MRI: Normal Variants and Pitfalls. Laura W. Bancroft, Melena D. Bridges (authors). Wolters Kluwer|Lippincot Williams & Wilkins 2008, 850 pages, 1828 illustrations, $185.00.
Often a confounding issue in image interpretation is distinguishing a normal variant from a pathologic condition, and in MR imaging, this problem can be particularly vexing. In an attempt to clarify some of these problems, Drs. Bancroft and Bridges have published a textbook MRI: Normal Variants and Pitfalls; unfortunately, the neuroradiology portions of this book fail to clarify many of the issues involved in neuro MR imaging. In the Head chapter in particular, the material ranges between inaccurate, misleading, inadequate, and confusing. The chapters on spine and neck are better, but they also fall short of what one would expect. While not examined in this review, the hope is that the remaining chapters on the Upper Extremity, Chest, Abdomen, Pelvis, and Lower Extremity are more accurate than what appear in the Head Chapter.
Space does not allow a compilation of all problems identified in the neuroradiology sections of this book, but a few examples should suffice to convey to the reader of this review the inadequacies of that portion of the book. Either care was not taken either in labeling of images or in the wording of the legends or there is frank misunderstanding by the authors of the anatomy. For example: an arrow points to the pineal gland and the legends call this an aplastic rostrum of the corpus callosum; the authors relates Virchow-Robbins spaces to “axonal pathways of the basal ganglia”; an arrow points to the inferior portion of the 3rd ventricle on a coronal image and they indicate that it is a cavum vellum interposition; they fail to explain why one case shows “fluid superior to the cerebellum” but the case following it (nearly identical) is an arachnoid cyst; they place arrows on the tentorium and call these choroidal fissure asymmetries; they call an “absent” vessel on an MRA whereas the vessel may simply not be visualized because of its small size (i.e. saturated out); there is a failure to include labeling when the legends indicate arrows — as in a supposed case of fetal circulation, which incidentally is not properly demonstrated; a probable abnormal superior orbital vein which the authors say is “of no clinical consequence,” a coronal plane section which the authors say is through the level of the temporal lobes but in truth the coronal plane of section is through frontal lobes and orbits (here they are showing an example of a cyst of the incisive canal).
“Artifacts” are frequently mentioned in legends but there often is no brief explanation as to what causes the artifacts. For example an “artifact” is shown in a left lateral ventricle but no reason is given (same problem exists in their case of an “artifact” in the fourth ventricle); artifacts are simply called “system related instabilities” (what kind of explanation is that?).
The authors seem to mix up normal variants and pitfalls with true abnormalities. For example, if they believed that an arachnoid cyst of the posterior represented a pitfall they needed to have explained how the differentiation was made from a giant cisterna magna; terms are misused — the recurrently misused term “central canal of the spine” when they really simply mean the spinal canal, is annoying and inaccurate. From a neuroradiology perspective this material is poorly presented and is not recommended.
