acute phase following carpal injury is not common. Three-phase bone scintigraphy is routinely performed from at least 72 h after injury in patients with suspected scaphoid fracture and negative initial radiographs. We evaluated MRI in this patient group. The bone scan was used as the reference method. Nineteen patients were included. Bone scintigraphy was performed in all 19 patients, but MRI could be obtained in only 16 (in three patients, MRI was stopped owing to claustrophobia). In five patients, MRI confirmed a scintigraphically suspected scaphoid fracture. In one patient, a perilunar luxation, without a fracture, was seen on MRI, while bone scintigraphy showed a hot spot in the region of the lunate bone, suspected for fracture. This was confirmed by surgery. In two patients, a hot spot in the scaphoid region was suspected for scaphoid fracture, and immobilization and employed for a period of 12 weeks. MRI was negative in both cases; in one of them a scaphoid fracture was retrospectively proven on the initial X-ray series. In another two patients, a hot spot in the region of MCP I was found with a negative MRI. In both, the therapy was adjusted. In the remaining six patients, both modalities were negative. We conclude that in the diagnostic management of patients with suspected scaphoid fracture and negative initial radiographs, the use of MRI may be promising, but is not superior to three-phase bone scintigraphy.

Experimental evaluation of scaphoid X-series, carpal box radiographs, planar tomography, computed tomography, and magnetic resonance imaging in the diagnosis of scaphoid fracture.

AIM In this study, we evaluated scaphoid X-series, Carpal Box radiographs (longitudinal and transverse), planar tomography, computed tomography (CT), and magnetic resonance imaging (MRI) in the diagnosis of scaphoid fracture. The aim of this study was to evaluate the planar technique in the diagnosis of scaphoid fracture. The use of planar tomography, CT, and MRI was to see whether these methods are useful in the diagnosis of scaphoid fracture when other diagnostics modalities remains negative. METHODS Twenty-eight embalmed human cadaver specimens were used, in 23 of which fractures of the scaphoid were produced mechanically. Scaphoid X-series, Carpal Box posterior-anterior radiographs in ulnar deviation (X-CB), Carpal Box posterior-anterior views with the hand in 15-degree supination and ulnar deviation (X-CB 15-degree) were acted in all specimens, CT in eight wrists, planar tomography in seven wrists, and MRI in five wrists. The anatomic analysis of the specimens was used as the gold standard for comparison. Scaphoid X-series, Carpal Box radiographs, and planar tomography were judged independently and in a blind fashion by six observers, and CT and MRI were also judged independently and in a blind fashion by three radiologists. The observers were asked if they could recognize a scaphoid fracture. The agreement among the six observers for the scaphoid X-series and X-CB was measured. RESULTS In the 23 fractured wrists, scaphoid X-series, X-CB, X-CB 15-degree, was true positive in 12, 14, and 15 wrists, respectively, whereas these methods were true negative in cadaver wrists 1, 3, and 5. CT was true positive in five of five fractured wrists and true negative in three of three negative wrists. Planar tomography was true positive in one of four fractured wrists and true negative in two of three nonfractured wrists. MRI was obtained in five wrists (one without a fracture), of which the fracture was recognized in only two. The highest agreement between observers was found in the X-CB 15-degree. CONCLUSION From the planar investigated methods, the 15-degree Carpal Box posterior-anterior, longitudinal and transverse views were most accurate in recognizing scaphoid fracture with also the highest agreement between the observers.

CARPAL BOX RADIOGRAPHY IN SUSPECTED SCAPHOID FRACTURE

We have assessed the value of using a simple apparatus,the Carpal Box, in patients with suspected scaphoid fracture, to produce elongated and magnified radiographs of the carpus. The interobserver agreement between 60 observers of standard scaphoid radiographs and longitudinal and transverse Carpal Box radiographs (X-CB) was compared in 11 patients. Three-phase bone scanning was used as a comparative standard. If at least 75% of the observers agreed and the result was confirmed by three-phase bone scanning, the outcome was termed reliable. Scaphoid radiographs and the longitudinal X-CB films were reliable in four patients and the transverse X-CB films in six patients. The bone scan suggested a scaphoid fracture in five of the 11 patients. Agreement in the interpretation of the standard scaphoid radiographs was acceptable in only 36% of patients: in interpretation of transverse Carpal Box radiographs this figure increased to 55%.

Should imaging at stress always be followed by imaging at rest in Tc-99m MIBI SPECT?

Objectives. We addressed the question whether in patients with cardiac chest pain referred for stress myocardial perfusion scintigraphy, Tc-99m MIBI SPECT stress imaging should always be followed by a rest imaging procedure. Background. Using Tc-99m MIBI imaging a stress-rest sequence is usually performed implying that the resting study always follows the stress study irrespective of the results of the stress study. As a normal stress study would eliminate a subsequent resting study, it appears desirable to potentially define certain subsets of patients in whom a normal stress study can be expected in order to determine a more selective referral approach to the nuclear medicine department. The consequences of such a more streamlined approach would less impose on the logistics of the department of nuclear medicine, with decrease of investigation time, radiation dose, and costs in a time of retrenchment in the medical sector. Methods. A consecutive series of 460 patients (mean age 58.2 years) was studied who were stratified to 269 patients without prior myocardial infarction, and to 191 patients with documented evidence of a previously sustained mycoardial infarction. All patients underwent Tc-99m MIBI SPECT imaging according to a two-day stress-rest protocol. Results. Patients with and without a previous myocardial infarction showed suboptimal overall predictive accuracies for the exercise electrocardiograms (58% and 60%, respectively). In the total group of 460 patients, 94 (20%) patients showed a normal stress-rest Tc-99m MIBI SPECT; this occurred in 86/269 (32%) patients without a previous myocardial infarction and in only 8/191 (4%) patients with a previous myocardial infarction. Conclusions. Patients with a stress defect at Tc-99m MIBI SPECT imaging should always undergo a resting SPECT study irrespective of the clinical and stress electrocardiographic findings. As patients without a previous myocardial infarction had a normal stress SPECT study in almost one-third (32%) of patients compared to only 4% in patients with a previous myocardial infarction, it may be useful to employ different referral and imaging strategies i.e. a stress-only versus a stress-rest procedure. To schedule referring patients differently according to the presence or absence of a previously sustained myocardial infarction may be cost-saving, less demanding for the nuclear medicine personnel, and patient-convenient. In addition, a stress-only imaging procedure reduces radiation exposure to the individual patient.

Gastric Emptying, CCK Release, and Satiety in Weight-Stable Obese Subjects.

Scintigraphic gastric emptying studies are far from conclusive in obesity. The aim was to investigate gastric emptying and CCK release in weight-stable obese subjects on their usual diet and to study the impact of factors known to determine gastric emptying. Patients entering a weight reduction program were asked to participate in a study examining gastric emptying by scintigraphy and CCK release in response to a meal with questionnaires on feelings of satiety. Forty-five patients (9 M, 36 F) with a mean (SD) BMI of 37.0 (4.0) kg/m2 entered the study. The mean T50 (emptying of 50%) of fluids was 20.7 (10.3) min, and that of solids 141.9 (168.3) min. The percentage emptying of solids was 34.5 (19.9)%/hr. CCK values peaked within 42 min and paralleled the subjective ratings of satiety but did not correlate with gastric emptying. Five of 45 subjects (11%) had very prolonged gastric emptying of solids; they showed higher caloric intakes and higher insulin levels. They did not differ in CCK values and ratings of satiety but scored higher in being active and awake. Without these five subjects the T50 of solids was 94.3 (36.1) min, and the percentage of emptying 37.9 (18.4)%/hr. Liquid emptying was faster and solid emptying similar compared with those of normal-weight individuals. Height, fat-free mass, and waist–hip circumference were positively related to solid emptying. In weight-stable obese subjects liquid emptying was faster and solid emptying similar to those in normal-weight subjects. Higher caloric intakes and insulin levels were present in subjects with prolonged solid emptying; they also appeared more vigilant. Body size and composition were the only determinants suggesting a faster solid emptying in taller and muscular subjects or in subjects with more intraabdominal fat.