Achievements

Numerous medical conditions have multiorgan imaging findings. Here, we review specifically the hand and cardiothoracic findings of selected infectious, inflammatory, connective tissue, neoplastic, and hereditary disorders. These correlations are meant to remind the astute clinician that certain hand findings should trigger a careful radiologic evaluation that includes imaging of the chest.

PURPOSE Bipolar disorder is a disabling mood disorder. Lithium (7Li) carbonate has used as a treatment for this disease with widely variable therapeutic response. Prediction of responders vs nonresponders would assist with clinical treatment. Recently an animal study demonstrated bi-exponential T2 decay for 7Li in vivo, thought to correspond to the intracellular and extracellular 7Li fraction. The objectives of this study included development an MRS technique to measure 7Li levels and intracellular / extracellular fractions. METHOD AND MATERIALS The study was performed with IRB approval (10-002069). Study subjects were recruited from our Mood Disorders Clinic. Inclusion criteria were bipolar patients taking 7Li for the treatment of their disease. Scans were performed on an MNS-equipped GE 3T MRI scanner (14.0 M5) using a dual-tuned quadrature 1H/7Li head coil (Clinical MR Solutions). A modified GE ECHOCSI pulse sequence was used. Scan sessions consisted of a pack of spin-echo T1-weighted images to grossly shim over the volume, followed by 7Li manual shimming and transmit power calibration, followed by eight “single slice” 7Li MRS scans. Using SAGE, spectra were reconstructed and area under the peak was measured. Area data were fit in MATLAB using nonlinear least squares regression techniques. RESULTS The ECHOCSI spin-echo spectroscopy pulse sequence was modified with a 90° SLR slice selective pulse, a non-selective 180° refocusing pulse and max gradient amplitude to reduce the pulse width of the crusher gradient; these modifications achieved minimum echo time of 3.9ms. We recruited a cohort of 9 euthymic bipolar patients taking 7Li therapy. Six patients had a bi-exponential 7Li T2 decay pattern; T2short was 4.5ms, T2long was 61.6 ms. Two patients had a mono-exponential 7Li T2 decay pattern with T2=47.3ms and no second exponential component. CONCLUSION To our knowledge, this is the first study of 7Li T2 decay times in human bipolar patients taking 7Li. Two T2 decay patterns were identified: bi-exponential decay in 75% and mono-exponential decay in 25% of patients. Further work in a larger cohort of bipolar patients is needed to determine the clinical utility of this technique, but these early results are intriguing. CLINICAL RELEVANCE/APPLICATION Bipolar disorder is a disabling mood disorder which can be successfully treated with lithium in select patients. Prospective prediction of clinical response to 7Li could accelerate mood stabilization.