Normal intrahepatic bile ducts: CT depiction.

Visualization of intrahepatic bile ducts (IHBDs) at computed tomography (CT) has previously been considered evidence of biliary obstruction. The authors have found that hepatic CT enhanced with contrast material and with the use of ceramic scintillation detectors allows frequent visualization of normal IHBDs. One hundred patients without imaging, laboratory, or clinical evidence of hepatobiliary or pancreatic disease were prospectively examined to assess the frequency of visualization, location, and size of IHBDs. IHBDs were visualized in 40% of the patients and had an average size of 2.0 mm in the central part of the liver and 1.8 mm in the peripheral part of the liver. Ducts were seen in the right lobe more often than in the left lobe. There was no statistically significant relationship between visualization of IHBDs and patient age. Demonstration of IHBDs on current CT scanners is a normal finding and does not indicate biliary obstruction.

Arterial injury complicating knee disruption. Third place winner: Conrad Jobst award.

Because dislocation of the knee (DK) is accompanied by a substantial risk of popliteal artery injury, the importance of arteriography in ruling out occult arterial damage in such patients is well accepted. However, because antecedent DK cannot be ruled out in a trauma victim presenting only with severe knee ligamentous disruption (LD), we have routinely performed arteriography in all patients presenting with grossly unstable knees, whether or not DK is present. To evaluate this policy we reviewed the records of 30 patients with either DK (n = 19) or severe LD (n = 11). There was no significant difference between DK and LD in the frequency of major (22% vs 18%) or minor (38% vs 36%) vascular abnormalities. We also found that Doppler pressure measurements were highly predictive of major arterial trauma in patients in whom it was used. We conclude that arterial injury should be ruled out in all trauma victims with severe knee ligament disruption, whether or not actual joint dislocation is present.

Myocutaneous flap failure: early detection with Gd-DTPA-enhanced MR imaging.

Magnetic resonance (MR) imaging was used to evaluate myocutaneous flap viability in an animal model. Bilateral myocutaneous panniculus carnosus groin flaps were created in 14 piglets. Eight of the piglets underwent early occlusion of the vascular pedicle to one flap that resulted in flap failure in all cases. Six piglets underwent late occlusion of the vascular pedicle to one flap that resulted in flap survival in all cases. Spin-echo T1- and T2-weighted MR images were obtained from all piglets 2 and 24 hours after occlusion. Additional gadolinium diethylene-triaminepentaacetic acid (DTPA)-enhanced serial T1-weighted images were obtained in four piglets who underwent early occlusion and in four piglets who underwent late occlusion of the pedicle. The T2-weighted images showed increased signal intensity in both occluded and control flaps and thus did not help predict flap viability. Gd-DTPA-enhanced images enabled accurate prediction of flap viability. The images of early-occluded (non-viable) flaps demonstrated no contrast material enhancement, while both the late-occluded (viable) flaps and the control flaps were contrast enhanced. The authors conclude that Gd-DTPA-enhanced MR imaging can help predict myocutaneous flap viability in piglets.

Adult respiratory distress syndrome from overdose of tricyclic antidepressants.

Adult respiratory distress syndrome (ARDS) from overdose of tricyclic antidepressants (TCA) has been reported but is not well known. During a 1-year period, 81 patients with serious overdose from tranquilizers and other psychotropic drugs were examined. TCA alone induced overdose in 30 patients or were combined with other drugs in 26 patients. Twenty-five (31%) patients had overdose from drugs other than TCA. Chest radiography revealed that 30 (54%) patients with TCA overdose and six (24%) patients with non-TCA overdose had abnormalities. Clinical and radiographic findings consistent with ARDS were noted in five (9%) patients with TCA overdose and none of the patients with non-TCA overdose. Five patients with TCA overdose and one (4%) patient with non-TCA overdose had interstitial edema that never progressed to ARDS. TCA should be added to the list of drugs associated with the development of ARDS.

CT diagnosis of toxic brain injury in cyanide poisoning: considerations for forensic medicine.

Two deaths occurred after ingestion of cyanide-containing Extra-Strength Excedrin capsules. Cranial CT scans obtained within 3 hr of each patient's collapse showed diffuse cerebral swelling and loss of gray-white differentiation. Most diffuse cerebral insults (hypoxia, ischemia) do not show such changes so soon after injury. The early onset of diffuse cerebral edema with loss of gray-white differentiation may be a clue to the diagnosis of acute cyanide poisoning.