Needle-tip localization during CT-guided abdominal biopsy: comparison of conventional and spiral CT

Helical CT versus intermittent CT fluoroscopic guidance for musculoskeletal needle biopsies: impact on radiation exposure, procedure time, diagnostic yield, and adverse events

OBJECTIVE

Image-guided percutaneous needle biopsies are essential in the workup of musculoskeletal (MSK) lesions. While helical CT (HCT) is well established, intermittent CT fluoroscopy (iCTF) is an increasingly used alternative. The purpose of this study is to establish whether differences in subject radiation exposure, procedure time, yield, or adverse events exist between HCT and iCTF guidance.

MATERIALS AND METHODS

This retrospective cohort study included consecutive MSK needle biopsies performed on a single-CT scanner over a 12-month period at a tertiary academic center. Subject demographics, radiation dose, and outcomes were abstracted from the medical record. Comparisons between the two cohorts were performed using Student's t-test for continuous data and using Fisher's exact test for categorical data and a two-tailed p value less than 0.05 was considered significant.

RESULTS

Two hundred sixteen adults (115 (53.2%) females) with a mean age of 58.8 ± 18.4 years, underwent 216 biopsies (109 (50.5%) HCT guided, 107 (49.5%) iCTF guided) between June 2017 and June 2018. Dose-length product (DLP) and volume CT dose index (CTDIvol) were significantly higher for the HCT cohort (HCT 698.9 ± 400.8 mGycm vs iCTF 312.8 ± 170.8 mGycm; p < 0.005 and HCT 19.1 mGy ± 8.8 vs iCTF 6.9 mGy ± 1.5, p < 0.001). No significant difference in diagnostic yield, procedure time, or adverse event rate was identified.

CONCLUSION

For CT-guided MSK needle biopsies, iCTF decreases subject radiation dose compared to HCT without negatively affecting outcomes. iCTF should be strongly considered by radiologists performing MSK biopsies given the reduced patient radiation exposure.

Body interventional procedures: which is the best method for CT guidance?

OBJECTIVES

To compare sequential fluoroscopy guidance with spiral guidance in terms of safety, effectiveness, speed and radiation in interventional whole body procedures.

METHODS

This study was a retrospective analysis of data from the prospective, randomised controlled, multicentre CTNAV2 study. The present analysis included 385 patients: 247 in the sequential group (SEQ) and 138 in the spiral group (SPI). Safety was assessed by the number of major complications. Effectiveness was measured according to the number of targets reached. Data on procedural time and radiation delivered to patients were also collected.

RESULTS

There was no significant difference between the two groups (SEQ vs SPI) regarding the success rate (99.6% vs 99.3%, p = 0.680), procedural time (7 min 40 s ± 5 min 48 s vs 7 min 13 s ± 7 min 33 s, p = 0.507), or major complications (2.43% vs 5.8%, p = 0.101). Radiation dose to patients was 84% lower in the sequential group (54.8 ± 51.8 mGy cm vs 352.6 ± 404 mGy cm, p < 0.0001).

CONCLUSIONS

Sequential CT fluoroscopy-guided whole-body interventional procedures seems to be as safe, effective and fast as spiral guidance, while also yielding a significant decrease in the radiation dose to patients.

KEY POINTS

• Sequential CT fluoroscopy and spiral acquisition are comparable in terms of safety, effectiveness and speed. • Procedural times are comparable despite an increased number of acquisitions in sequential fluoroscopy. • Radiation dose to patients is 84% lower in sequential fluoroscopy compared with spiral CT.

Transthoracic needle biopsy

Transthoracic needle biopsy (TTNB) is integral in the diagnosis and treatment of many thoracic diseases, and is an important alternative to more invasive surgical procedures. Both computed tomography and ultrasound may be used as imaging guidance for TTNB, with CT being more commonly utilized. Needle choice depends mostly upon lesion characteristics and location. During the procedure, patients must be able to follow breathing instructions. Common complications of TTNB include pneumothorax and hemoptysis.

Real time CT-fluoroscopy: diagnostic and therapeutic applications

The synergetic progression of CT technology and computer hardware has made ultrafast acquisition and image reconstruction possible. This has lead to the availability of CT interactive diagnosis and therapeutic procedures. Making use of our own material (337 intervention procedures during the last 17 months), we have compared our techniques and results to the recent literature data. One of the advantages of the biopsy technique is an improved sensitivity for neoplastic lesions, most certainly in cases of intrapulmonary lesions, surrounded by aerated tissue (now 94% compared to 87% in our previous study). A second advantage is the safety of the technique (only one major complication in our series). Fluid collection drainages, and more complex interventions like local injection of drugs, radio-frequency ablation, wire hook placement and ethanol injection were performed without complication. Yet another interesting feature is the shortening of the procedure time (reduced in average to an 'in-room' time of less than 30 min), which has definite economical implications. Furthermore it increases the patient's comfort and safety, and extends the scope of outpatient procedures (80% outpatient procedures in our material). On the other side the radiation exposure can be raised as an issue, especially when we consider the operator's hands. However, the described technique and the use of dedicated tools can alleviate the problem. As a conclusion, real time CT fluoroscopy has given a new input and broadens the scope of clinical indications of CT-guided diagnostic and therapeutic procedures.

CT fluoroscopy-guided abdominal interventions: techniques, results, and radiation exposure

PURPOSE

To evaluate the benefits of computed tomographic (CT) fluoroscopy-guided interventions and assess radiation exposures incurred with CT fluoroscopy.

MATERIALS AND METHODS

A 6-month period of use of CT fluoroscopy to guide abdominal biopsy procedures and catheter drainage was analyzed. Efficacy measures and needle placement and procedure room times were compared with those of the preceding 6 months during which conventional CT was used. CT fluoroscopic times and estimated radiation exposures were compared for two CT fluoroscopic methods.

RESULTS

The sensitivity and negative predictive values for biopsy procedures and the success rate for needle aspiration or catheter drainages for CT fluoroscopy--98%, 86%, and 100%, respectively--were not significantly different from those for conventional CT--95%, 80%, and 97%, respectively. Room time was not reduced significantly, but mean needle placement time for CT fluoroscopy (29 minutes; n = 95) was significantly lower than that for conventional CT (36 minutes; n = 93; P < .005). The mean patient dose index was 74 cGy. Limiting CT fluoroscopy to scanning the needle tip rather than scanning the entire needle pass significantly reduced the dose to the patient and the operator.

CONCLUSION

Although CT fluoroscopy is a useful targeting technique, significant radiation exposures may result. Therefore, radiologists need to be aware of different methods of CT fluoroscopic guidance and the factors that contribute to radiation exposure.

Spiral CT of the abdomen: increased diagnostic potential

Over the last 10 years, spiral CT has become the optimal method of performing all CT within the abdomen and pelvis. Not only has the technique improved the quality of individual examinations, it has also opened up many new diagnostic possibilities which are currently being evaluated and compared with the concurrent advances in ultrasound and MRI. These new diagnostic possibilities are discussed in this review article. So too are the economic advantages of the shorter data-acquisition times which also make the examination much better tolerated by the patient.

Dorsal approach to presacral biopsy: technical case report

OBJECTIVE AND IMPORTANCE

Biopsy of the presacral space is often awkward, technically difficult, and unrewarding when the sacrum is intact and the procedure is performed either by open operation or with computed tomographic guidance through the abdomen or perineum.

CLINICAL PRESENTATION

We describe a patient with metastatic adenocarcinoma who presented with leg pain and computed tomographic evidence of a high, small mass anterior to an intact sacrum.

TECHNIQUE

By drilling a hole through the sacrum lateral to the canal and between the roots, a biopsy of such a mass may be performed easily, safely, and quickly.

CONCLUSION

A dorsal approach to presacral biopsy may be easily performed with readily available technology.

Efficacy of unanesthetized spiral computed tomography scanning in initial evaluation of childhood leukocoria

PURPOSE

To evaluate the use of spiral/helical computed tomography (CT) in the preoperative evaluation of pediatric leukocoria.

METHODS

A total of 34 patient charts and imaging studies were reviewed from a consecutive series of children referred with the diagnosis of presumed retinoblastoma. Of these patients, 31 had a confirmed diagnosis of retinoblastoma. Three patients had simulating lesions, including one patient with persistent hyperplastic primary vitreous and two with Coats disease.

RESULTS

In all patients, a diagnosis of intraocular retinoblastoma could be established or excluded at the same clinical level by spiral CT as by conventional CT. Spiral CT of the eye, orbit, and midline structures was performed without a requirement for patient anesthesia. This technique resulted in a reduced volume of contrast material required for evaluation of the central nervous system and a small decrease in total radiation exposure. There was an attendant reduction in the amount of monitoring equipment required and the necessity for attending anesthesia staff.

CONCLUSIONS

The primary advantage of spiral CT is reduced anesthesia risk in small children. In addition, this technique provides necessary clinical information with a reduction in image acquisition time, monitoring equipment, and monitoring staff.

Spiral CT of the abdomen: region coverage with a 24-second breath-hold

A retrospective review of 75 spiral CT examinations of the abdomen was performed to assess: (1) patient's ability to sustain a 24-s breath-hold, and (2) the proportion of targeted regions or organs that were completely imaged at different table feed speeds. Seventy of 72 patients sustained a 24-s breath-hold without motion artifact. Region coverage depended on the prescribed table feed speed and length of exposure. With a fixed exposure time, there was a tradeoff between the volume of tissue that could be imaged and the slice colimation.

Dual-angled CT-guided biopsy

A new computed tomographic (CT)-guided biopsy technique is described which employs angling both the CT-gantry and the patient to access lesions considered unapproachable using conventional CT techniques. Angling the gantry and the patient, or dual angulation, was applied in five patients with masses located in the pelvis and retroperitoneum that were not easily accessible using gantry angling or patient tilting alone. In each case, the needle tip was demonstrated in the lesion and diagnostic tissue was retrieved. No complications were recorded. A dual-angled approach defines a safe path to a mass and allows obtaining a CT image in the plane of the biopsy needle.