Raman spectroscopy: a real-time tool for identifying microcalcifications during stereotactic breast core needle biopsies.

Microcalcifications are an early mammographic sign of breast cancer and a target for stereotactic breast needle biopsy. We present here a Raman spectroscopic tool for detecting microcalcifications in breast tissue based on their chemical composition. We collected ex vivo Raman spectra from 159 tissue sites in fresh stereotactic breast needle biopsies from 33 patients, including 54 normal sites, 75 lesions with microcalcifications and 30 lesions without microcalcifications. Application of our Raman technique resulted in a positive predictive value of 97% for detecting microcalcifications. This study shows that Raman spectroscopy has the potential to detect microcalcifications during stereotactic breast core biopsies and provide real-time feedback to radiologists, thus reducing non-diagnostic and false negative biopsies.

Imaging of bone marrow disease in the spine.

Bone marrow imaging has been greatly advanced with magnetic resonance (MR) imaging. Bone marrow contains fat and nonfat cells, which makes imaging with MR imaging the modality of choice, particularly within the spine. Any alteration within the marrow makeup is usually well seen with different MR imaging sequences. Conventional spin-echo sequences are helpful because of their great signal-to-noise ratio, and anatomic detail. Other, newer sequences--such as short T1 inversion recovery (STIR), diffusion weighted, fat suppression techniques; as well as in- and opposed-phase images--may also help to increase detection of or characterize certain diseases of the bone marrow within the spine. This article deals with the different imaging sequences available to radiologists when imaging the spinal bone marrow.

Liver biopsy: effects of biopsy needle caliber on bleeding and tissue recovery.

PURPOSE: To evaluate different-caliber biopsy cutting needles in terms of the benefits and potential risk of bleeding in a swine model. MATERIALS AND METHODS: A total of 190 sequential liver biopsy specimens were obtained in 11 Yorkshire pigs (weight, 50-70 lb [22.5-31.5 kg]) by using 14-, 18-, and 20-gauge cutting needles. For each biopsy procedure, blood loss was determined by weighing sponges used to absorb bleeding, and sample-tissue DNA content was measured with spectrofluorometry. Analysis of variance was used to compare results. RESULTS: The larger the caliber of needle, the greater the absolute blood loss (for 14-gauge, 1.69 g; for 18-gauge, 0.74 g; for 20-gauge, 0.32 g) and DNA content per sample (for 14 gauge, 40.38 microg; for 18-gauge, 12.18 microg; for 20-gauge, 5.86 microg). The ratio of blood loss to amount of DNA recovered did not differ among the different-caliber needles. To obtain the same amount of diagnostic tissue, more passes were needed with the smaller-caliber needles. CONCLUSION: Use of larger-caliber needles is more efficient despite the greater amount of blood loss, because more tissue can be recovered and because fewer passes are necessary, which reduces the chances of complications.

Musculoskeletal disorders: improving diagnostic accuracy with MRI.

Magnetic resonance imaging (MRI) is gaining wider acceptance for the diagnosis of musculoskeletal disorders in the elderly, including internal joint derangements, neoplasms, and osteonecrosis. For internal derangement of large joints such as the knee, MRI is a noninvasive alternative to arthrography and offers excellent visualization. It plays an important role in the diagnosis and staging of primary and secondary neoplasms, including both osseous and soft tissue sarcomas. MRI is also indicated for diagnosing osteonecrosis that cannot be detected using other imaging modalities.

Invasive diagnostic imaging of the lower extremities.

Invasive arterial imaging techniques are crucial to the preoperative evaluation of patients requiring arterial surgery. Venography is important in patients who are candidates for venous reconstruction, and it is also useful in the difficult diagnosis of deep venous thrombosis. The authors discuss the development of angiographic techniques, indications for use, patient preparation, and potential complications. Several examples of these tests are illustrated.

Pelvic abscesses: CT-guided transrectal drainage.

Percutaneous drainage of pelvic abscesses has been performed by using a number of approaches, including transabdominal, transgluteal, and transrectal. The authors present a technique for the drainage of pelvic abscesses by a transrectal route with use of computed tomographic (CT) guidance. Equipment for the technique included a plastic introducer tube, standard needle, angiographic guide wire, and pigtail catheters. The pelvic abscesses of 10 patients (six after appendectomy, three after colon resection, one secondary to diverticulitis) were successfully drained by using the new technique. No complications or recurrences were experienced. After initial catheter placement, patients were treated with use of gravity drainage and appropriate antibiotics. Success of drainage was determined with sequential CT scans. Compared with the transgluteal approach, the transrectal approach offered increased patient comfort and minimal risk of potential complications such as injury to the sciatic nerve or tracking of the abscess. Use of the plastic introducer tube promoted operator safety by protecting the guiding finger. On the basis of this initial series, CT-guided transrectal drainage appears to be an effective and well-tolerated method for the drainage of pelvic abscesses.

Localization of vagal preganglionic somata controlling sinoatrial and atrioventricular nodes.

Canine cardiac vagal ganglia in the region of the inferior vena cava and inferior left atrium (IVC-ILA) and at the junction of the right pulmonary veins and left atrium (PVFP) control atrioventricular conduction and heart rate, respectively. After retrograde transport of horseradish peroxidase (HRP) injected separately into these ganglia in different dogs, the left and right and longitudinal distributions of brain stem somata terminating in these ganglia were compared with functional dominance of left and right vagal control of heart rate and atrioventricular conduction. Labeled somata innervating these ganglia had quite similar longitudinal distribution patterns. Although functional dominance of heart rate was found to be in either the right vagus or bilaterally in both vagi, a corresponding difference in somata innervating the PVFP ganglia was not found. Functional vagal dominance of atrioventricular conduction was found to be either right, bilateral, or left with correspondence between left-right distributions of somata after HRP injection into the IVC-ILA region. However, these results should be cautiously interpreted because these ganglia mediate other cardiac functions.