Sensitivity and specificity of CT scanning for determining the number of internally concealed packages in 'body-packers'

INTRODUCTION

If package counts on abdominal CTs of body-packers were known to be accurate, follow-up CTs could be avoided. The objective was to determine the accuracy of CT for the number of concealed packages in body-packers, and the reliability of package counts reported by body-packers who admit to concealing drugs.

METHODS

Suspected body-packers were identified from the emergency departments (ED) database. The medical record and radiology reports were reviewed for package counts determined by CT, patient-reported and physically retrieved. The last method was used as the reference standard. Sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) were calculated for CT package count accuracy. Reliability of patient-reported package counts was assessed using Pearson's correlation coefficient.

RESULTS

There were 50 confirmed body-packers on whom 104 CT scans were performed. Data for the index and reference tests were available for 84 scans. The sensitivity, specificity, PPV and NPV for CT package count were 63% (95% CI 46% to 77%), 82% (95% CI 67% to 92%), 76% (95% CI 58% to 89%) and 71% (95% CI 56% to 83%) respectively. For CTs with a package count<15, the sensitivity, specificity, PPV and NPV for CT package count were 96% (95% CI 80% to 99%), 95% (95% CI 82% to 99%), 93% (95% CI 76% to 99%) and 97% (95% CI 86% to 100%), respectively. Correlation between patient-reported package counts and the number of packages retrieved was high (r=0.90, p<0.001, R2=81%).

CONCLUSIONS

The accuracy of CT for determining the number of concealed packages is poor, although when applied to patients with few concealed packages accuracy is high and is useful as a rule-out test. Among patients who have admitted to drug concealment, the number of packages reported to be concealed is reliable.

Proper compression landmark and depth for cardiopulmonary resuscitation in patients with pectus excavatum: a study using CT

OBJECTIVE

To determine by chest CT the proper compression landmark and depth for cardiopulmonary resuscitation in patients with pectus excavatum (PE).

METHODS

The chest CT of 22 patients with PE (mean age=27 years; range 16-53 years, 10 male) from March 2002 to September 2011 were retrospectively evaluated as follows: length of sternum, external thickness/internal thickness (ET/IT) of the chest and the intrathoracic structures in the level of lower half (LH) of the sternum. In addition, Haller index (HI) and the degree of leftward displacement of the heart were measured. Finally, variables were also measured in an age/sex-matched control group (n=22) with no evidence of any chest wall deformity.

RESULTS

The sternal length was not different and LH of the sternum was adequate to compress left ventricle (LV) in both groups. Patients had a significant higher HI and showed a greater leftward displacement of LV centre with a mean difference of 11 mm. PE patients showed a lesser ET/IT with a mean difference of approximately 20 mm than controls (mean ET/IT=174±18/70±10 mm vs 199±23/93±15 mm, p<0.001).

CONCLUSIONS

The LH of the sternum is an appropriate chest compression landmark in PE patients to compress LV, although the centre of LV shows slightly leftward displacement. Since PE patients have sunken chest, a 3-4 cm may be the proper compression depth in the patients when considering the current compression guideline in normal subjects is 5-6 cm.